Here’s what I understand:
1. Light is photons.
2. Photons are created when an electron moves from a higher energy orbital to a lower energy orbital (loses energy).
My question: what causes this constant source of (energy loss of electrons?) photons? When I turn on a light, light is emitted constantly. This means that electrons are continuously dropping in orbital levels emitting a constant stream of photons creating light. Let’s take the incandescent light bulb for example. I send current into a filament to heat it up due to its resistance. The filament gets so hot that it glows, producing light. Likely due to my lack of complete understanding of particle physics, I see we are introducing a continuous form of energy, and it makes sense that tons of electrons would begin moving up orbitals as they’ve become excited. What is causing this same constant drop of energy of other electrons entering the lower orbitals. My question might even be better phrased, what causes electrons to drop into lower orbitals?
In: Physics
If I understand your question right, you are asking if we have pushed the electrons to a higher energy state by heating the wire up, why do they not just stay there. If the wire is hot, how can the electrons fall back down to emit light.
Humans are big, which means from our perspective, our surroundings don’t fluctuate very much. If you are in a room with a heater running, the whole room is going to be pretty warm, and all over your body is going to be more or less the same temperature.
On a small scale, this is not the case. In the wire of the light bulb, we are looking at single atoms emitting photons. On the level of a single atom, the local energy level is constantly fluctuating, the single atom is never exactly the same temperate nanosecond to nanosecond. Energy comes in, which knocks the electrons into a higher orbit, but you then have a period of time (very brief to our perspective) where there isn’t any new energy coming in. Maybe think of it like a balloon: you push in a big breath of air which inflates the balloon, but then you have to pull your mouth away and take in another breath, and during that time the air can flow back out of the balloon. So, the tungsten atoms in the light bulb filament are receiving some energy (in the form of energy leached from the electrons passing through the wire by the resistance of the wire), and they get energized, electrons get pushed to a higher orbital. Then, on the level of an individual atom, there is a brief ‘lull’ in ambient energy; there isn’t more input in that moment to keep the electron in a higher orbital. Which allows the electron to fall back down, emitting light.
This isn’t quite accurate, but hopefully it explains the idea.
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