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An old professor of mine loved the "Throw something at the blackboard" technique. Great way to get the class potheads to wake up
how many potheads did you have in your quantum mechanics class?
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Lagrangian mechanics is equivalent to Newtonian mechanics, but doesn't involve force https://en.wikipedia.org/wiki/Lagrangian_mechanics The idea of replacing a 'gravitational force' with spacetime curvature gave us General Relativity; extending this same idea to electromagnetism gives us Kaluza-Klein theory https://en.wikipedia.org/wiki/Kaluza%E2%80%93Klein_theory The current state of the art is Quantum Field Theory…
I still need someone to ELI5 to me how space curvature model explains the attraction between two bodies that have a delta-v of 0.
Instead, you keep the rubber sheet and the single ball. Instead of placing other objects on the curved rubber, project (using a projector if you want) a straight line (from a flat surface) down onto the rubber. If you trace the projection of the line onto the rubber, you'll notice that it is no longer straight - it curves with the rubber (especially if you subsequently flatten the rubber out). That's a world line[1]. That's the direction of movement that an object would see as its "momentum" - but it wouldn't actually follow the world line, as the world line changes when the object moves.
To build a geodesic (the actual orbit/movement of the object), you need to move along the world line and then build a new one, repeatedly. I haven't completely figured out the instructions to build a geodesic in this analogy, but seeing/imagining the curved world line should be enlightening:
There is no attraction.
[1]: https://en.wikipedia.org/wiki/World_line#World_lines_in_gene...
Can anyone explain in layman's terms why this is important?
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To clarify, for those not familiar with this topic, this experiment is making measurements at such exquisite precision that even the calculations for the theoretical prediction are extremely non-trivial and require careful estimation of many many pieces which are then combined. Which is to say that debugging the theoretical prediction is (almost) as hard as debugging the experiment. So I would expect the particle phy…
it's not good to cherry-pick paragraphs from the whole artile. > But as the Brookhaven team accrued 10 times more data, their measurement of the muon’s g-factor stayed the same while the error bars around the measurement shrank. The discrepancy with theory grew back to three sigma by the time of the experiment’s final report in 2006.
Any change in the theoretical estimates could in principle drastically change the number of sigmas mismatch with experiment in either direction (but as the scientific endeavor is human after all, typically each helps debug the other and the two converge over time).
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An old professor of mine loved the "Throw something at the blackboard" technique. Great way to get the class potheads to wake up
how many potheads did you have in your quantum mechanics class?
Physics noob question: is there any physical framework that does away with the concept of "force"? I know a bit about how it is reconceptualized as space-time deformation in the context of general relativity, but that's about it. It just seems like one of those inherently anthropocentric concepts that (potentially) holds us back from exploring something different?
Why is it an anthropocentric concept, did you never place anything on a scale? Or have a wire rip from a weight hanging on it?
So now all that matters is what kind of article do your want to write. A sensationalist one to get eyeballs or a realistic one that is far less exciting. Thus the exact same discovery can be presented via two radically different headlines:
BBC goes with "Muons: 'Strong' evidence found for a new force of nature" https://www.bbc.com/news/56643677
> "Now, physicists say they have found possible signs of a fifth fundamental force of nature"
ScienceDaily says: "The muon's magnetic moment fits just fine" https://www.sciencedaily.com/releases/2021/04/210407114159.h...
> "A new estimate of the strength of the sub-atomic particle's magnetic field aligns with the standard model of particle physics."
There you have it, the mainstream media is not credible even when they attempt to write about a physics experiment ...
The Quanta write up is a bit more neutral on this announcement. There is a computational result that was not included in the theoretical value used to bench the test against. Once reviewed, this difference may yet go back to oblivion. https://www.quantamagazine.org/muon-g-2-experiment-at-fermil...
This is a pre-print https://arxiv.org/abs/2002.12347
This is the link to the Nature publication: https://www.nature.com/articles/s41586-021-03418-1
Honestly feel sorry for particle physicists... Their entire gig is spending billions on fancy equipment, and hoping that observe something unexpected. If they see exactly what they expected to see, all that effort was basically wasted. Also, a lot of "discoveries" turn out to be equipment miscalibration - remember those particles which supposedly moved faster than light a few years back? Always struck me as an odd wa…
This isn’t the way I would frame it. No one will fund billions on fancy equipment for unexpected results, and no one is flipping a coin expecting something other than heads/tails. The usual course is that there is some theoretical expectation/justification of a result, however we then need to build the experimental capacity to see if it is true.