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Biden says that 'if Trump wasn’t running, I’m not sure I’d be running'
  • he was also all geared up to run in 2016, but then his son died. If I recall, Hilary Clinton actually waited for Biden to decide he couldn't run before she entered the race.

  • Activists calling for Gaza ceasefire begin hunger strike outside White House
  • Article says the ceasefire was originally planned for 4 days, so they made the hunger strike coincide with the end of the ceasefire. But then the ceasefire was extended. But they went ahead with hunger strike anyway? Ok…

  • Activists calling for Gaza ceasefire begin hunger strike outside White House
  • Is this news current? Isn’t the conflict in like day 3 of ceasefire? Are they still on hunger strike?

  • Donald Trump says he never swore oath "to support the Constitution"
  • It’s obviously an overly legalistic and technical argument that doesn’t speak to the merits. But it’s an appeals case, you have to argue legal errors not factual ones. I’m not a lawyer and have no idea how likely it is to succeed, but I think “throw everything at the wall and see what sticks” is best legal practice, so I don’t see how this filing hangs him out to dry. It’s bad optics but I don’t think is gonna matter to anyone.

  • Donald Trump says he never swore oath "to support the Constitution"
  • Did you not read the article?

    and that Trump technically did not swear an oath to "support" the Constitution. Instead, during his January 2017 inauguration, Trump swore to "preserve, protect and defend" the Constitution during his role as president.

    You’re talking about the reasoning in the ruling by the district judge. This article is about trump’s argument in filings to the appeals court.

  • ‘NORMALITY’ [OC]
  • Here’s wiktionary:

    Although sometimes used, normalcy is less common than normality in American English. It is very rarely used in the UK, Canada, Australia, and New Zealand. It is frequent in India and Zimbabwe however.

    So it’s a regional thing.

    Although the claim that in US English the “normality” form is more common does not match my experience as a speaker of US English.

  • ‘NORMALITY’ [OC]
  • I did not recognize that form and assumed it was not a word. I stand corrected.

  • ‘NORMALITY’ [OC]
  • the word is "normalcy"

  • Speediest little fella.
  • Lie groups are my favorite thing in all of mathematics, and gauge theory is my favorite thing in physics. E8 and all its connections to other subjects is one example of how amazing this subject can be.

    It would be a coup de grace of the highest order, just the crowning intellectual achievement of mankind, if we could stumble upon a theory of everything explaining the entire Standard Model, just by fiddling around with how to fit SU(3)xSU(2)xU(1) fits inside E8 or whatever.

    But I guess it's not going to happen.

  • Will this also affect lemmy.ml?
  • you don't need a uniform distribution. if the server distribution mirrors the population distribution (and why wouldn't it?), that will still achieve the desired effect.

  • Will this also affect lemmy.ml?
  • Do people not remember back in the 2010s when bit.ly was the main link shortener used everywhere on the internet, and then Ghadafi, the then dictator of Libya, declared the site to be incompatible with Muslin decency norms because it was used for porn? And then all bit.ly links were just dead links?

    How many times do we have to learn this lesson? Domain name hacks are fun but just not worth it. And in 2023, now we have all the new TLDs. This was a dumb decision

  • Speediest little fella.
  • I'll level with you. I know how to use QED to compute the cross section of a scattering reaction. But I do not remember, or perhaps never knew, what the QED theoretic description of classical wave mechanical phenomena like diffraction, reflection, refraction, and dispersion look like.

    Well... actually of those phenomena, I think diffraction is fine. A single waveform will exhibit diffraction. It doesn't entail any interactions. A single photon can still exhibit a diffraction pattern. It doesn't mean that the photon has changed directions or circled around or in any way accelerated. The only reason you might think so is that you're thinking of photons as billiard ball type classical particles, but of course they are not, they are quantum particles with spread out wavefunctions.

    Dispersion I guess is just scattering combined with absorption re-emission (and as we discussed, even scattering is itself a form of absorption & re-emission). But as for reflection and refraction? Those are the phenomena that Entropius was pointing to elsewhere in this thread. I remember how those look in terms of solutions to Maxwell's equations and boundary conditions, but that's classical wave mechanics. I do not remember how to translate that into the language of QED.

    QED is a fundamental theory, so I assume that a description exists, and of course because I know what QED looks like, so I am certain that it will still be true that in this description, photons will be absorbed & emitted by charged particles, but photons will not interact with photons. However beyond that I cannot say much. How do we describe reflection of light in a mirror as photons scattering off electrons? I don't know exactly.

    One thing I can say is that generally classical states are modeled in quantum mechanics as coherent states, which are eigenstates of the annihilation operator. They look something like exp(N)|0> where N is the number operator, which means that they are states with a superposition of 0 photons, 1 photons, 2 photons, etc. They don't have a well defined number of particles. So maybe if you want a QED theoretic description of reflection, you can have it, but you won't be able to talk about specific numbers of photons. But again, I don't know the details of this.

