are we alone in the universe?
 

I wasnt sure if I should post this here or in the Nasa folder. I think it deals more with science in general so I posted it here.

This is a subject I have been thinking about for a couple years. For several decades now scientists and the general public have assumed there must be hundreds or even thousands of advanced civilizations in our galaxy

and many more planets with simpler life forms

but the thinking is starting to swing the other way, for many reasons.

I put all my thoughts on a web-page that Im hosting, rather than paste it all here ill post the link instead.

I think this is something that will eventaully change humanitys way of thinking - about ourselves and our purpose in the biggest sense.

http://www.us-spark.com

-Ken

Re: are we alone in the universe?
 

Very interesting read. Thanks.

I have a question about one thing. You say that if life on earth dies (and assuming it is the only life in the universe) then the universe will "burn out" before the "blender" can recombine all the atoms into DNA again, therfore there will be no more life.

My question is which is longer, the time between the "big bang" and now or the time between now and the "heat death" or burn out?

Because if the time between now and the "heat death" burnout is more than the time between the "big bang" and now, then how did all the atoms have enough time to correctly combine to make life in the first place if they wouldn't have time to reorganize before the burnout?

Also, while you probably are correct in saying there wouldn't be enough time to try all the combinations of atoms, it does only take once to get it right. It wouldn't necessarily be the last possible combination that it works out right. You might get it on the firs try. Just like, to absolutely win the lotto it would cost more to buy all the tickets than what you would win, but all it takes to win is that one "lucky" ticket which can come at any time without having to buy all the tickets.

Does anyone have a clue what I just said? I probably confused the heck out of everyone. Please someone tell me you understand.

Re: are we alone in the universe?
 

If I may borrow a line from the movie Contact: if we are the only life in the universe, its an awful waste of space.

And a line from Hitchhikers Guide to the Galaxy: "Space," it says, "is big. Really big. You just won't believe how vastly hugely mindboggingly big it is. I mean you may think it's a long way down the road to the chemist, but that's just peanuts to space. Listen ..."

When you start playing with infinities, I would believe that normal physics and equations go out the window. This is why it is hard to figure out exact science behind black holes.

(I spend too much time watching Mega Science on the Science Channel while at my dad's house)

I agree with most points made in this article, especially backing everything by the mathematical formulas. However I believe things start getting shaky when questioning how the 1E350 chance of life happening on Earth originally got here. Without turning this into a religious thread doomed to be locked, I also disagree with the thought it was intentionally sent here from another civilization. There could have been many other ways that the building blocks could have found residence here on this planet, and there are many other theories on this.

I agree humanity ultimately must attempt to colonize elsewhere. However, I don't think doing it for the sake of doing it will be a popular opinion. In order to spend the energy on trying to journey to another galaxy, there would have to be a strong reason that our own is in danger (or we could make some serious money doing so).

Heat death is one theory, another is that the universe will indeed collapse back on itself and there will eventually be another big bang. The universe is still currently expanding. I do not understand this whole process really myself, its a bit too mindbogglying for my brain to comprehend how something that is infinitely large is still expanding.

I applaud this article and thinking, and that you have posted it open to criticism. It was an extremely interesting read and had some ideas I hadn't thought of before.

Re: are we alone in the universe?
 

Interesting read, Ken.

Eh? :ahh:

Of course, there's a whole heck of a lot more chances with the lotto. (Or is there... goes off to let someone else do the math. ;))

Re: are we alone in the universe?
 

You are correct, the ingrained belief (almost a religion) that the galaxy is somehow filled with advanced civilations just waiting to make contact with us is slowly waning, despite the best efforts of the Sagan-Drake proponents. Fermi's paradox (The galaxy should have been completely colonized by now and Earth should have been visited many times. So, where are they?) has never been adequately answered by the 'we are not alone crowd'. More recent info makes Fermi look even smarter because of the solar type stars in the Galaxy, our Sun is one of the youngest by far. The implication is that civilizations as we know it, evolving on solar-type stars, should on average be way ahead of us technologically. So -- where are they?

Re: are we alone in the universe?
 

I will try to hit all the questions and points raised so far in this thread in this one reply.

Probability tells us how likely something is to occur. While its true that is is possible to win the lottery the first time you play, and then to win it again the second time you play, its not very likely

and the question is, what course does humanity take, based on the scientific evidence, based on what we know. I could have taken all my college tuition money and spent it on lottery tickets instead of becoming an engineer, and I might have made a million dollars that way, but I would have no control over that outcome. By getting my BSEE degree, and working as an engineer for the last 21 years, I have earned $1.2M dollars so far. I have played the lottery from time to time over those 20 years, and I think maybe Ive won $40 total

probability tells us what we should do to have the best chance of success.

If something has 1E3 possible combinations then you have to have 1000 random trials on average to get the desired outcome to happen once. If you have 100,000 trials, then it really does average out that you will see your desired outcome around 100 times. If not, then the thing you are predicting is not really random.

So, how long till heat death? on average we would have to get another 1E250 seconds before we can reasonably expect to see life happen again spontainiously, and that is assuming every single atom in the universe is recombining once every second in a place where life COULD exist if it happened to assemble by chance. In my equation I used every single atom in the universe, including the atoms that are in the stars, and the cores of all planets, and drifting through space. Obviously if any of those atoms assembled into a single cell lifeform by random chance, it could not survive or reproduce.

On the comments about the universe being infinite, its not. Everything we are able to observe says the entire universe began at one point, and spread out from there, around 16 billion years ago. If something started from a single point, with a fixed amount of mass and energy, then it cannot 'become infinite' no matter how long you wait. If there are other 'universes' (Im mangling the word here) that are so far away that we cant detect them, then for all practical purposes they dont exist, because we will never have a means of interacting with them.

The universe is expanding at a rate that will keep it from collasping back in on itself. This has been confirmed by recent observations. In fact, the universe is expanding at an accelerating rate, something we are at a total loss to explain, without involking things like anti-gravity particles (something we have never observed).

Someone has calculated that one civilization able to travel from star to star at sublight speeds would be able to expand out and colonize our entire galaxy, and it would only take them 2 million years. As another has pointed out in this thread, since the universe is 16 billion years ago, 2 million years is a very small fraction. If anyone is out there, they should have colonized the entire galaxy by now, they should have been here many times over.

bottom line is, as far as we are able to observe, and from what we know about the size of the universe and the complexity required for life to establish itself: we are (most likely) entirely alone.

I agree, this understanding calls for a new way of thinking for our species - to see ourselves not as individuals, not even as a species, but as the only lifeform in existance that has the ability to carry life from one star system to another. We dont have to jump from galaxy to galaxy. Jumping from star to star will do (for the next few billion years at least).

I cant see our culture launching any nationalized efforts towards this goal in my lifetime, but I can see our species stepping up to the plate in a hundred years or so, and begin an organized effort.

In the meantime, I think the most we can hope for is individuals seeing the reality of this, and slowly it will begin to change the way we see ourselves, our relationship with with the other lifeforms on this planet, and our purpose in the universe.

Re: are we alone in the universe?
 

i pose it as this. the chance for life as we know it to exist can be broken down like this (note these are estimates off the top of my head that I'm using to prove a point). the chances of a planet being in the right proximity and stable orbit of a star, made of a solid composition, able to support a stable atmosphere, and posses the necessary resources to sustain any life is like 1 to 1,000,000,000 (probably much more) and that does not even guaranty the existence of life. as i understand what the current popular theory it was a set of pure accidents in chemical composition of materials on earth as well as atmospheric shifts. also taking into account that any number of things (meteors, collapsing stars, change in orbit, reactions in the atmosphere, if ANYTHING and i mean ANYTHING becomes unstable) can end all life that cannot immediately adapt to it. and yet despite all these odds i pose to you that the universe as i come to understand it is infinite (or at least REALLY (i feel that it truly deserves a capitol really) big and im talking of space not matter and we also assume theres only one big bang) and so there are probably an uncountable number of worlds with life. and that is just our definition of what life is. do i think life exist? undoubtedly. do i ever think we will find it? almost certainly not. even if we could travel the distances of space instantly we might never come across life or find it and not recognize it for what it is. ooh deep stuff. :)

Re: are we alone in the universe?
 

I agree with your conclusion that we will never find life anywhere

but I do want to comment, in science and engineering infinity is not a real number. you will never end up with an equation or measure a parameter or characteristic in the real world where one of the numbers is infinity.

there are websites that explain how scientists calculated the number of atoms in the universe. the number is big, but its not infinity.

just as you can sit on a beach and count the grains of sand in a cubic centimeter of the waterline, and then calculate how many grains of sand there are on that whole beach, it is also possible to calculate how many atoms there are in the universe.

and space itself is not infinite. I know this sounds like nonsense, but empty space and time itself did not exists before the big bang, and empty space did not immediately spring into existance everywhere at the big bang. Empty space and time do not exist outside the boundary of the expanding universe.

Its almost impossible to comprehend that, but this is what modern physics tells us.

