[Iceman]

Appealing to the authority of a quote you found from one physicist while also discounting the work of countless others when it comes to rocket development, orbital calculations, space travel, rover design and implementation...

[fisherman]

He's not a physicist. He's a historian and a philosopher. It doesn't matter if he writes about it. He doesn't know the physics as well as an expert in physics. I have quoted multiple physicists. Physicists would know physics to a better degree than a historian and a philosopher would.

I would suggest getting better qualified expert sources than that paltry attempt

.

Paltry??? John Norton is one of the most respected academics on Einstein in the world and is cited in literally thousands of scientific works.  You obviously don't understand what "philosophy of science" means or the significance of the fact that he undertook the analysis of Einstein's Zurich notebook.  If you don't think that required an understanding of the physics involved...well, let's just say I am not surprised.

Telling a story is different than knowing the physics.

Philosophy of Science is "telling the story of the physics".  You can't tell the story of how Einstein came up with GR without understanding the physics.


Here's a few excerpts from his analysis.

Suddenly, without any warning of the transition, we find the basic notion of general relativity, the "line element" written at the top of the page.
line element
The coefficients Gμν enable us to compute the spatio-temporal interval ds between events separated by infinitesimal coordinate differences dxμ. If these coefficients assign spatio-temporal intervals that do not conform to a flat geometry, then we have captured the full range of gravitational effects in the manner of Einstein's general theory.

This is quite possibly the first time Einstein has written down this expression. The coefficients Gμν of what we now know as the "metric tensor" are written with an upper case G. Einstein shifted within a few pages to the lower case g, which remained his standard notation from then on.

The big project is to find how this quantity gμν, the metric tensor, is generated by source masses. These are the "gravitational field equations." That is this theory's analog of Newton's inverse square law of gravity. The lower half of the page is clearly making rudimentary efforts in that direction. There Einstein chooses a "Spezialfall" -- a special case -- in which the coefficients of the metric tensor revert to the values of special relativity, excepting G44 = c2. Einstein then tries to apply the gravitational field equation from his 1912 theory of static gravitational fields.

Einstein's analysis continues at this simple level on the facing page.There he asks beginner's questions. He looks at the coordinate divergence of the metric tensor and asks "Ist dies invariant?"-- "Is this invariant?" As the computation that follows immediately shows, it is not.

On this page Einstein sets up the equations for conservation of energy and momentum for continuous matter in general relativity. He starts with the equation of motion for a point mass--the geodesic equation--but now written in the form of an Euler-Lagrange equation:
5R snip1
He then applies this to a cloud of non-interacting dust particles in free fall to arrive at what we now recognize to be the condition of the vanishing of the covariant divergence of the stress energy tensor Tμν.
5R snip
However there is good evidence that Einstein's knowledge of tensor calculus is still limited. He does not know or is not sure that the operator acting on Tμν in this equation is a generally covariant operator. To check the operator, he replaces Tμν by the tensor gμν and sees whether the result is zero or a four vector ("0 oder Vierervektor"), as it should be if the operator is generally covariant. It proves to be zero and Einstein is satisfied. He writes "Stimmt"--"Correct".

http://www.pitt.edu/~jdnorton/Goodies/Zurich_Notebook/index.html

He literally goes through Einstein's private calculations on GR and explains them page by page, line by line and calculation by calculation. And this is just an informal commentary on his website. The actual textbook he wrote is introduced by

The notes documenting Einstein’s search for field equations for this theory take up the better part of the notebook. They start on pp. 39L–41R and continue on pp. 5R–29L and pp. 42L–43L. Our text is a detailed running commentary on these notes. 2 It provides line-by-line reconstructions of all calculations and discusses the purpose behind them.

Yeah, that's a guy who doesn't understand physics. 

Logunov rejected GR in favor of his own theory of gravitation...which has its own explanation as to why inertial mass and gravitational mass are equivalent.  So take your pick on either theory.  Either way, its not a mystery or a coincidence.

[AATW]

Physicist > Someone with a history and philosophy degree

And what shape do physicists think the earth is?
Your "appeal to authority" thing is very selective, you cherry pick bits and pieces from people you regard as authorities when you think their (often out of context) comments back up your beliefs.
But you reject their thoughts on gravity being a thing or the shape of the earth.

[Dr David Thork]

Physicist > Someone with a history and philosophy degree

And what shape do physicists think the earth is?
Your "appeal to authority" thing is very selective, you cherry pick bits and pieces from people you regard as authorities when you think their (often out of context) comments back up your beliefs.
But you reject their thoughts on gravity being a thing or the shape of the earth.

