I don't think it has anything to do with the earth being "geometrically" flat. My interpretation of this is that Einstein's argument was that Newtonian Gravity is curious in that it operates as if the earth were accelerating upwards.
Firstly, Newton's gravity has all objects move at the same rate towards the earth uniformly. That is its defining feature, and this operation is suspiciously as if the earth were accelerating upwards.
Secondly, objects in free fall experience an opposite "fake" force of gravity of the same magnitude in which they are exactly weightless. An astronomical coincidence. Einstein says that the idea that the object is stationary and the earth is accelerating into it is the best conclusion and the best way to make sense of Newton's Gravity.
I don't think it has anything to do with the earth being "geometrically" flat. My interpretation of this is that Einstein's argument was that Newtonian Gravity is curious in that it operates as if the earth were accelerating upwards.
Firstly, Newton's gravity has all objects move at the same rate towards the earth uniformly. That is its defining feature, and this operation is suspiciously as if the earth were accelerating upwards.
Secondly, objects in free fall experience an opposite "fake" force of gravity of the same magnitude in which they are exactly weightless. An astronomical coincidence. Einstein says that the idea that the object is stationary and the earth is accelerating into it is the best conclusion and the best way to make sense of Newton's Gravity.
sort of. you're getting a lot of the details wrong.
einstein's argument is simply that a free-falling frame of reference has the same properties as an inertial frame. start the video at 8:00. newton says that free-falling frames cannot be inertial because they accelerate with respect to one another. einstein resolves this with general relativity: these objects are actually following straight line paths in a curved space.
einstein isn't making the argument that "lol gravity doesn't make sense, so it must be that the earth is accelerating." he's arguing that two different frames (earth frame vs. free-fall frame) are actually equivalent. the implication of this equivalence is that there is no "force" of gravity. space itself is curved, and objects in free-fall are simply following straight lines embedded in a curved space.
Watch at 6:13: https://youtu.be/NblR01hHK6U?t=6m13s (https://youtu.be/NblR01hHK6U?t=6m13s)
When bodies are in free-fall in Newtonian Gravity the downwards force exactly cancels out the fake upwards force, creating weightlessness. Einstein questions Newton on this astounding coincidence and wins the argument with his upwards accelerating earth idea.
einsteain resolves this by saying that the above is only true if space is geometrically flat. if it is curved, then objects can travel in straight lines at a constant velocity because those lines are in a curved space.
After Einstein won the argument with his accelerating earth concept, the narrator then says that seven years later Einstein develops the GR bendy space to get the upwards acceleration idea working in the Round Earth model.
After Einstein won the argument with his accelerating earth concept, the narrator then says that seven years later Einstein develops the GR bendy space to get the upwards acceleration idea working in the Round Earth model.
that's not even remotely close to what this video says. or what einstein says.
you're taking the conceit of this video far too literally. it wasn't an actual argument, and he's not laying things out in any kind of chronological order. it's just a line of reasoning that you're stopping in the middle of for some reason.
If, instead the world has non-eculidean and curved spacetime then straight lines and constant speed doesn't mean what you think it means. And it turns out that inertial frames in curved space time can basically do whatever they want. It took Einstein about seven years to realize that. But once he did, a beautiful model of the world emerged called General Relativity. One of the central precepts of General Relativity is that we inhabit curved space-time.
After Einstein won the argument with his accelerating earth concept, the narrator then says that seven years later Einstein develops the GR bendy space to get the upwards acceleration idea working in the Round Earth model.
that's not even remotely close to what this video says. or what einstein says.
you're taking the conceit of this video far too literally. it wasn't an actual argument, and he's not laying things out in any kind of chronological order. it's just a line of reasoning that you're stopping in the middle of for some reason.
newton and einstein are arguing about whether or not a free-falling frame of reference is inertial. newton says that free-falling objects can accelerate with respect to one another, and with respect to the earth; therefore, gravity is a force. einstein resolves this by saying that newton is right only if space is geometrically flat. if space itself can curve, then free-falling frames can be inertial for the reasons given in videos two, three, and four. therefore, gravity is not a force; it's just the curvature of space.
After Einstein won the argument with his accelerating earth concept, the narrator then says that seven years later Einstein develops the GR bendy space to get the upwards acceleration idea working in the Round Earth model.
that's not even remotely close to what this video says. or what einstein says.
you're taking the conceit of this video far too literally. it wasn't an actual argument, and he's not laying things out in any kind of chronological order. it's just a line of reasoning that you're stopping in the middle of for some reason.
