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Einstein's Other Theory of Everything

nautil.us

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Re: Einstein's Other Theory of Everything

#101

Post by pdonis »

XorNot wrote: post #97
pdonis wrote: post #89

Earlier quoted context omitted.

> electrons orbiting protons don't emit synchrotron radiation Not in atoms, no. But I mentioned scattering, which is a different scenario.

And I have absolutely no idea what you think this explains. Which is the point of physics you know: to convey actionable concepts about the behavior of experiments. Not be cryptic and vague.

> I have absolutely no idea what you think this explains.

It explains the case where an electron and a proton scatter off each other and do not form a bound hydrogen atom.

Re: Einstein's Other Theory of Everything

#102

Post by imglorp »

frede wrote: post #84

This recent presentation from Kepler Airospace claims that Einstein was on the right track and a goes even further, stating that gravity can be manipulated through EM. I've graduated in Physics but not quite sure what to make of it. https://www.researchgate.net/publication/383609891_Gravity_M...

Given how easy it seems to reproduce, someone had better explain this effect if it's not what is claimed there...

PS: this looks like anyone could reproduce or refute it in their basement for a few hundred dollars given all the details in the slides. I'm hoping some amateurs step in.

Re: Einstein's Other Theory of Everything

#103

Post by breck »

bmitc wrote: post #98
breck wrote: post #86

Earlier quoted context omitted.

Fair enough. I think Linus might be a good comparison. Linux in his 20's, which turned world on its had, but it masterpiece Git at age ~36.

I don't fetishize physicists by any means, but Linux and Git are nerdy pursuits that caught on somehow, mainly as a revolt against paid software. Git is pretty bad at times, terrible UX, tons of edge cases, and treats the world as if its made from text. Einstein set forth some of the most foundational and tested theories ever.

Have you thought about the deeper aspects of what git is doing?

Re: Einstein's Other Theory of Everything

#104

Post by raattgift »

cyberax wrote: post #28
raattgift wrote: post #15

Earlier quoted context omitted.

The "balls on a rubber sheet" is a pain because nothing is in free-fall: there are dissipative contact forces between the balls and the rubber sheet. Consequently realistic initial [position, velocity] values for the test ball cannot give you a stable circular orbit around the central mass ball. Venus isn't about to fall into the sun. Now try setting up Earth-Moon or the Jovian-Gallilean systems on the rubber sheet.…

> The "balls on a rubber sheet" is a pain because nothing is in free-fall The balls on a rubber sheet model is actually really great, but not in the way it's typically presented (rolling a ball down the curvature). Instead, just use a pen to draw lines to show the concept of geodesics. Start like this: 1. Imagine that you can move without friction if you stay at the same vertical level. 2. Draw a line on a flat rubbe…

> concept of geodesics

Ok, you brought in the "g" word. I think that makes it fair to ask how you plan to calculate the analog of spacetime intervals along your rubber sheet.

The general curves (not just geodesics) down to the heavy central ball all end up where the ball and sheet are in contact unless blocked by earlier contact with the central ball. How do you recover anything like the behaviour of a smaller ball bound to a non-spacelike radial geodesic with one end normal to the central ball's surface and the other "at infinity" (or at least in the part of the sheet that is asymptotically parallel to the ground)?

How do we show students, using your adapted rubber sheet, that spacetime curvature around a spherically symmetrical mass is symmetrical in all the spatial dimensions and that there is a curvature induced on the timelike dimension too.

What's the relationship between your pen lines and the Christoffel symbols (notably \Gamma^{1}_{00}) or Euler-Lagrange?

How does your "3." work with highly eccentric elliptical orbits? How about a grazing hyperbolic orbit? Think Halley's comet and 1l/`Oumuamua.

Re: Einstein's Other Theory of Everything

#105

Post by [deleted] »

frede wrote: post #84

This recent presentation from Kepler Airospace claims that Einstein was on the right track and a goes even further, stating that gravity can be manipulated through EM. I've graduated in Physics but not quite sure what to make of it. https://www.researchgate.net/publication/383609891_Gravity_M...

[deleted]

Re: Einstein's Other Theory of Everything

#106

Post by Pompidou »

imglorp wrote: post #102
frede wrote: post #84

This recent presentation from Kepler Airospace claims that Einstein was on the right track and a goes even further, stating that gravity can be manipulated through EM. I've graduated in Physics but not quite sure what to make of it. https://www.researchgate.net/publication/383609891_Gravity_M...

Given how easy it seems to reproduce, someone had better explain this effect if it's not what is claimed there... PS: this looks like anyone could reproduce or refute it in their basement for a few hundred dollars given all the details in the slides. I'm hoping some amateurs step in.

