• @[email protected]
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      181 month ago

      The laser pointer can travel the light of speed? If you turn it on, does the laser not come out of the laser pointer?

      • @OneWomanCreamTeam
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        41 month ago

        The laser and the laser pointer are both traveling away from each other at the speed of light, so from the pointer’s perspective the laser is traveling at twice the speed of light.

        • @[email protected]
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          331 month ago

          You are being downvoted as if your point was offensive or harmful. You are wrong, but it’s totally counter intuitive and I think this is a mistake that everyone makes when studying introductory physics. This would be correct for anything moving at relatively low speeds. But when you’re talking about light, or anything that goes so fast that “percentage of the speed of light” starts being a useful unit to describe their speed, this concept starts being a bit weirder.

          This is actually the basic principle of Einstein’s theory of relativity: the speed of light (in a vacuum) is the same for all observers, regardless of their frame of reference. That means that if the laser pointer emits a laser, the light is moving away from the pointer at the speed of light. If the pointer itself is moving at a speed reeeeeally close to the speed of light… Then the laser will STILL be traveling away from the pointer at the speed of light. And if you, an observer in a frame, see the pointer moving at near the speed of light emit a laser… The laser that the laser emitted is also traveling at the speed of light from your point of view.

          And there’s no wordplay here. I don’t mean that it’s light, so of course any speed it travels at is the speed of light. I mean that if you measure its speed from any reference frame, you will get around 300000000 m/s, or around 671 million miles per hour. No matter if you are also traveling at near light speed.

        • @funkless_eck
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          21 month ago

          speed is distance over time, and for light both of those are undefined.

          • dream_weasel
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            71 month ago

            I think you’ve got to be a little careful how you say what you mean here:

            In light’s own reference frame, this is true-ish from a pure special relativity perspective. Velocity is sort of undefined in that case because at c, Lorentz transformations bring all distances to zero, meaning that the photon is everywhere at the SAME time. Or said another way, it’s everywhere on its own simultaneity curve. Maybe this is splitting hairs on the definition of “undefined” because, mathematically yeah you’re right, but a rock also moves zero distance in zero time. Its more like it’s velocity doesnt make sense to compute.

            From the outside though (as in a non photon frame) this is not true at all. Using laws of refraction you can compute, and even photograph and verify a real, defined speed for a photon in a medium.

    • @[email protected]
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      41 month ago

      That’s impressive. Having a non-photon mass traveling at the speed of light would break our understanding of physics. Get that laser pointer to the lab ASAP

    • @[email protected]
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      21 month ago

      Wait, how do you make the laser pointer travel at the speed of light? I assume it has some mass.

  • Dyskolos
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    701 month ago

    Impressive. The future is awesome! Can we maybe apply this to regular light too? Maybe even green light? Or purple? I’m so excited.

    • Karyoplasma
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      1 month ago

      When you go from green to purple, the light gets more excited too.

    • @[email protected]
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      141 month ago

      Well, for the green light we already have FTL tech, it was invented and perfected by the car behind you as you are waiting for the light to turn green.

      • skulblaka
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        11 month ago

        No, but violet is, and that’s pretty close.

  • andrew_bidlaw
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    1 month ago

    According to the Gell-Mann amnesia effect, the same people also write about politics, environment and society.

  • Julian
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    231 month ago

    Wait until they see the speaker that makes noise at the speed of sound.

  • @mindbleach
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    221 month ago

    Honestly I’d be more impressed by the Star Wars kind that go about thirty miles an hour.

    • Jolteon
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      91 month ago

      Those aren’t lasers. They’re contained plasma projectiles.

    • @[email protected]
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      1 month ago

      There was an auction that started at the price of 69420 USD on the 1st of april of 2022

      . .

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      (The lightsaber is real, selling an extremely dangerous weapon was the joke)

  • Annoyed_🦀 🏅
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    161 month ago

    Have you not seen those Blaster from the galaxy far far away that fire laser half the speed of sound?

      • Codex
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        51 month ago

        Indeed, many would argue that water can’t be wet, only things that water gets on/in.