Is the current definition of gravity accurate?

[Antony Death]

The current definition of Gravity is: The force of attraction between bodies as a result of their mass.
Gravity affects both the space and time of the area surrounding a mass, diminishing with distance, so is the current accepted definition truly accurate? Do I have the correct definition and if so, is it possible that the Gravity of a mass is attracting the space and time occupied by the second mass, and not the second mass itself?
I am a keen amateur so an expert opinion would be greatly appreciated.
Thanks. Antony

 

[Nugatory]

The current definition of Gravity is: The force of attraction between bodies as a result of their mass.

That's not the current definition. General relativity, developed more than a century ago, makes it clear that gravity is not a force, attractive or otherwise.

Unfortunately there aren't many readily available explanations of general relativity that will work for a keen amateur. Search this forum for videos by our member A.T. and that will get you started... or if you want the real thing, try https://www.preposterousuniverse.com/grnotes/

 

[Ibix]

Gravity is spacetime curvature. It is not typically modeled as a force. The source term for gravity is the stress-energy tensor. This includes mass, but also other things such as pressure.

I don't think its accurate to say gravity is attracting space and time. For a start, the underlying structure of general relativity is spacetime - how you separate it into space and time (if you do) is generally an arbitrary decision in some sense. Second, to imagine it as an attraction you'd somehow have to associate events in a curved spacetime with those in a flat one, and that would be an arbitrary process.

That said, gravity is sometimes described using a "waterfall" model, explaining things like black holes as places where it's impossible to move "upstream". Although I see the analogy I don't find it particularly helpful, since there's nothing actually flowing in the maths - no source or sink terms, for example. And it's hard to see things like the cosmological solution to Einstein's field equations in such terms, so I think it's rather limited anyway.

To note: the "level" of a thread is meant to refer to your level of knowledge, not how complicated you think the topic is. The idea is for it to be an at-a-glance estimate of how likely a reader is to understand the answer, and to give us an idea of what level to pitch our responses. Edit: I see it's been changed while I was typing.

 

[Antony Death]

Thank you both for your replies and thank you Ibix for correcting me on the 'level' of a thread. This was my first thread since joining so apologies for that and I note that this has already been corrected on my behalf.
I did already understand that gravity is not considered a force. I have an understanding of the concept from studying Leo Sartori's book "Understanding Relativity" but obviously not the higher complexities, applications and math. I was using the most scientific definition of Gravity that I could find which is what led to my query. I had also realized my space and time error before I read your reply. I do prefer to do my own research than just asking, as suggested by Nugatory. I only ask when I cannot find a resolution through research.
Once again, thank you both for your responses and I may well call on your expertise again in the future, if that's ok.
Regards
Antony

 

[Ibix]

Once again, thank you both for your responses and I may well call on your expertise again in the future, if that's ok.

Of course. That's why we post here.

I do prefer to do my own research than just asking, as suggested by Nugatory.

Just be careful what sources you use - even some work by serious scientists can be very misleading when they aren't writing in professional journals or textbooks. It's difficult to express mathematical concepts in words, and people forget how much they know and say things that assume common knowledge that's only common in very specialist quarters. So I strongly recommend asking questions as well as self-study.

 

[Antony Death]

You are quite correct that I should ask questions as well as self-study because self-study has determined that Albert Einstein’s Theory of Relativity is wrong.

To that end would anyone like to play my game with me?

[Mentors' note: A very long explanation of the rules of the proposed game has been removed from this post]

 

[Nugatory]

You are quite correct that I should ask questions as well as self-study because self-study has determined that Albert Einstein’s Theory of Relativity is wrong.

No, your self-study has gone wrong somewhere, and what appears to you be an error or inconsistency in the theory will be a misunderstanding on your part. If you were to tell us exactly where you're finding a problem, we can help you over the misunderstanding.

 

[Antony Death]

Dear Nugatory
These were the first nine statements I was intending to make. The 10th statement was merely a logic loop to create a respectful draw end to the game.THE STATEMENTS THAT I BELIEVE TO BE TRUE:
1: The Lorentz Transformation Formula was designed by Henrik A Larson.
2: The Michelson-Morley Experiments always determined that the speed of light is 299,792,458m/s.
3: Albert Einstein conceived of a genius concept, as yet unmatched by any other human in history.
4: Albert Einstein, age 26, made a simple basic human error.
5: Albert Einstein published his paper on Special Relativity in 1905.
6: Albert Einstein knew at that time that V=d/t.
7: Albert Einstein knew, at that time how to draw a triangle.
8: Albert Einstein knew, at that time that t is a variable.
9: Velocity and the Lorentz Transformation formula does not know that t is a variable.

