That’s the case for the galaxies furthest away from us. Closer galaxies are receding less quickly and Andromeda is actually coming towards us.

Indeed, and will merge with ours to become..the Milkdromeda (TBD) galaxy. Looking forward to the fireworks.

https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_co...

Humans (assuming we are still around) will have to watch from another planet: the collision will happen in ~4.5 billion years [1], and Earth will be uninhabitable long before then [2].

[1] https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_co...

[2] https://en.wikipedia.org/wiki/Timeline_of_the_far_future#Fut...

That second link I'd read through before, but oh my, you're right there's a number of critical events ahead: an ice age around 50k years from now; in ~300mil years (oh cool never noticed this before), "All the continents on Earth may fuse into a supercontinent"..resulting in another glacial age; in 700 mil years, "The death of most plant life"..

Also realized, there won't be much "fireworks", since apparently the stars are far enough apart that the merging of two galaxies won't cause much collision.

Still fun to imagine things on that scale, especially in light of some of NASA's beautiful photos of colliding galaxies (like https://www.nasa.gov/image-feature/goddard/2019/hubble-s-daz...).

If we can figure out how to solve our political issues and become a eusocial species, we may be able to build some generational starships. In 4.5 billion years we could potentially colonize many of the planets in the habitable zone of stars in the Milky Way.

Sure, it could take millions of years to cross the galaxy, but we could grow exponentially (like lily pads crossing a pond), at least until other limiting factors kick in.

Plus it’ll take quite a while to complete.

Why would some things be bound by the speed of light and not others? I always thought of this limitation as an all-or-nothing law.

Think like it is a shadow or a light trace.

If you point a laser pointer device to moon from earth (assuming it's a really strong laser), rotating it for a few degrees on earth will result a light mark kms long on moon. The build up time for the mark will even exceed the speed of light if your hand is fast enough. This doesn't mean you broke the law. It just means multiple objects (in this case, each photon hitting the moon) created the illusion of a single object, moving really fast. Background light trying to reach us from the edge of the universe mimics a similar behavior with the added extra spacial dimension. Locations in space aren't objects. They are some points objects can leave marks on. Tracking their speed can always create faster than light situations if you pick a bunch of them conveniently.

Everything that moves through space is bound by the speed of light. But space itself is expanding at a rate such that two distant points can move away from each other faster than the speed of light. Think of it like two ants on opposite sides of a balloon, one ant starts moving toward the other as fast as it can go, but then you start to inflate the balloon. The distance between the two ants expands faster than an ant can move and they'll never meet.

Thanks for this clarification.

So, we can calculate speed of Earth relatively to our segment of space, right? Can you do the calculation and tell us speed of Ether Wind, please?

It is. Nothing can move through space faster than the speed of light. That's not what's happening with the expansion of the universe. Space itself is expanding.

Silly ananlogy that absolutely should not be taken too far: imagine somehow shimming an extra micron into every metre here on Earth every second. Or an extra nanometre into every millimetre. Locally, nothing much changes at a scale you can observe, but Los Angeles is moving away from New York City at about 4m/s. And getting faster because we're still shimming extra length into "old metres"; the metre itself hasn't changed, but now there are more of them. If there were something a thousand times farther away from New York than LA, it would be moving at 4km/s and accelerating. A million times farther and it's 4000km/s. A hundred million times farther, and you're at 400,000km/s - but light can't go that fast, so you can't see it as the light can never reach you. Nothing is "moving" (other than the light in this case), but the distances between things is getting bigger nonetheless.

Posted this to a point above, but probably more pertinent here, so reposting - Some of the confusion is, I think from referring to speed of light as "speed of light". When it really is speed limit of causality between 2 points in space. And light (em waves) just happen to be able to hit that limit. Now since expansion of space is itself not going to allow one point in space to cause any effect on another, it (the expansion) can be faster than speed of causality. PBS space time has a good video on this - https://www.youtube.com/watch?v=msVuCEs8Ydo

Roughly, anything that can be used as an information carrier is limited by the speed of light (a good rule of thumb is that such things have some mass or energy). Things that can not be exploited on their own for information transfer do not need to obey that limit (stretching of space, entangling of particles, maybe other things).

PS It is an open question how that does not lead to contradictions when you start considering energy density of the vacuum or the extremely small gravitational waves (which can in principle transmit information) created by the changes in the latter systems. But these effects are astronomically small and it is difficult to imagine even a thought experiment that can detect them.

Everything that moves is bound by the speed of light.

But when you create space between 2 points they can appear to move faster than the speed of light, despite not actually moving - it's just that there's new space created between them, so the distance between them grows faster than the speed of light.

Things can't move faster than light through space. The space itself has no such limitation. You can imagine an expanding balloon and ants walking on it that have a limit to how fast they can move relative to the surface of the balloon.

Then space itself is a thing, not a nothing, thus Theory of Relativity is wrong, because we can attach point to space itself. Chose your poison.

Not an expert but the speed of light limitation seems to be derived from special relativity considerations the constancy of that speed and the use of light to carry information about events. So a train cannot accelerate to beyond c because of this. But not every phenomenon is limited by this.

As an example if you shine a torch at a really far away rock the dot can move faster than c transversally when you wiggle the torch. But the actual light is going at c to the rock and back to you.