41–50 of 85 posts
Earlier quoted context omitted.
I think you will find all the models are false to a degree. A model is only an approximation of the real thing. Quantum mechanics and General relatively cannot both be right. The obvious answer is that they are both wrong.
Isn't that just relativistic quantum field theory?
Also, a simple explanation for the layman: http://www.alphagalileo.org/ViewItem.aspx?ItemId=169788&Cult...
> In the same way that temperature arises from the movement of microscopic particles, gravity emerges from the changes of fundamental bits of information, stored in the very structure of spacetime.
It doesn't explain how gravity emerges from bits of information. I'd love to understand how those bits make apples move from trees to the ground, the equivalence between gravity and acceleration and the weightless free fall experience. That should be one paragraph for the general principle and one for each example. Then it's for the layman, and me too :-)
Also, a simple explanation for the layman: http://www.alphagalileo.org/ViewItem.aspx?ItemId=169788&Cult...
Thanks for the link (+1) but it's very far from being an explanation for the layman. > In the same way that temperature arises from the movement of microscopic particles, gravity emerges from the changes of fundamental bits of information, stored in the very structure of spacetime. It doesn't explain how gravity emerges from bits of information. I'd love to understand how those bits make apples move from trees to the…
To what degree does this contradict Einstein's theory of gravity?
Don't think of a theory so much as "what is true" but rather as a set of propositions and equations which are designed to model the way physical processes are observed to occur.
Theories exist within their own provenance of observation. Both Einstein and Newton's theories reflect reality within certain limits, but outside those limits they do not. To allow Einstein's theory to apply at larger scales, we proposed dark matter because Einstein could not account for the behavior of galaxies unless there was some hidden element involved. Thus we proposed dark matter. It is a reasonable accommodation, but one that has defied confirmation.
The emergent theory embraces both Newton and Einstein, eliminates any need for dark matter, and attempts to explain all current observations within a single framework.
Einstein's theory made testable predictions which were later proven to be true. The emergent theory lacks such confirmation, and so time will tell whether it reflects reality.
To what degree does this contradict Einstein's theory of gravity?
It does not contradict Einstein's theory of gravity, just as Einstein did not contradict Newton. All three are different models explaining progressively more thorough levels of observation. Don't think of a theory so much as "what is true" but rather as a set of propositions and equations which are designed to model the way physical processes are observed to occur. Theories exist within their own provenance of observ…
The author claims to be making a few novel predictions which, he claims, astronomers can go check. He also retrodicts several things we observe, though I'm not enough of a physicist to say if he's using a simple enough model for that to be interesting.
Earlier quoted context omitted.
I think you will find all the models are false to a degree. A model is only an approximation of the real thing. Quantum mechanics and General relatively cannot both be right. The obvious answer is that they are both wrong.
A thought experiment of mine. Assume that all possible hypothesis or theories (explanations in general) form part of an "explanation space." Some explanations are good (theories), some have no evidence (hypothesis) and some are false (we are riding a giant turtle). Given the number of false explanations, the overall space is infinite. Hypothesis spaces would be islands within the false explanation space, theories isl…
The theory space is definitely infinite, in either the interesting sense of something like "the space of all possible programs, treated as causal or directed-generative models" or in the trivial sense that you can take any simple, well-supported theory and come up with mathematical elaborations that don't change any of the pre-existing empirical predictions.
In a certain sense, "the truth" may constitute an infinitely small point in a space that's more continuous than discrete.
Earlier quoted context omitted.
No, a gravitational wave has mass (carries mass is more accurate), but a graviton does not. They are not two aspects of the same thing.
Gravitational wave doesn't carry mass. It travels at the speed of light, so it has to be massless. In fact, in 4D gravitational waves can arise even without any mass/energy source.
I suppose I should have said energy, not mass, but unlike a photon which can disappear into nothing, leaving just the energy, a gravitational wave can't ever vanish entirely, so it's more like mass in that regard.
And don't forget that a wave can travel at the speed of light even if the wave is carried by massy particles that can not.
Earlier quoted context omitted.
No, a gravitational wave has mass (carries mass is more accurate), but a graviton does not. They are not two aspects of the same thing.
Can you elaborate on what you mean by "a gravitational wave has mass (carries mass is more accurate)"? That doesn't fit my understanding of gravitational waves.
Earlier quoted context omitted.
No, a gravitational wave has mass (carries mass is more accurate), but a graviton does not. They are not two aspects of the same thing.
In a quantum field theory, a wave implies a force carrying particle, does it not?