If you need super heavy-duty cooling, then phase change systems for water can transfer literally gigawatts of heat power because of how much energy it takes to turn water into steam.

This is effectively what most steam turbine based power plants do after all. A few kg/s through a pipe of steam is many megawatts of enthalpy. If you look at h_fg on a steam table, you can see it's like more than 2 megajoules per kg or so.

For more familiar numbers divide everything by a thousand. Just half a gram of steam per second is over a kilowatt.

To explain this just a bit further for people who have never taken thermodynamics.

You can't take heat and turn it into useful work. You always need to raise entropy in any spontaneous process (second law of thermodynamics).

Cutting out the motivations, basically taking a (infinitely small) amount of heat energy out of a system reduces it's entropy by Q/T where Q is heat in joules and T is absolute temperature in kelvin. Adding that much heat energy also adds that much entropy.

If you have a hot and a cold reservoir with temperatures T_h and T_c then and you are taking heat Q_h out of T_h and putting heat Q_c into T_c then because the entropy change must be positive you get that Q_c/T_c > Q_h/T_h.

By energy conservation the work you get out of this process is W = Q_h - Q_c. If you do some basic algebra you can figure out that W/Q_h < (T_h - T_c) / T_h

The cool thing is the algebraic derivations for this efficiency are very easy although the verbal explaining for why entropy works like this is much more complex.

Putting numbers to this:

If we approximate earth as a conductive sphere with a particular radius in a vaccuum. It's capacitance to infinity is equal to  C = 4πϵ_0R.

Plugging in the radius of the earth into that you get a capacitence of Q=710 uF.

By definition of capacitence Q=CV. V=Q/C gives you the voltage.

Now for a mass (m) to gravitationationally escape earth then you need E=GMm/R energy where M is earth's mass and R is earth's radius.

Now if you set that energy to E>V*q where q is the charge of that charged mass it is energetic favourable for that mass to escape earth.

Put together you get the final big equation out:

Q = GM4πϵ_0*(m/q). This is how much charge you need on the surface of earth to start to fling stuff off earth.

If you want to fling out electrons then it turns out you need a net negative charge of 252 nano culombs.

To fling out a hydrogen ion / a proton you would need 463 uC. To fling out an alpha particle would take 920 uC.

It's not a ton really. Considering how big the earth is.

Just be careful with specific technical definitions of things.

A capacitance of 710 uF just means that if you charge up the earth's surface with 710 uC of charge then dragging an electron from infinity onto earth will impart 1 eV of energy to it. (One volt of potential from infinity)

That's not what you are doing when you are analyzing some circuit grounded to earth. If you throw a bucket of salt water onto some transformer or something and short some high voltage line to ground then you are actually just redistributing electrons and ions around within the earth's surface and in the atmosphere. You can do this "infinitely" because those electrons eventually will go back to / come back from wherever this high voltage is originating from.

However as a caveat there genuinely is a lot of voltage created from all these charge imbalances and therefore the capacitences of these systems is indeed quite small just like theoretical equations predict. Like the atmosphere has something like a few hundred volts per meter potential if you are going straight up and as I understand this huge potential is created by a relatively small numner of imbalanced ions in the atmosphere. Also if you actually fault a grounding connection in practice then you do get a large potentially dangerous amount of voltage on the soil.

Maybe this is wrong, but as I understand it the more correct model would be having a resistor connected to a small capacitor which is the earth, but this small capacitor has a discharge resistor that eventually drains all the voltage away as the charges return to the source.

If you have a low pressure gas where molecules are isolated from each other then the simple answer is that photons of the incorrect frequencies simply can't be absorbed very well. You can see this by shining broad spectrum light like from the sun or a tungsten lamp through the gas and seeing that fairly distinct narrow bands of frequencies will be missing corresponding exactly to the emmission spectrum of the same element. You can visually see this by splitting the resulting light through a prisim.

It is called the absorption spectra of elements. This is a well known and well studied phenomenon, it's taught to high school chemistry students often including a practical experiment. It has a lot of applications in analysis and astronomy.

http://www.dynamicscience.com.au/tester/solutions1/space%20science/absorptionspectroscopy.htm

The reason it can't like just go into the kinetic energy of the atom is that you need to conserve momentum amoung other things and if other molecules aren't around to take part in the interaction this just isn't possible.

When you have a more dense material you can get more much more interesting pathways however. A relatively simple one is that the excess energy goes into producing a phonon which is a quantum vibrational mode of a lattice, basically just heat.

However there are some really strange things that can happen with dense materials though. For example you can get crystals that take a photon and split it into two.

I think its better to think of the colony as a single reproductive evolutionary unit, not as a collection of individuals. Ant colonies produce a large number of new queen's and drones for nuptial flights. Unless they are very lucky to find a good unoccupied spot most of the next generation perish.

In that sense ants don't put too much investment into reproduction.