    I wonder whether this concept of classical waveforms as coherent states with a superposition of all numbers of particles will help at all with this philosophical debate about whether two photons are the same particle or not, or about whether you can have a universe with only 3 photons

  • Imaginary friends.
  • complex numbers are just numbers in a plane instead of a line. saying you don't believe in i is like saying you don't believe in "up"

  • Speediest little fella.
  • Look bro. Your top level comment that I replied to was generally correct, and also very helpful. I liked it. I liked the suggestion for people to look at the Feynman diagrams. I agreed with it. I upvoted it.

    I hope I'm not giving you the impression that I'm taking a personal issue with you. I'm not. I like you and I hope we'll still be friends when this is all over. I promise to read Discworld soon.

    The only quibble I had with what you wrote was this one sentence:

    So for a photon to change course, aka accelerate, it does it by absorbing a virtual photon and emitting another.

    Photons do not absorb virtual photons. And real on-shell photons do not interact. In Compton scattering and 1 loop photon-photon scattering, you can think of photons emitting e+e- pairs. But never do they emit or absorb other photons.

    Maybe that's not what you meant with that sentence, and I misunderstood. If that's the case, my bad. Maybe you didn't need the explanation. If someone else made the same misunderstanding reading your comment that I did, then maybe my comments will help them even if you don't need them. Or if not, if it's just me being dumb, well c'est la vie.

    Cheers bro.

  • Speediest little fella.
  • I am indeed denying the existence of photons interacting with virtual photons. I am also saying there is no tree level photon-photon interaction of on shell photons. Neither Compton scattering nor Bhabha nor pair production nor pair annihilation involves a photon-photon interaction. There is no photon-photon vertex in QED. There is no tree level Feynman diagram that you can look at and say “this is, at least philosophically, a photon changing its momentum”.

    There is a 1 loop diagram that represents photon-photon scattering. But even that doesn’t have any photon-photon vertices, instead it is mediated by electron-positron pair.

    Non-abelian gauge bosons (gluons) couple to themselves. So does gravity (gravitons). Abelian ones (photons) do not.

    Photons don’t accelerate. They are emitted or absorbed. That’s their only interaction.

  • Speediest little fella.
  • The electromagnetic field does have a force carrier. It is the photon.

    The photon mediates the force between electrically charged particles. It cannot mediate any reaction between two neutral photons.

  • Speediest little fella.
  • the speed of light expressed in units of distance per time, is a dimensionful quantity so it probably doesn’t mean anything to say some theory does or does not predict a value for it. The value is entirely determined by how big you choose your yardsticks and sundials to be, which is arbitrary convention.

    It is only meaningful to talk about theoretical predictions of the values of constants if they are dimensionless, like the fine structure constant.

    However relativity does suggest as a natural point of view that space and time are just orthogonal directions in a unified spacetime. In this point of view, relativity gives you the option of measuring your timelike and spacelike coordinates with the same yardstick (which you may still choose arbitrarily). And then relativity does predict its value. It’s 1. No units.

  • Speediest little fella.
  • There is no tree level photon-photon interaction. Photons scatter off electrons (or any other charged particle), not off neutral photons.

  • Speediest little fella.
  • Ok but photons don’t change direction either. Treating photon scattering as an individual particle accelerating due to an applied force, well that’s just not a correct description of how perturbative QED models photon interactions.

  • Speediest little fella.
  • The fact that light cannot change speed is one of the core axioms of relativity

  • I can post but not comment

    I was able to successfully create a post to c/support. But I cannot reply to any comment.

    I'm experiencing a lot of connectivity issues. I'm trying to figure out whether the site is just slow, or there's a problem with my account. My account recently gained a pretty large negative karma due to making some statements in defense of not defederating Facebook Threads, which were wildly unpopular. I received a lot of downvotes and now my account karma stands at –77.

    Since then, I have not been able to reply to any comment. I was able to post successfully, but I cannot reply to any comment response to my post.

    But also lemmy.world seems to be struggling with the recent uptick in traffic, so maybe it's just slow?

    Is my account shadowbanned for comments, or is the site just slow for everyone?

    Edit to add:

    Here is what I see when I try to post a reply comment on memmy for ios, while I am definitely logged in:

    !here

    And

    !here is what it looks like on desktop. It says not logged in but also the profile shows logged in. Double checked by logging out and back in.

    If my account is fucked and unrecoverable, I wish lemmy.world could just let me know and i will try to move on to another platform. Thanks for any advice you can give.

    4
    am I blocked?

    I'm unable to comment on any post, so I'm testing a post submission to support. Does this work?

    7
    ziggurism ziggurism @lemmy.world
    Posts 2
    Comments 120