How we can
say that light travelles in live
Answers
Light is a form of energy produced by a light source. Light is made of photons that travel very fast. Photons of light behave like both waves and particles.
Luminescent sources are normally cooler and can be produced by chemical reactions, such as in a glowstick or a glow-worm. Other luminescent sources include a computer screen, fluorescent lights and LEDs.
Sound only travels at about 330 m/s through the air, so light is nearly a million times faster than sound.
Light takes about 8 minutes and 20 seconds to reach the Earth from the Sun. When we see the Sun, we are seeing what it looked like over 8 minutes ago.
Light can travel through empty space
Unlike sound, which needs a medium (like air or water) to travel through, light can travel in the vacuum of space.
Light travels in straight lines
Once light has been produced, it will keep travelling in a straight line until it hits something else.
Shadows are evidence of light travelling in straight lines. An object blocks light so that it can’t reach the surface where we see the shadow. Light fills up all of the space before it hits the object, but the whole region between the object and the surface is in shadow. Shadows don’t appear totally dark because there is still some light reaching the surface that has been reflected off other objects.
Once light has hit another surface or particles, it is then absorbed, reflected (bounces off), scattered (bounces off in all directions), refracted (direction and speed changes) or transmitted (passes straight through).
Models for light
The debate of whether light is made of waves or particles has been going for hundreds of years. Sir Isaac Newton thought that shadows proved that light was made of particles, but there is a lot of evidence that light is made of waves.
Light as waves
Rainbows and prisms can split white light up into different colours. Experiments can be used to show that each of these colours has a different wavelength.
At the beach, the wavelength of water waves might be measured in metres, but the wavelength of light is measured in nanometres – 10-9 (0.000,000,001) of a metre. Red light has a wavelength of nearly 700 nm (that’s 7 ten-thousandths of a millimetre) while violet light is only 400 nm (4 ten-thousandths of a millimetre).
Hope it helps ☺️☘️
Light is a form of energy produced by a light source. Light is made of photons that travel very fast. Photons of light behave like both waves and particles.
Luminescent sources are normally cooler and can be produced by chemical reactions, such as in a glowstick or a glow-worm. Other luminescent sources include a computer screen, fluorescent lights and LEDs.
Sound only travels at about 330 m/s through the air, so light is nearly a million times faster than sound.
Light takes about 8 minutes and 20 seconds to reach the Earth from the Sun. When we see the Sun, we are seeing what it looked like over 8 minutes ago.
Light can travel through empty space
Unlike sound, which needs a medium (like air or water) to travel through, light can travel in the vacuum of space.
Light travels in straight lines
Once light has been produced, it will keep travelling in a straight line until it hits something else.
Shadows are evidence of light travelling in straight lines. An object blocks light so that it can’t reach the surface where we see the shadow. Light fills up all of the space before it hits the object, but the whole region between the object and the surface is in shadow. Shadows don’t appear totally dark because there is still some light reaching the surface that has been reflected off other objects.
Once light has hit another surface or particles, it is then absorbed, reflected (bounces off), scattered (bounces off in all directions), refracted (direction and speed changes) or transmitted (passes straight through).
Models for light
The debate of whether light is made of waves or particles has been going for hundreds of years. Sir Isaac Newton thought that shadows proved that light was made of particles, but there is a lot of evidence that light is made of waves.
Light as waves
Rainbows and prisms can split white light up into different colours. Experiments can be used to show that each of these colours has a different wavelength.
At the beach, the wavelength of water waves might be measured in metres, but the wavelength of light is measured in nanometres – 10-9 (0.000,000,001) of a metre. Red light has a wavelength of nearly 700 nm (that’s 7 ten-thousandths of a millimetre) while violet light is only 400 nm (4 ten-thousandths of a millimetre).