After the accelerating earth drama and Einstein winning the exchange with the Newtonians the narrator continues:QuoteIf, instead the world has non-eculidean and curved spacetime then straight lines and constant speed doesn't mean what you think it means. And it turns out that inertial frames in curved space time can basically do whatever they want. It took Einstein about seven years to realize that. But once he did, a beautiful model of the world emerged called General Relativity. One of the central precepts of General Relativity is that we inhabit curved space-time.
Einstein was not using his bendy space arguments against the Newtonians. He was using the accelerating earth argument, just as the narrator states. The upwardly accelerating earth is the premise of the video. The bendy space arguments did not come until later.
This is what the video literally says. If you want to make up your own version of the video and what happened, feel free. That is not what the astrophysicist says and how the situation is portrayed, however.
After the accelerating earth drama and Einstein winning the exchange with the Newtonians the narrator continues:QuoteIt took Einstein about seven years to realize that.
This is what the video literally says. If you want to make up your own version of the video and what happened, feel free. That is not what the astrophysicist says and how the situation is portrayed, however.
Well, not so fast, says Einstein. Maybe there is. What about a frame that's in freefall? Think about it. If I put you in a box and drop you off a cliff, then in the frame of the box, everything just floats, weightless. The falling frame of the box behaves just like a stationary inertial frame that's way out in intergalactic space where there's no gravity. So why can't the box's frame be inertial?
...
Einstein says, look buddy, I'm just following your rules. You established the test for what an inertial frame is-- release a force-free object and it stays put. Stationary frames in intergalactic space pass that test. But freely-falling frames here on Earth also pass that test if your so-called gravity is fictitious.
...
This inability to distinguish freefall from lack of gravity has a name, by the way. Einstein called it the equivalence principle, and if you buy it, then maybe the falling frames really are inertial. If so, then it's the falling frames that establish the standard of non-acceleration, in which case, it's really the ground that's accelerating upward and what we've always been calling a gravitational force is an artifact of being in an accelerated frame of reference.
Isaac Newton said that an Apple falls because a gravitational force accelerates it toward the ground, but what if it's really the ground accelerating up to meet the Apple?
Suppose I drop an apple according to Isaac Newton the ground can be considered at rest Earth applies a gravitational force to the Apple and that force causes the Apple to accelerate downward but according to Einstein there's no such thing as a gravitational force instead it's more appropriate to think of the Apple as stationary and the ground along with everything on the ground as accelerating upward into the Apple.
Now what I just said sounds preposterous and maybe even moronic, but it's not sophistry. There's something substantive here, and today I'm going to clarify what exactly this point of view means why Einstein came to adopt it and how it planted the seeds for what would eventually become General Relativity.
...
Now, in Newtonian physics this is just an accounting trick that has no broader significance. Really, Dustin's car is accelerating and this extra backwards gravity is fake, but Einstein asked: Hold on, what if the so-called real downward gravity from Earth is also fake? A side effect generated because Earth's surface is really accelerating upward.
Now, you know what Newton would say. He'd say “that's crazy” and would remind us that inertial frames are the standard for measuring true acceleration. So you can only say earth is really accelerating upward if you can identify an inertial frame relative to which Earth's surface accelerates upward and there's obviously no inertial frame like that.
“Well, not so fast” says Einstein, maybe there is.
What about a frame that's in freefall? Think about it. If I put you in a box and drop you off a cliff, in the frame of the box everything just float weightless. The falling frame of the box behaves just like a stationary inertial frame that's way out in intergalactic space where there's no gravity. So why can't the box's frame be inertial as well?
Because, Newton says, that falling frame can't be inertial. It's really accelerating downward at 9.8 m/s^2. The interior just seems like zero-g because the downward acceleration acts like a fake extra upward gravitational field that, from the perspective of the box, just happens to exactly cancel the real downward gravitational field of Earth.
By coincidence.
Really Newton? Really?
Einstein says: Look buddy, I'm just following your rules. You established the test for what an inertial frame is. Release a object and it stays put. Stationary frames in intergalactic space passed that test, but freely falling frames here on earth also pass that test if your so-called gravity is fictitious.
