1: I think its better to say that the population explosion and climate change are both a result of the industrial revolution.

2: No. Populations dont have some innate ideal size that nature regulates for. But of course no population can grow forever, it will always be limited by some resource eventually. But there is nothing that ensures a population will collapse after reaching a limit, although it does happen sometimes.

By adding salt to the water you are increasing the number of dissolved particles in the water (this is quantitated as the molality of the solution). This decreases the freezing point of water and therefore the temperature of the ice/water mixture because it will always equilibrate at the freezing point of water as long as there is both ice and water present in the mixture. This is known as "freezing point depression".

Expanding is "a thing space can do" according to general relativity, but there is no corresponding theoretical explanation for how or why objects would shrink. It's also not clear how objects shrinking would reproduce observations like Hubble's law - why would objects further from us be shrinking faster?

What would happen if you slowly removed matter from a neutron star?

Is there a point where a sudden (explosive?) transition to non neutron degenerate matter occurs? Or is the transition more gradual with more and more of the neutron star becoming normal matter?

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It does. Any finitely-sized region of the universe today shrinks toward zero volume as you approach the Big Bang, but the universe as a whole can still be large, even infinitely so, at the moment of the Big Bang.

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Answer:

Salt acts as an antifreeze, which lowers the freezing temperature of water below 32F / 0C.

This allows the water to get colder.

It works because the salt ions interfere with the hydrogen bonding in water, preventing it from crystallizing into Ice.

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Sound travels in all directions. High pressure waves expand in all directions. But in string instruments you hear mostly the vibrating instrument that holds the string, which is why it's not the string that costs a million dollars, but the wood that holds it.

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Why are we seriously considering encampments on Mars, and floating balloon colonies around Venus, but not looking seriously at colonizing moons of the gas giants?

Could a Dyson structure wrapped around a black hole get energy from harnessing hawking radiation, and how would it compare to capturing the energy output from a sun?

Ice in equilibrium with (pure) water will stay at 0 degrees C. No higher and no lower. If you add salt to the water, the equilibrium temperature will decrease. So a brine ice mixture can be lowered below 0 degrees C. This lower temperature system would "stay cool longer" because it is colder.

>It's as if they're saying that by adding salt, they've removed even more energy (heat) from the mass

Melting is an endothermic process. This process will "remove" heat via bond breaking in the ice. So by adding salt to the water and lowering the equilibrium temperature, the system will respond by melting some of the ice. This consumes energy and lowers the temperature until equilibrium temperature is reached.

EDIT: To clarify a misconception, an observed decrease in temperature does not equate to the "removal of energy from the system" (when simply adding salt). A decrease in temperature can occur when there is a transfer of kinetic energy to potential (when ice melts endothermically). Regardless, in the water-ice system the temperature is not actually proportional to kinetic energy. That is only the case in an ideal gas.

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We say that the universe is expanding at an accelerating rate. I understand why we say that. But is there any specific reason we think that space is the thing that's expanding INSTEAD of just everything the universe shrinking? Or are they just the same idea with a different frame of reference?

> Now, this is only accurate a few hundred years either side, due to the nature of carbon dating.

This would be a pretty terrible radiocarbon date, most have uncertainty in the range a few decades at most (e.g., Scott et al., 2007).

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That's not possible theoretically either. The geometry of black holes makes it that the speed needed to escape is basically ∞. All pathways simply lead inside. There is no “theoretically.”

No. The geometry of black holes is curved that every direction leads to the singularity. Unless that speed was ∞, no.

That's not anti matter. It's dark matter. And if it was anti matter then we wouldn't exist at all. And yes we don't know what it is.