Re: are we alone in the universe?
 

first of all that assumes that mathmatics can be applied to the universe, second how do we know that their arent multiple expanding universes, and third after reading a little on quantum theory as i understand it there is no such thing as space or time on the quantum level.

Re: are we alone in the universe?
 

Let's think about this. How in the world (haha, maybe "world" is not the right word) , er, what could possibly be making the universe expand at an accelerating rate. To have acceleration you must have force (as far as we know). Gravitational force is really the only thing big enough to move plantes and the such right? But masses have attracting gravitational force which would infer that the universe should be negatively accelerating and eventually reverse and get smaller and ultimately collapse back on itself. So what could possibly be providing the force allowing it to expand (and at an accelerated rate)? Is there a group of even larger masses beyond the universe whose gravity is pulling our universe apart? Perhaps some sort of increidbly large electromagnetic force of some sort?

Also, we talk about how the universe started about 16 billion years ago. It is so funny to talk about things like the universe (which is far as we know is EVERYTHING that exists) in terms of time units from Earth. I wish scientists would develop some sort of univeral time unit for all throughout space, but I have no idea how that would work. Especially when you get into time warpage and stuff like that.

Last, does anyone believe that sending life to other planets could be potentially damaging to our own in the long long run? I don't think you'd want to start life on nearby planets. I'm thinking War of the Worlds but like for reals. What if in 5 billion years they come to attack us (given that we are still here) and destroy us? I think if we plant life in the universe then we should send it really far away. Also, I think we should be able to monitor it, but not leave and evidence as to where it came from. I'm thinking that one day if two intelligent life forms from different planets interacted, it would have very violent results.

For starting life elsewhere, I had once heard something about how the ice caps on Mars could be melted to produce C02 which would warm the planet to make it much more suitable for life. They said something if the technology was available to do it on that large of a scale, it would only take about 20 years to complete. I forget exactly how they thought it could be done though.

Re: are we alone in the universe?
 

there is a really good book that talks about the whole ideology of intergalactic war and expansion and it has a lot of firmly rooted ideas its called Jentry's Envy

Re: are we alone in the universe?
 

I know this is semantics, but the word 'universe' by definition means 'everything there is'

there could be more galaxies and things out there that we cant see, but everything that we can see (and we can see unbeliveably far) has all the characteristics of expanding out from one original big bang

Re: are we alone in the universe?
 

we have already measured the rate of expansion, and the universe is expanding faster than (for lack of the exactly correct expression) the universal escape velocity. The matter is already expanding out faster than gravity can pull it all back together to make it collapse back in on itself

I dont want to delve into a discussion on how its possible that this expansion is accelerating - physicists dont have a good answer, and neither do I. It is an interesting subject, and theres lots of information out there.

Regarding the dangers of interstellar exploration and colonization, I had considered this as a possible reason why we might have come here from another star system, and decided to erase the tracks as it were.

If our species had a violent history on our previous planet, we might have decided to break the link between the colonies - to keep one from turning against the other

but I tend to think if we are able to pull together as a species to organize something as complex as interstellar travel and colonization, that we would also be able to learn to live with each other, here and everywhere else we travel.

And then there is always the chance that we will send a probe or starship to another system and discover it is already inhabited, that they dont appreciate the intrusion, and they are able to trace the trajectory of the vessel back to its origin and come after us. It is possible, but the whole point of my message is that, based on what science is telling us, its very unlikely that any lifeforms are out there at all.

Re: are we alone in the universe?
 

Wait a minute. Homo sapiens didn't arrive here from another planet. They evolved here beginning with single celled organisms (or so we think). Or maybe I misunderstood you. Are you saying that perhaps homo sapiens perhaps evolved somewhere else and then that "somewhere else" started life in it's most basic forms here on Earth and then it evolved into us? How would we even know about a link to break with our "planters" if we think that we started here by evolving from single celled organisms? Also, it seems reasonable that humans did not learn about space and planets and whatnot until very recently in the history of our species.

EDIT: Also, I just wanted to comment that it seems there is a large amount of people thinking that if there is other intelligent life out there that is looks like us. Due to different conditions even such as different amounts of gravity, it could look totally different. People think intelligent life in the universe would be a lot like humans which probably most likely it would not be. It would be just like thinking everyone in the world speaks English, which most certainly isn't the case.

If intelligent life it found, it will probably be so mind boggling strange that we can't comprehend it.

Finally, I believe that possibly by the end of my lifetime scientists will be able to create life from non-living matter. It is simply a problem of making the most complex (metaphorical) photocopier ever.

Re: are we alone in the universe?
 

i think we were created by the mice! :D okay on a more serious note what happens if we DO come across life and either A) dont recognize it for what it is. or B) the lifeform is so alien from us that we have no point of reference. (yes i know catagory A automatically fits into catagory B)

Re: are we alone in the universe?
 

I think that it is almost statistically impossible for Earth to be the only planet that has life on it. Now there may not be other life forms in our galaxy, but there are sure to be some somewhere at some other infinitesimal part of the universe. On the second slide from this powerpoint presentation given by my astronomy professor for next semester really shows how large the universe is when compared to the Earth. Really, the universe is beyond HUGE, and contains billions and billions (if not more) stars, and with many of those stars come planets, however the vast amount of these cannot be seen from Earth.

And I'd also like to bring up another point to add to the discussion. In every case that I have seen, scientists look for signs of water that would be able to sustain alien life. But who says that these life forms are dependent on water? Given a completely different planet with a completely different set of environments, I think it would be possible that the life on that planet would develop so that it actually lives off some completely different natural resources. It could be that a planet is inhabited by life that lives off of Helium in the air and some kind of Jello for food. Then we have a nice planet of squeaky-voiced Bill Cosby aliens.

Also, it may be that alien life forms have or will exist. Given the great amount of time that the universe has been around and probably will be around, all life forms on a planet may have already died out, or are just coming into existence. The possibilities truly are endless.

However, given the size and scope of the universe, I believe it to be very unlikely that we will ever come in contact with any such civilization, because it would take nothing short of science fiction to allow for such beings to travel the great distances of space to just-so-happen to pass by our planet.

My 2.5 cents ;)

Re: are we alone in the universe?
 

Maybe we can somehow generate and extremely massive electromagnetic storm so that if any other intelliegent beings are out there we could let them know that we are here. Didn't at one time the US have like 70,000 nukes. Maybe they still do. What if we sent them way out to space and blew them up all at once to make a signal of our presence.

Re: are we alone in the universe?
 

I hate posting things I can't explain and things I am not very knowledgeable about, but I wanted to throw this into the mix:

Astronomers have calculated stars seemingly to be older than 16 billion years old. They can not explain how a star can be older than the universe itself. How could it have existed before the calculated time before the big bang? Its like having a child older than its grandmother.

Re: are we alone in the universe?
 

Here's the problem as I see it. As has been mentioned previously and numerous times, the universe is very big. I'll add that it's also very old. In terms of astronomy, Earth is only +/- 4.4 billion years old. I saw a special on either the National Geographic channel or the Discovery channel a few months back which chronicled the development of the Earth from debris field to the formation of our solar system, to the development of life. According to the show, the earliest signs of life on Earth showed up only a few hundred thousand years after the planet formed. They were simple bacteria, and helped process the hydrogen and carbon dioxide rich atmosphere into the oxygen we all know and love. What's not yet known is what kicked off the reaction which led to the amino acids to form into bacteria.

The problem is humanity has developed the tools to help observe and understand the nature of the universe only in more recent years. The telescope was invented around 1608, and computers and space telescopes have only really been in service since the early 90s. (Hubble was in development since 1977, but wasn't launched until 1990). So, for all intents and purposes, humanity has really only had eyes in the sky since 1608, and the ability to track stellar events since the early 90s. So we have roughly 400 years of data. Out of the 16 billion year old universe, we've only been watching it for 0.000000025% of it's existence. That's like watching 1/125th of a single frame of a 2 hour movie on TV (at 30fps). Of course, we can apply our knowledge of physics as we know it and extrapolate approximate positions, speeds, distances, etc. based on what we see. But what we see now is less than a fraction of what's happened/happening out there. Add to that the problem of the speed of light, where what we see from the other side of the galaxy happened thousands of years ago, and the picture becomes a bit murky. Add in a dash of the human lifespan, and we have a pretty good recipe for misconceptions and misunderstandings.

It took until the late 1400's for people to understand the world was round instead of flat, and the 1500's to find out the Earth rotated around the Sun. That's roughly 500 years ago. Space is a new frontier we're only beginning to explore and understand. Things like dark matter and anti-gravity particles have yet to be definitively discovered, and for all we know there could be structures of even more curious things floating around up there. Therefore, at this point any equations are based on a number of unconfirmed variables.

Also, the assumption that all life is based on DNA is a bit presumptuous. They key words are "life as we know it." Like Ken, I don't want this to become a religious debate, but let's say for the sake of argument that life on earth did start from a spontaneous chemical reaction, producing bacteria which then evolved into higher life as conditions became more favorable. Given that if all life rose from simple amino acids and then bacteria, it only makes sense that all life here would share the same structure in DNA. However, the theoretical existence of silicon based life-forms means there may be life in places carbon-based life couldn't possibly survive. In any case, my feeling is there's really not enough data either way to draw any sure conclusions. My personal feeling is we are not alone. Perhaps more advanced civilizations have visited our solar system at one point, or still do. If they have, maybe they consider our species to be too primitive, selfish, and greedy to make any meaningful contact worthwhile. I'd also guess if they have the technology to travel between stars, they would have the capability of hiding themselves from our relatively primitive telescopes.

