So, the earth is falling around the sun, the the sun/solar system is falling (around?) within the Milky Way, is the entire Milky Way falling? Is everything in space continuously falling at relative velocities to each other? If everything is falling does the expansion of space mean there’s always room for everything to continuously fall? Or if space is 4 dimensional and finite does everything just fall and curve in a way we can’t perceive?

I’ve got a lot fundamentally wrong in my thinking, I have no doubt.

Astronomers/planetary scientists. Could you please explain why the earliest sunrise, and latest sunset, are not synced up? Similarly for latest sunrise and earliest sunset. The shortest day (typically December 22nd) is the average in between these two peaks. I have looked it up before, and it had something to do with the precession of the earth, but I still don't fully understand. I would love to be able to picture what happens in a model with the sun and the earth.

Will the Alcubierre drive ever be possible?

Would this be a good way to dispose of spent nuclear fuel?

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There are a bunch of factors. One of those though would be the ocean, which does take longer to change temperature.

If the star is massive enough, wait, or add more material to increase its fusion rate so you have to wait less.

If the star is not massive enough, add more material and then see above. For most stars that means you'll have to multiply their mass by a factor 10-100 or so. At this point, do you still make the original star have a supernova? Or do you just throw the original star into a larger star which ends up in a supernova soon?

This does actually make the water actually colder though, it decreases in temperature to that new phase change temperature melting some of the ice in the process.

The salt makes the water colder than 32F/0C. Once it’s a slurry, it increases temp by heat transferring to it. Without open air pockets, there’s much less surface area to recieve heat transfer. Water becomes denser and won’t accept heat transfer as easily.

What is the current best guess about the composition of the moon's core and the age of those materials (if from an impact)?

Is there a list of theorized dates for effects that helped to seed earth with rare materials (heavy elements) after its initial formation?

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Coolers keep things cool longer. I can see the salty ice water absorbing heat from the fish faster (thus slightly warming the salty ice water faster than non-salty ice water, but it doesn’t make sense that the contents of the cooler would take less time to reach room temperature. If you start off with a cooler at -15 degrees, it will take longer to reach room temperature than a cooler at 0 degrees; If not, then you don’t have a insulated chest, you have a bucket of ice.

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Making stars go supernova is a popular theme in science fiction. According to our current understanding of physics what would be the easiest (least completely impractical) way to artificially induce a supernova.

Both these possibilities are well explored in the Expanse series of books (and TV shows).

If a ship is always under thrust, people inside will experience the equivalent of gravity. Humans need gravity (as evidenced by issues of returning astronauts).

If you had a VERY efficient fuel source, you could remain under thrust throughout your journey except at the mid point where the ship must flip (i.e. accelerate at 1.0 g for half the trip and then decelerate for the second half and so have almost constant gravity). This uses a LOT of fuel though so is not practical with any known propulsion system.

As long as you are creating a bespoke planet, make it the right size and the right distance from the right sized sun with the right gas mix and it is possible that a breathable atmosphere at a livable temperature will exist at an elevation so that the gas pressure is one atmosphere.

You can float at this pressure so yes it is possible.

You would have to deal with wind though but it may be possible with the correct gas mix, spin, solar distance etc that wind could be minimized. Gas giants (well at least the ones we know about) tend to be pretty stormy.

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There is a process to create jet fuel using the energy from a nuclear reactor and sea water (basically driving the burning reaction backwards) that has been developed for use by aircraft carriers. http://large.stanford.edu/courses/2012/ph240/klopfer1/

In simple terms "oil" is just a mix of hydrocarbons, all of which are easily synthesized in a lab but the energy required must come from somewhere.

The "rate of change" is proportional to the difference in the temperature between the glasses of water and their environment (Newton's Law of Cooling).

This means that the colder glass is changing temperature faster (it's rate of change is larger because its difference is larger).

Think of it like two balls rolling down a hill, where one ball is starting further back but is also steeper.

The ball on the steeper hill will be going faster... but that is no guarantee it will get to the end of the hill faster, because it started further back.

Depending on the exact setup, you could either have the ball on the steeper hill gain enough extra speed to make up for the extra distance it has to travel and win the race. Or it could also lose the race because it started too fast back for the extra speed to be enough.

tl;dr the ice water will be "cooling" faster (the temperature change will be more rapid"). But will it "finish" cooling to room temperature faster? Maybe... need more math.

I am pretty sure the gravity of the expanded star overcomes the outward pressure caused by the fusion reaction and thus it collapses into a dwarf star that is heavily compressed. So no, it won't stabilise, but during and after its expansion, there would be new Goldilocks zones.

Can't speak to what you're talking about, but there are definitely well preserved examples of other organisms such as those from the Cambrian explosion in the Burgess Shales, or the fishes and archaeopteryx found in limestone. Crinoids, afaik, still exist and have existed for a long time. It is likely the ones you've seen are relatively young and we're preserved through other methods. 3D fossils typically form due to replacement of the original minerals by dissolution and then infilling by precipitation of dissolved minerals in water, or by sulphur-respiring bacteria that form pyrite in place of the original mineral.

It's been a while since I learned all of this so anyone who is up-to-date, feel free to correct me.