• themeatbridge@lemmy.world
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    9 hours ago

    There are an infinite number of numbers between 1 and 2. Infinite doesn’t mean boundless. So if you had a number line, and you place an infinite number of points on that line, you could then extend that line to be between 0 and 3. There would still be an infinite number of points, but those points would be further apart.

    Likewise the Universe is infinte in time and space. There’s always more time, more space, but also the time between points in time can grow and shrink, and the space between points in space can grow and shrink.

  • Grandwolf319@sh.itjust.works
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    22 hours ago

    Look, the universe is big, it has to constantly prove that by being both infinite, expanding, and accelerating that expansion. It used to be very small and now it’s clearly overcompensating.

    Time to reverse that insecurity with yo momma jokes about the universe.

    • dohpaz42@lemmy.world
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      22 hours ago
      1. Yo mama so fat that not even light can escape her gravitational pull.
      2. Yo mama so fat that our galaxy revolves around her.
      3. Yo mama so fat that when she last farted, they called it the Big Bang.
      4. Yo mama so fat she’s expanding faster than the speed of light.
      • Nougat@fedia.io
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        23 hours ago

        If we are considering “the universe” to mean the spacetime that we exist in, there could be an “outside,” but we just don’t know, and there’s no indication of such an outside, or anything about what it would be like.

        By way of infinite spacetime, yes, there is only a part of spacetime that we can observe, because the farthest part is moving away from us faster than the speed of light. I seem to recall there having been some estimations of how large all of spacetime is, observable and unobservable, and that it has a finite size.

        That said, there does not appear to be a limit to the size of spacetime. Based on what is currently known, spacetime is expanding, the expansion is accelerating, and there is no limit to the expansion.

        • dohpaz42@lemmy.world
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          22 hours ago

          Honest question: if “nothing is faster than the speed of light,” then how could the universe be expanding faster than the fastest thing?

          • Nougat@fedia.io
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            22 hours ago

            So all space is expanding. Locally, that’s “just a teeny tiny bit,” and the force of gravity is plenty strong enough to keep things up to about the size of galaxies (maybe galaxy clusters) gravitationally bound. Andromeda, for example, is the only galaxy that is heading towards us.

            But all of space is quite big. Over the vast distances of space, all of the “teeny tiny” local expansions add up. This means that the galaxies which are furthest away from us are also receding from us most quickly. This is not because those galaxies are moving through space; it’s because of all the expanding space in between them and us.

            The speed of light (in a vacuum) is the fastest anything can move through space.

            • dohpaz42@lemmy.world
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              21 hours ago

              Would a fair, albeit crude, analogy be like when I fart and the gas forces my butt cheeks apart (the expansion between two objects)? (_|_)💨

              • Nougat@fedia.io
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                21 hours ago

                Crude, yes. Fair, no.

                Consider a balloon. Uninflated, make a mark on opposite sides, and then make a third mark right next to one of those. When you inflate that balloon, the two points on opposite sides of it become farther apart because of the stretching of the whole balloon, but the two marks right next to each other don’t become nearly as far apart, because they are only experiencing “local” expansion.

                • dohpaz42@lemmy.world
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                  21 hours ago

                  I wanted to make a fart joke.

                  But I like your balloon explanation. That makes sense to me.

          • Vespair@lemm.ee
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            17 hours ago

            It took my awhile to get it until somebody put it this way. The objects aren’t exactly “moving” apart from each other, rather space in between them is expanding. So instead of thinking of it like a bunch of objects in a line being pulled away from each other, instead imagine it like a bunch of vector based objects random placed on an infinite canvas - now rather than moving the objects at all, try to imagine instead reducing the scale of all of the objects equally. Now of course this isn’t perfect, as really what is happening is kind of the opposite, as the objects remain the same but the space between increases, but the relationship is the same here. So nothing is exactly “moving” in relative space, but everything is still expanding. Thus this expansion can happen infinitely without anything breaking the speed of light.

          • Backlog3231@reddthat.com
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            19 hours ago

            ELI5: If I’m moving away from you at 50 KPH and you’re moving away from me in the opposite direction at 50 KPH then after 1 hour we will be 100 kilometers away from each other even though the speed limit is 75 and neither of us broke it.

            That’s an extreme reduction but gets the general idea across.

          • nothing@lemm.ee
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            22 hours ago

            Wait until you hear about relativity.

            And also we don’t know that C is the limit entirely, but it is so far. Also, we don’t know if there are more dimensions in our reality or not because we cannot observe them. And no, I don’t have much of a better answer.

            Basically, we still know we don’t know a lot, and we probably don’t know a ton of what we don’t know that we don’t know. Also magic.

            • Backlog3231@reddthat.com
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              18 hours ago

              That isnt how it works. The speed of light is the speed of causality; it doesn’t have anything to do with light. Its just the fastest speed at which things can happen. Light, being massless, happens to travel at that speed.

              In your scenario, the light beam would just be stretched along its length and the 2D interface on the surface of the moon would just “lag behind” from your POV. But it would lag at the speed of light.

      • Lost_My_Mind@lemmy.world
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        23 hours ago

        One day…we’re going to observe the non-observable universe, and discover that it’s exactly like this universe, except it"s last week. And then we’ll do it again in a different direction, and it’ll be next week. And we’ll do it again, and again, and again, and again, and eventually figure out that everything we do, ever have done, or ever will do, only applies to THIS observable universe. And that we’re one of an uncountable number of universes. Each a slightly different time than ours.

        And no, it’s not time travel. If you go to another universe, and kill Tom, then come back here, Tom is still alive. If you go back to that universe, Tom is still dead and you get arrested.

    • oce 🐆@jlai.lu
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      22 hours ago

      Itself. The distance between objects at inter-galactic scale is expending regardless of their relative movements.
      P.S.: and the speed of expension is proportional to the distance between the objects.

    • SzethFriendOfNimi@lemmy.world
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      22 hours ago

      A great channel for topics like this.

      This video goes into the expansion of spacetime as well as cover how internally those forces don’t affect local spacetime because of the mass/spacetime curvature.

      Space DOES NOT Expand Everywhere

      Although I have to agree with the top comment regarding this being my favorite channel I don’t understand. But the more I watch it the more I start to get a sense of a lot of it and I actually am understanding some of it

      And yeah, we don’t know what, if there’s anything, it’s expanding into.

      https://youtu.be/bUHZ2k9DYHY?t=537

    • disguy_ovahea@lemmy.world
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      22 hours ago

      Nothing. It’s the same nothing that existed where we are right now, right at the moment the Big Bang occurred. It’s so nothing, that astrophysicists theorize that time doesn’t even exist there yet.

      • Nougat@fedia.io
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        22 hours ago

        Time is a property of spacetime, its own dimension. We have no reason to believe that time can exist without being part of spacetime.

        • disguy_ovahea@lemmy.world
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          10 hours ago

          Of course. I was simplifying and attempting to illustrate the difference between the vacuum of space and absolute nothingness.

  • GoofSchmoofer@lemmy.world
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    21 hours ago

    The one that gets me is that if the Universe is infinite but how matter can organize itself is finite (albeit a very large number) then there is another galaxy just like ours, another Earth just like ours, and there is another GoofSchmoofer writing this exact some thing in the exact same way somewhere out there.

    And if this is true then how many GoofSchmoofer’s are there in this infinite Universe?