Re: are we alone in the universe?
 

if there are 10,000 earth like planets in our galaxy, then the odds are 1:10,000 that any given planet is the single origin of life

if we came here from somewhere else, then either we were involved in that transfer (as a species) or it was done by a species more evolved than us, and we were just cargo along for the ride.

But I think if we were going to colonize another star system, I cant think of any reason to send only one-cell organisms. I would send the most complex life forms we could, including humans if humans can survive on the new world.

so from what we know about earths biological history - tens of millions of years of life existed before humans showed up. Therefore, if we came here from somewhere else there must have been a very long program of first seeding the planet with plant and animal life, and then after 50 million years or more we came here too (after the earth was ready) ?

We only assume humans evolved from other lifeforms here on earth, because there is no other explaination based on what we have found here on earth. But if we came here from another world, then we dont know our own history as a species

which would be very strange.

we dont really know. Unless we find a starship buried under the pyramids Im inclined to believe we evolved here, and we are the only life in the galaxy.

Re: are we alone in the universe?
 

that ratio of 1:10,000 isn't any good lets say you add all the neighboring universes then your ratio could be 1:,100,000 and the actual ratio might end up being 1:1,000,000,000,000,000,000,000,000,000,000,000 (and actually i wouldnt be surprised if thats right)

Re: are we alone in the universe?
 

I believe that I saw some article a few months back that said something about there being some form of clay that actually, when reacted with water (I think) it creates amino acids.

Re: are we alone in the universe?
 

this is what I meant when I said the astronomers have not been talking to the bilogists. When Darwin first proposed that single cell organisms could easly assemble themselves in primortal soup I dont think we even knew about atoms and molecules yet (I will have to double check this). To Dawin a single cell organism was simple, a handfull of elements mixed together.

but we know know that a one cell organism is incredibly complex - and we can put a number on that complexity (how many atoms or molecules there are, and how many possible combinations)

so while the universe is very large (1E66 atoms in the universe), the most simple life forms are way more complex (1E350 possible combinations to get one cell correct)

Re: are we alone in the universe?
 

actually we know exactly how they are made and are even able to create them in labratories by simulating earths environment (not with some fancy machine) and chemicals present at the time. the word Atom comes from the greek word Atomos which was basically thought to be the smallest particle of matter. however no real knowledge came until Rutherford and the plum pudding model which comes after Darwin.

Re: are we alone in the universe?
 

it may seem presumtuous at first, but DNA based life is the only form of life in existance on the earth, the moon, on Mars - everywhere we have been able to investigate so far

and its incredibly complex. If simpler life forms could exists then probability says they would have spontaiously been created long before DNA life would, and there would be billions and billions of different life forms - all based on different molecular arrangements

but we find none, nothing here, only DNA life

now if lifeforms other than DNA based can exist, but they are more complex than DNA, then the probability equations hold true for them. They would be even more unlikely to spring into existance spontainously than we were

so (according to statisics) they are not out there either.

Re: are we alone in the universe?
 

you are correct, but the complexity of 1E3 is not the complexity of life based molecules (DNA)

the complexity of the most simple DNA is 1E350, and as I explained on the wesite, every single atom everywhere (universe) times every single second since the big bang only gets you to around 1E100.

Re: are we alone in the universe?
 

we are able to create amino acids in the lab, yes - but there are countless variations of amino acids. Most of them are tar like substances and are toxic.

To build one DNA strand every molecule, every atom has to be in the right place, or the DNA cannot reproduce, and it would not be suitable for life.

the fact that we can create amino acids in the lab is like taking 1 million dice and throwing them all on the floor - yes we can throw them, but we cant make them all come up 6 at the same time

we cant fabricate DNA from the raw elements

Re: are we alone in the universe?
 

However.... i think certian material made today merit attention. there are materials with a "memory" for their shape. i know it may not merit much at first glance but neither would amino acids to an alien. also if their is life like us than they probably wont be the ambasidors for their kind. look at our robotic research is the human race that far a way from giving birth to a mechanical life. and if so will they have a glowing red light that goes back and forth accross their faces. yes deep questions are these. and in responce to the last post the statment was that we didnt know how amino acids were created not DNA.

Re: are we alone in the universe?
 

it becomes a chicken/egg problem. DNA based single cell organisms can take oxygen, carbon, hydrogen... and build its own amino acids, its own protien strands, and create a complete perfect copy of itself

but anything less than that one cell organism cant - cant build any of the molecules needed

so that puts you back down to random chance - back to the 1E350 probability of it happening at random

it only has to happen at random once, in the right place, and the spark of life is ignited. All life on the planet can be the result of that one spark

but it has to happen spontainiously at least once.

Re: are we alone in the universe?
 

first of all viruses can be considered to do those things and what i ment was i was responding to the statement that we didnt know how amino acids were created.

Re: are we alone in the universe?
 

If I understand it correctly, viruses dont reproduce themselves, they infect a DNA based lifeform and cause it to reporduce the virus (RNA strands) instead of reproducing DNA - so a virus could not be first, without DNA cells to reproduce them

most likely a virus is a mutation of a DNA cell that causes DNA cells to become corrupted.

I have to take off and dont know if I will be back online this weekend.

Its not really my intention to convince everyone that my ideas on the webpage are absolutely correct. The main thing is the idea that life is rare, and that possibly the earth contains all the life there is

I know that is a big leap for most people who want to believe in star wars and star trek like galaxies, but science is cold and un-emotional. The facts are what they are.

I did some surfing on the web and found a few other sites that explore the same idea from different angles. As I have time I will update us-spark.com and include links to those sites.

Like the name implies, the concept is a spark, a hope of starting a new way of thinking - a new level of responsibility for humanity.

If it doenst sit well with you for one reason or another, thats ok. Im not thinking in terms of individuals, or of today or tomorrow. The idea of humanity spreading life throughout the galaxy pushes you out into the realm of the universe, into a task that will take millions of people to engage, and might take a million years to accomplish.

Re: are we alone in the universe?
 

Viruses reproduce just fine with only a fraction of the complexity of a full-blown cell. They can't do it without the proper conditions, but given the appropriate environment they manage. Mitochondria are an interesting example as well, as they appear to be genetically distinct from the cells they inhabit.

Amino acids are easily created in the laboratory using chemicals and processes intended to mimic the young Earth's environment. Some of them combine on their own to form peptides, and given enough time there's a nonzero probability that relatively complex molecules will arise just from random mixing. Hundreds of thousands of years of such mixing is going to yield a lot of potential precursors to life as we know it using non-living processes. It's not much of a stretch to imagine a short chain of RNA that spontaneously duplicates in the presence of the right mix of amino acids.

Why don't we see this happening in the laboratory, or the wild, now? In the lab, there arguably hasn't been enough time for it to occur at random. In the wild, the environment is no longer amenable to such processes.

Re: are we alone in the universe?
 

maybe Im not understanding this correctly, but from the way I read it, a virus on its own cannot reproduce, there has to be a full (DNA) based cell for it to infect or take over. A virus is like a parasite, it cannot exists (spread) by itself - it needs the higher lifeform (the DNA cell) to propagate

or am I missing something?

http://biology.about.com/library/weekly/aa110900a.htm

Re: are we alone in the universe?
 

I'm jumping into this thread a bit late, but I have to ask....

What would it matter if we find other signs of life? If we do find any other signs, they'll almost positively be in some form of non-natural radiation (ie decodable radio signals, etc). However, if we do find anything like that, it will have come from so mind-bogglingly far away, that our 1E350th children probably wouldn't even meet them.

Yeah it'd be cool to know we're not alone, but in the end, you end up knowing no more than when you started. Just that someone up there has got a big radio.

Dave

Re: are we alone in the universe?
 

from the perspective that I tried to convey on the us-spark.com site, if we know for certain that we are not alone, then one major issue is different

look at it this way. If my wife and I are one of 6 billion people on the planet, then what we do as individuals is not really that important in the larger scheme of things. We could have a family or not, do what is most important to us as individuals.

But if we know we are the last two humans on earth, then we would have a very strong direction to re-establish the species, to have as many children as possible

same with our planet as a whole. If everything we are able to measure and observe tells us we are alone in the galaxy, or the universe, then we have a responsibility to ensure the survival of life, because we have control over all life.

thats why its important to know.

Re: are we alone in the universe?
 

Personally, I believe that there is life outside of Earth that we have not found. We probably haven't heard from them because they can't "see" us, or they are activly trying to not contact us. For the relativaly short period of time that we have been transmitting radio signals (50 years) its no wonder no one has found us. It is really possible that the first, relativly weak radio signals have remained at a reasonable strength for ET's to recieve it and understand it? And even if they did get it, why would they want to visit us?