Scientists have changed the definition of Gravity and what they think it is consistently since antiquity.

https://en.wikipedia.org/wiki/History_of_gravitational_theory

Why would I believe that right now at this point in history, they finally have it nailed down? Because I happen to be alive at the exact point when it is understood? I'm sure someone could have claimed the same in 1400 AD. If we had the same conversation in the 1940's you'd be saying Einstein knew all with his general relativity and Edwin Hubble confirmed it and I am so stupid thinking they are wrong.

And yet here we are in 2021 and

Several decades after the discovery of general relativity, it was realized that it cannot be the complete theory of gravity because it is incompatible with quantum mechanics.[72] Later it was understood that it is possible to describe gravity in the framework of quantum field theory like the other fundamental forces. In this framework, the attractive force of gravity arises due to exchange of virtual gravitons, in the same way as the electromagnetic force arises from exchange of virtual photons.[73][74] This reproduces general relativity in the classical limit, but only at the linearized level and postulating that the conditions for the applicability of Ehrenfest theorem holds, which is not always the case. Moreover, this approach fails at short distances of the order of the Planck length.[72]

Theoretical models such as string theory and loop quantum gravity are current candidates for a possible 'theory of everything'.

They'll change it all again at some point in the future. In other words, they still can't explain gravity and you write

But you reject their thoughts on gravity being a thing

Yes, they only have models that don't work. They'll tell you that themselves.

[fisherman]

Physicist > Someone with a history and philosophy degree

And what shape do physicists think the earth is?
Your "appeal to authority" thing is very selective, you cherry pick bits and pieces from people you regard as authorities when you think their (often out of context) comments back up your beliefs.
But you reject their thoughts on gravity being a thing or the shape of the earth.

The level of cherry picking and hypocrisy is mind blowing.

Not only does he use an introductory quote from a paper written by someone he claims “doesn’t understand the physics” to support his position, the whole purpose of the paper he quotes is to contradict the very position he uses it to support.  If he’d actually read the whole paper without cherry picking, he would see that the whole paper is Norton (using the physics he doesn’t understand) explaining how and why Einstein ultimately “solved” the “coincidence” of the equality of inertial and gravitational mass...and that is the whole purpose of the paper.

Einstein's principle of equivalence asserted that the properties of space that manifest themselves in inertial effects are really the properties of a field structure in space: moreover this same structure also governs gravitational effects. As a result, the privileged inertial states of motion defined by inertial eff ects are not properties of space but of this structure and the various possible dispositions of inertial motions in space are determined completely by it. Space of itself is to be expected to designate no states of motion as privileged Einstein's principle of Equivalence 41 This principle guided Einstein to seek his general theory of relativity as a gravitation theory of which special relativity was a special case. There the principle found precise theoretical expression. The structure responsible for inertial and gravitational effects is the metric tensor. The space-time manifold itself has no properties that would enable us to designate the motion associated with any given world line as privileged, that is as \inertial" or \unaccelerated." This designation depends entirely on the metric and the and structure for space-time that it determines.

To claim that the equivalence of gravitational and inertial mass is considered a coincidence in GR shows a basic lack of understanding of it.  The solution to the coincidence, the existence of the gravitational-inertial field, is the very heart of GR.  Without solving that coincidence, there is no GR.

Moreover, the same paper he cites to support using the EP as evidence of UA, explicitly contradicts that it can be used to support UA, using Einstein’s own words.

He explained this to a correspondent in a letter of July 12, 1953, reminding him that the principle could not be used to generate arbitrary gravitational fields by acceleration:

The equivalence principle does not assert that every gravitational field (e.g., the one associated with the Earth) can be produced by acceleration of the coordinate system. It only asserts that the qualities of physical space, as they present themselves from an accelerated coordinate system, represent a special case of the gravitational field. It is the same in the case of the rotation of the coordinate system: there is de facto no reason to trace centrifugal effects back to a `real' rotation.19

Cognitive dissonance is a powerful thing.

[AATW]

Why would I believe that right now at this point in history, they finally have it nailed down? Because I happen to be alive at the exact point when it is understood?

Because there's a rover sitting on Mars right now.
Because your phone has GPS.
Because there's an ISS which you can literally see from the ground exactly when the website tells you it will be overhead.
Because they predicted the path of the solar eclipse to the block level.
Because there's a whole area of expertise which uses gravity to find resources underground.