More to the point, Newton, if you're inside the box there's no way for you to know that you're not in intergalactic space. This inability to distinguish free fall from lack of gravity has a name by the way. Einstein called it the Equivalence Principle. And if you buy it then maybe the falling frames really are inertial. If so, then it's the falling frames that establish the standard of non acceleration, in which case it's really the ground that's accelerating upward and what we've always been calling a gravitational force is an artifact of being in an accelerated frame of reference.
It's not different from the weird backward jolt that you experience on the train that you know perfectly well isn't being caused by anything, so why are you insisting that the downward jolt we experience every day on earth has a physical origin? Maybe gravity, just like that backward jolt on the train, is an illusion. Doesn't that point of view seem simpler?
Now, Newton says: Nice try Einstein, but you forgot something. Earth is round. Down isn't really down, it's radially inward, and this creates two problems with thinking about freely falling frames as inertial, or thinking about gravity as an illusion.
...
If, instead the world has non-eculidean and curved spacetime then straight lines and constant speed doesn't mean what you think it means. And it turns out that inertial frames in curved space time can basically do whatever you want. It took Einstein about seven years to realize that. But once he did, a beautiful model of the world emerged called General Relativity. One of the central precepts of General Relativity is that we inhabit curved space-time.
Einstein won the issue by calling gravity an illusion, and saying that an accelerating earth makes more sense. This is exactly what the narrator states. Do you know more about this than the author?
This inability to distinguish free fall from lack of gravity has a name by the way. Einstein called it the Equivalence Principle. And if you buy it then maybe the falling frames really are inertial. If so, then it's the falling frames that establish the standard of non acceleration, in which case it's really the ground that's accelerating upward and what we've always been calling a gravitational force is an artifact of being in an accelerated frame of reference.
...
[Newton objects]: Nice try Einstein, but you forgot something. Earth is round. Down isn't really down, it's radially inward, and this creates two problems with thinking about freely falling frames as inertial, or thinking about gravity as an illusion...
We actually started this campaign in our "Is Gravity an Illustion?" episode. In that episode we noted objections to Einstein's viewpoint...Now ultimately, the way around those objections is to realize that if the world is a curved spacetime, then the familiar meanings of terms like a constant velocity straight line and acceleration will become ambiguous. We'll be forced to redefine them, and once we do there's no longer going to be an inconsistency with saying that falling frames are inertial, even though they accelerate relative to one another.
Our goal in this series of videos is to explain that last statement, and to explain how it lets you account for the motion we observe even if there's no Newtonian force of gravity.
I believe you to be mistaken. The entire episode is about an accelerating earth. Einstein is talking about an accelerating earth, not "bendy space," in his argument to the Newtonians. He didn't come up with bendy space until seven years later.
This is literally what it says in the video. From the transcript:QuoteIsaac Newton said that an Apple falls because a gravitational force accelerates it toward the ground, but what if it's really the ground accelerating up to meet the Apple?
Suppose I drop an apple according to Isaac Newton the ground can be considered at rest Earth applies a gravitational force to the Apple and that force causes the Apple to accelerate downward but according to Einstein there's no such thing as a gravitational force instead it's more appropriate to think of the Apple as stationary and the ground along with everything on the ground as accelerating upward into the Apple.
Now what I just said sounds preposterous and maybe even moronic, but it's not sophistry. There's something substantive here, and today I'm going to clarify what exactly this point of view means why Einstein came to adopt it and how it planted the seeds for what would eventually become General Relativity.
...
Now, in Newtonian physics this is just an accounting trick that has no broader significance. Really, Dustin's car is accelerating and this extra backwards gravity is fake, but Einstein asked: Hold on, what if the so-called real downward gravity from Earth is also fake? A side effect generated because Earth's surface is really accelerating upward.
Now, you know what Newton would say. He'd say “that's crazy” and would remind us that inertial frames are the standard for measuring true acceleration. So you can only say earth is really accelerating upward if you can identify an inertial frame relative to which Earth's surface accelerates upward and there's obviously no inertial frame like that.
“Well, not so fast” says Einstein, maybe there is.
What about a frame that's in freefall? Think about it. If I put you in a box and drop you off a cliff, in the frame of the box everything just float weightless. The falling frame of the box behaves just like a stationary inertial frame that's way out in intergalactic space where there's no gravity. So why can't the box's frame be inertial as well?