Re: are we alone in the universe?
 

Let's consider this for a minute:

Assume that the universe has a finite lifespan, but time is infinte. Every something-billion years, someone hits the reset button and everything starts over. Let's also assume that it has different inital conditions each time. We now have a random universe generator with infinite trials (not necessairly infinite initial conditions though).

We know for a fact that AT LEAST one of these universes supports life. Any universes that don't support life would go unnoticed. Those that do support life will probably contain beings having the same discussion we are right now. This means, however, that life isn't that improbable. If the universe doesn't support life, there's nobody around to care. The only universes that have beings to define the improbablity of life are those that support life anyway.

I know it doesn't address the original topic, but it's something to think about...

Re: are we alone in the universe?
 

Im hoping to get some free time to add more to the us-spark web site. I think the idea that some aspect of the universe is god-like permeates human thinking

and I think infinity is one of those aspects - if we can somehow involk infinity into the equation, making the universe infinitely large or infinitely repeating, then we are saved in a way, because we have this unlimited amount of time or matter or energy

so whether you apply these god-characteristics to a conscious being and call it God, or you apply them to the universe, and say the universe is unlimited in some way, isnt that really like throwing your hands up and saying "I dont have to worry about this because God or the universe will take care of it for me".

?

The laws of physics as we have been able to observe them require that space and even time itself did not exist before the big bang - so there was a discontinuity there. The universe cannot collaspe back in on itself and start over, because time and space are already in existance now, they did not exist before the big bang. We can never get back to those initial conditions.

Besides, the universe expansion has been measured, and it is expanding too fast to fall back in on itself.

Re: are we alone in the universe?
 

i know Ive pointed this out before (looks back yep definitely said it) but due to the vast amount of undiscovered molecules and forms of planar existence (I'm talking about general things that exist out their) that we know nothing about and due to the fact that if life is like us it means the life form would have to develop in very similar conditions as us I'm willing to bet all my worldly possessions that any "being" (the quotes are their for a reason) we discover will be very different than us and almost guaranteed to be overlooked as intelligent maybe it wont even have any form of "thought'. our ideas of aliens are limited to the examples of life found around us and are thus almost guaranteed to be wrong. anything a terrestrial animal has is in no way needed for an alien. an alien might lack a circulatory or nerves system it might not even have a body. a great example to their potential abstractness is the virus. scientists are debating if a virus is a living organism. it pushes the bounds of what we consider life but what if somethings not even in those bounds (cold you have for example life that has no body or maybe lack a recognizable brain). and finally I'm curious to what constitutes intelligence. the only thing that truly makes us a thinking being as apposed to lets say a chimpanzee is a more developed prefrontal cortex (the tool using and adaptation part of our brain) the main difference that sets us apart from other primates.

Re: are we alone in the universe?
 

so, from what you have said, it sounds like we really need to define the words "life" and "intelligent" before we can determine if those things exists outside our planet.

Id be hesitant to delve into matter and molecules or forms of energy that do not exist here on earth. We can fill in the periodic table of elements with all the reasonable combinations, from one proton and electron up.

but if forms or states of matter and energy exist outside our solar system, which we cannot observe or interact with, then I dont see the rational behind that

why would basic laws of physics or types of matter exist in one part of the galaxy, but not be present here?

Re: are we alone in the universe?
 

even in this galaxy there are things that do not hold with modern physics and also some affects may be unique to a single galaxy as it might be the creation of a rare occurrence. we don't have the whole galaxy in our backyard so there are guaranteed to be things we have no knowledge of or redefines physics (which happens often enough as it is). saying everything in the galaxy is going to fit in our understanding of the existence is a dangerous statement as it is almost guaranteed to be proven wrong.

Re: are we alone in the universe?
 

I agree that we dont know what new things we will find when we venture to other star systems, good things and not so good things

and by the same reasoning, we dont know what things (new types of matter or energy, or celestral objects) will cross our planets path, some of which might threaten our existance, if we sit on our hands, stay here on earth, and wait to see what happens?

the unknown is part of the threat, and part of the logic that spreading life around as much as possible is the best path to take, to ensure that life itself does not become extinct.

Re: are we alone in the universe?
 

spreading is essential. the book ive talked about Jentry's Envy talks about this exact subject but not in the way you consider it. think not of the outer danger but of the inner danger. without expansion society falters, falls, and stagnates. its like genetic research and darwin. darwin states that life evolves as a member of a species is able to reproduce most. this is normally the creaure that fits the most efficiently in its nitch. yet what predetors do WE have? weve eliminated almost everything that can harm us. already our genetics have stagnated and evolution in my opinion has stopped even fall apart. think about genes that normally would kill a creature now can be ignored. the only cure for this is genetic research to keep the gene pools reinvigerated. i view space travel similary. with out it we will eventually crumble.

Re: are we alone in the universe?
 

"We are Devo, D-E-V-O..."

Re: are we alone in the universe?
 

???? :confused:

Re: are we alone in the universe?
 

Devo - the name of the band was originally a contraction of "de-evolution"

the idea that we are no longer evolving, we are devolving. That humanity is getting weaker and weaker as a species.

Re: are we alone in the universe?
 

i think i can say i agree with that since we have removed many of the elements that spur evolution. that is why i think genetic research is so important.

Re: are we alone in the universe?
 

Re: are we alone in the universe?
 

Why does it rain often in the pacific northwest but not in the pacific southwest? Environments are based on a number of conditions, and with the relatively small amount of knowledge we have about the composition of the universe, it's a good bet there are many conditions we don't yet know about. Dark matter has yet to be proven or dis proven. There was a time when the Atom was the smallest known particle. Now we know about Quarks and Gluons, and are just starting to understand their functions and behavior. There may yet be smaller particles, and particles smaller than them. As far as the periodic table goes, we only have local materials available to study, and only limited capacity to manipulate a sample at the atomic level. I'll go out on a limb and say what if black holes were considered an element, with some insanely high density. If that were the case, anything between element 118 and black hole has yet to be discovered. And I'm sure there are plenty of places in the universe with high enough energy to maintain materials of that density.

As far as time goes, I'm of the mindset that it's linear and infinite. Here's my reasoning- I think time is merely a concept, created by humans to help us keep track of things. Our time here on Earth is based on the rotation of the Earth itself, and it's position in rotating about the Sun. It's how we keep seconds, minutes, hours, etc. Merely a measurement of how long object A takes to move around object B. Or more recently with Atomic clocks, a measurement of the transition of Caesium-133 atoms. It's just a comparison we use for convenience. We've even extrapolated our concept of time to determine the earth is 4.4ish billion years old, and the universe anywhere between 14 and 18 billion of our years old, from the theoretical date of the big bang. Due to the nature of the big bang, and it having spawned the universe as we know it, there's really no way (at this point) to know what was there before the big bang. However, assuming the laws of conservation of mass and energy hold true throughout the universe, I think it's safe to assume *something* existed prior to the big bang, and as long as something exists to use as the basis for a comparison, so must time exist. Space time, or the combination of space (3 dimensions) with time (the 4th dimension?) would still seem to hold true, again, provided something existed before the big bang.

Re: are we alone in the universe?
 

i concur with mark. he however does a better job putting words to my thoughts. also our understanding of atoms is based on natural formations within our universe but what happens if quarks form in other manors for all we know there could be a whole new "class" of atomic structure. this is just one thing to consider along with all the unique biological aspects of life we might come across.

Re: are we alone in the universe?
 

this is an interesting subject that warrents further study

time is not a concept created by humans. Time is one of the 4 dimensions of our physical universe, and it cannot be broken out separately. Einstein has proven that time and space are interconnected, and react to each other.

The laws of physics as we are able to observe and measure them break down when you compress the entire universe back to the point of the big bang. The only possible solution is that time and space and matter and energy did not exist before the big bang. Therefore time is not infinte, it had a beginning.

"Dont think about that too long or blood will gush out of your nose!" -Lewis Black

as for matter and the laws of physics being the same throughout the galaxy or universe, the fact that we did not know about subatomic particles 100 years ago doenst mean they did not exist on the earth. They have always been here, and everywhere else. Thats the point I was trying to make. There is no reason to expect we will find totally different types of matter or energy in the next star system, or on the other side of the galaxy. Logic dictates the most basic laws of physics and the most basic forms of matter must be scattered everywhere throughout the universe.

Re: are we alone in the universe?
 

we live in a very small portion of the galaxy so ill simplify the point. lets say we didnt have space travel yet and you said that we can find an example of everything in the universe on earth. then we go to the moon and find moon rocks. emagine now that earth is a representation of earth. its kind of funny to think we have a sample of everything in the entire universe right in this galaxy. its like saying you have all of existance in your backyard. plus from light passing through galaxies we are able to tell the composition of other galaxies and i think we have already discovered things we cant explain. plus if you need a very detailed example look at the cats eye nebula you will not find a cats eye nebula in the milky way (unless its in it in which case pick another nebula) it is something that we have not explored and have no exmple of such a formation in our own galaxy. finally i find one large flaw with physics. measurement does not exist. seconds, inches, pounds, hertz are all human concept aplied to existance to help define it but ultimatly dont exist as anything except a abstract idea. its funny to think that physics is based on something that doesnt exist.

