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What happens to photons from flashlight?
When you turn on a flashlight, you are creating a source of photons (see How Light Works for details on photons). The photons leave the flashlight and they immediately start to spread out in a cone-shaped beam. Provided that they don’t hit anything, each individual photon travels through space forever.
Do astronauts use flashlights?
Yes, and flashlights work quite well in vacuum and space. There’s no air to absorb their light. Flashlights are common on US space suits, as shown in the picture below. Lights are also mounted on spacecraft, like the navigation lights of the SpaceX Dragon Capsule.
How many photons can occupy the same space?
They’re bosons, and as a consequence of that they are not subject to the Pauli exclusion principle, so if you have a photon occupying some space (whatever that may mean), you can in theory pack an unlimited number of additional photons into the same space.
Can photons push things?
– Physics Stack Exchange Photons have no mass but they can push things, as evidenced by laser propulsion. Can photons push the source which is emitting them? If yes, will a more intense flashlight accelerate me more?
Why is the force of light conserved in a flashlight?
The force is proportional to the flashlight power, but the frequency $\ u$ cancels out so the frequency of the light doesn’t matter. Momentum is conserved because it’s the momentum carried by the photons that creates the force.
What makes a photon visible or invisible?
When electrons, such as the electrons of a tungsten filament, make a downward leap that translates to a frequency lying within this spectrum, the photons produced are visible. Leaps to a space outside this range, whether larger or smaller, will produce photons that are invisible.
What happens to photons when they hit you in space?
If you are floating in space the photons that hit you are also exerting a force. When you float in space a large number of photons emitted by the sun will hit you. These photons exert a force, this mechanism is referred to as radiation pressure. This force is significant enough that you can actually control a spacecraft with it.