are we alone in the universe?

[mechanicalbrain]

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.

[KenWittlief]

Originally Posted by mechanicalbrain

second how do we know that their arent multiple expanding universes...

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

[Marc P.]

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.

[Joshua May]

Originally Posted by Marc P.

What's not yet known is what kicked off the reaction which led to the amino acids to form into bacteria.

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.

[mechanicalbrain]

Originally Posted by Marc P.

What's not yet known is what kicked off the reaction which led to the amino acids to form into bacteria.

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.

[KenWittlief]

Originally Posted by mechanicalbrain

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.

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

[KenWittlief]

Originally Posted by Marc P.

...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.

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.

[mechanicalbrain]

Originally Posted by KenWittlief

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.

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.

[KenWittlief]

Originally Posted by mechanicalbrain

...in response to the last post the statment was that we didnt know how amino acids were created not DNA.

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.

[mechanicalbrain]

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.

[KenWittlief]

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.

[Alan Anderson]

Originally Posted by KenWittlief

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

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.

[KenWittlief]

Originally Posted by Alan Anderson

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.

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

[MrToast]

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

[KenWittlief]

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.