Re: are we alone in the universe?
 

I'll admit I don't know enough about astrophysics and Einstein's theorys to comment on that (though I'll definitely read up on whatever papers I can find online, it's interesting stuff).

Agreed ;)

My point here wasn't that these particles didn't exist 100 years ago, or that they don't exist anywhere else in the universe. I meant to say we didn't know much about particle matter 100 years ago, and given the progress made in the past century, I can only wonder what we'll know 100 or 1000 years in the future. I'm saying at this stage in the game, there's still an unknown amount of knowledge we don't yet have. If these particles exist throughout the galaxy, their behavior may differ slightly from galaxy to galaxy, as conditions change. On Earth, the best we can do is throw some particles into an accelerator and smash them into each other to see what happens. In other solar systems or galaxies, the conditions in space itself may be closer to what's going on in our particle accelerators, and there's still plenty we're learning from such experiments about the nature of particles. I'm convinced sometime in the next few centuries discoveries will be made which rock the foundations of physics as we know it, just as discoveries were made indicating the Earth wasn't flat, the Earth revolved around the sun, and stars were really burning globs of gas hundreds of light years away.

Sometimes the hardest part of science is letting go of long assumed facts.

Re: are we alone in the universe?
 

I've always had trouble with time as a dimension, something that is that malleable doesn't rate in my opinion. After all, remember the name of Mr. Einstein's famous theory. I suspect rather that there is more complexity under there and we have only a little of the picture, much like the blind men and the elephant. I also rather suspect that this "relativeness" of time has something to do with Mr. Heisenberg, so if any of you figure that out please let us know, we are still looking for the TOE. Anyway, this brings me to my point: there is much we make use of today, that our observations let us use well, but don't ask us to explain why it works. Such questions as to where magnetism or gravity arise from have yet to be understood. Which brings on the remainder of my point: I think that as a species we have just barely scratched the surface of what there is to know, so folks, have fun! Let us know what you learn!

Re: are we alone in the universe?
 

still do you believe we are alone?

Re: are we alone in the universe?
 

I assume the question is directed to me?

Ans: Yes, absolutely.

One of the basic tenents of science is an assumed uniformity, an implied consistancy.

Going back to my career as an example again: when I was 18 I might have said to myself, instead of going to college I think I will take my money and get a sailboat and travel around the world. Maybe I will find an island that is solid gold and encrused with saphires and emeralds, and I will be the richest man on earth

but from what we know about gold and precious stones such a place is very unlikely

the same logic applies to exploring the galaxy, we might find all kinds of strange life and strange forms of matter and energy, but (this is the key) from what we know about matter and energy and life so far, the odds are we will not find any life out there at all.

Isnt that what science is all about? learning everything you can about the universe, and making a rational projection about the things you have not yet explored?

We have landed on,or at least crashed probes into Mercury, Venus, the moon, Mars, Jupiter, moons of Jupiter, and probed Saturn, Uranus, Neptune and Pluto. Voyager 1 is something like 5 or 10 times the orbit radius of Pluto out past the edge of our solar system. We have also landed a probe on an asteroid, and blew a chunk out of a comet. Add in the extensive study of our own sun and you have quite a bit of data and directly observed knowledge.

Now if we found all sorts of strange things on each stellar object we have directly observed here, I might be inclined to say the galaxy is a strange and upredictable place.

But everything we have explored and probed so far has been consistant with what we expected to find. No major surprizes.

Therefore, from a scientific perspective, based on everything we know so far, there probabally isnt life anywhere else in our galaxy, maybe not even in the entire universe.

I can imagine lots of things, like a solid gold island in the South Pacific, encrusted with precious gems, but I dont expect to find one.

Re: are we alone in the universe?
 

:ahh: WHAT? NO MAJOR SURPRISES? read about some of the things we find. examples like the storm on mars, traces of water on the moon and mars. virtually the abundance of unique effects on life that only space can have. we have found so many things in space that raised so many eyebrows at NASA that i don't know how you can say that. and i was asking the person above me if he thought their was life since he forgot to mention his opinion. finally i assure you space is full of gold and emeralds because NASA keeps raking them in.

Re: are we alone in the universe?
 

But at the same time, we only have one sample from which to collect data. I was always tought in science classes that more samples means more accurate conclusions. Unfortunately for us, the closest stars are 4.3 light years away. Even going 1/10th the speed of light (which may be possible in the relatively near future with developing modern propulsion techniques), that's at least 43 years away, plus 4.3 years for any transmitted data to make it's way back here.

It's an inference problem. I see a cat. It's an orange tabby. By looking at one cat, is it logical to infer no other cats in the world are orange tabbys? Statistically, we know one orange tabby exists. We also know there are hundreds of millions of cats on the planet. If I can only see other cats from 500 meters away, is it fair to say either statistically or otherwise that there are no other orange tabbys? I can see that there are a few other orange cats in the distance, but I can't see enough detail to tell what type of cat it is. If I took a sample of 1,000 random cats, examined them closely, say, from 10' away, and I see only that one orange tabby out of 1,000, I'd feel a little more confident that there is only one orange tabby. However, there are still hundreds of millions of other cats out there, many of which I can't see because they are too far away or hidden behind something. At that point, the best we can say is "Out of 1,000 cats, we see only 1 is an orange tabby." In reality, even our sample of 1,000 cats is miniscule compared to the hundreds of millions. Extrapolated out, even 1/1000 in the context of hundreds of millions comes out to a few tens of thousands of potential orange tabby's. We just don't know.

Unfortunately, the only way to answer the cat question conclusively is to survey every possible cat, and compile a database of types of cats. Only then can we find out for sure how many orange tabbys exist.

I can see on your site, you quote the number of stars in the galaxy as 40 million. A quick google search came up with numbers between 100 and 500 billion. Along the way, I came accross this:

"How many stars are there like our sun within the Milky Way?"
Quite a lot, but hard to estimate. There are perhaps 500 billion stars in the Milky Way, of which something like 0.002 G-type stars with the same luminosity as the sun, per cubic parsec. There are about 0.13 stars/cubic parsec in total, so that sun-like stars are about 1.5 percent of the total population, which makes for about 7 billion stars like our sun in spectral class and brightness by my estimates.

So we've got potentially 7 billion stars to look at. Planet discovery is in it's infancy, and I believe the smallest planet to be discovered yet is still 14 times more massive than Earth. I've read that an ideal solar system to support potential life would have a gas giant such as Jupiter in a protecting orbit, which isn't too uncommon according to recent planet discovery. Out of 7 billion potential sun-like stars I think your equation may need to be readjusted. The possibility of life can't be ruled out until all 7 billion stars have been surveyed for Earth-like planets.


So, some trillionaire builds a massive zeppelin of solid gold, encrusted with precious gems, builds some type of nuclear engine to get it off the ground, and it crashes into a sand bar in the pacific. It's really far fetched, but nothing's quite impossible ;)

Re: are we alone in the universe?
 

I think the number of stars in our galaxy being 40 million might be the original number used in Drakes equation back in the early '60s. Im not certain.

but the effect of increasing the number of stars from 4E6 to 1E9 or 2E9 doesnt bring us much closer to 1E350 from 1E100

the vastness of the galaxy is far exceeded by the complexity of even a one cell organism, you have to look at both astronomy and biology

and biology says it is a waste of time to search those billions of stars one by one looking for life. I know this boggles the mind but there arent enough atoms in the entire universe to bring the odds of finding another planet with life on it anywhere near 1:1

Your analogy of studying cats by looking at only one up close somewhat ignores the amount of information we can gleen by studying the light that comes from stars, even if they are thousands of light years away, we can still tell how large they are, how fast they are consuming their fuel, what elements are present, which way they are moving relative to the earth, and how fast they are moving. We know that all stars are giant fusion reactors, where hydrogen is turned into helium at a temperature of millions of degrees.

Its not like we are going to find plasma stars and gasoline stars and wood burning stars - we can tell from here that the same core mechanism is functioning in all of them.

Bythe way, your analogy falls into line with what I have been saying: a cat is an incredibly complex lifeform. The basic laws of physics, matter and energy are extremely simple by comparison. We cannot read the DNA of a cat that is 10 light years away, that would be impossible. But if you were to incinerate a cat 10 light years away, we could tell what elements it was composed of by means of spectral analysis of the light that it gives off as it burns.

Re: are we alone in the universe?
 

Ken,

That 1E350 is an interesting number. How did you come up with it?

Greg

Re: are we alone in the universe?
 

I didnt come up with it myself.

It is based on the number of molecules in the most simple - single cell organisms

and the number that have to be right for the (DNA based) cell to live and reproduce.

This is not too hard to understand, since most people are familar with binary counting.

