Re: anti-gravity? [OT]

On 4/23/2024 8:57 AM, Martin Brown wrote:

On 22/04/2024 17:11, John Larkin wrote:

On Mon, 22 Apr 2024 15:00:21 -0000 (UTC), Phil Hobbs

 

So no, these sorts of theories are not good candidates to explain gravity
or other relativistic effects.

 +1
 The trouble is that simple *wrong* answers appeal to a lot of people.
The "Einstein was wrong" brigade have been going ever since he first published the special theory of relativity.
 https://skepticalinquirer.org/2020/11/100-authors-against-einstein-a-look-in-the-rearview-mirror/
 His repost to "A hundred authors against Einstein" was that it would only take one iff they were actually correct. That is true of all science. It doesn't matter how elegant the theory is it can still be refuted by an experimental test where it predicts the wrong answer.
 

Cheers
>
Phil Hobbs

>
Is there any deeper explanation for conservation of energy, and for
Newton's laws, other than that's just the way things are?
>
(That gets philosophical, namely why does mathematics define the
world?)

 Invariants of motion are a higher level version of the classical conservation laws that can be formulated in general relativity.
 Mathematical notation is just our best way so far of ensuring accuracy, logical consistency and precision in our description of things.
 Hand waving with "just so" stories can only get you so far. Natural language is far too ambiguous and flexible to be effective for science.
 

I don't know whether it's appropriate to say that conservation laws are "caused" by Noether's theorem, but in the Lagrangian/Hamiltonian formulation it's easier to see what symmetries/invariant lead to what conserved quantities as opposed to the Newtonian form.
Maybe one could say at some level the "cause" of those symmetries (which then have associated conservation laws) is the principle of least action.