Jane,
Our fake tree has a large dowel running up the middle to which all the branches attach. It would fit into the tree stand either way. However, gravity keeps all the branches in place. I am not sure they would stay put in an inverted position.
A quick search showed that manufacturers have been making inverted trees for a few years. Although the practice started in the middle ages in Europe, it appears to be more of a floor space saving effort than anything else. Those consumers who have used them in recent times, like the fact that ornaments are more visible.
A simple attachment can be made once the position of a beam is determined. A screw eye or other threaded device for wood would make a small hole in the ceiling and could be used throughout the year for a hanging basket or planter.
Our initial reason is the dogs. We have sizes XL through S. They are all very young and this would be the first tree for all of them.
XL is the one who could eat the tree in one bite. L and M are the ones who would mangle/destroy/create chaos with the tree in no time flat. S is the one who would bat the ornaments around, steal them, and hide them under the bed. My days of crawling under the bed to retrieve toys and hidden treasure are over. At least I hope they are.
Thanks for the suggestions and the humorous comments, all. Well, almost all.
Jane
Buy a tree from Australia. It should arrive inverted.
Just don’t try to flush any of the needles - your toilet may explode.
Yes. Very carefully!

When dealing with pets who like to have fun with the tree, your best bet is to try to train them to stay away from it. With my family’s cats, we’d put small bells around the bottom of the tree. If we heard jingling, a chase would ensue, to the accompaniment of “Bad cat! Bad! Aahh! Bad cat!”
Or, in this case, put bells at the top of the tree…
“Would you be prepared if gravity suddenly reversed itself?”
Sounds like Jane is just being prepared.
Precisely, exactly.
There are people in my house that think along the lines of a certain Mr. Lavery and his very large vertical lazy susan suggestion. I do want to be somewhat assured that I will still have a semblance of a ceiling remaining following the hanging of the upside-down tree. Assurance is a good thing. Your photo is not helping with that. 
Eric - you are using rational thinking. That does not necessarily apply to my marvelous but bouncy pups.
Send pictures 
Hide a fake squirrel in the very top with its head poking out – they’ll stare at the tree for hours 
XL = Fox Hound
L = Coon Hound
M = Queensland Heeler (they don’t understand gravity)
I have many stories of live squirrels in the top of trees poking their heads out and what XL, L, and M are capable of.
You, too, are not helping.
Well, that’s not true. You are helping me understand that they are capable of demolishing a tree hung from the ceiling. hm…
Perhaps if you hung the pets from harnesses attached to the ceiling instead.
Sort of like live “walk-the-dog” yo-yos :yikes:
I can envision them all swaying to-and-fro…
the cat batting at the dogs…
Hmmm… I wonder what it would take to teach the critters to not take the tree down…
Maybe insulation-less wiring on/around the tree?
And I think Mr. Forbes has better things to do than sit at the “top” of a tree as hound bait.:p:p:D:D
Well since its a fake tree, just put it together the “wrong” way. No holes, no lazy susans needed.
Depends on the tree, Conor. My family’s fake tree (which we’ve used about as long as I can remember) has two sections and a stand. The branches fold upwards for storage/space when we’re done with it. It’s impossible to put together wrong…
If using that type of tree, you’ll also need to make sure the branches stay up. Wedges or fishing line tying the branches together and to the top rope would work for that.
And keep in mind that a main reason is that 3 of us really would like to see what an up-side down tree would look like. The 4th person is the one who might not keep the ceiling intact as much as I would like but will go along with the idea and try to help.
I think I like the idea of a readymade upside-down tree that we can attach to the ceiling.
that’s what I was thinking, too…
Plant an acorn in your ceiling.
Somebody teach the boy the difference between deciduous and conifer.