Comment on [troll science]: Unruh particle shower on a centrifuge

• lime@feddit.nu ⁨3⁩ ⁨days⁩ ago

  the unruh effect is apparently a hypothetical situation where an accelerating body in a complete vacuum still encounters particles. i had no idea about this, sounds weird as hell.

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  • TauZero@mander.xyz ⁨3⁩ ⁨days⁩ ago

    Like many other popular weird physics effects, it has been accepted non-controversially by scientists and then popularized for decades in fun thought experiments and pop-sci videos, all of which neglecting to mention that no actual experiments have yet been performed. This lack of grounding leads to spread of confusing statements like “the Unruh particles exist in the accelerated frame but not in the lab frame”, which make no sense, for how can there be two separate realities that coexist? Luckily we now do have a first Unruh experiment from 2019 arxiv.org/abs/1903.00043v7 and the temperature did rise and reality did not split apart. So no longer hypothetical, just routine and boring.

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    • porous_grey_matter@lemmy.ml ⁨3⁩ ⁨days⁩ ago

      Routine maybe, I don’t think it’s that boring

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      • TauZero@mander.xyz ⁨3⁩ ⁨days⁩ ago

        Oh for sure, science is never boring :D but compare the intense situation in the troll science pic to the displayable results from the actual experiment (fig. 1c):

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        Tip: evidence for the Unruh effect you are looking for is this 2mm difference right here:

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        The teal dashed line is the power spectrum predicted from theory including the Unruh effect, and violet dashed line is without it. The data points match the teal line better. But you can’t even see that by eye from the noisy dots! You need to do chi-square statistics to even prove it. (The dots below 30GeV - outside the “accelerated thermality” region - are not included in the analysis because they are guaranteed to be incorrect, as the experiment wasn’t sensitive in that range.) Boooring!

        What the authors of the paper glance over in a single sentence before moving on to better things is that they had to shoot a FRICKING POSITRON DEATH BEAM FROM THE MFKING LHC through a crystal target and watch the resulting Bremsstrahlung gamma rays that would melt your bones off to obtain these datapoints. Talk about intense!

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  • Scubus@sh.itjust.works ⁨2⁩ ⁨days⁩ ago

    Didnt read that yet, this is all from memory.

    From my recollection, the unruh effect is a side effect of referance frames and event horizons. For any given object, you can calculate that objects future path through space time. There will be objects that are too far away for that object to interact with until a certain amount of time has passed. That means those objects are beyond the causality of your original object. This creates an expansign event horizon where anything before it can theoretically be interacted with, and anything past it cannot until the future. The issue is that on the border, on the event horizon, you have virtual particles popping in and out of existance. These particles normally annhilate each other and therefore measurably dont matter. But you have the ability to interact with one without interacting with the other, because its beyond your sphere of influence. But if you can interact with it, it can interact with you. This means you measure a noticable increase in energy at the event horizon because youre only measuring half of the virtual particle, the half that you can interact with and the half that can interact with you.

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