Photons

Comments

• ryedaft@sh.itjust.works ⁨1⁩ ⁨week⁩ ago

  Photons don’t gather energy and they definitely don’t move slowly through the sun.

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  • Artyom@lemm.ee ⁨1⁩ ⁨week⁩ ago

    1. They’re traveling in a medium, so they move slower than in space
    2. Due to the random walk caused by multiple scattering, it can take millions of years for a photon to escape the sun after bring produced in the core.

    You are right that they don’t gather energy, but they do multiply. What would be a single high energy x ray in the core will eventually downscatter into an army of optical photons.

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  • bdonvr@thelemmy.club ⁨1⁩ ⁨week⁩ ago

    It can definitely take millions of years for photons to leave a star due to dense protons causing collisions.

    futurism.com/photons-million-year-journey-center-…

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    • stebo02@lemmy.dbzer0.com ⁨1⁩ ⁨week⁩ ago

      I get what you’re saying but taking a long time is not the same as moving slowly

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    • eatCasserole@lemmy.world ⁨1⁩ ⁨week⁩ ago

      🤯

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  • take6056@feddit.nl ⁨1⁩ ⁨week⁩ ago

    For photons, their moving relatively slow from the inside to the outside of the sun. Although, I think, it’s technically a bunch of photons bumping each other into existence.

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  • gubblebumbum@lemm.ee ⁨1⁩ ⁨week⁩ ago

    also temperature doesn’t really exist at that scale.

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• Diplomjodler3@lemmy.world ⁨1⁩ ⁨week⁩ ago

  Just eat your ice cream before it melts. Glad i could help.

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  • portuga@lemmy.world ⁨1⁩ ⁨week⁩ ago

    Or just eat them by night. It’s pretty hard to escape those thousand year photons specifically targeting OP’s icecream by day

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• GooberEar@lemmy.wtf ⁨1⁩ ⁨week⁩ ago

  From the perspective of the photon, this all happens more or less instantaneously. Or so I have been told. I was also told that my tongue has 5 or 6 zones where different aspects of flavor are detected and I now know that to be wrong. So maybe fuck your ice cream.

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  • psud@aussie.zone ⁨1⁩ ⁨week⁩ ago

    more or less instantaneously

    That’s relativity. The faster a thing goes the slower time runs for them. Photons are travelling at light speed and so they don’t experience time at all

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  • portuga@lemmy.world ⁨1⁩ ⁨week⁩ ago

    Now you got me curious about photons, I mean what is wrong with your tongue? Thoughts and prayers

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• Eheran@lemmy.world ⁨1⁩ ⁨week⁩ ago

  It is not direct sunlight that is melting your ice mate. Let’s say the scoop has 10 cm² getting blasted from the sun, that’s 1 Watt of heat under maximum possible conditions (Sun vertically above you, perfectly black ice, etc.). tl;dr: In total from convention 1.8 W and condensation 2.5 W and radiation 0.65 W = 4.95 W -> maximum possible sunlight on earth would only increase this by 20 %, more realistic sunlight something like 10 %.

  Actual math: Compare that to ambient temperatures of say, 30 °C, and let’s again say 10 cm² cross section, which translates to a diameter of 3.57 cm, so a sphere with a surface of 40 cm². The heat transfer coefficient under normal conditions is about 15 W/(m²K), so we get: 15 W/(m²K) * 0.004 m² * 30 K = 1.8 W

  Additionally, we have latent heat from water (humidity) condensing on the cold surface: Let’s assume a Schmidt number of 0.6, so we get a mass transfer coefficient of: 15 W/(m²K) / [1.2 kg/m³ * 1000 J/(kgK)] * 0.6^(-2/3) = 0.0176 m/s Specific gas constant: 8.314 J/(molK) / 0.018 kg/mol = 462 J/(kgK) So the mass flux (condensation speed) is: 0.0176 m/s * 2000 Pa / [462 J/(kgK) * 273 K] = 0.00038 kg/(m²s)

  Given the heat of condensation of 2257 kJ/kg water we thus get: 0.00038 kg/(m²*s) * 2257000 J/kg = 632 W/m²

  And thus for our little sphere: 632 W/m² * 0.004 m² = 2.5 W

  … Then we also have radiation from the hot surrounding, let’s assume 30 °C again, we get: Q = 5.67E-8 W/(m²*K^4) * 0.004 m² * (303 K^4 - 273 K^4) = 0.65 W (omitting radiation from the sky)

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  • JohnDClay@sh.itjust.works ⁨1⁩ ⁨week⁩ ago

    So made this meme is eating ice cream when it’s below or near freezing? Because you still get ice melting below freezing due to radiation.

