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Einstein's dream of a unified field theory accomplished?

phys.org

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Re: Einstein's dream of a unified field theory accomplished?

#11

Post by floxy »

nchagnet wrote: post #4

The title of the phys.org article is a bit more misleading than the article itself (when are they not). What the authors did is build a unified setup for classical gravity and electromagnetism as the solution of one action, under specific assumptions (Weyl geometry, etc...). Usually we consider gravity as the curvature of spacetime, and electromagnetic forces as the curvature of the electromagnetic field. The authors…

What would be a better title? "Unifying gravity and electromagnetism in a classical theory"?

Re: Einstein's dream of a unified field theory accomplished?

#12

Post by nchagnet »

floxy wrote: post #10
nchagnet wrote: post #8

Earlier quoted context omitted.

This is what I was trying to convey: this is already how we think about it. In general relativity, mass is not more fundamental than the gravitational field and its curvature. While we generally speak of spacetime curving because of mass, this doesn't mean this is a one way relation. The stress energy tensor is equal to the Einstein tensor (roughly curvature), so the relationship is already two-way. It's a cool thing…

Interesting, I've never heard that before. Do you know of a lay-man's article / book that goes more in-depth into treating mass as a curvature of space-time?

Sadly no, most examples I'm familiar with are within research articles. A typical thing done within such articles is to consider a spacetime geometry, calculate its Einstein tensor and map it to some ansatz like that of a perfect relativistic fluid. It's a neat way to interpret the geometry in question as an energy/matter content.

Hope that helps point you in the correct direction!

Re: Einstein's dream of a unified field theory accomplished?

#13

Post by nchagnet »

floxy wrote: post #11
nchagnet wrote: post #4

The title of the phys.org article is a bit more misleading than the article itself (when are they not). What the authors did is build a unified setup for classical gravity and electromagnetism as the solution of one action, under specific assumptions (Weyl geometry, etc...). Usually we consider gravity as the curvature of spacetime, and electromagnetic forces as the curvature of the electromagnetic field. The authors…

What would be a better title? "Unifying gravity and electromagnetism in a classical theory"?

That'd be a good start. This article is well anchored within geometrodynamics (the theories which attempt to explain all physics as geometry), so maybe making that clear would avoid confusions already.

Re: Einstein's dream of a unified field theory accomplished?

#14

Post by floxy »

kelseyfrog wrote: post #3

How? The paper barely mentions gravity and completely omits strong and weak forces.

Did Einstein "dream" about unifying the strong and weak forces with gravity? Anyone have a good timeline on what we knew about the weak force and when? Maybe most of the developments occurred after or just prior to his death in 1955? He was already 53 when the neutron was discovered. I kind of thought most of the strong interaction stuff wasn't really figured out until the mid 1960's.

Re: Einstein's dream of a unified field theory accomplished?

#15

Post by kelseyfrog »

floxy wrote: post #14
kelseyfrog wrote: post #3

How? The paper barely mentions gravity and completely omits strong and weak forces.

Did Einstein "dream" about unifying the strong and weak forces with gravity? Anyone have a good timeline on what we knew about the weak force and when? Maybe most of the developments occurred after or just prior to his death in 1955? He was already 53 when the neutron was discovered. I kind of thought most of the strong interaction stuff wasn't really figured out until the mid 1960's.

Thank you for your input. I apologize. I was trying to get curious.

Re: Einstein's dream of a unified field theory accomplished?

#16

Post by yndoendo »

floxy wrote: post #14
kelseyfrog wrote: post #3

How? The paper barely mentions gravity and completely omits strong and weak forces.

Did Einstein "dream" about unifying the strong and weak forces with gravity? Anyone have a good timeline on what we knew about the weak force and when? Maybe most of the developments occurred after or just prior to his death in 1955? He was already 53 when the neutron was discovered. I kind of thought most of the strong interaction stuff wasn't really figured out until the mid 1960's.

Einstein died before we learned that quantum entanglement was not local and occurs over distance. The book "Einstein's Unfinished Revolution"[0] talks about what he knew and what was found after his death. It also talks about where and why modern quantum mechanics diverge from his theories.

[0] https://en.m.wikipedia.org/wiki/Einstein's_Unfinished_Revolu...

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