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gdpudasaini
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i think realtivity is the most beautiful theory in the history of physics. what i doubt in this theory is the existence funny objects like wormhole.
Most of the "funny" solutions in GR like traversable wormholes are of questionable reality since there isn't any obvious way to create them in a universe that doesn't have them to begin with, and also because the matter/energy distributions which are needed would violate various energy conditions...I think wormholes violate both the weak and null energy conditions, and although a lot of physicists do believe weak energy condition can probably be violated by quantum effects, I think violations of the null energy condition are a lot more questionable. That's what I've gotten from skimming a few papers on arxiv.org anyway, someone correct me if I'm wrong.gdpudasaini said:i think realtivity is the most beautiful theory in the history of physics. what i doubt in this theory is the existence funny objects like wormhole.
I don't really understand the details of the energy conditions myself, but they're basically just all restrictions on what types of distributions of energy are considered physically realistic. For example, I think the "weak energy condition" basically translates to the condition that there be no such thing as negative energy, so the energy density everywhere must either be positive or zero.gdpudasaini said:Thanks for your reply but man I am a intermediate student so i can not understand your reply totally. Please tell me detail about energy condition.
The only way to keep a traversable wormhole open is to have negative energy densities in the "throat", without them the wormhole collapses before anything can get through. I'm not sure how it violates the null energy condition though...I've read in a few papers that it does.gdpudasaini said:Then how does wormhole violate energy condition?
General relativity doesn't require there to be anything outside it. In this sort of universe the universe is curved into a 4-dimensional sphere whose "surface" is all of 3D space, there's no direction you can travel in space that will take you off this surface.gdpudasaini said:Man let's forget this. According to general relativity space and time is bend due to presence of matter in it. Then isn't it possible that the whole universe is completely curved into a spherical shape so that the universe is finite. But what may lie outside such universe. Do you some idea?
I agree with that. However, a potential danger is that it could be too beautiful to be correct.gdpudasaini said:i think realtivity is the most beautiful theory in the history of physics.
Are you talking about the many-worlds-interpretation of quantum mechanics? The different "worlds" in this interpretation aren't thought to be separated in space, in fact they exist as a quantum superposition in the same space...check out where are the other worlds? from the Everett interpretation FAQ for more info.gdpudasaini said:But according to quantum mechanics there may be infinite no. of universes that has own physical laws. Every universe is self contained and each universe is separated with another and no matter or energy can ever be exchanged between these univeses. How the idea is?
If you click my name you'll see an option to send me a private message...but if you want to talk physics, why not just do it on the thread so anyone can contribute?gdpudasaini said:Man i want to have some personal
talk with you. send me your email adress in your reply please.
No, in the many-worlds interpretation there is no such barrier--the fact that we don't see photons from alternate "worlds" is explained in terms of a quantum phenomenon called decoherence, see the FAQ for more details.gdpudasaini said:Yes they all exist in same space. But they must be separated from each other by a horizon the barrior from which light can't escape.
You may have read about something different than the many-worlds interpretation, then. Perhaps you were reading about the idea of "chaotic" or "eternal" inflation discussed here and here, in which new "baby universes" inflate from tiny regions of previous universes.gdpudasaini said:So there exists no connection between these worlds at all. Right now many of these universe may be dying in Big Crunch or something like that and many of them may be in Big Bang condition. I even read that to make one such universe you won't need to much energy only but such energy should be confined in very small regions of space like black hole which we can't.
gdpudasaini said:So relativity will never be endangered man.
Relativity is a theory in physics that was developed by Albert Einstein in the early 20th century. It is based on the idea that the laws of physics are the same for all observers, regardless of their relative motion.
The two types of relativity are special relativity and general relativity. Special relativity deals with the behavior of objects moving at constant speeds, while general relativity deals with the effects of gravity on the motion of objects.
Relativity has many practical applications, such as GPS technology, which relies on the principles of special and general relativity to accurately determine the location of objects on Earth. Relativity also plays a crucial role in the development of nuclear power and nuclear weapons.
Relativity states that space and time are not absolute, but rather are relative to the observer's frame of reference. This means that the measurements of space and time can differ for different observers, depending on their relative motion and the presence of gravity.
Yes, relativity has been extensively tested and has been confirmed to be accurate in numerous experiments and observations. It has also been integrated into many other areas of physics and has stood the test of time as one of the most elegant and beautiful theories in all of physics.