Because, Newton says, that falling frame can't be inertial. It's really accelerating downward at 9.8 m/s^2. The interior just seems like zero-g because the downward acceleration acts like a fake extra upward gravitational field that, from the perspective of the box, just happens to exactly cancel the real downward gravitational field of Earth.
By coincidence.
Really Newton? Really?
Einstein says: Look buddy, I'm just following your rules. You established the test for what an inertial frame is. Release a object and it stays put. Stationary frames in intergalactic space passed that test, but freely falling frames here on earth also pass that test if your so-called gravity is fictitious.
More to the point, Newton, if you're inside the box there's no way for you to know that you're not in intergalactic space. This inability to distinguish free fall from lack of gravity has a name by the way. Einstein called it the Equivalence Principle. And if you buy it then maybe the falling frames really are inertial. If so, then it's the falling frames that establish the standard of non acceleration, in which case it's really the ground that's accelerating upward and what we've always been calling a gravitational force is an artifact of being in an accelerated frame of reference.
It's not different from the weird backward jolt that you experience on the train that you know perfectly well isn't being caused by anything, so why are you insisting that the downward jolt we experience every day on earth has a physical origin? Maybe gravity, just like that backward jolt on the train, is an illusion. Doesn't that point of view seem simpler?
Now, Newton says: Nice try Einstein, but you forgot something. Earth is round. Down isn't really down, it's radially inward, and this creates two problems with thinking about freely falling frames as inertial, or thinking about gravity as an illusion.
...
If, instead the world has non-eculidean and curved spacetime then straight lines and constant speed doesn't mean what you think it means. And it turns out that inertial frames in curved space time can basically do whatever you want. It took Einstein about seven years to realize that. But once he did, a beautiful model of the world emerged called General Relativity. One of the central precepts of General Relativity is that we inhabit curved space-time.
Einstein won the issue by calling gravity an illusion, and saying that an accelerating earth makes more sense. This is exactly what the narrator states. Do you know more about this than the author?
So no, the bendy space stuff wasn't dreamed up until later. Seven years later. This is what is literally stated. You are making a scenario up, imagining that Einstein was really using his bending space explanation all along and never thought of an accelerating earth or used that argument.
The story is in chronological order, indeed. The Equivalence Principal was developed long before General Relativity. You are trying your hardest to remove all references to an accelerating earth. This is factually incorrect to the content of the video.
Feel free to argue "The video is wrong!" and "The scientist is wrong" all you wish. This is what the video portrays and the counter argument of "well, he's wrong" is decidedly weak.
"Einstein won the issue by calling gravity an illusion, and saying that an accelerating earth makes more sense. This is exactly what the narrator states. Do you know more about this than the author?"
Quite possibly, but that is difficult to evaluate. I am only saying that I do not think you understand what the author means.
Now that is quite a claim for me to make, so I better justify it with solid reasoning!
Gravity is an illusion, according to Einstein. What Newton called a force, Einstein demonstrated is a geometrical consequence of space. But wait, how does a curved space manifest as an acceleration? Well, objects follow the most direct path through space, we call this a geodesic, and we quantify such paths using mathematical objects called metrics. Relative to an external observer, an object moving through curved space will bend. Since its direction is changing, we perceive this as an acceleration.
read the quotes you posted:QuoteThis inability to distinguish free fall from lack of gravity has a name by the way. Einstein called it the Equivalence Principle. And if you buy it then maybe the falling frames really are inertial. If so, then it's the falling frames that establish the standard of non acceleration, in which case it's really the ground that's accelerating upward and what we've always been calling a gravitational force is an artifact of being in an accelerated frame of reference.
...
[Newton objects]: Nice try Einstein, but you forgot something. Earth is round. Down isn't really down, it's radially inward, and this creates two problems with thinking about freely falling frames as inertial, or thinking about gravity as an illusion...
this is the "objection" it took einstein seven years to answer. without answering it, he could not argue that "an accelerating earth makes more sense." he answered it with curved space.
Einstein didn't come up with the curved space stuff until 7 years later.Even if that is true...so what?
"Einstein won the issue by calling gravity an illusion, and saying that an accelerating earth makes more sense. This is exactly what the narrator states. Do you know more about this than the author?"
Quite possibly, but that is difficult to evaluate. I am only saying that I do not think you understand what the author means.
Now that is quite a claim for me to make, so I better justify it with solid reasoning!