If a molecule has four atoms for example, and each location in that molecule could be oxygen or carbon, then there are 16 possible combinations

OOOO
OOOC
OOCO
OOCC
....
CCCC

or 2^length of the strand, in this case 2^4 = 16. This is not taking into account mirror image (reversed) combinations that look the same

if there could be 4 elements in each position, then you end up with 4^4 = 256 possible combinations. You can start to see how unwieldly this will get

if the molecule is 100 atoms long, and has 4 possible elements in each position, then there are 4^100 = 1.6E60 possible combinations. This is still a realitively small molecule, and you have already matched the number of atoms in the entire universe.

Im only giving a simplified answer here. The 1E350 number has many factors to take into consideration. I think you can google this subject and come up with several websites that go into more detail on the 1E350 number.

This has been part of the evolution vs creation ongoing debate. Some people say the incredible complexity of the most basic lifeforms requires a creator (the watchmaker argument). Some try to dispute the 1E350 number, saying atoms will have some inherent preference to form DNA cells on their own.

But if you take the discussion out of the creation vs evolution debate forum, and look at it strickly from a scientific method (as some people are starting to do), it leads us down a different path.

Scientists, to some extent, assumed the religious concept of life only existing on earth must be wrong, for the simple reason that the conclusion was based on religion and not on science. Drake assigning a very high probability of spontainious life on almost every possible planet was to some extent a knee jerk reaction - bleedover from the creation vs evolution debate.

If we get past the reactionary thought processes, and look at the data we have, then if life sprang into existance spontainiously it was an extreemly rare event.

Re: are we alone in the universe?
 

I'll add what I've been able to observe so far.
Life comes from life. Life doesn't just spontaneously occur.
Where did the first life come from? Thats metaphysics argue on.

To me life is an example of complexity ( a complex system). Complexity tends to be driven by the flow of energy from an area of high concentration to areas of low concentration. If the flow is high enough and there is a disturbance factor a complex system will form. Complex systems tend to be very durable as long as the energy flow rate is maintained. Could it be that the flow of energy from a star can only drive drive life to a certain limit of complexity and that limit is not enough to spread threw space. These thoughts come from chaos theory. You could build a religion out of chaos theory.

As to the post about their not really being anything in the universe that is an example of infinity. Humans are uncomfortable with the concept of infinity so we try not to deal with it. We yell and scream at the mathematicians to do something about the infinities. They raise their math wands and make the infinities go away. Then we have theories that kind of work but have holes or a whole set of solutions that aren't observed. But, heh there aren't any infinities to worry about. I believe Steven Hawkings first claim to fame was he made an infinity disappear.

Ill stop here before I really get on a philosophical rant.

Re: are we alone in the universe?
 

Im not sure what you are trying to say here?

mathematics is abstract - physics deals with reality

can you think of any real physical world characteristic that is infinite?

Re: are we alone in the universe?
 

The number of different polarizations a given photon is capable of having.

The number of paths that lead from one place to another.

The number of directions you can point from a given location.

The acceleration experienced by an object reaching the center of a black hole.

(Okay, we're not quite sure about that last one.)

Re: are we alone in the universe?
 

I'm sorry but the idea of not believing that their isn't life in the universe just because religion says its true is ridiculous. what would have happened if we didn't believe in antimatter just because it came from a patent clerk? (no I'm not comparing religion to Einstein I'm showing that just because an scientific idea come from a unusual source is stupid) besides now creationism (not that god created life but still life spontaneously forming) is the accepted reason for life on earth.

Re: are we alone in the universe?
 

if matter (and even time) is quantitized, is that really true?

I understood that space is digital, not linear. There is a minimun dimension below which you cannot make smaller increments- as if atoms or subatomic particles exist on a grid, with 'snap to grid' enabled ?

Re: are we alone in the universe?
 

But life began from simple amino-acids, with nothing more than a mixture of hydrogen, water, methane, and ammonia, all of which are common materials, no doubt found throughout the universe. Amino-acids have been created in a lab under conditions simulating the environment of early Earth. From another site:

Further studies showed that some amino acids would have combined with hydrogen cyanide (HCN), which is a byproduct of volcanic activity. This combination would form purines and pyrinidines, which are used to make nucleic acids, which in turn create DNA.

So essentially, atoms wouldn't have to form complex cells initially, but rather, start with more simple organic compounds, and combine/evolve into more complex molecules from there. This seems much more likely, and as it's been proven in the lab, is far from impossible to happen in other solar systems.

Re: are we alone in the universe?
 

This is targeted more toward the discussion in general than the issue at hand.

We all live in a delusional state. Actually, I haven't quite decided whether it's a delusion or an illusion. We see the world however we want to see it. If I want to believe that Microsoft is an evil corporate conglomerate, I’ll be able to find evidence to support it and I’ll be able to find a way to counter any evidence against my belief. (Do some research on dihydrogen monoxide if you’ve never heard of it before) We have a limited view of the world around us. We use what we can see to construct our delusion of the world. Let’s consider the following situation:

Ed walks into the other room. You hear the chop saw spin up, then Ed screams. As someone opens the door, you see red splatters all over the walls.

What happened? Well, it would be easy to assume that Ed cut his hand off. However, he didn’t. He wanted to get the ketchup out of the bottle, but didn’t realize that it would splatter all over the place when he cut into it. You didn’t have enough information to find the correct solution, but you did have enough to make a very good educated guess. If you never saw Ed again and never found out about the ketchup, you would have gone on believing that he’s missing a hand.

Anything you see can be interpreted in many different ways. With something on a large scale, like whether life exists anywhere other than earth, the number possible interpretations increases. Until we’ve checked every planet in the universe (or just find life elsewhere) this discussion will continue forever.

Re: are we alone in the universe?
 

that is what is so good about discusions. you see when we discuss our limited view evolves and changes and allows us to create a more educated opinion.

Re: are we alone in the universe?
 

The original post as stated is a question of metaphysics. And as such we can not apply the scientific method to it. All we can do is state our individual human feelings and perceptions on the subject. We can not quantify our common perceptions and apply the tool of mathematics to come up with a model that many can agree is a valid model of our common perceptions of reality.
This post is a great example of why every student who is going to go to college for the sciences should take a course in philosophy and study metaphysics and religions. Religions is plural. Part of doing good science is understanding what questions can be studied scientifically and what ones can't.

Re: are we alone in the universe?
 

I dont understand the assertion that the question of the extent of life spread through the universe is a matter of metaphysics?

We have no problem clearly defining what is alive here on earth, and what is not 'life'. Why should there be any difficulty determining the probability of finding life elsewhere, based on what we already know.

Is their any question of whether we have found life on the moon, venus, mars, jupiter? is there any question of whether we can reasonably expect to find life on the sun?

Life interacts with the physical world in a well established manner. When does the search for life stop being a matter of physics and probability, and start becoming a matter of philosophy or metaphysics? When does it stop being hard-core science? when we get to the nearest star? the next one after that? 100 light years away?

Im speaking of life as we know it: physical organismism that interact with the physical world.

Re: are we alone in the universe?
 

I agree that the first living cell could have been a combination of the right types of amino acids, but each molecule of that cell had to be the right type, in the right place, in the right sequence.

If you start with a swimming pool full of random amino acids, most of what you have in there will be tar or oil or other toxic substances, not the material you need to form protien, and then DNA.

Saying you will form DNA by forming the right amino acids first, and then combining them, doesnt diminish the probability of an entire cell forming by random. Its like saying I will guess this weeks lottery numbers, but I will guess them one at a time. It makes no difference. In the end, the odds are the same. The probability of that first cell forming spontainiously remains the same: astronomically small.

Re: are we alone in the universe?
 

i believe ken posted earlier that if their were life it would have DNA but i thought allot about that. if DNA is formed by specific amino acids and these in turn are created by specific reactions with certain chemicals than the only way aliens would have a similar form of DNA would for their to be similar conditions present. given the extremely distant probability of earth having a twin i doubt life will have similar building blocks. however how would other chemicals or the same chemicals form with completely different environmental stimuli (like extreme gravity or radiation). if we meet life biologist will have a field day and much of the founding blocks (DNA or even amino acids) will be insanely different from what we know. this of course assumes that the life we meet even has a chemical biology.

Re: are we alone in the universe?
 

How about this:

We've concluded that the probability of life starting in the first place is obscenely low. We know for a fact that it has happened at least once though. What if it happened ONLY once? Not necessarily here though. They've found what could be bacteria in meteorites... If I'm not mistaken, they've found such mereorites a couple times. Some planet with life blew up (possibly Superman style) and something landed on earth providing the beginnings of life here. I think we decided that evolution works? If so, to me, that seems probable. Actually, it seems more likely than life starting on multiple planets... Something else that doesn't seem unreasonable to me is some advanced civilization "seeding" earth. If we ever acquire some sort of interplanetary travel, I'm sure someone would try it. (wait...I think that was on an episode of Star Trek...yes it was...but that doesn't change the fact that it's possible) I don't even think we need interplanetary travel. I'm sure Voyager has all sorts of stuff on it. Think of what would happen if it crashes into some earth-like planet. We could probably launch a few thousand canisters of stuff into space. They'll eventually crash into something.

Re: are we alone in the universe?
 

