The same is true in GR — Agustino
No it doesn't. Spacetime itself expands faster than light, but spacetime isn't actually an object the way galaxies, planets, etc. are. Galaxies, etc. travel in spacetime, but spacetime doesn't travel in anything.If you look at the link, you will observe that GR is used in the explanation for galaxies accelerating faster than light, even though SR denies the possibility. — Rich
No it doesn't. Spacetime itself expands faster than light, but spacetime isn't actually an object the way galaxies, planets, etc. are. Galaxies, etc. travel in spacetime, but spacetime doesn't travel in anything. — Agustino
Yes of course they are! What did you expect? It's like telling me that space is defined differently in Euclidean and Non-Euclidean geometry. This of course doesn't change the fact that Euclidean geometry is nothing but a subset of Non-Euclidean geometry, just like SR is a subset of GR which applies only in a LIMITED set of circumstances/conditions.Space-time are defined differently in SR and GR. — Rich
This one?I provided the link which clearly states the contradiction. — Rich
That 'contradiction' was resolved by GR. That's why GR was invented."The upshot of this is that free fall is inertial motion: an object in free fall is falling because that is how objects move when there is no force being exerted on them, instead of this being due to the force of gravity as is the case in classical mechanics.This is incompatible with classical mechanics and special relativity because in those theories inertially moving objects cannot accelerate with respect to each other, but objects in free fall do so. To resolve this difficulty Einstein first proposed that spacetime is curved. In 1915, he devised the Einstein field equations which relate the curvature of spacetime with the mass, energy, and any momentum within it." — Rich
I can confirm this attitude in Physics forums. They are very good at regurgitating textbook knowledge and abhor critical questions. I have even been banned just for daring claim that Optics is not necessarily correct. My confidence in critical thinking among scientists, whether forum users or academics, is very low. — Hachem
SR has been dropped when GR has been adopted. Really... you seem behind on science.I suggest then that SR be dropped and all that it implies. That will really eliminate the contradictions! — Rich
Are you doing this on purpose?! Do all books on Newton's theories have to be dropped out of the library because his theory has been replaced by GR?! Do we need to get rid of Euclid's Elements because Euclidean geometry has been replaced by Non-Euclidean geometry (which by the way, also includes Euclidean geometry itself?)?Whoops! All those books on SR need to be pulled from the library immediately. This can be a PR nightmare. What should we do about the information on the Internet? — Rich
None, that's why SR, much like Newton's theory and Euclidean geometry provide USEFUL approximations. They're easier to work with and calculate than their more complex parents.Exactly how many areas of the universe are without gravitational space-time?
Really, must we go through this? — Rich
Are you doing this on purpose?! Do all books on Newton's theories have to be dropped out of the library because his theory has been replaced by GR?! — Agustino
It seems you are confused. When I assume that the internal angles of a triangle are 180 degrees and proceed to calculate using that assumption, I don't actually think it's true. Absolutely not. I think it's an approximation of the truth, which is good enough to give me an estimate for the answer that I'm looking for with sufficient precision for my needs.I say drop SR and all of its implications including no preferred frame of reference. — Rich
Sure. So what? Newton isn't applicable where SR is applicable, BUT SR is applicable where Newton is applicable. Likewise, SR isn't applicable where GR is applicable, but GR is applicable where SR is applicable.All of the implications of Newton's theories contradict SR. You can say there is a preferred frame a reference, then say there isn't, and then say they is. Actually, you can, because that is exactly what Relativists are doing. — Rich
When you say this, it's just as silly as telling me to drop Euclid's 5th Postulate when doing Euclidean geometry because it's not true. Absurd.I say drop SR and all of its implications including no preferred frame of reference. — Rich
Yes, but this belies a complete misunderstanding of how science works. Science doesn't work by finding out what is "true". It works by approximating what is true. It says for this group of situations, things behave as if the internal angles of a triangle add up to 180 degrees because the curvature of spacetime is almost 0.There it goes. I'm confused. OK. I'm OK with that. As I said, I invite others to investigate and come to their own conclusions. — Rich
The assumptions you are worrying about are neither true nor false, but useful. That's why they are assumptions and postulates, and not truths. — Agustino
That is what I meant that cosmology is metaphysics with mathematical formulas, and that is what I think Rich means when we say we should beware to give ontological values to RT and QM — Hachem
It depends which equations you elevate to ontology. You should elevate the most general framework. In the case of gravity, this would be general relativity, and NOT special relativity or Newton's laws.This was the essential object that Bergson had to Relativity. Robbins raises the same objection.
It is one thing to say that the equations are useful. It is quite another to elevate the equations to an ontology. — Rich
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