Expert: Jayendra Upadhye - 3/1/2007

Question
I've been tearing into this subject lately like a dog with a bone. If you were in 5 dimensional space, how would matter coelesce? Could a sphere shape be possible? Is gravity possible, the way we know it?

Answer
Hi,
Paul..you are doing this for what?...i mean the returns...
the "what's in it for me in the end" part..

Is this line of work fruitful really?

Ok ..now to your question.
Few people can boast visualising anything 4 dimensional let alone 5 dimensional.

Of course strictly speaking we do come across 4 and n dimensional matrices in some daily situations , in engineering etc.
[Even in programming whith multidimensional arrays].

But applying more than 3 dim to space is another thing.
in that we would be like snails trying to describe spheres!
or the proverbial blind men describing an elephant.
But we can go by analogies.

1 - two dim space is a subset of 3 dim space so likewise, 3 dim space would be subset of 4 dim and 4 dim would be subset of 5 dim space.

2 - a two dim creature trapped in a closed circle would be surprised to know its 3 dim cousin just hopped "over " it and plopped back "outside" so easily.
Likewise, 4 dim "people" could get out of closed 3 dim rooms by momentarily using the 4th dim unknown to us!!
i cannot give such a 4d example as neither of us can describe what 4d closed surfaces look like!!

3 - Forces of nature i believe are truly universal.
There is no such thing as a separate 4 d universe etc.
remember we said each space is a subset of the higher one.
so our 3d universe is a subset of the 4d one and it in the end is a subset of a very real 5 d one and so on.

4 - In 4 d land, our "curved space universe" which is centerless from our point of view (the bang "happened everywhere" simultanously), as its center lies inside a 4 d expanding sphere of whcih we are the surface, will be seen to very much have a "locatable" starting point.

5 - Consequence of that being that the 4d world will be able to see a zillion such big bag events happening as different separate entities in themselves. what we see as a single "all encompassing" universe will be seen as but one particular entity belonging to a "class" of entities.

6 - Gravity wells felt but not seen by us, will appear as dreadful real entities "seen" by the 4d guys!! just as we see mountains and vales in "our" real 3 world!!

7 - Gravity will be there, but may be some of its aspects unknown to us will become understandable to 4d guys!!

Many possibilities, but as i said "what's in this study to benefit us in near future"?

But all analogy studies are in the end beneficial. they help us to expand our horizons and mainly "see links" that others do not "see".

That is no small blessing!!

In the end as i believe the british astronomer eddington said, the universe itself is multidim, we "limit" it by our own "limited" percemptions!!

Jayen


Post script:-
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Thank you for the rating.

Paul! Strive one must!!
For learning never stops...and if you see my profile you will find we are like minded creatures!
For one must first learn "for the sake of it"!
All else merely follows!!

Had bernoulli not come up with his equations, [as applied to pressure diffrerentials in fluid flow over an aerofoil] the wright brothers would not have flown their craft at kitty hawk!

Attitudes towards pure knowledge do matter..whole technologies flow from them.

The transister & the laser are cases in point.
Jayen