Gravity is an illusion, according to Einstein. What Newton called a force, Einstein demonstrated is a geometrical consequence of space. But wait, how does a curved space manifest as an acceleration? Well, objects follow the most direct path through space, we call this a geodesic, and we quantify such paths using mathematical objects called metrics. Relative to an external observer, an object moving through curved space will bend. Since its direction is changing, we perceive this as an acceleration.
You are incorrect in your chronology. This discussion was about the upward accelerating surface making more sense than Newtonian Gravity, due to the coincidences. Einstein didn't come up with the curved space stuff until 7 years later. The Equivalence Principle stuff happened way before the General Relativity stuff.
From Wikipedia:
"The equivalence principle was properly introduced by Albert Einstein in 1907, when he observed that the acceleration of bodies towards the center of the Earth at a rate of 1g (g = 9.81 m/s2 being a standard reference of gravitational acceleration at the Earth's surface) is equivalent to the acceleration of an inertially moving body"
"General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics."read the quotes you posted:QuoteThis inability to distinguish free fall from lack of gravity has a name by the way. Einstein called it the Equivalence Principle. And if you buy it then maybe the falling frames really are inertial. If so, then it's the falling frames that establish the standard of non acceleration, in which case it's really the ground that's accelerating upward and what we've always been calling a gravitational force is an artifact of being in an accelerated frame of reference.
...
[Newton objects]: Nice try Einstein, but you forgot something. Earth is round. Down isn't really down, it's radially inward, and this creates two problems with thinking about freely falling frames as inertial, or thinking about gravity as an illusion...
this is the "objection" it took einstein seven years to answer. without answering it, he could not argue that "an accelerating earth makes more sense." he answered it with curved space.
Sure. It took Einstein seven years to make his "gravity is the upwards acceleration of the surface" idea work with the Round Earth Theory. I have no disagreement with that.
Ok. Not sure what that’s got to do with the way you cherry pick little bits of science you don’t really understand when it suits you and dismiss the rest.
That is not true. I only dismiss things when there is not enough emperical evidence.Rubbish. You dismiss things when they don't fit your agenda and cherry pick things which do.
The real crime is the position of appealing to authority and accepting everything you are told.A reasonable point, but a strange one coming from someone who regularly appeals to Rowbotham's authority (ironic, as he has none) and accepts everything he tells you. A prime example - I pick this because it's been so much discussed here - is his assertion that the horizon always rises to eye level. Bobby has shown very clearly that it doesn't but you continue to blindly accept Rowbotham's pontification about this and resuse to do any tests - note, looking at the horizon and thinking "looks about eye level" is not a valid test of this when the dip angle is so small.
Tom, are you forgetting about gravitational lensing? That was literally one of the first experimental tests of GR and bendy space-time.Ok. Not sure what that’s got to do with the way you cherry pick little bits of science you don’t really understand when it suits you and dismiss the rest.
That is not true. I only dismiss things when there is not enough emperical evidence. There have been relative motion experiments, but I know of no experiments which show gravity to be a 'bending of space'.
No, because Einstein never "showed gravity to be a 'bending of space' " but:Ok. Not sure what that’s got to do with the way you cherry pick little bits of science you don’t really understand when it suits you and dismiss the rest.
That is not true. I only dismiss things when there is not enough emperical evidence. There have been relative motion experiments, but I know of no experiments which show gravity to be a 'bending of space'.
The real crime is the position of appealing to authority and accepting everything you are told.
In Einstein’s view of the world, gravity is the curvature of spacetime caused by massive objects.And there is a huge and highly significant difference between "a 'bending of space' " and "the curvature of spacetime".
From: Understanding gravity—warps and ripples in space and time (https://www.science.org.au/curious/space-time/gravity)
One condition the new equations must satisfy is that they must return Newtonian results for ordinary conditions. For Newton's theory works extraordinarily well for the weak, static gravitational fields of our solar system. The sentence highlighted in red says:
"However it turns out the this tensor does not reduce to the [Newtonian expression] Δφ in the case of infinitely weak, static gravitational fields."
Tom, are you forgetting about gravitational lensing? That was literally one of the first experimental tests of GR and bendy space-time.Ok. Not sure what that’s got to do with the way you cherry pick little bits of science you don’t really understand when it suits you and dismiss the rest.
