About "Light", need better understanding of it.

In summary, light is made up of photons of a certain wavelength and has two properties: the number of photons and their energy. There are different types of light, including visible light, which is just a small part of the electromagnetic spectrum. Light interacts with matter through photons, which are not actually particles in the classical sense. The difference between a flashlight and the Sun is the amount of energy they have available to produce light. The Sun has a much larger reserve of energy, allowing it to shine for billions of years, while a flashlight can only stay lit for a few hours. Light sources, such as lasers, flashlights, and the Sun, have different characteristics because of the underlying physics behind their generation. Darkness is the absence of photons hitting
  • #1
lukestar
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Is there different types of light/particles of light? because all of these lights are different how it works, laser light, light from flash light, sun light. Why does flash light only illuminate only less area/more area depending on how much volts the battery is and a sun illuminates a whole Earth and stays on illuminating? What is darkness in a room with light off and what is illumination in a room with light on?
 
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  • #2
Are you really asking why a flashlight isn't like a star?

Light are photons of a certain wave length. Both a star like our sun and a flashlight generate them, only one of them generates a lot more of them.
So light has two properties. The number of photons and their energy/wave length/frequency.

What is darkness? No photons hitting your retina and thus no nerve signal to your brain.
 
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  • #3
If you're in a room where nothing moves then you will hear no sound, nothing will hit your ear drum. The harder you hit something, meaning the more energy you put into it the more that will reach your ear.
 
  • #4
lukestar said:
Is there different types of light/particles of light?

Visible light is but one small section of the larger electromagnetic spectrum. Light, and everything else on this spectrum, is first and foremost an electromagnetic wave. This EM wave interacts with matter via 'photons', which we call the particle of light. (But in reality they are nothing like a particle in the classical sense) The only difference between, say, radio waves and visible light, is that radio waves have a much longer wavelength and much smaller energy per photon than visible light.

lukestar said:
Why does flash light only illuminate only less area/more area depending on how much volts the battery is and a sun illuminates a whole Earth and stays on illuminating?

Creating light requires energy. A flashlight only puts out a small amount of energy per second in the form of light, while the Sun puts out an enormous amount thanks to its temperature and sheer size. (Energy per second is known as 'power') The more power your flashlight puts out, the brighter the light is. A flashlight's energy source is its battery, which only holds a small amount compared to the Sun. The Sun simply has a much, MUCH larger reserve of energy in the form of gravitational potential energy and nuclear fusion. So while your flashlight can only stay lit up for a few hours, maybe a day or two if you have a newer LED flashlight, the Sun can shine for billions of years.
 
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  • #5
lukestar said:
because all of these lights are different how it works, laser light, light from flash light, sun light.
What you are writing there are light sources, not the light itself. Some basic properties of light have been pointed out by Drakkith. While those lightsources emits different light characteristics (e.g. power, spectrum, directionality, coherence) because the underlying physics behind the generation is different as well.
 
  • #6
Thank you all for the answers! :)
 

Related to About "Light", need better understanding of it.

1. What is light?

Light is a form of electromagnetic radiation that is visible to the human eye. It is made up of particles called photons that travel in waves at a speed of about 299,792,458 meters per second.

2. How does light travel?

Light travels in straight lines called rays. These rays can be reflected, refracted, or absorbed depending on the surface they encounter. Light also travels faster in vacuum than in any other medium.

3. What is the electromagnetic spectrum?

The electromagnetic spectrum is the range of all types of electromagnetic radiation. This includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Visible light is only a small portion of the electromagnetic spectrum.

4. What is the difference between white light and colored light?

White light is a combination of all the colors in the visible spectrum, while colored light is made up of only a specific range of colors. When white light is passed through a prism, it separates into its component colors, creating a rainbow. The color of light is determined by its wavelength.

5. What is the importance of light in our daily lives?

Light plays a crucial role in our daily lives. It enables us to see the world around us, and it also has many practical applications such as lighting, communication, and energy production. Light is also essential for the growth of plants through the process of photosynthesis.

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