In a torch, electrons in the battery are energized by chemical means and then run to the filament in the bulb or to an LED where they decide to make photons and shoot them out to get rid of the chemical energy they picked up in the battery.

1. You can turn on the flashlight on most Androids by pulling down the Quick Settings menu from the top of the screen and tapping the flashlight button.
2. You can also turn on the flashlight with a voice command to Google Assistant.
3. Some Android phones also let you turn on the flashlight with a gesture or a shake.

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.

When the flashlight is turned on, the chemical energy is first transformed into electrical energy and then into light energy.

Any wavelength of light will. This becomes a problem for space probes, because electronics and power supplies turning on and off create heat in the infrared spectrum, and these infrared photons cause a small thrust which over long periods of time will cause the probe to veer off course.

In empty space, absolute motion can’t be defined without a reference point but we can talk about the CHANGE of motion, or acceleration, of the flashlight. That means it will accelerate, just as a rocket accelerates opposite to the momentum of hot gases expelled. Given the relatively small momentum of photons vs.

Put more simply, we need a flashlight in space because, while there is light all around, it is far, far, far too weak to illuminate anything. Even if light intensity dropped off in direct proportion to distance, I believe the Sun would still account for 99.99% of all the light we receive from space.

Re: How far can a flashlight be seen? 50 miles in clear atmosphere for a sufficiently bright and/or focused light.

Yes photons do have momentum, producing, absorbing or reflecting light does impart thrust. Light though is leaving the system just as any other propellant, only difference is other propellants have true mass and light does not.

So yes, in principle, you can propel a spacecraft by shooting a powerful light out the back. But the momentum of each photon is very, very small. If you could guide these photons in one direction, you’d have a photon rocket, which would indeed be a terrific way to get around in space.

Yes it would. Photons have momentum and since momentum is conserved the Torch light is acted upon by a force.

Light carries momentum that can push on an object, but it can also move an object through thermal forces. Light can also exert force through the photophoretic effect, where preferential absorption of light on one side of an object leads to a temperature difference that causes the object to move.

Yes indeed, light can generate a force. Even from the classical point of view electromagnetic waves can cause a force. For example the force on a charged particle is F = q(E + V x B) which implies that electromagnetic fields carry momentum. If you view a photon as a classical wave it still carries momentum.

Originally Answered: Can you push things with light? Yes, as stated by Jaakko T Orso, light has momentum and you this allows you to use it to push things around. However, compared with using matter it takes a great deal of kinetic energy to convey noticeable momentum.

Dust particle’s size is comparable to wavelength of light due to which it disperses light waves and makes itself visible. When you see a beam of light,small floating particles too are seen moving and then almost disappearing when they move away from light ,they are nothing but dust particles.

HERE IS YOUR ANSWER: This happens due to the scattering phenomenon of light by dust particles. Light travels in a straight line path. Then the path of light is deviated from its straight line path and, as a result of this the dust particles become visible.

Light waves are electromagnetic transversal waves. They can travel through a vacuum and any particles they contact slow them down. So when they move through denser water they are slowed down more.

Air’s refractive index is about 1.0003, while water’s is about 1.3. This means that light is “slower” in water than air. This is because it’s more likely to hit a molecule and then get re-emitted, lengthening the amount of time the light takes to get through a certain distance of the medium.