I got a couple questions about the membranes that string theory proposes. I read that the end of our membrane is really only about 3 millimeters away from us. How can this be? Does it mean this on a different scale or what? If our univerese is comprised in a membrane then what's our membrane (and the other membranes) in? If our universe is not the end, then why should we believe that these membranes are? Please Register or Log in to view the hidden image! :bugeye:
3 mm?? Our membrane? This raises so many questions and I am willing to listen. Any further reading on this subject?
It basically says that these membranse are like slices of bread and each membrane contains a seperate universe. These membranes can be 2 dimensional, 3 dimensional, or more. I read that the membrane for our universe is only 3mm away from us but I can't figure out how that is unless they are using a different type of size scale...Just read up on string theory to learn more about all of it... (Also it says that the big bang may actually be caused by 2 membranes bumping into each other and that it has happened before and will happen many more times (infinite i guess)). Anyways, if anybody can give an answer or explanation to these questions I'd like that. Please Register or Log in to view the hidden image! EDIT: I just saw something on the internet that said something like this: "The membrane of our universe may only be a millimeter away from us in the extra dimensions." So would that mean that yes it is only a millimeter away, but we would have to go through the other tiny dimensions to get to it?
I am not at all familiar with String Theory, so I am only guessing at this. Imagine 2D creatures living on a plane surface. They can deal with 3D spaces mathematically, but cannot visualize 3D objects. For such creatrures, a plane parallel to theirs could be even less than 3mm away in a direction they cannot imagine. To them a circle can be used as a prison because they cannot move up off their plane. That plane parallelto theirs is unseeable and equivalent to their entire universe, yet it it only a short distance away
I think you answered your own question... Measurement loses its meaning when applied to (your) string theory.
Predictions made on energy content dependancy theorize that a string could expand and form a sort of membrane. An expanded membrane can become as large as the whole universe and when two small branes (short for membranes) of high energy content collide with each other, an explosion like the ‘big bang’ can take place. The big bang, which created our universe was the result of collision of two such branes. The theory also predicts that our universe is situated within a megaverse, which may be enveloping numerous other universes like ours. The strings attached to these various universes may vibrate with different frequencies. Vibrations of a string define the properties of the corresponding elementary particles that the vibrating strings represent because each material particle is nothing but the vibrations of a string. The vibrations of different branes (universes) may thus assign different laws of nature to the plethora of universes. The unification that is being sought is for the unification of the fundamental forces in our universe and such a unified theory will not be applicable in other universes. And these different forms of vibrations are interpreted as different elementary particles: quarks, electrons, photons. All are different forms of vibration of the same basic string. Unity of the different forces and particles is achieved because they all come from different kinds of vibrations of the same basic string, So the fuzziness that is displayed by the duality of wave and the material structure of the particles, is somehow explained by the vibrating string. Physics without strings is roughly analogous to mathematics without complex numbers.
Do we really know that when 2 membranes collide they make a 'big bang' type of thing? Also, I thought in string theory one theory is that since the universe can't get smaller than a string, as it starts to collapse smaller and smaller, it eventually reaches a minimum size and therefore starts to expand back... Edit: I also have another question... If string theory's graviton is found and it is indeed able to escape our membrane...then would that be disproving general relativity? Because why would warped space need a messenger particle?
This idea resembles The M Theory, where two membranes collided creating a quantum fluctuation. If the membranes did meet, then time did not exist so there was no 'before' the big bang. It also raises the question of 'information'. Was this created at the time of the 'bang' or was it all contained in the point singularity? Well singularities are avoided because the observed consequences of " big crunches" never reach zero size. In fact, should the universe begin a "big crunch" sort of process, string theory dictates that the universe could never be smaller than the size of a string, at which point it would actually begin expanding. Because of quantum fluctuations, empty space must have undulating gravitational field, an effect that becomes more and more apparent as the scale decreases. At tiny scales, there is violent warping and turbulence, so called quantum foam (Wheeler). Thus at very small scales, the smooth spatial geometry required of general relativity is destroyed. Calculations attempting to merge general relativity and gravitation with quantum mechanics thus fail due to resultant infinities (singularities). The fabric of space appears smooth except at the ultramicroscopic level. The scale on which this problem emerges is the Planck length = sqrt(h-bar*G/c3) = 1.616x10-33 cm (some authors use h and obtain 4x10-33 cm). This is an important (though controversial) incompatibility, despite the fact that it only occurs at this tiny scale, and the resolution of this lies in superstring theory.
The problem with gravitons is that they won't renormalize. This places the problem with the graviton on the quantum side, not on the GR side. Quantum Field Theory (QFT) has some unsightly infinities. Renormalization is the trick that allows us to sidestep these infinities. Unfortunately this trick won't work with GR, so we are stuck with nonsensical infinite results when we attempt to use standard methods to quantize gravity. We can deal with non-quantized gravity just fine with classical GR. The problem with the idea of the gravition is with the quantum mechanical aspects of quantizing gravity.