Expanding out the Lorentz Transformation formula to its' component parts results in error values for dx2 and tx2.

Please advice
Kind regards
Antony

 

[Antony Death]

Addendum to previous comment: when analysed for the two separate aspects of the equation for time and distance.

 

[jbriggs444]

THE STATEMENTS THAT I BELIEVE TO BE TRUE:
1: The Lorentz Transformation Formula was designed by Henrik A Larson.
2: The Michelson-Morley Experiments always determined that the speed of light is 299,792,458m/s.
3: Albert Einstein conceived of a genius concept, as yet unmatched by any other human in history.
4: Albert Einstein, age 26, made a simple basic human error.
5: Albert Einstein published his paper on Special Relativity in 1905.
6: Albert Einstein knew at that time that V=d/t.
7: Albert Einstein knew, at that time how to draw a triangle.
8: Albert Einstein knew, at that time that t is a variable.
9: Velocity and the Lorentz Transformation formula does not know that t is a variable.

If you are intent on creating some sort of ironclad promotion of a personal misunderstanding (which seems to be the thrust here), premises such as #1, #3, #4, #5, #6, #7 and #8 are irrelevant. Nobody cares who came up with a premise, how smart they were to do so or whether they are able to walk and chew gum at the same time. It does not matter. A claim stands or falls on its merits. Furthermore, formulas do not "know" anything. It is an error to personify them. So #9 is irrelevant.

That leaves you with a claim that the speed of light is 299,792,458 m/s. But the speed of light is currently a defined constant. So that's an empty claim as well.

Why be coy? Explain the problem you think you see simply and directly.

 

[Ibix]

1: The Lorentz Transformation Formula was designed by Henrik A Larson.

Hendrik A. Lorentz, in fact.

2: The Michelson-Morley Experiments always determined that the speed of light is 299,792,458m/s.

No. The Michelson Morley experiment does not measure the speed of light. It merely shows that its speed does not vary with direction, whatever the state of motion of the apparatus.

I am afraid that I cannot make head nor tail of the rest of your post, although I have the impression that you think there's a problem with the Lorentz transforms. Please post the maths you believe to lead to an error, along with an explanation of what you are doing. You can use LaTeX to post maths (there is a link to a tutorial below the reply box if you don't know how to use it).

 

[Antony Death]

With all due respect, my lack of formal education had been alluded to as an explanation for my perceived lack of understanding so I did my own studies and was attempting to obtain the respect I would expect to receive by right so as to provide my conclusions. Einstein did not have sufficient information to create a triangle of velocity (hyp) time (adj) and distance (opp). He only had 1 side and zero angles. I believe a basic human error of assumption was caused by the repeated velocity value resulting from Michelson-Morley experiments. Time dilation is the genius of Einstein and his own math, which he compared against Lorentz Transformation (i.e. its' mirrored math) and Einstein then had to add the entire universe into his theory to make the numbers correlate. There is an alternative theory that fully complies with the physical law that every action has an equal and opposite reaction.
It is not my intention to annoy or irritate but I could see no other respectful way of gaining respect for my own abilities (or lack thereof).
Regards
Ant

 

[Nugatory]

Albert Einstein, age 26, made a simple basic human error.

Like misplacing his wallet or overcooking dinner? Quite likely, everyone makes these simple human errors.
But if you believe you see an error in the theory of relativity... would you please just state what it is? It’s impossible to respond sensibly otherwise.

Also, you have to remember that these days the theory of relativity can be, and usually is, described in a very different way than Einstein’s original development of the theory. Einstein found the answer first, but once we knew the answer we found easier and more compelling ways of coming to the same conclusion. That’s why modern textbooks don’t follow in Einstein’s footsteps - there are better ways of getting there. Thus, a problem you find in Einstein’s analysis doesn’t invalidate the theory; you would have to show that the same problem appears in modern formulations of the theory.

 

[PeterDonis]

It is not my intention to annoy or irritate but I could see no other respectful way of gaining respect for my own abilities (or lack thereof).

Unfortunately, what you have actually done is to erode any respect that might previously have existed for your abilities. What you should have done is, first, this:

if you believe you see an error in the theory of relativity... would you please just state what it is?

And second, be prepared, once you state the error you think you see, to have it explained to you why it is you who are wrong, not all of the physicists who use relativity every day because it makes accurate predictions.

 

[berkeman]

The OP has left the building. Have a nice day.