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    • Eheran@lemmy.world ⁨1⁩ ⁨week⁩ ago

      Yes, while the radiation puts more energy in than the convective etc. cooling removes. So near 0 this is guaranteed, since the temperature difference from ice to ambient is almost 0 while radiation keeps pumping in something like 0.5 W. But who eats ice at freezing temperatures… And outside?

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  • frezik@midwest.social ⁨1⁩ ⁨week⁩ ago

    The science on this is relatively recent, but it turns out there is a photomolecular effect on evaporating water that can’t be explained with heat.

    news.mit.edu/…/how-light-can-vaporize-water-witho….

    Not quite sure how this would affect melting ice cream. It does fill in some missing pieces to climate models. There are more clouds around than the models predict, which raises the planet’s albedo.

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• expatriado@lemmy.world ⁨1⁩ ⁨week⁩ ago

  photons are generated at the core from matter by hydrogen fusion (bigger elements later in the star life), the photons travel to the surface by absorption and re-emition taking about 100,000 years in average to scape, despite traveling at the speed of light. so the slow part depends of perspective

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  • I_Has_A_Hat@lemmy.world ⁨1⁩ ⁨week⁩ ago

    And from the proton’s perspective, it is created and arrives at its ultimate destination instantly.

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    • SnowmenMelt@lemmy.world ⁨1⁩ ⁨week⁩ ago

      Thinking about a photon’s perspective is nonsensical. You are asking for a frame of reference where the photon is at rest but the very definition of a frame of reference in relativity is one where photon’s are travelling at the speed of light. Therefore there cannot be a frame of refernece where a photon is at rest and so a photon can never have a perspective, and neither can anything travelling at the speed of light.

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    • henfredemars@infosec.pub ⁨1⁩ ⁨week⁩ ago

      One has to imagine whether their life is satisfying provided it contains no journey whatsoever. Only destination.

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• mojofrododojo@lemmy.world ⁨1⁩ ⁨week⁩ ago

  it can take tens of thousands of years bouncing around inside the sun before they exit too. always thought that was pretty neat.

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• don@lemm.ee ⁨1⁩ ⁨week⁩ ago

  “It took me a _hundred thousand years to escape the prison of a motherfucking star, and you have the gall to complain about your little ice cream cone melting?!

  Fuck you.”

  Me: well when you put it like that

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• hakunawazo@lemmy.world ⁨1⁩ ⁨week⁩ ago

  Image

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• RustyEarthfire@lemmy.world ⁨1⁩ ⁨week⁩ ago

  Could have been worse:
  lemmy.world/post/24169630

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• LanguageIsCool@lemmy.world ⁨1⁩ ⁨week⁩ ago

  Everyone knows the sun’s core makes vitamin D

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• Engywuck@lemm.ee ⁨1⁩ ⁨week⁩ ago

  Love this

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• Anticorp@lemmy.world ⁨1⁩ ⁨week⁩ ago

  You so easily could have made this a happy comic instead.

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  • TriflingToad@sh.itjust.works ⁨1⁩ ⁨week⁩ ago

    “to land in your Nintendo 64 and to give you the world record”
    /last frame is them celebrating together with matching Mario shirts/

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• Kolanaki@yiffit.net ⁨1⁩ ⁨week⁩ ago

  Just look at or don’t look at the photons so they behave like a wave, and then keep your ice cream in the peaks or valleys where the wave doesn’t touch it. 🤷🏻‍♂️

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• lugal@sopuli.xyz ⁨1⁩ ⁨week⁩ ago

  I don’t believe in conspiracy theories

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