wat

Comments

• EggInDisguise@lemmy.blahaj.zone ⁨1⁩ ⁨hour⁩ ago

  Take a balloon.

  Blow it upto about 50mm

  Make a couple dots around it

  Blow it up a little more.

  Now there’s distance between the dots.

  Imagine an ant walking between the dots. That ant is going at the speed of light (as fast as it can go) relative to the dots.

  Now as it walks between the dots, blow the balloon up really big

  The dots aren’t moving, they’re stuck to the surface of the balloon. The balloon itself is expanding. The ant is going at the speed of ant-light, but now the dots are all “moving away” faster than the ant can walk.

  The speed of the ant hasn’t changed, the space the ant is traveling has changed. And faster than the ant can move, because the balloon isn’t limited by the same things the ant is.

  source

  • yermaw@sh.itjust.works ⁨7⁩ ⁨minutes⁩ ago

    Thanks for that that’s actually a really helpful analogy.

    I mean i still dont understand. Brain hurty. But thanks anyway

    source
• Chrobin@discuss.tchncs.de ⁨1⁩ ⁨hour⁩ ago

  Well, nothing (with nonnegative mass) can move faster than light through space. Space itself can do whatever it wants to.

  source

  • booscience@beehaw.org ⁨1⁩ ⁨hour⁩ ago

    Well, the thing space is moving into and across

    source
• baguettefish@discuss.tchncs.de ⁨36⁩ ⁨minutes⁩ ago

  my personal headcanon is that the universe is a giant living being and we are its fundamental particles or some other infeasibly tiny thing

  source
• IAmNorRealTakeYourMeds@lemmy.world ⁨35⁩ ⁨minutes⁩ ago

  Fuck it, question that I had since 10 years old.

  if I have a very long stick, and I flick it. what would happen to the tip? what if a laser pointer is used? at a certain distance, the beam would be moving (sideways) faster than light.

  it might work better with a whip rather than a solid stick.

  source

  • skisnow@lemmy.ca ⁨33⁩ ⁨minutes⁩ ago

    The end of the stick would respond at the speed of sound travelling through the medium of a stick.

    source
  • midribbon_action@lemmy.blahaj.zone ⁨23⁩ ⁨minutes⁩ ago

    First question: two reasons that wouldn’t work: the stick would just break, obviously, but if it was a super duper stick, the torque required to accelerate the end past the speed of light is directly related to how long the stick is, so any increase in speed from a longer stick will be offset by the need to apply more force at your end. Therefore the energy required to flick a stick to the speed of light does not depend on the length of the stick, you are simply creating a reverse lever of sorts. It’s still an infinite energy requirement, assuming the stick has mass.

    The second question is a lot easier. The light is traveling directly away from you at all times, there is no sideways motion.

    source

    • sneezycat@sopuli.xyz ⁨18⁩ ⁨minutes⁩ ago

      It’s actually simpler: the stick will deform because whatever movement you do travels at the speed of sound of the material the stick is made out of.

      source

      • -> View More Comments
• DmMacniel@feddit.org ⁨1⁩ ⁨hour⁩ ago

  Well duh. When a thing moves away from another thing, that is moving at the speed of light, at the speed of light, you have speed of light time two!

  source

  • TheTechnician27@lemmy.world ⁨1⁩ ⁨hour⁩ ago

    This explanation is the wrong intuition for why space can expand FtL. It’s an understandable one to infer, but the balloon one further down is correct and the one most commonly used by cosmologists for a lay audience.

    Our current understanding of cosmological expansion works by Hubble’s law, and that equation puts no such 2x cap on the recession speed.

    source
• BurgerBaron@quokk.au ⁨1⁩ ⁨hour⁩ ago

  That’s so no matter how much knowledge we gain we can never escape the bad place to kill the Demiurge.

  source
• Blue_Morpho@lemmy.world ⁨1⁩ ⁨hour⁩ ago

  A shadow can move faster than light too.

  source
• funkless_eck@sh.itjust.works ⁨1⁩ ⁨hour⁩ ago

  you running vs a train vs you running on a train vs measuring two people running away from each other on two trains travelling in opposite directions

  source