Now, of course our model of gravity has changed over time, but it's hardly true to say that Newton was some old duffer. Einstein's equations reduce to Newton's for all practical purposes.
GPS does need to take account of Relativistic effects because if you want a precise position you need a very precise timestamp, but for things like rockets going to Mars Newton will do fine, thanks very much. Of course science should always be looking to improve models, but the ones we have seem to work pretty well for most practical purposes.

Yes, they only have models that don't work. They'll tell you that themselves.

You'll have to tell that to the ISS and the Perseverance Rover.

[Dr David Thork]

Because there's a rover sitting on Mars right now.

No there isn't.

Because your phone has GPS.

No it doesn't.

Because there's an ISS which you can literally see from the ground exactly when the website tells you it will be overhead.

No I can't.

Because they predicted the path of the solar eclipse to the block level.

No, you are being absurd.

Because there's a whole area of expertise which uses gravity to find resources underground.

No, you're just repeating made up lies.

Now, of course our model of gravity has changed over time, but it's hardly true to say that Newton was some old duffer.

The guy was into alchemy, a creationist, believed that metals vegetate, that the whole cosmos/matter is alive and that gravity is caused by emissions of an alchemical principle he called salniter. But hey, I wouldn't accuse you of picking and choosing.

Einstein's equations reduce to Newton's for all practical purposes.

It is possible they are both wrong being as one leans on the work of the other.

GPS does need to take account of Relativistic effects because if you want a precise position you need a very precise timestamp, but for things like rockets going to Mars Newton will do fine, thanks very much. Of course science should always be looking to improve models, but the ones we have seem to work pretty well for most practical purposes.

And everyone lived happily ever after? I love your little stories.

Yes, they only have models that don't work. They'll tell you that themselves.

You'll have to tell that to the ISS and the Perseverance Rover.

They'd have to exist first.

[AATW]

Right. So your counter argument is basically “nuh-uh”?

And sure, Newton probably did believe some crazy stuff. It’s easy to point and laugh at people who lived centuries ago. We are all products of the era we grew up in. As you’ve intimated, it’s likely that in the future people will look back at some of our beliefs and scoff. But our current models are good enough to do the things I’ve mentioned. Just denying them isn’t a counter argument. So I think many of our current beliefs will stand the test of time, as have Newton’s.

[stack]

Because there's a rover sitting on Mars right now.

No there isn't.

How do you know?

Because your phone has GPS.

No it doesn't.

What kind of mobile do you have? Mine has GPS. Maybe you need to upgrade from your Nokia brick.

Because there's an ISS which you can literally see from the ground exactly when the website tells you it will be overhead.

No I can't.

Maybe you can't because your Nokia brick doesn't have app support. But if you upgrade, you can get something like the ISS spotter app (https://apps.apple.com/us/app/iss-spotter/id523486350), track the ISS and when overhead, snap a picture like this:



Here's a beginner's guide for tracking and capturing the ISS:
A Beginner’s Guide to Photographing The International Space Station (ISS)
https://www.universetoday.com/93588/a-beginners-guide-to-photographing-the-international-space-station-iss/

Because they predicted the path of the solar eclipse to the block level.

No, you are being absurd.

You can look this up too, but I'll give you a head start of just how precise the path predictions are and how they come about them:

How Scientists Predict the Path of the 2017 Total Solar Eclipse
https://www.space.com/37128-how-to-predict-eclipse-2017-path.html

Because there's a whole area of expertise which uses gravity to find resources underground.

No, you're just repeating made up lies.

Geodesy & Gravimetry. Look them up.

Now, of course our model of gravity has changed over time, but it's hardly true to say that Newton was some old duffer.

The guy was into alchemy, a creationist, believed that metals vegetate, that the whole cosmos/matter is alive and that gravity is caused by emissions of an alchemical principle he called salniter. But hey, I wouldn't accuse you of picking and choosing.

We didn't stop exploring gravity 300 years ago. Like a lot of things, we've learned a thing or two in the past few centuries.

Einstein's equations reduce to Newton's for all practical purposes.

It is possible they are both wrong being as one leans on the work of the other.

Anything is possible. We sure do rely on building a bunch of stuff because of those two. Even your Nokia brick.

GPS does need to take account of Relativistic effects because if you want a precise position you need a very precise timestamp, but for things like rockets going to Mars Newton will do fine, thanks very much. Of course science should always be looking to improve models, but the ones we have seem to work pretty well for most practical purposes.

