Comment on 8 Minutes

cmgvd3lw@discuss.tchncs.de ⁨2⁩ ⁨months⁩ ago

• hemko@lemmy.dbzer0.com ⁨2⁩ ⁨months⁩ ago

  Moon would “disappear” when it no longer reflected Sun’s light.

  It would also start getting very cold fast

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  • marcos@lemmy.world ⁨2⁩ ⁨months⁩ ago

    It would probably take more than a day for the cold to be so intense that you can’t possibly explain with some normal local phenomenon.

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  • tate@lemmy.sdf.org ⁨2⁩ ⁨months⁩ ago

    The moon might be on the daylight side, so we wouldn’t necessarily observe that.

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  • Routhinator@startrek.website ⁨2⁩ ⁨months⁩ ago

    Any visible planet or asteroid would. So some stars would also appear to blink out, but those would take longer to blink out. So the moon would go after 8 minutes, Jupiter would take 43 minutes to stop receiving light, and another 35-52 minutes to disappear for earth depending on orbital locations.

    Presumably we would get something on radio/tv/internet from the side facing the sun once they realized it, that of course being only if they hadn’t already been eradicated by a horrific shockwave caused by whatever event caused the sun to vanish before they had a chance to report what they saw, because supernovae tend to travel at very close to the speed of light, so there wouldn’t be much time for them to react.

    And if this is a supernova, you might just have time to grok what happened before the planet was obliterated under your feet from the shockwave.

    So I guess… chances are we would just barely understand what happened before we were gone.

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    • Emmie@lemm.ee ⁨2⁩ ⁨months⁩ ago

      It’s kind of odd that it doesn’t matter for a single human whether they die from sudden car accident or obliteration by supernova

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  • Anticorp@lemmy.world ⁨2⁩ ⁨months⁩ ago

    Does heat travel at the speed of light? I just realized I have no idea how the heat from the sun travels to earth.

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    • ironhydroxide@sh.itjust.works ⁨2⁩ ⁨months⁩ ago

      The “heat” IS the radiation. So, yes.

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    • 0ops@lemm.ee ⁨2⁩ ⁨months⁩ ago

      Someone correct me if I’m missing some nuance here, but heat doesn’t get transferred directly through space because heat is vibrating molecules and space is a vacuum. The sun radiates (speed O’ light). A lot of that radiation just reflects off the earth (or we wouldn’t be able to see it), but a lot of it gets absorbed. THAT’s when it’s converted into heat energy. It’s also why the greenhouse effect is a global phenomena: light energy comes in across the vacuum relatively easily, turns to heat on Earth instead of being reflected, heat energy cannot escape as easily as light energy.

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      • GreyEyedGhost@lemmy.ca ⁨2⁩ ⁨months⁩ ago

        Infrared light is absorbed quite easily, producing heat, and the sun emits a lot of it. Of course, all photons that are absorbed and not reflected will produce thermal energy, and infrared radiation is commonly referred to as radiant heat. The other two heat transfer methods are conduction and convection, which requires a medium to transfer through.

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      • Anticorp@lemmy.world ⁨2⁩ ⁨months⁩ ago

        Neat! Thanks for sharing.

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    • emuspawn@orbiting.observer ⁨2⁩ ⁨months⁩ ago

      When there is a total solar eclipse, the temperature does drop dramatically. But it might not be detectable on the other side right away for sure.

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      • 200ok@lemmy.world ⁨2⁩ ⁨months⁩ ago

        It does! And if you’re in a place where night animals are noisy, they get noisy for the length of “dusk”, totality, and “dawn”!

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    • theneverfox@pawb.social ⁨2⁩ ⁨months⁩ ago

      Yes, we have conduction, convection, and radiative heat transfer. Vacuum insulates the first two, it’s the light from the sun that heats us up

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  • Rai@lemmy.dbzer0.com ⁨2⁩ ⁨months⁩ ago

    I wonder how cold how fast.

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    • WolfLink@sh.itjust.works ⁨2⁩ ⁨months⁩ ago

      It wouldn’t really be faster than normal nighttime cooling. However, that cooling would continue instead of having the sun to start warming stuff up in the morning.

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• bluemellophone@lemmy.world ⁨2⁩ ⁨months⁩ ago

  It takes 8 minutes for the light to travel from the sun to Earth. Because light in a vacuum travels faster than anything, including information, we would not and could not know it had disappeared for 8 minutes. This means Earth would continue to follow its orbit around a non-existent sun for 8 minutes because the Sun’s gravity would still be acting on the Earth.

  If it was nighttime, you wouldn’t notice the sudden lack of sunlight (other than if it was a full moon) but you’d almost certainly notice the change in gravity.

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  • ironhydroxide@sh.itjust.works ⁨2⁩ ⁨months⁩ ago

    I don’t think you’d actually “notice” the gravity.

    Earth would still retain it’s mass, and we’re much closer to it, so it’s lesser mass acts much more on us than the sun’s greater.

    Though, the moon would stop orbiting the sun and travel on a mostly tangential path, instead of the elliptical path it currently travels.

    This is a very interesting physics question that I may look into further. Specifically what would the theoretical acceleration be, due to the lack of the sun? Is it above a humans level of perception?

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    • ironhydroxide@sh.itjust.works ⁨2⁩ ⁨months⁩ ago

      Gravitysimulator.org has an interface you can simulate what happens, though it’s timeframe is on the order of days. Not seconds.

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    • Tlaloc_Temporal@lemmy.ca ⁨2⁩ ⁨months⁩ ago

      Why would it travel radially away? The resulting gravity wave from a disappearing stun much push the Earth a little, but changing its orbit that drastically would mostly destroy Earth anyway.

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  • cmgvd3lw@discuss.tchncs.de ⁨2⁩ ⁨months⁩ ago

    Interesting, so you are saying light is faster than gravity?

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    • hemko@lemmy.dbzer0.com ⁨2⁩ ⁨months⁩ ago

      Equal to speed of light in vacuum

      en.m.wikipedia.org/wiki/Speed_of_gravity

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    • nublug@lemmy.blahaj.zone ⁨2⁩ ⁨months⁩ ago

      light speed = gravity speed

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    • FundMECFSResearch@lemmy.blahaj.zone ⁨2⁩ ⁨months⁩ ago

      If someone who has the mental energy factchecks this pls share

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  • mattreb@feddit.it ⁨2⁩ ⁨months⁩ ago

    you’d almost certainly notice the change in gravity.

    Really? can you actually percieve the sun gravity? Do you mean that we would get like a tsunami beause of the tidal effect? Now I kinda want a documentary about this.

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  • abfarid@startrek.website ⁨2⁩ ⁨months⁩ ago

    It’s weird to say that light travels faster than information, because light is information. In other words, top speed for information IS speed of light.

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    • lone_faerie@lemmy.blahaj.zone ⁨2⁩ ⁨months⁩ ago

      I think that’s just the wording. My interpretation of that is any satellite or space probe sending back readings to Earth wouldn’t be faster than the sun visually disappearing from the sky. Even with the information being transmitted at the speed of light, there’s always going to be some sort of processing delay, along with the limited bandwidth of the transmission.

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• Nakoichi@hexbear.net ⁨2⁩ ⁨months⁩ ago

  Yes, because of the medium of communication you are using right now.

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