That is not true. I only dismiss things when there is not enough emperical evidence. There have been relative motion experiments, but I know of no experiments which show gravity to be a 'bending of space'.
Therefore there are "no experiments which show gravity to be a 'bending of space' " but there are experiments which show gravitation to result from a curvature of spacetime caused by massive objects".
I can understand why an acceleration of the flat earth (in some unspecified vector direction) would hold all of us on the ground. The flat earth theories also seem to require a firmament (dome) to keep the sea water and air from falling off the edge. Additionally, the Sun and Moon are inside the dome and rotate at a certain rate to match what is seen by humans on the surface of the earth. Now the big question is what keeps the moon (a sphere of 32 miles) at 3000 miles above the earth's surface in place? I suppose that there could be a cable that holds the moon to the top of the dome but no one has mentioned that. You can also see a lot of surface damage (craters) on the moon. I was always told that they were produced by the collisions of asteroids. Did these asteroids come thru the dome or was the moon made that way (by unspecified beings) before it was suspended inside the dome?The big question is whether UA is action at a distance, or at a point. If the former, this explains why the moon is accelerating upwards as well as the earth, but does not explain why the action does not also affect humans, buildings, things in coal mines etc. If the latter, it is difficult to explain why the moon and the heavens do not come crashing down.
I can understand why an acceleration of the flat earth (in some unspecified vector direction) would hold all of us on the ground. The flat earth theories also seem to require a firmament (dome) to keep the sea water and air from falling off the edge. Additionally, the Sun and Moon are inside the dome and rotate at a certain rate to match what is seen by humans on the surface of the earth. Now the big question is what keeps the moon (a sphere of 32 miles) at 3000 miles above the earth's surface in place? I suppose that there could be a cable that holds the moon to the top of the dome but no one has mentioned that. You can also see a lot of surface damage (craters) on the moon. I was always told that they were produced by the collisions of asteroids. Did these asteroids come thru the dome or was the moon made that way (by unspecified beings) before it was suspended inside the dome?The big question is whether UA is action at a distance, or at a point. If the former, this explains why the moon is accelerating upwards as well as the earth, but does not explain why the action does not also affect humans, buildings, things in coal mines etc. If the latter, it is difficult to explain why the moon and the heavens do not come crashing down.
OK, so you'd prefer to go with what Professor Charles Lane Poor wrote:Tom, are you forgetting about gravitational lensing? That was literally one of the first experimental tests of GR and bendy space-time.Ok. Not sure what that’s got to do with the way you cherry pick little bits of science you don’t really understand when it suits you and dismiss the rest.
That is not true. I only dismiss things when there is not enough emperical evidence. There have been relative motion experiments, but I know of no experiments which show gravity to be a 'bending of space'.
Professor Charles Lane Poor says that there are other causes for the "lensing" that is seen that have nothing to do with curving space or "gravity". (http://gsjournal.net/Science-Journals/Historical%20Papers-Relativity%20Theory/Download/2626) Also see his other papers on the matter (http://gsjournal.net/Science-Journals-Papers/Author/545/Charles%20Lane,%20Poor).
And my previous post contained:(https://www.dropbox.com/s/7qtpv96d6e4w2ec/Is%20Einstein%20Wrong%20--%20A%20Debate%2C%20Charles%20Lane%20Poor.png?dl=1)
for ordinary calculations within the solar system, Newton's Laws are extraordinarily accurate.Professor Charles Lane Poor is simply claiming that since Newton Law of Universal Gravitation is so much simpler, and it is, that it should be accepted over Einstein's Theory of General Relativity.
See this quote from Einstein's Pathway to General Relativity by John D. Norton (https://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/general_relativity_pathway/index.html)QuoteOne condition the new equations must satisfy is that they must return Newtonian results for ordinary conditions. For Newton's theory works extraordinarily well for the weak, static gravitational fields of our solar system.
In fact, this phenomenon was known about long before Einstein came up with GR.See above, "Newtonian Gravitation predicts that massive objects will bend light".
Sure, "Quantum Mechanics proposes" with proposes being the important word but, other than near singularities (the centres of black holes) GR does work.Quote from: rabinozTherefore there are "no experiments which show gravity to be a 'bending of space' " but there are experiments which show gravitation to result from a curvature of spacetime caused by massive objects".
Quantum Mechanics proposes an entirely different mechanism for gravity where space-time does not bend or curve.