The problem isnt crashing into something. Think about this. Take an ameba and put it on the moon how long will it last? How about mars? maybe neptune? The fact is that life is very picky about its home. I would like to see some articles about life in meteors. Ive also heard about this but I would like to know the extent of this life.

Re: are we alone in the universe?
 

I could accept the idea of life spreading from one planet to another within the same solar systems, organic material being blasted off one planet, frozen in space, and managing to land on another planet and carry on there.

But I find that much less likely to happen between star systems, where the nearest inhabitable star/planet might be 20 or 50 light years away. For life to be moved from one star system to another by natural forces, the time involved would be tens of thousands of years in transit, and the acceleration required to obtain those speeds would shred the cells.

But if intelligent life is colonizing the galaxy, with sub-light speed space craft, then studies have shown our entire galaxy could be colonized in about 2 million years.

Which is another argument for a lifeless galaxy/universe. The galaxy is 16 billion years old. If it only take 2 million years (0.0125%) to colonize the galaxy then, where are they? Where are the other colonies and why are we not in contact with them? Every inhabitable planet in the galaxy should be colonized by now.

Re: are we alone in the universe?
 

Ah, but it hasn't had all of the 16 billion years, present theory has it taking 3 generations of stars to go supernova before the elements required for life as we understand it came into being, so I guess the question is what is the mean time to failure of a star. We also suffer a second interesting phenomena, and that is the cyclic nature of the solar system oscillating up and down though the galactic arm creating the potential for extinction events. And unfortunately this doesn't even begin to address our most pressing issue: intelligence may not be a long term survival strategy. Look how long the dinosaurs lasted; 20 thousand years ago Neanderthals were still wandering around.

Re: are we alone in the universe?
 

Ok, then let the galaxy stew for 8 billion years for the first intelligent life to evolve. 2 million years to colonized the galaxy is still only 0.025% of the remaining 8 billion years. Our galaxy could have been completely colonized 4,000 times by now

Re: are we alone in the universe?
 

Well, I'm not necessarily talking about dropping off living things, just the beginnings of it. We decided that getting the correct chemicals going is hard enough, so why not drop those off?

Re: are we alone in the universe?
 

I was thinking, wouldnt it be ironic if some advanced alien life was colonizing the galaxy, and they discovered you cant put higher lifeforms on a lifeless planet, because there is no organic material for plants and such

so you have to start out by maybe introducing algee into the waters, let that take for a few million years, then maybe seaweed and some plankton, wait another 10 million years

then add fish, and maybe some smaller land based plants and animals, slowly working your way up

so that after 50 million years you would have a planet that was stable and suitable for intelligent lifeforms to colonize

wouldnt it be ironic if they were doing that here on earth, and humans evolved by chance, or by mistake

and they show up someday and say "What are you doing here? you totally screwed up the whole planet!"

we may have to start all over now!

they walk away muttering "Oh man! you turn your back for 100,000 years and look what happens!"

Re: are we alone in the universe?
 

Well, I'd assume there's only a few inhabitable planets. Therefore, there's only a few other colonies. I feel safe saying that some of them would have destroyed themselves by now - look how close we are... The remaining ones may have forgotten we're here.

Another likely scenario is something out of Stargate. Some advanced civilization wanted slaves, so they grabbed humans (or maybe other humans took human slaves). With their development stunted, most of the colonies aren't capable of interplanetary travel/communication. They don't necessarily have to be slaves either. Maybe some crackpot or a facist government was running an experiment...or trying to get rid of people...

Re: are we alone in the universe?
 

makes me wonder, how advanced would our science have to be to take a planet that is not suitable for life - totally unsuitable, and make major corrections

for example - we discoved this solar system, and the most ideal planet was between mars and jupiter

it was the right size, but its orbit was too far from the sun, and it had two moons, one of which was so large it caused destructive tidal forces

so major adjustments were needed.

1. obliverate the massive moon (resulting in the asteriod belt)

2. drop the planet into a better orbit, between Venus and Mars

3. Introduce basic life forms

4. Let the planet stew in its own juices for 50 million years

and Walla! Earth!

Advanced terraforming 527. For this course you will be required to alter the orbit of a class M planet....

Re: are we alone in the universe?
 

I think you're talking about the Planck length. It's not exactly evidence that space is digital; it's just that quantum effects mean you can't meaningfully measure a smaller distance. The "snap to grid" idea is amusing, though you have to account for the fact that exactly which gridpoint gets snapped to is a probabilistic choice, and things can sometimes jump from one point to another even if there's something else in the way.

Even if space is quantized, the number of directions from one intersection that eventually lead to another on a regular grid is unlimited -- you can always point between two destinations and find another one farther away. Even with a finite number of roads, the number of different trips one can take is unlimited -- you can always add another loop or round-trip down a path.

Re: are we alone in the universe?
 

Bacteria survived on Surveyor 3's camera for a year and a half before the Apollo 12 crew brought them back from the moon.

Re: are we alone in the universe?
 

With all those discussions why not put your energy into practice? There is only one way to find out..Join SETI@Home (http://setiathome.berkeley.edu/) :P

We don't know how big our universe is, but one thing we are certain is that univserse is huugggee. It contains trillions and trillions of stars and one of them must have a planet that could have condition that could support life and I have a feeling that we are not alone.

Re: are we alone in the universe?
 

well thats sorta the point Ive been trying to make. From what we are able to observe about astromony and biology, SETI not likely to find anything.

Im hoping that once it starts to sink in that theres nobody else out there, then humanity will start to take ownership of life seriously, and put our collective energy as a species into an effort to find ways to spread life as far and wide as we can.

The first step is to understand our real situation. Not what we wish it to be. What it actually is.

Re: are we alone in the universe?
 

This sort of comes back to my points. If we're supposed to spread out, who's to say that we're not the result of another civilization that decided to do the same? Not having contact with them doesn't mean anything. There's orphans out there that have no idea who their biological parents are, much less talk to them. That doesn't mean that they don't exist.

Again, evidence can be interpreted any way that you want to. Just because everyone sees that the earth is a sphere doesn't mean that it is. It just means that everyone is having the same delusion. Maybe it actually is flat but some sort of Einstein-like space-time curvature makes it appear to be round. There's no such thing as conclusive evidence, just evidence strong enough to make a very good guess. Your version of reality only exists in your mind.

Re: are we alone in the universe?
 

there you go now you know. slightly off topic but has anyone seen this http://www.mirror.co.uk/printable_ve...siteid=947 62. Before people say its far fetched. Everything on this is being studied and have had plenty of success. I know this because i looked up each one and some like medicine fruit already exists and is working its way through testing. nice to know i was born in time for immortality! :D

Re: are we alone in the universe?
 

if we were part of this effort to spread life, and the 'project' has already been underway for thousands or millions of years, then breaking the continuity of knowledge of the project would be counter-productive to the project itself.

That would be like us deciding as a society, instead of teaching each generation of our children all the things we know (language, science, math, medicine) we will let each of them find their own language, and re-invent everything from scratch. If we did that we would keep humanity in the stone age forever.

On the other hand, if we were placed here without our own knowledge, then our situation remains the same: as far as we can tell we are alone.


as a scientist and engineer I must disagree with this. One of the foundations of science is that the universe is knowable, and the laws of physics are predictable. If I design a circuit, and it does not work correctly, the logical thing to do is test and debug based on what I can observe and measure. If I tell my boss that reality only exists in our minds, and the circuit may or may not be actually working, I will be out on the street so fast my head would spin.

If reality is unknowable, then science is a waste of time.

All we can ever do is make our best observations and measurements, and proceed towards our goals with the information we have.

Re: are we alone in the universe?
 

Of course it would be. But think of how much knowlege has just been lost over time. Wars have spured the burning of libraries. Anything held in these libraries is lost. If stuff disappears, people start to forget it and it becomes myth. I'm sure that with some slight modification, most creation stories could support an interplanetary colonization project. I also recall something about the only copy of a book by Archimedes being erased because some monks needed paper. In it, he had the beginnings of calculus (the concepts of infinity and integrals) and some very advanced geometry. We didn't have the technology to read the erased ink until recently. With this knowledge gone, Newton had to reinvent calculus from scratch.

You are right in that all we can do is make our best guess. If we didn't, we wouldn't be doing anything. I'm just trying to point out that concrete evidence is only as strong as the wrecking ball that tries to destroy it. There used to be solid evidence that the world is flat. At the time, there were people that believed that and people that believed it was round. Current evidence supports that it's round. Future evidence may support that it's actually a cube. Until then, we have to pick one.

You have to realize, however, that science and religion are the same thing. They are merely different ways of arriving at the same place. The ultimate goal of both is to understand the universe. The only difference is that one resides in observations and the other resides in thought. So your notion of an unknowable universe would invalidate both. The reason that both are valid, however, is that the universe is knowable; you just can't be sure if what you know is true.

One following says that candles emit light. The heat excites the electrons in the atoms and they spit out photons. Another train of thought says that candles suck darkness. The black stuff on the wick is the collected darkness. Shadows are a result of the candle's dark sucking capability being blocked by an object. Combining this theory with some form of areodynamics could explain defraction. The photon theory is just an illusion, like the flat earth notion that people used to have. Both theories have valid points. The best we can do is pick one and see where it takes us. Like science and religion, some will choose to follow one path, some will choose to go another.