And everyone lived happily ever after? I love your little stories.

How does GPS work without Relativistic effects?

Yes, they only have models that don't work. They'll tell you that themselves.

You'll have to tell that to the ISS and the Perseverance Rover.

They'd have to exist first.

See above.

[Dr David Thork]

Right. So your counter argument is basically “nuh-uh”?

And sure, Newton probably did believe some crazy stuff. It’s easy to point and laugh at people who lived centuries ago. We are all products of the era we grew up in. As you’ve intimated, it’s likely that in the future people will look back at some of our beliefs and scoff. But our current models are good enough to do the things I’ve mentioned. Just denying them isn’t a counter argument. So I think many of our current beliefs will stand the test of time, as have Newton’s.

So you are picking and choosing. You don't like his theories on turning base metals into gold. Or on a clockwork universe crafted by God. You don't like his work on the elixir of life and immortality. You aren't keen on his work predicting the end of the earth in 2060. But you do like his work on how apples fall off trees because it reassures you that the earth is round.    As time has gone on, more and more of Newton's theories have been scrubbed as farcical. The trend is that one day we'll realise the guy was an absolute nugget who set science back centuries. 

@Stack, no. We aren't arguing 18 points at once. Pick your favourite and go with that.

[stack]

Right. So your counter argument is basically “nuh-uh”?

And sure, Newton probably did believe some crazy stuff. It’s easy to point and laugh at people who lived centuries ago. We are all products of the era we grew up in. As you’ve intimated, it’s likely that in the future people will look back at some of our beliefs and scoff. But our current models are good enough to do the things I’ve mentioned. Just denying them isn’t a counter argument. So I think many of our current beliefs will stand the test of time, as have Newton’s.

So you are picking and choosing. You don't like his theories on turning base metals into gold. Or on a clockwork universe crafted by God. You don't like his work on the elixir of life and immortality. You aren't keen on his work predicting the end of the earth in 2060. But you do like his work on how apples fall off trees because it reassures you that the earth is round.    As time has gone on, more and more of Newton's theories have been scrubbed as farcical. The trend is that one day we'll realise the guy was an absolute nugget who set science back centuries. 

@Stack, no. We aren't arguing 18 points at once. Pick your favourite and go with that.

You're the one that parsed them out...

But in any case. What is that thing in the sky you can track and image known commonly as the ISS?

[existoid]

To again try to get this back on track 

@stevecanuck, - you could add to your OP that RET also explains how WW2 carrier battles were fought as depicted by all sailors and airmen (both US and Japanese), i.e., by the use of plotting boards which would not work south of the equator on a FET monopole map.

As described in detail in my one original contribution to the overall FET/RET debate:
https://forum.tfes.org/index.php?topic=16428.0

 

[AATW]

So you are picking and choosing.

If you want to call it that then so are you.
You don't like his theory about gravity because he believed some other things which turned out to be wrong and it means your delusion about the shape of the earth is wrong.

But you do like his work on how apples fall off trees because it reassures you that the earth is round.

I don't need reassuring. It is of no consequence what shape the earth is. It just happens to be a globe but it wouldn't affect my life one jot if it were not. It's not about whether I "like" his work, it's simply that it turned out to be a jolly good model of how things work and can actually explain observations. It helped us discover Neptune and put men on the moon and do all the other things I mentioned.
Not bad for an "absolute nugget" who thought he might be able to turn base metals into gold.

As time has gone on, more and more of Newton's theories have been scrubbed as farcical. The trend is that one day we'll realise the guy was an absolute nugget who set science back centuries.

You'll have to tell the ISS that. It passed over England this week, you know. You could have done some investigation if you'd bothered to.
Just saying "nuh-uh" isn't a counter-argument.

[SteelyBob]

I love that ISS picture, and others like it. I'm really curious to know what FEers think the ISS is...you can literally see it yourself with relatively cheap equipment and a clear night. And you can see the shape of it. It's clearly heavier than air and non-aerodynamic. And it looks exactly like the diagrams of it. So what's holding it up and causing it to move so fast, if not orbital mechanics?

[Dr David Thork]

It just happens to be a globe but it wouldn't affect my life one jot if it were not. It's not about whether I "like" his work, it's simply that it turned out to be a jolly good model of how things work and can actually explain observations.