The last time I checked there was no Grand Unification Theory or verification of the curving space theory. Please provide a link to the Nobel prize winner so that we may congratulate him or her. Thank you.There are not likely to be any Nobel prize winners in verifying GR but there is a certain Nobel prize for the first person to disprove GR.
The last time I checked there was no . . . . . verification of the curving space theory.There is no "curving space theory" of gravitation! Please read my previous post. "Curved Space" only becomes significant near objects like neutron stars and black holes. "Space" curvature even near the sun is quite insignificant.
OK, so you'd prefer to go with what Professor Charles Lane Poor wrote:Tom, are you forgetting about gravitational lensing? That was literally one of the first experimental tests of GR and bendy space-time.Ok. Not sure what that’s got to do with the way you cherry pick little bits of science you don’t really understand when it suits you and dismiss the rest.
That is not true. I only dismiss things when there is not enough emperical evidence. There have been relative motion experiments, but I know of no experiments which show gravity to be a 'bending of space'.
Professor Charles Lane Poor says that there are other causes for the "lensing" that is seen that have nothing to do with curving space or "gravity". (http://gsjournal.net/Science-Journals/Historical%20Papers-Relativity%20Theory/Download/2626) Also see his other papers on the matter (http://gsjournal.net/Science-Journals-Papers/Author/545/Charles%20Lane,%20Poor).Quote from: Professor Charles Lane PoorAnd my previous post contained:(https://www.dropbox.com/s/7qtpv96d6e4w2ec/Is%20Einstein%20Wrong%20--%20A%20Debate%2C%20Charles%20Lane%20Poor.png?dl=1)for ordinary calculations within the solar system, Newton's Laws are extraordinarily accurate.Professor Charles Lane Poor is simply claiming that since Newton Law of Universal Gravitation is so much simpler, and it is, that it should be accepted over Einstein's Theory of General Relativity.
See this quote from Einstein's Pathway to General Relativity by John D. Norton (https://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/general_relativity_pathway/index.html)QuoteOne condition the new equations must satisfy is that they must return Newtonian results for ordinary conditions. For Newton's theory works extraordinarily well for the weak, static gravitational fields of our solar system.
But:So can we say that if you don't agree with Einstein's GR that you do accept the Newtonian Law of Universal Gravitation, as Professor Charles Lane Poor does.
- I believe that Professor Charles Lane Poor wrote that in 1924 - and there's been "a lot of water under the bridge since then".
- Even Newtonian Gravitation predicts that massive objects will bend light, though only by half as much as Einstein's GR.
Otherwise, it seems quite inconsistent for you to appeal to an authority that you, yourself regard as in error.
Read the article again. The bending of starlight around the sun is explained with neither Newtonian Gravity or Relativity.Do you mean "The bending of starlight around the sun is explained with either Newtonian Gravity or Relativity"?
Thus the original, but now unquoted and apparently forgotten, paper of Einstein shows, directly and without the possibility of doubt, that his formula of planetary motion is based upon and involves the Newtonian law of inverse squares; shows that he derived his formula from that of Newton by a direct transformation in time units.
The so-called relativity rotation of planetary orbits is a mathematical illusion: an illusion due to an incomplete mathematical transformation and to an illogical interpretation of the resulting formula. The Newtonian law has not been abolished: there is no Einsteinian law of gravitation.
One condition the new equations must satisfy is that they must return Newtonian results for ordinary conditions. For Newton's theory works extraordinarily well for the weak, static gravitational fields of our solar system.
Again, my comment to you is to read the article to the very end. Poor does not describe the cause of the bending of starlight around the sun to be due to Newtonian Gravity or Relativity at all.All I see is Professor Charles Lane Poor postulating an excuse for the observations made during those eclipses. He knows that the results far exceed that from simple Newtonian gravitation but still cannot accept that Einstein might be right.
In its passage from a distant star to the telescope in Australia or Mexico, the ray of light passes through the atmosphere of the sun, it passes through though the atmosphere of the earth.Astronomers are very aware of the effect of refraction but I would suspect that any change in refraction due to his postulated temperature change would be all in a similar direction for all the stars and the sun's corona.
In the former it may get bent, in the latter it certainly is bent out of its straight path. Everyone is familar with the effects of refraction.
