Gravitational Theories in Higher Dimensions

[MentalManager]

Hello! I just had an stupid idea and i want to know what do you think of it. Let's say thers an creature who is living in 2d world. An 3d world hole in his 2d world plane would feel for this creature like gravitation. Wouldnt it? An 3d mountain would feel for him like ant-grav or somethink like this. Its because the creature doesn't know 3rd dimension.

The question. Would the 4D be for humans like gravitation? And 4D mountain like anti-grav. I have to say that I am only 17 years old and i don't know much physics. In my text can be mistakes.

 

[PRodQuanta]

You often hear that we live in a 3-d world. Those 3 dimensions are our spatial dimensions (length, width, depth). Our 4th dimension is time, not gravity.
Paden Roder

 

[MentalManager]

I see that you didnt understand what i meant. I meant 4th dimension not as time but geometrical axis. I wanted to what do you think: can 4th dimension holes make in 3d some kind of barricade or gravitation.

 

[modmans2ndcoming]

a good Relativistic way to look at gravity would be through compression.

if you took a 3 diminutional chunk of Space-Time, gravity to us would be the compression of space-time toward a center...anti-gravity would be as if you decompressed space-time.

however, the relativistic way of looking at gravity is flawed since gravity has no ability to mesh with the Quantum world, which is why M-Theory is so nice.

check out "the elegant universe". it is a special on PBS...you can watch it on the web on PBS.org for free.

M-Theory though might be wrong...but hey...it explains things so well that it just has to be right :-)

 

[MentalManager]

I saw this "elegant universe" after i posted this question(or how do you called it) and i find this very interesting, but we cannot be sure that this string theory is right, we cannot be even sure the theory of relativity is right.

 

[modmans2ndcoming]

true, however, a theory that best reflects what we observe is considered to be right until we find a problem with it.

at the moment, GR and QM are the most right...however, we know that neither are totally right...the theory that explains the universe must explain from the very large to the infinitesimal.

M-Theory IMHO does this very well, and even though we cannot see strings today, we will be able to see hints of strings, we will have an idea that the theory is correct when we observe graviton's just before they move off our membrane, and when we observe Sparticles.

and as it said in the last hour, we should be able to see impressions left by strings from the time of the big bang.

I personally think that M-Theory does a good job of explaining things, but as Ed Witten says, he thinks we lack the mathematical tools today that will allow us to fully understand it.