Disproving parts of the theory of relativity

[Mukilab]

Hello, I've heard lots of credible sources pointing out that part of Einstein's theory of relativity is false (in the case of singularities) but I have found nothing in writing to prove this. Can anyone provide anything?

[insane_alien]

singularities don't appear to happen in reality. the fact that relativity predicts these and they are not seen proves there are problems with relativity.

 

the fact that it doesn't work with quantum mechanics either also proves thereare problems with it.

 

It is very important to note that despite these inconsistencies with reality, it does not mean that relativity is suddenly completely useless. its still a damn sight better than newtonian mechanics and can be used in conditions where whatever model would provide accurate representations of reality will simplify down to it.

[Mr Skeptic]

To be fair, the singularities predicted by general relativity would occur inside a black hole, and would be unobservable anyways (and hence not part of science). From a philosophy of science perspective, no one seems to like singularities.

[D H]

Black holes however do appear to happen in reality. We have plenty of observations of both stellar black holes and supermassive black holes. General explains the motion of Mercury and the behavior of clocks on an orbiting spacecraft. It is a very good model of reality, better (more accurate) than is Newtonian mechanics.

 

Every scientific theory is but a model of reality. Just because Mercury's motion falsifies Newtonian mechanics does not mean we should not use Newtonian mechanics. It is still widely used, and it is perfectly valid to do so. Suppose some bright future Einstein figures out how to marry general relativity and quantum mechanics. Will that mean we should throw out general relativity (and quantum mechanics)?

 

Probably not. To do that, this new theory would either have to show that general relativity (and quantum mechanics) are wrong everywhere or it would have to be easier to use computationally than general relativity (and quantum mechanics). We know the former is not the case; general relativity and quantum mechanics are extremely accurate at describing the nature of the universe and at predicting the outcomes of experiments. Whether this new theory is easier to use, who knows? That new theory doesn't exist.

 

The reason we still use Newtonian mechanics is because it is considerably easier to use than general relativity and quantum mechanics within the limited domain in which it is applicable. The same will most likely hold true for this new theory (which of course does not exist yet).

[ajb]

To be fair, the singularities predicted by general relativity would occur inside a black hole, and would be unobservable anyways (and hence not part of science). From a philosophy of science perspective, no one seems to like singularities.

 

I thought it was not clear if one can have naked singulariteis or not in general relativity.

[Mukilab]

Thank you everyone!

 

On another note, I recently read up about schrodinger's cat and a scientist talking about how we will never die within our 'parallel universe' or whatever you like to call it because there are always several scenarios and you can never die from your POV.

 

I find such theories annoying but intriguing because as soon as such multiple dimensions were created then we would be allowed to view only one. Does this mean that the universe literally revolves around you? Everything depends on your actions....

 

Could this be somehow related to Black Holes. If this is taken to Young's slit experiment, how can we still see both things (if you do not think about normal quantum mechanics [which I understand, please don't explain that] but think about this 'pseudo theory')

[Mr Skeptic]

On another note, I recently read up about schrodinger's cat and a scientist talking about how we will never die within our 'parallel universe' or whatever you like to call it because there are always several scenarios and you can never die from your POV.

 

I find such theories annoying but intriguing because as soon as such multiple dimensions were created then we would be allowed to view only one. Does this mean that the universe literally revolves around you? Everything depends on your actions....

 

It's the multiworlds hypothesis, where everything that is possible happens, and you have exponentially many universes. Because it is possible to be immortal, in a fraction of those universes you will never die. However, that doesn't mean that the you that never dies is the same you that you are now. In any case, you can see yourself die, like if someone shoots you in the heart you will realize you are bleeding to death and lose consciousness. Sure you won't actually see yourself die because to die you have to be unconscious, but other people certainly can see you die.

 

In the many worlds model, this applies to everything, from the most insignificant spec of dust to the most important person in the world. There's nothing special about "you" whoever that may be.

[Mukilab]

Ok, thanks for clearing that up.

 

Do you have any resources for a simplified explanation of the Planck constant and schrodinger's equation? Wikipedia is doing my head in.

[ajb]

Eric Weisstein's World of Physics.

 

PlanetMath has eneteries on Schrodinger's wave equation, Schrodinger operators etc...

 

Both may be of help. If you have specific questions you can ask them here.

[Mukilab]

Thank you, I am currently looking through them. Good luck on getting that PhD!

[smoore]

Thank you everyone!

 

On another note, I recently read up about schrodinger's cat and a scientist talking about how we will never die within our 'parallel universe' or whatever you like to call it because there are always several scenarios and you can never die from your POV.

 

I find such theories annoying but intriguing because as soon as such multiple dimensions were created then we would be allowed to view only one. Does this mean that the universe literally revolves around you? Everything depends on your actions....

 

Could this be somehow related to Black Holes. If this is taken to Young's slit experiment, how can we still see both things (if you do not think about normal quantum mechanics [which I understand, please don't explain that] but think about this 'pseudo theory')

 

wouldn't you eventually die of old age in every dimmension though?

and what about dying instantlyyou would see it or at least a 30fps of it.

so to be honest you can never see all of anything because you only see evry 30th of a second...

Edited December 20, 2009 by smoore

[Mukilab]

wouldn't you eventually die of old age in every dimmension though?

and what about dying instantlyyou would see it or at least a 30fps of it.

so to be honest you can never see all of anything because you only see evry 30th of a second...

 

No because there is a possibility that you won't die. You won't get 'transported', your version of the world will still be consistent and uninterrupted.

[Sisyphus]

"Dying of old age" is just the phenomenon that something is more and more likely to kill you the older you get. However, it's not like there's a set time limit. You could live to 200, it's just ridiculously unlikely. But if every possible universe exists, then there are universes (a tiny, tiny, tiny minority) in which you do.

 

However, I've never understood how this equates to "I cannot die." Most of the "yous" do die. The "you can't experience it" argument doesn't make sense to me. I guess you can't experience oblivion by definition, but that doesn't mean it doesn't happen. I lose consciousness every single night.

 

...and we should be glad of that. Because the way I see it, of all the ways you could manage to still be alive and conscious despite overwhelming odds, most of them will leave you horribly disfigured or something. That is, unless the quantum immortality people also think it's impossible to experience your own suffering...

[Mukilab]

I never realized those implications...

 

Thank you for the great answer.

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Consecutive posts merged

Also, why does air act as such an effective insulator? Does heat have to 'adapt' or something when it passes through different materials? Are the particles too spread out for good kinetic energy and then heat?

[swansont]

I never realized those implications...

 

Thank you for the great answer.

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Merged post follows:

Consecutive posts merged

Also, why does air act as such an effective insulator? Does heat have to 'adapt' or something when it passes through different materials? Are the particles too spread out for good kinetic energy and then heat?

 

It's better to make a new thread for a new topic. I've copied this question here

[Baby Astronaut]

emphasis mine,

 

It's the multiworlds hypothesis, where everything that is possible happens, and you have exponentially many universes.

The key is "everything that is possible". It could be that at some juncture, your body's life capacity in every universe will have reached a point/threshold of where it's no longer a matter of (increasing or decreasing) likelihood, but of certainty. However, who knows really, the other universes if they exist could have unimagined possibilities.