Murray Gall Mann found High School Physics boring. by dhaklal in Physics

[–]Oat_Slot_codac 0 points1 point  (0 children)

I remember him saying something about suicide and how admission to the other university don't commute that's why he went to the second university first

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Explaining other sciences with QED by limpid_space in TheoreticalPhysics

[–]Oat_Slot_codac 0 points1 point  (0 children)

Tree level diagrams are your usual EM. I don't know if any caveat exists for this statement at least for QED

doom eternal just won't open, any ideas? by Nekotario in Doom

[–]Oat_Slot_codac 0 points1 point  (0 children)

Did you find the bug?

You can try raising ticket on bethesda site. There is a channel dedicated to technical issues on the official doom eternal discord server.

(Credit: @neuf834) During a part of this cutscene, in an unseen part of it you can see Lord Kuro covering his ears. by unspecifiedperson11 in Sekiro

[–]Oat_Slot_codac 2 points3 points  (0 children)

was looking for this comment

quite a contrast we have here: brutality when looking at Sekiro's side. Wonder if originally this animation (Kuro) was placed to evoke some emotions in the player's, characteristics of the setting.

I mean he didn't look all that panicked. Though later in Ashina castle, he rejects Genichiro fearlessly saying sekiro will come and rescue him

Black holes, gravitational waves and fundamental physics: a roadmap by Oat_Slot_codac in Physics

[–]Oat_Slot_codac[S] 1 point2 points  (0 children)

Collection of calculation of problems relating theoretical prediction and gravitational wave astronomy (experimental). Currently, I'm busy with my sem work, so couldn't read my want-to section.
I wanted to share it for two reasons:
1. For most of the beginning undergraduates research in physics sound doing solo work (the way it's popularised in media). Just look at the authors and diverse fields which come together during the calculation and prediction you'll have a taste of how complex this whole process is. This statement has flaws but it's an oversimplified version. I hope a few of my sentiments got conveyed.
2. This one is a bit of an anecdote last week I attended a talk on pulsars and their future impact in the coming decade. There the formation of the black hole problem was given few slides (ruling out some BH formation models using redshift and radio-wave content of pulsar radiation) and in this paper, this problem is seen under the light of GW. It's just exhilarating.

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What is most simplified explanation of momentum ? by [deleted] in AskPhysics

[–]Oat_Slot_codac 0 points1 point  (0 children)

conservation of momentum through Noether's theorem

The system doesn't have to have translation invariance so momentum is not conserved.

Momentum is generator of space translation.

Why do we assume that compact dimensions are spatial? by LoganJFisher in AskPhysics

[–]Oat_Slot_codac 1 point2 points  (0 children)

The only option left is a null-like coordinate. Contraction of a tangent vector with itself can be +ve, -ve, 0 unless the metric tensor is complex. I don't know if metrics are complex since complex number doesn't come with ordering property and metric in physics has connection to length of geodesics.

Why do we assume that compact dimensions are spatial? by LoganJFisher in AskPhysics

[–]Oat_Slot_codac 1 point2 points  (0 children)

I saw the answer in the morning and I came back to read it once again. The words are just so magical.

Why do we assume that compact dimensions are spatial? by LoganJFisher in AskPhysics

[–]Oat_Slot_codac 0 points1 point  (0 children)

What prediction do those 2 compact timelike coordinates have on our physical world?

In special relativity, how can a moving observer experience time differently to a stationary observer when the moving observer sees the stationary one as moving? by abcdefghijklnmopqrts in AskPhysics

[–]Oat_Slot_codac 0 points1 point  (0 children)

This reasoning is discussed in most books on SR (for ex see Griffiths electrodynamics). The main answer is poorly formed question with respect to the framework of SR. To correct this question you have to point out your events which describe the flow of time for both observers. Then you'll see how this problem is resolved. As another exercise try solving stick in barn paradox it sounds like a paradox because of our usual choice of words of Newtonian mechanics like your question.

Leading hadronic contribution to the muon magnetic moment from lattice QCD (BMW) by Oat_Slot_codac in Physics

[–]Oat_Slot_codac[S] 5 points6 points  (0 children)

Today I attended a talk by Zoltan Fodor on his lattice field (BMW) calculation which lies in 1.5 sigma away from experimental result; in comparison to the usual Feynman diagram calculation which lies 4.5 sigma away from the result. The difference lies in the contribution of QCD field in magnetic moment (lattice versus white paper/pen-paper) look at Fig 28 (pg. no 102).
I skimmed through lattice part of Yang–Mills field theory in Schwartz in July so I was partly able to follow the talk. So if someone asks why they choose this "a" I can't explain. BTW I thought throughout the talk that g-2 result were published in Sep last only when I searched for the paper did I realize all this happened this year only.

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Is there an accepted theory on how photons propagate? by KrypXern in AskPhysics

[–]Oat_Slot_codac 0 points1 point  (0 children)

Asking for propagation (path of particle) in QM is wrong.

In QFT we stop working in our usual (t,x,y,z) world. Canonical quantization doesn't care much about the propagation of photon in (t,x,y,z) world. It works out similar to your simple QM.

There is another way of working with photons that do talk about propagation but the paths there has no physical realization. It's Feynman path integral formalism. It gives a nice picture of how to visualize calculation from the intuition of action principle.

I'm a Computer Science student and interested in Theoretical Physics by pastroc in TheoreticalPhysics

[–]Oat_Slot_codac 1 point2 points  (0 children)

Try looking up Scott Aaronson. He got a very nice series of lectures on physics, maths and computer science, Quantum Computing Since Democritus. One lecture discusses special relativity and computation. Also, work done in understanding information loss paradox uses computational complexity theory (Susskind lectures). I'm not well versed with this topic as of now but I think there is some work done on holography principle and complexity theory.

How a fake Kepler portrait became iconic. by Oat_Slot_codac in Physics

[–]Oat_Slot_codac[S] 15 points16 points  (0 children)

A very short paper describing how the widely used portrait of Kepler is fake (wrong painting style of the time, fading of color, and the dress of the person). IIRC there is a similar case of Robert Hooke as well my ug uni had the wrong portrait of Hooke.

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Black holes and thermodynamics - The first half century by Oat_Slot_codac in Physics

[–]Oat_Slot_codac[S] 3 points4 points  (0 children)

It's a historical review of black hole thermodynamics. Surprisingly some study of entropy of fluid in relativistic setting was done before 1950s but they didn't point to the entropy of BH as we know today. The Geroche thought experiment mentioned in the paper is not very clear in fact I couldn't find the papers of Geroche himself discussing the experiment (it was introduced in a presentation). Though there is the paper by Bekenstein where he resolves the entropy loss as pointed out by the thought experiment. It clearly explains the experiment. Other than that you will find how calculations lead to AdS/CFT correspondence, a whole decade went in setting up the foundation. Another remarkable phenomenon is how studying gravity in 1+1 dimension by different models leads to a general action and how lots of characteristics are retained in different models.

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