# Distance between photons?

• Chelle12
In summary: But you need some information about the beam to start with. Let's say for example that:1. The beam has a power of 5.0 milliwatts (typical for a handheld laser pointer).2. The beam's cross-section is circular, with a radius of 1.0 millimeter.3. The light has a wavelength of 670 nanometers.From the first two, you can calculate the energy density (joules per cubic meter) inside the beam. From the third

#### Chelle12

What is the distance between two photons in a ray of light?

Photons are bosons, which means that you can have as many photons in the same state as you want. This means that an arbitrary number of photons can be in the exact same place, moving in the exact same direction with the same polarization.

In a laser, we try stack as many photons on top of each other in as small a space as we can. The density of photons that we get depends mostly on the technical limitations of the laser.

LukeD said:
Photons are bosons, which means that you can have as many photons in the same state as you want. This means that an arbitrary number of photons can be in the exact same place, moving in the exact same direction with the same polarization.

In a laser, we try stack as many photons on top of each other in as small a space as we can. The density of photons that we get depends mostly on the technical limitations of the laser.

ok, when light travels in a ray of light, isn't there some distance between them, otherwise I guess it wouldn't be quanta. Or when a laser is beamed towards the moon for measurement, the light disparses, so distance would increase. In an experiment done with a single photon counting CCD camera, the distance between the photons was 2km (http://ophelia.princeton.edu/~page/single_photon.html"). Is it wave related?

Last edited by a moderator:
A laser disperses because of the motion of a single photon* not because photons bump into each other. Photons can pass right through each other and lie on top of each other without feeling each other at all (they only interact through gravity as far as we can tell)

* a laser disperses because a single photon is a wave... it also has a definite position - those are very vague statements, do not ponder them for too long, they will drive you mad unless you learn more about them

LukeD said:
* a laser disperses because a single photon is a wave... it also has a definite position

I wasn't suggesting they would bump into each other. I just wanted to have an idea what the distance, definite positions, between these single waves are in a normal ray of light or a laser beam. Thus when light "travels", and before the distances get bigger when they disperse.

The point LukeD is trying to make, is that if you have a strong enough beam e.g. laser light, there is zero distance between them - they overlap. You can in principle even have what "looks" like a single photon, that actually is 2 photons overlapping completely - just twice as "strong".

Chelle12 said:
isn't there some distance between them, otherwise I guess it wouldn't be quanta
Again, as LukeD said they are bosons so not only can there be 0 distance between them they can also be in otherwise completely identical states of polarization momentum etc.

DaleSpam said:
they are bosons so not only can there be 0 distance between them they can also be in otherwise completely identical states of polarization momentum etc.

Is there such a thing as "bosonized", like in the sense of "ionized", where matter can become more charged?

Getting back to your original question, it's possible to find a number that would be the distance between photons, if photons really were pointlike objects traveling along the beam, like a stream of tiny bullets. But you need some information about the beam to start with. Let's say for example that:

1. The beam has a power of 5.0 milliwatts (typical for a handheld laser pointer).

2. The beam's cross-section is circular, with a radius of 1.0 millimeter.

3. The light has a wavelength of 670 nanometers.

From the first two, you can calculate the energy density (joules per cubic meter) inside the beam. From the third, you can calculate the energy (joules) per photon. Using these two numbers, you can find the average distance between photons.

Last edited:
Chelle12 said:
Is there such a thing as "bosonized", like in the sense of "ionized", where matter can become more charged?
Not really. Although you can annihilate matter with antimatter and turn it into light and therefore bosons.

## 1. What is the distance between photons?

The distance between photons is not a fixed value, as it depends on the context in which they are being measured. In a vacuum, photons travel at the speed of light and therefore do not have a physical distance between them. However, in a medium such as air or water, photons can travel at slightly slower speeds and therefore have a measurable distance between them.

## 2. How is the distance between photons calculated?

The distance between photons can be calculated using the formula: distance = velocity x time. Since photons travel at the speed of light, the distance between them can be calculated by multiplying the speed of light (in a vacuum, this is approximately 299,792,458 meters per second) by the time it takes for the photons to travel.

## 3. Can the distance between photons change?

Yes, the distance between photons can change depending on the medium through which they are traveling. As mentioned earlier, in a vacuum, photons travel at a constant speed and therefore do not have a measurable distance between them. However, in a medium such as air or water, the speed of light is slightly slower and therefore the distance between photons is slightly longer.

## 4. How does the distance between photons affect light waves?

The distance between photons does not directly affect light waves. Light waves are made up of a stream of photons, and the distance between these photons determines the frequency and wavelength of the light wave. However, the distance between photons is not the only factor that affects light waves, as factors such as the medium through which the photons are traveling and the type of light source also play a role.

## 5. Is there a minimum distance between photons?

In a vacuum, there is no minimum distance between photons as they travel at the speed of light. However, in a medium such as air or water, there is a minimum distance that can be measured between photons due to their slightly slower speed. This minimum distance can also vary depending on the wavelength and frequency of the light wave.