how does young's double slit experiment thing demonstrate light is a wave?

Question

is it actually a wave? don't waves need mediums to "go through" and if so how does it get from the sun to the earth? thanks

Answer 1

By definition, waves are classified as either mechanical or electromagnetic. Mechanical waves (like sound) require a medium to travel through. Electromagnetic waves (like light) do not require a medium. Instead they are created by accelerating electrical charges which create oscillating electric and magnetic fields that radiate outward. These fields are what make light and they travel best where there is nothing - a vacuum. That's how light can get from the Sun to the Earth.

Young's double-slit experiment showed that light exhibits interference which is a wave property. When a part of a wave with a positive amplitude (size) meets a part of another wave with a negative amplitude, they will cancel each other out as they pass through each other. This is known as destructive interference. The cancellation isn't permanent. As the waves move past each other, they will regain their original form. In another form of interference, two positive or negative waves may temporarily add to make an ever more powerful wave. This is called constructive interference.

Young's experiment took a narrow beam of light, and shined it through very close slits. When the light went through the slits, it spread out so that by the time it got to a screen, light from the left slit would overlap light from the right slit. Where the overlapping occurred, interference took place and alternating bands of light and dark were seen as constructive and destructive interference took place.

If light were made of particles and had no wave-like properties, the results of the experiment would have simply been brighter light where the light from the two sources met, and dimmer farther away.

Other experiments have shown that light can behave as a particle as well as wave, but if you test it for wave properties, it will show them.

Answer 2

In the experiment, you take a beam of light and shine it on 2 slits. The light that makes it through the slits strikes a 'wall'. The light from the two slits interacts with each other and for a pattern called an Interference Pattern (such a pattern can be seen when waves in water interact). It's the existence of this pattern that proves that light is a wave.

Having said that, you can rig up an experiment that proves that light is a particle as well. As a result, light is considered a photon, both a particle and a wave. Which aspect you see is dependent on which experiment you perform.

Because of its dual nature, light doesn't need a medium to travel through

MistWing SilverTail

Answer 3

Young's double slit experiment demonstrates that light is a wave because in order for this experiment to be carried out, two things that only waves can do must take place. 1. difraction 2. wave interferance. (In other words, if light were not a wave, you would be able to observe nothing during this experiment.

1. difraction: if you follow the link below, see how "rings" are formed as light pass through each slit? that's something that only waves do. if light were a paticles, diffraction wouldn't happen.

2. wave interference: as light pass through two adjacent slits, diffraction occurs on both slits, and it's like there were two sources that send out waves that interact with each other. the pattern that is formed as the light waves interfere, is called the interference pattern. if light were not a wave, this pattern would not occur.

Because of duality of matter (light is both wave and particle) light is able to travel where there is a lack of medium. In such a circumstance think of it as a photon traveling through space.

Answer 4

Light is both a wave and a particle. Young's experiment shows the wave part because there is a cancellation pattern that is observed. The two slits have the same beam of light but the light at one slit is slightly out of phase with the other because it traveled a different distance. These two links might help some. :-)

Answer 5

you'll in trouble-free terms want a show with 2 skinny slits, a source of light like a sodium lamp which will furnish a unmarried wave-length emission of light and yet another show behind the slit-show to observe the diffration fringes.