The Bohr model is a jolly good model. But it has no basis in reality. ... oooh, maybe I should formulate a flat atom theory. 🤔

[stevecanuck]

Yup. And we're still waiting for Tom to follow up on his "There are many problems with RE" statement.

It's pretty much documented in the Wiki.

The question for me at this point is more of a matter of what does work, rather than what doesn't work. I also suspect that the topics described are incomplete on the numerous issues plaguing RE. The problems and anomalies and contradictions tend to be suppressed and ignored rather than publicized and celebrated.

Here are some I find interesting:

Mechanics

The physics of the giant RE galaxies don't work - https://wiki.tfes.org/Problems_of_the_Galaxies

The model of the RE Sun doesn't work - https://wiki.tfes.org/Magnification_of_the_Sun_at_Sunset#Inconsistent_Brightness:_A_Round_Earth_Mystery

Cosmology

RE Cosmology doesn't work. Scientific American calls modern cosmology a folk tale - https://wiki.tfes.org/Cosmology_Has_Some_Big_Problems

Perspective

The celestial bodies don't shrink according to the laws of perspective.

RE Stars don't shrink to perspective: https://wiki.tfes.org/Star_Size_Illusion

RE Galaxies don't shrink to perspective: https://wiki.tfes.org/Problems_of_the_Galaxies#Angular_Size_of_Galaxies

Gravity

Can't truly model more than two bodies at a time - https://wiki.tfes.org/Three_Body_Problem

The equivalency of gravitational and inertial mass, as seen in laboratory experiment, is a coincidence, even in GR - https://wiki.tfes.org/Equivalence_Principle

Astrophysicist Ryan Martin: "As we will see, both Newton’s Universal Theory of Gravity and Einstein Theory of General Relativity assume that the two are indeed equal. In fact, it is a key requirement for Einstein’s Theory that the two be equal (the assumption that they are equal is called the “Equivalence Principle”). You should however keep in mind that there is no physical reason that the two are the same, and that as far as we know, it is a coincidence!"

Variations of gravity inconsistent, contradictory - https://wiki.tfes.org/Variations_in_Gravity

Relativity

Light's velocity does not change on a horizonal plane from the earth's movement around the Sun, but does change when the detectors and receivers move in a laboratory experiment.

Earth's movement has no affect on light velocity on an experiment on a horizontal plane - https://wiki.tfes.org/Michelson-Morley_Experiment

Devices with moving detectors and receivers in a laboratory do measure a change - https://wiki.tfes.org/Sagnac_Experiment

Also, a change is detected on a vertical plane - https://wiki.tfes.org/Evidence_for_Universal_Acceleration#Vertical_Michelson-Morley_Experiments

None of that has anything to do with the shape of the earth.

[AATW]

It just happens to be a globe but it wouldn't affect my life one jot if it were not. It's not about whether I "like" his work, it's simply that it turned out to be a jolly good model of how things work and can actually explain observations.

The Bohr model is a jolly good model. But it has no basis in reality. ... oooh, maybe I should formulate a flat atom theory. 🤔

https://www.intelligentspeculation.com/blog/false-equivalence

The clear difference being that the earth is something we can directly observe. And have.
Spoiler: It's a globe.

[Tom Bishop]

Not only does he use an introductory quote from a paper written by someone he claims “doesn’t understand the physics” to support his position, the whole purpose of the paper he quotes is to contradict the very position he uses it to support.  If he’d actually read the whole paper without cherry picking, he would see that the whole paper is Norton (using the physics he doesn’t understand) explaining how and why Einstein ultimately “solved” the “coincidence” of the equality of inertial and gravitational mass...and that is the whole purpose of the paper.

A historian is an appropriate source to cite on an undisputed topic or factoid about physics. However, if a physicist disagrees with him, the historian's opinion is pretty much garbage. He simply doesn't have the required credentials to rebut a physicist, no matter how many times anyone calls him an 'expert'.

Now, when you have a qualified source for us on this, do let us know.

None of that has anything to do with the shape of the earth.

Actually, it does. The giant and distant sun and large universe is part of the RE Theory.

https://web.archive.org/web/20120205001209/http://blog.modernmechanix.com/2006/05/19/5000-for-proving-the-earth-is-a-globe/

[Iceman]

A historian is an appropriate source to cite on an undisputed topic or factoid about physics. However, if a physicist disagrees with him, the historian's opinion is pretty much garbage. He simply doesn't have the required credentials to rebut a physicist, no matter how many times anyone calls him an 'expert'.