Whenever a ray of light passes from one medium to another, from air to glass, or from air to water, it is bent out of its straight path. Upon this fact are constructed telescopes, risms, and eye-glasses.
Under ordinary conditions the amount of refraction suffered by very markedly with changes in the temperature of the air.
When, in an eclipse, the sun disappears behind the moon it ceases for the moment to warm the air, and the temperature of our atmosphere drops suddenly. With this change in temperature the amount of the refraction changes, and the star appears to change its position.
And no thermometer can record these sudden changes, no computation can take account of the abnormal and unknown changes in refraction caused by the eclipse shadow.
Tests of general relativity, Deflection of light by the Sun (https://en.m.wikipedia.org/wiki/Tests_of_general_relativity)This paper lists 12 sets of data from 1919 to 1973, On the Gravitational Bending of Light—Was Sir Arthur Stanley Eddington Right? G. G. Nyambuya, W. Simango (https://www.academia.edu/6519356/On_the_Gravitational_Bending_of_Light_Was_Sir_Arthur_Stanley_Eddington_Right)
The early accuracy, however, was poor. The results were argued by some to have been plagued by systematic error and possibly confirmation bias, although modern reanalysis of the dataset suggests that Eddington's analysis was accurate. The measurement was repeated by a team from the Lick Observatory in the 1922 eclipse, with results that agreed with the 1919 results and has been repeated several times since, most notably in 1953 by Yerkes Observatory astronomers and in 1973 by a team from the University of Texas. Considerable uncertainty remained in these measurements for almost fifty years, until observations started being made at radio frequencies.
Tom, are you forgetting about gravitational lensing? That was literally one of the first experimental tests of GR and bendy space-time.Ok. Not sure what that’s got to do with the way you cherry pick little bits of science you don’t really understand when it suits you and dismiss the rest.
That is not true. I only dismiss things when there is not enough emperical evidence. There have been relative motion experiments, but I know of no experiments which show gravity to be a 'bending of space'.
Professor Charles Lane Poor says that there are other causes for the "lensing" that is seen that have nothing to do with curving space or "gravity". (http://gsjournal.net/Science-Journals/Historical%20Papers-Relativity%20Theory/Download/2626) Also see his other papers on the matter (http://gsjournal.net/Science-Journals-Papers/Author/545/Charles%20Lane,%20Poor).
In fact, this phenomenon was known about long before Einstein came up with GR.Quote from: rabinozTherefore there are "no experiments which show gravity to be a 'bending of space' " but there are experiments which show gravitation to result from a curvature of spacetime caused by massive objects".
Quantum Mechanics proposes an entirely different mechanism for gravity where space-time does not bend or curve. The last time I checked there was no Grand Unification Theory or verification of the curving space theory. Please provide a link to the Nobel prize winner so that we may congratulate him or her. Thank you.
Quantum Mechanics says that gravity is caused by an undiscovered sub-atomic particle known as the graviton.Actually, QM doesn't say that at all. You're probably thinking about quantum gravity, which is an attempt to unify quantum mechanics and general relativity.
GR cannot predict the position of the planets: https://wiki.tfes.org/Astronomical_Prediction_Based_on_PatternsNot true. One of the first predictions of GR was an accurate description of the precession of Mercury's orbit where Newton's gravity fell short.
GR cannot describe the movement and motion of the galaxies: https://wiki.tfes.org/Problems_of_the_GalaxiesAgain, not true.
GR cannot seem to do anything of importance.Do you think that planet orbits and galaxy rotations are important? ???
What good is it?Well, it's quite handy if you rely on GPS, among other things.
It GR a gravitational lensing simulator?Gravitational lensing may have been observed before GR, but was it predictable?
Gravitational Lensing was known about long before Einstein ever published his theory. How do we know that he didn't tailor his theory to predict one of the very few things it asserts to predict?
Quantum Mechanics says that gravity is mediated by a sub-atomic particle known as the graviton. That should have been taught to you in school, in your studies for your physics degree. Why are you asking me?
GR cannot predict the position of the planets, and is not used: https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns
GR cannot describe the movement and motion of the galaxies: https://wiki.tfes.org/Problems_of_the_Galaxies
GR cannot seem to do anything of importance.
What good is it? It GR a gravitational lensing simulator?
Gravitational Lensing was known about long before Einstein ever published his theory. How do we know that he didn't tailor his theory to predict one of the very few things it asserts to predict?