This page is the evolutionary result of a bunch of questions I have about light and heat.  Answers (after I've located them) are in [square brackets].  Questions without answers are bold.

• If I seal a light source inside an opaque box (in the real world, not some uber, EM-proof box), qualitatively how much of the energy originally produced by the light will be converted to "heat" inside the box?  AKA: if you close the curtains, does a 60W light bulb heat up a room about as well as a 60W radiating heater?  A 60W ceramic heater with a fan?
• Why does infrared radiation "feel" warm, when light radiation (which has more energy!) does not feel warm? [more generally: infrared and wavelengths produce molecular motion.  infrared causes molecular bonds to move, and microwaves cause molecules to spin or move.  But humans are mostly transparent to microwaves and radio waves, so out of the lower wavelengths, infrared is the main cause of our molecules gaining kinetic energy.  Light and UV radiation is mainly associated with electron level jumps, so if an electron jumps up and then back down the same gap again, we produce a photon, and again, no kinetic energy is added.  I guess that's just describing light reflecting off our bodies.  To the extent that we aren't pitch black holes in space, we reflect a lot of light.  I guess we'd experience light as heat if: 1. the light excited an electron; 2. the electron jumped back down in two stages, emitting at least one infrared photon; 3. that photon then hit another molecule and excited molecular bonds.  Finally, we become transparent to higher frequency radiation like X-rays again.  And when X-rays interact with our atoms, electrons are ionized.  Compton scattering produces another longer wavelength X-ray, which (because we're mainly transparent) again doesn't cause much heat.  Plus you'd have other problems (like being dead) if too many X-rays interacted with your atoms.]
• Why does blackbody radiation have a continuous spectrum?  I thought electron decay was discrete -- is it something other than electron decay causing the spectrum?  [Blackbody radiation is particular to solids (or "condensed matter" in general?).  It's still caused by electron decay, but electron energy levels in a large molecule (10^20 atoms?) is not actually discrete like atomic orbitals are in a single atom, or molecular orbitals are in a small molecule.  Instead, electrons can occupy any energy level in a set of ranges called "bands"]
• Related: In the example of a hollow container with a small aperture, I don't understand why just by em radiation bouncing around inside, the spectrum becomes continuous no matter what the material is. [It's due to the band structure -- electron energy levels are continuous in a large enough solid]
• Does that mean that the sun, and stars in general are condensed matter (not gasses?)  Probably the electron band model doesn't apply to something as extreme as the Sun?
• Is an incandescent bulb a blackbody radiator? [yes in the ideal case since the filament has close to the necessary number of atoms in it to have continous bands]
• Do LEDs and fluorescent bulbs (even the new "warm" ones) produce only discrete electron shell spectra?  [Yes for LEDs, although there are various "broadening" phenomena that cause the peaks in the spectrum to spread out a bit.  White LEDs use a (solid) phosphorescent coating, so the electron band effect causes their spectrum to be more continuous.
• Are there physical processes other than electron decay which produce light? [Bremsstrahlung and Cherenkov radiation seem fundamentally different.  Bremsstrahlung can happen if a single electron not under the influence of a nucleus is flying along and hits something.  I don't begin to understand Cherenkov radiation]
• (random semi-related question: how exactly do diodes work?  semiconductor transistors make sense to me, but diodes don't) [that turned out to be simple.  It works the same as a transistor, but the semiconductors are touching each other so that the area of variable resistance is in series (and physically between) the two semiconductors.  When the current is in the right direction, it pushes the electrons (and holes) closer to the middle of the diode, and the electrons are allowed to jump the gap one after each other (replaced by the incoming wire).  When the current is in the wrong direction, it pulls the electrons away from the middle of the diode, turning the vacated space into an insulator.
• Is phosphorescence somehow fundamentally different from other ways of producing light?  [yes and no -- it still involves electron level decay, but there's some kind of cool quantum exclusion involved which prevents the electron from decaying until it's excited even further, which is why phosphorescent materials take a while to release all their energy]
• (another random note: I only just now realized that "solid state", like in "solid state physics" or "solid state electronics" simply means "the physics of solids".  Solid state matter is associated with continuous spectra, and gasseous state matter is associated with discrete.)

Wikipedia's http://en.wikipedia.org/wiki/List_of_light_sources and http://en.wikipedia.org/wiki/Luminescence were useful.

There's some kind of ontology of light-producing mechanisms.  This is what I understand so far:

• Light
• Transmission (no effect)
• Absorbtion (EM wave -> heat)
• Reflection (EM wave -> EM wave)
• Specular: follows the law of reflection
• Scattering (Diffuse Reflection): does not follow said law
• Elastic: reflected radiation loses no energy
• Rayleigh scattering
• Inelastic: reflected radiation loses energy.  Due to Kirchhoff's law, that lost energy must heat the object or be lost through emission
• Refraction: radiation changes speed
• Emission (Energy -> EM wave)
• Stimulated Emission (laser): electron decay caused prematurely by incoming photon
• Luminescence: energy emitted via electron decay(?) at a different wavelength than absorbed
• by electron decay time
• Fluorescence: energy emitted with little delay (electron decay)
• Scintillation: a particular type of fluorescence?
• Phosphorescence: energy emiited after some delay (also electron decay, but the initial excitation needs to be followed by a second temperature-induced excitation before it can drop back to the low energy state)
• by original energy source
• Radioluminescence
• Chemoluminescence
• Bioluminscence
• Electroluminescence: LEDs, 
• etc.
• Incandescence: (Energy -> Heat -> EM wave)
• Blackbody Radiation: idealized incandescence when a substance absorbs all radiation.  Other types of incandescence seem to be defined by how they differ from blackbody radiation
• Other (?)
• Bremsstrahlung: produced when charged particles accelerate, like when electrons hit something and stop
• Cherenkov: produced when a charged particle is moving faster than light in a medium