I don't disagree with you... but I would say the historian in question is a bit of a special case.

More importantly though, relying on subject matter experts is a good way to gather information on relevant subjects (I know, what a deep, insightful proposition). So I would then ask... what subject matter experts form the basis of understanding antarctica or the ice wall? The glaciologists I know view the ice wall as the marine terminus of ice streams, which are fed by ice flowing from accumulation areas thousands of kilometers inland, and hundreds of meters higher in elevation (Bennett, 2003; Wellner et al. 2006; Wingham et al 2006; Bell et al 2007; Ò'Cofaigh et al. 2008; Livinstone et al. 2012; Rignot et al. 2019)*.

Or maybe we should ask the explorers? Historical and modern men and women who have crossed the continent or conducted research at the south pole?

If you're going to defend your position on one aspect of things by allowing the opinions of a subject matter expert outweigh the work of others with less foundational background in the subject, I would suggest you consider applying the same level of scrutiny to other aspects of FET.

*enter those those names/year+Antarctica+ "ice streams" in a google scholar search...as memory serves, most or all are open access publications

[fisherman]

However, if a physicist disagrees with him, the historian's opinion is pretty much garbage. He simply doesn't have the required credentials to rebut a physicist, no matter how many times anyone calls him an 'expert'.

Now, when you have a qualified source for us on this, do let us know.

Physicists don’t disagree with him, not even the ones you quote. Is another one of your own sources qualified enough for you?

The guy who said “There is no a-priori reason why the quantity that determines the magnitude of the gravitational force on the particle should equal the quantity that determines the particle’s resistance to an an applied force in general”, also said, in the very same book you quote

“These observations led Einstein to make a profound proposal that simultaneously provides for a relativistic description of gravity and incorporates in a natural way the equivalence principle and consequently the equivalence of gravitational and inertial mass. Einstein’s proposal was that gravity should no longer be regarded as a force in the conventional sense but rather as a manifestation of the curvature of the spacetime”

Do you need to discredit him also now?

The book you quote by Ryan Martin is about Classical Physics so it is no surprise that he would describe the equivalence of inertial and gravitational mass as a coincidence.  In classical physics, it is.

If you read Einstein’s quote that Nigel Calder references, you’ll find that Einstein goes on to explain the “astonishing fact” of the equivalence of inertial and gravitational force.

You obviously didn’t even read the whole context of anything you quoted. Just cherry picked quotes you thought would support your point and not a single one of them does.  If John Norton is so unreliable why did you quote him?  You obviously had no idea who he is or what his credentials are, but he sounded good and that’s good enough for you.

You now have to resort to discrediting one of your own sources because you either can’t be bothered to actually read them or are incapable of understanding that he was contradicting the very point you were trying to make. It doesn’t matter if Norton is right or wrong, the smartest person in the world or a lunatic. You quoted him without the slightest idea of what he was talking about and completely missed the larger point I was making, which is your “wiki”, at least on this point, is the poorest excuse for “research” or “scholarship” I have ever seen.

Since you can’t be bothered with actually doing your own research, I’ll explain to you exactly why GR solves the great mystery. In GR, gravity is not a force, if gravity is not a force, then it can’t effect mass. A non-force can’t act on mass and mass can’t resist a non-force. The distinction between gravitational and inertial mass is a false one. They are the same thing...just “mass” whose behavior that we perceive as gravitational effects is determined by the spacetime curvature. 

When you see the term gravitational mass in the context of GR, it is referring to active gravitational mass, which is mass that gives rise to the gravitational field...which according to FE doesn't exist.

In General Relativity and in other geometric theories of gravity, the gravitational mass must always be taken to be the active gravitational mass, because in such theories there is no passive gravitational mass. A body in a gravitational field moves in response to the curved spacetime geometry, not in response to an impressed gravitational force; thus, the mass of the body is not a receptor of gravitational force, and passive mass is a meaningless concept—it is merely an artifact of the Newtonian approximation

https://arxiv.org/ftp/arxiv/papers/1010/1010.5557.pdf

Hans Ohanian studied physics at Berkeley and at Princeton, where he worked on relativity with John A. Wheeler.  He taught at Rensselaer Polytechnic Institute, Union College, the University of Rome, and the University of Vermont. He's written several physics textbooks and dozens of articles dealing with relativity, gravitation, and quantum theory, including numerous articles on fundamental physics published in the American Journal of Physics, where he served as associate editor for several years

Is he enough of a physicist for you?