Well, it's infinite. Always been. So it's just expanding. Not "into" anything.

It might help to think of it as "the universe is thinning out".

The thing is, the universe was in a state of expansion from day one. Pretty violent expansion. You could call it an explosion. Or a "big bang". It's been expanding / exploding ever since.

If you get sick, you just go to the doctor.

At no point you worry whether you can afford it.

The doctor looks at you and makes a list of what they think you need. At no point they ask you what you can afford. You just get what you need. It might be going through a multi-million dollar machine, operated by a very well paid specialist. No matter. You get sick, you get the machine. The CEO of some bank gets the same sickness, they gets the exact same prescription.

Depending on the details of the implementation, when it's all over, you're free to go, there's nothing to pay. In some implementations, there's a bill. But, you usually have enough change on you to pay it. It's very cheap, and doesn't actually cover the costs at all. Some implementation require people to pay a symbolic amount to avoid stuff like lonely people pretending to be sick just to have someone to talk to.

So, who pays? Taxes. It's not cheap either. Billions upon billions. But that's a choice societies make, and pretty much all societies that have the cash make the Universal Healthcare choice. I know of only one exception.

Muricka.

Hey thanks. I been wondering what the individual shots looked like. Where the sword from? Stock?

Not really. Ukraine has lost a lot of its power generation, and that alone is enough to account for all the tank diesel and jet fuel and explosions.

Russians were already impossibly wasteful before. Their energy is even cheaper now, but they can't possibly waste more.

War has always helped reduce pollution. Hell, just the act of killing humans reduces CO2.

That's a meteor. I saw one exactly like that in Reunion (what a coincidence) a few years ago.

Comets don't disappear.

When something vibrates, in air or in vacuum, the flexing of the molecular structure itself robs energy away from the movement and turns it into internal heat. So anything that vibrates will eventually come to a rest (ang get slightly warmer) even in a vacuum.

In air, the vibration is slowed down slightly faster with energy from the movement being robbed by air molecules and it becomes sound waves.

So, unsurprisingly, vibrating stuff will lose its energy faster in air than in vacuum.

To answer your question, the energy that would have gone into the sound remains in the vibrating material and goes to keeping it vibrating a little longer.

When something noisy is coming towards you, the noise gets louder and louder, until the thing passes nearest you (it's loudest then) and then it gets less and less loud

Now, if that thing is going faster than sound, you won't hear it coming. The thing travels faster than its own noise. There is no noise build-up as it approaches. Then it passes you, and the noise level goes from 0 to loudest all at once. One second later, the thing is hundreds of meters away and way less noisy. So it should like a thunderclap. The sonic boom.

Deep space just means you're not in orbit. Could be somewhere in the solar system, between solar systems or between galaxies.

If you're still in the solar system, then the sun is shining right at you. If you're in a space suit, doing some maintenance on your ship, you most probably oriented your ship so that you work in the sun. So you can see what you're doing. Your ship will be lit up as bright as day. Assuming you're at a distance equivalent to the Earth.

If you're much further, it will still feel like working at night but with a bright projector lighting up your work area.

If you're much closer, it might be too bright, you might actually orient the ship so you work in the shade. Then you won't be able to see squat without a flashlight. It'll be just as dark as if you were ligthyears away from a start system.

If you're between solar systems, it's as dark as a moonless night. You're still bathed in the light from the stars. Which is usually not enough light to do work outdoors. And whatever solar panels you brought are now just weighing you down. Jetison. If you're quite far from Earth, more towards the center of the galaxy, there'll be way more stars in the sky. But it'll still be too dark to read.

If you're out of the galaxy, then it's pitch black. I mean properly out, right. Of course if you have just left a galaxy, you'll still be able to see it if you turn around. I mean properly halfway between two averagely spaced galactic clusters. Proper intergalactic space.

Without a flashlight, you wont be able to see your hand waving in front of your face. There are galaxies full of stars all around you, but they are all billions of lightyears away, and your eyes aren't good enough to pick them up. I mean, Andromeda is a huge galaxy that is incredibly close to the Milky Way, and it appears at a diffuse cloud. Back in the days we didn't know about galaxies, we used to call it the andromeda "nebula" which is just latin or greek for "cloud". Pitch-ass black. nothing to see.