"Gem test" 1 and 2 on john brandenburg 's youtube channel :

https://www.youtube.com/watch?v=hqbOnqZtz3Y

https://www.youtube.com/watch?v=RSRbLA6dhtk

Re: Einstein's Other Theory of Everything

#107

Post by gus_massa »

motohagiography wrote: post #72
niederman wrote: post #43

Earlier quoted context omitted.

While something like this could be an interesting idea for a sci-fi novel, this is not at all how quantum entanglement works. Entanglement doesn't make one particle "[adopt] the dilated time/gravity of its remote counterpart", it just refers to a perfect correlation of certain measurements of the two particles. For example, if you produce two particles that you know have zero total momentum, but don't measure the mom…

interesting, content to be wrong based on an absolute ignorance of the topic. my laymans read of photon entanglement had to do with how it was described in quantum key distribution, where entangled photons maintained a kind of polarization state between each other over a long distance, where the observation of one of them caused a state change at the other "end". this idea of remote causality was what implied that th…

Just another interesting point:

You can entangle two photons in a lab, keep one of them and send the other far away. For example, you can construct the pair in a way that both give the same polarization. If you measure one and the result is horizontal, then the result of measuring the polarization of the other is horizontal. If you measure one and the result is vertical, then the result of measuring the polarization of the other is vertical.

But a trick that is usually untold is that you can put a device in the path of the photon that is going far away to rotate it 90 degrees. The important part is that the photon in the lab is not affected. You can't make any measurement in the photon that you keep in the lab to check if the photon far away passed through the device to rotate it or not. But now if you measure one and the result is horizontal, then the result of measuring the polarization of the other is vertical. If you measure one and the result is vertical, then the result of measuring the polarization of the other is horizontal.

Re: Einstein's Other Theory of Everything

#108

Post by tbrownaw »

frede wrote: post #84

This recent presentation from Kepler Airospace claims that Einstein was on the right track and a goes even further, stating that gravity can be manipulated through EM. I've graduated in Physics but not quite sure what to make of it. https://www.researchgate.net/publication/383609891_Gravity_M...

I wonder what he'd think of the "jumping ring" experiment: https://wonders.physics.wisc.edu/jumping-ring/

Re: Einstein's Other Theory of Everything

#109

Post by tbrownaw »

motohagiography wrote: post #72
niederman wrote: post #43

Earlier quoted context omitted.

While something like this could be an interesting idea for a sci-fi novel, this is not at all how quantum entanglement works. Entanglement doesn't make one particle "[adopt] the dilated time/gravity of its remote counterpart", it just refers to a perfect correlation of certain measurements of the two particles. For example, if you produce two particles that you know have zero total momentum, but don't measure the mom…

interesting, content to be wrong based on an absolute ignorance of the topic. my laymans read of photon entanglement had to do with how it was described in quantum key distribution, where entangled photons maintained a kind of polarization state between each other over a long distance, where the observation of one of them caused a state change at the other "end". this idea of remote causality was what implied that th…

> maintained a kind of polarization state between each other over a long distance, where the observation of one of them caused a state change at the other "end". this idea of remote causality

Operating on one half of an entangled pair does not transmit information to the other half. Therefore, the is no action or causation. Choices of vocabulary which imply otherwise are incorrect.

It also doesn't work by "hidden variables" - there isn't some secret value which we just don't know yet. So while it's probably least inaccurate to describe what happens in terms of our knowledge of the remote particle changing, is closer to the new facts we learned coming into existence as we learn them, rather than discovering an existing fact. Except that's also not quite right (information can never be created or destroyed).

Re: Einstein's Other Theory of Everything

#110

Post by tgarrett »

pdonis wrote: post #88
tgarrett wrote: post #78

Earlier quoted context omitted.

In a hypothetical pure GR universe what you're saying is correct, but our universe also includes QM and that makes BH physics much more subtle, e.g.: https://en.wikipedia.org/wiki/Firewall_(physics) and we can't state things with such certainty...

> our universe also includes QM and that makes BH physics much more subtle In some ways, yes, but none of that changes the particular thing I said about BH physics.

In pure GR an infalling observer will sail past the EH and not notice anything unusual since spacetime is locally Minkowski (ignoring tidal forces, which is valid e.g. for humans falling into supermassive BHs). If the (GR+QM) firewall hypothesis is correct (a big if), an infalling observer will instead be promptly incinerated within a Planck's length of the EH. The intuition one builds from a pure GR understanding of BHs may be dramatically wrong, not just at the singularity, but all the way out at the EH.
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