Someone mentioned earlier that there are infinite paths between two points in space. The same holds true in this journey to understanding the universe. How you get to the end doesn't really matter as long as you do. Some paths will be longer, some will be shorter. As long as everyone ultimately arives at the same place, it doesn't matter how they get there.

Re: are we alone in the universe?
 

What evidence is there now, or was there in the past that the earth is flat? In one day you can walk beyond the horizon and dissapear, and come back the next day and convey what you saw out there 'over the edge'. A person sitting in a tower or on a hill could watch you go and come back, or watch a ship with lights on its mast dissapear over the horizon at night, one light at a time.

people used a straight stick to determine the earth is a sphere a couple hundred years BC, by measureing the angle the sun made at noon at two locations about 100 miles north and south of each other. In fact, they were able to calculate the diameter of the earth to within a few percent, using nothing but those two wooden sticks.

The physical universe exists totally independant of my mind, and totally independant of my ability to observe and understand it. When I go to sleep at night the universe does not wink out of existance

My ability to observe, measure and predict physical interactions is a measure of the accuracy of my understanding of physics. Reality can be tested and verified by independant observers, through independant experiments.

Religion (by contrast) is based on information that is handed down, handed down from a higher authority. The information is not 'true' because you have independantly tested and verified its accuracy, its 'true' because someone told you its true. In fact, in some religions, questioning the truth of it is not allowed.

And if the religion is false, then you do not end up at the same final place that science would lead you. For example, the people who believed David Korey was Jesus and took up guns to protect him are all dead now. The followers of the Heavens Gate cult who thought a spaceship was hiding in the tail of a comet, and took posion to 'cross over', are all dead now.

We have the ability to scan a comets tail optically and with radar. There was no mothership. I dont understand how you can say those dead cult members have arrived at the same place, or conclusions as, lets say, the seven astronauts who have devoted their lives to science and engineering, who are now in orbit around the earth in the shuttle Discovery?

Re: are we alone in the universe?
 

Go out side. It looks flat to me. Open up a book and touch it to your nose. I garuntee you that you won't see words. Dark blobs maybe, but no words. The evidence that you have shows that you don't have a page with words, but maybe a page that was stained with ink instead.

If you find an old book about alchemy (I'm not sure if there even are any...) you'll probably see it as too superstious. To them, however, it was the closest thing they had to science. And I'm sure you know my favorite alchemist: Newton. Just because he didn't have a knowlege of modern nuclear chemistry doesn't mean that he was wrong. He did the best he could given the information he had, but he didn't have the correct answer. I refer you back to my dark sucking candle. The evidence supports it, but it isn't right (at least I hope not...that would destroy my argument).

Let's assume for a minute that Jesus did perform these so called miracles as described in the Bible. Let's also assume that he had access to advanced technology that was on par with today's (maybe he was a genius, maybe he was a time traveler, maybe he was an alien, it doesn't matter how he got it...). Water into wine? Go to the grocery store and get some Kool-Aid. Walking on water? Maybe some sort of clear pontoon shoes. Reviving the dead? CPR. Anything that people of the time could't explain was a miracle or an act of God. We can't condemn them for not having the knowledge that we do today.

If I wanted to be really persistant, I would ask you to prove it, but I won't. While the universe is still around, your individual perception of it does go away...well, probably closer to changing drastically than disappearing.

When's the last time you personally got some gold foil and an alpha particle source to verify Rutherford's findings? You're going on the word of the people that came before you that it's correct and that it even happened at all. A few hundred years from now, someone might pick up a copy of 1984 and think it was a history book that chronicled what happened to some guy named Winston Smith in 1984. If they find nothing else, they might have to assume that it is.

They were looking for the same thing that we are right now, weren't they? They wanted to know the "truth". What the universe is about and what's going on - the answer to life, the universe, and everything. Those individuals didn't make it to the end of the journey, but those that come after them are one step closer. Lesson learned: comets aren't spaceships. Just because lots of people died during the construction of the great wall of China doesn't mean that it didn't get built. They may not have seen the end, but others finished the journey for them. Scientists have been working on the theory of everything for decades. It will probably take many more decades and at least a few generations. Hawking and company will probably be long dead before it is found. They probably won't see the end themselves, but they will help others along the way.

Re: are we alone in the universe?
 

I cant say for certain what the people in the heavens gate cult were looking for? I dont know what drives a person into a position like that to the point where someone starts handing out dixie cups of Guiana Grape coolaid, and you drink it obediantly and without question

Personally I think they were looking more for a sense of belonging, something to make them feel important or special. Also I think people like Applegate knew that he was not god, or an alien, or a prophet - he knew full well that he was taking advantage of his followers, deceiving them, using them.

There is nothing honorable about a false religion, and there is no usefull knowledge gained from those peoples deaths. We knew there was no mothership behind that comet. Those people died for no reason.

Any one of those people could have looked for information from someone besides Applegate and saved himself from that fate. I dont think they really wanted to know the truth. They wanted to continue in their genuine self delusion, even at the cost of their own life.

That type of mentality has nothing to do with science.

Re: are we alone in the universe?
 

If you are designing a circuit, it's implied that you understand the unique properties of each component. You know what the expected behavior of a resistor, capacitor, transistor, transformer, etc. are. You know the operational parameters of each component. You can design your circuit based on the known properties of each piece. If something didn't work right, you can observe and measure values from each component to find out what the problem is.

It's easy to correlate this with our understanding of the universe, but that would also imply we know everything about how the universe operates. We don't. We can see through telescopes, and calculate trajectories, distances, speeds, etc. using our understanding of physics, but there are still many unknowns. We don't know what causes certain motions, we can't explain why certain stars are accelerating as though there's an unseen/undetectable mass present somewhere, we don't know precisely what causes gravity, we don't totally understand black holes, we don't know whether or not wormholes or exotic matter exist, we're only beginning to study quantum physics, and only starting to physically explore general relativity. In the electronics analogy, that would be like building a circuit without understanding what a transformer does, even if you know what voltage and current are. Without understanding what a certain piece of the puzzle does, or where it goes, it becomes far more difficult to troubleshoot the problem.

Re: are we alone in the universe?
 

I understand what you're trying to say, but you're choosing poor examples. When I used to ride a bicycle regularly, I got constant experience telling me that the earth was not flat. Knowing that, I can look beyond the superficial near-flatness and easily recognize the ubiquitous curvature. Indeed, living in north central Indiana where there are few hills or valleys actually makes it easier to for me to see the fact that the ground curves "downward" and over the horizon. Cellular telephone towers make a good analog to ships' masts; you can see that the bottom gets hidden behind the earth's curve before the top disappears from view.

I just held a book to my nose and not only saw words but read them. So the particular evidence you say is not there most certainly exists when I look.

Your point might be better made by mentioning the wave-particle duality of matter and energy, or the Van Allen radiation belts, or the shrinking of an object in the direction of its motion due to relativity. None of these are directly experienced in everyday life; it takes specific experimentation to demonstrate them. But a round earth, or printed words on an extremely close page? Sorry, I see them without even trying hard.

As for the original question of life being either vanishingly rare or commonplace in the universe, I will comment on one important fact and then withdraw from discussion. It is true that we have direct evidence of only one life-bearing planet. But we have evidence that life has existed on this planet since almost the moment such life was possible. Earth is the only place we have closely examined in which liquid water is commonplace. It is not reasonable to conclude that only Earth supports life, because we have never seen another planet having a similar environment that we can use as a comparison. Fermi's Paradox ("If there is life elsewhere, why isn't it everywhere?") is not a true paradox; call it Fermi's Question and it has many answers.

Re: are we alone in the universe?
 

Ripples...

Like a stone in a pond, every event has ripples. Along with these ripples (and the original event, I suppose) comes a new understanding of the way things work. Everything that happens, good or bad, changes the way we look at things. Everything we learn is a step along the way to understanding the universe.

Take war for instance. WWII lead us to develop nuclear technology. While the original application of this technology was bad, the successive developments furthered scientific knowledge. From a more religious/moral standpoint, we learned that modern warfare would be more devistating than ever before. With the power of current weapons, the next world war will probably be the last war. If played correctly, this may finally lead to peace.

New York, a place generally known for a lack of friendship and community was brought together on 9-11. In the wake of a disaster, they pulled together. People helped each other get through it. They banded together and did things that they normally wouldn't have done otherwise.

You're right, they chose the religious route.

Re: are we alone in the universe?
 

i love how threads tend to take on a life of their own. i would just point out that all our arguments are just conjecture as we truly don't know enough of the universe. I would say however that what ever you say is going to be wrong to some extent. reading your posts i could spend hours pointing out holes as you all have been doing to each other. i don't mean to discourage either of you as this type of debate inspires creativity. I seriously recommend reading Jentry's Envy or the Phoenix Exultant as these both while being great scifi novels also go into allot of what was discussed including allot that wasn't.