An Idea

[Profpat]

Hi Fredrick;

Indeed it would be difficult to seperate photons from particles in the solar wind. When a photon interacts with a particle you get absorption of the energy of the photon being absorbed by the electron. This is when a photon is acting like a particle. The question is what happens when a photon encounters another photon, and when waves interact with waves you get interference.

It's a valid question, one I don't have an answer to.

Best,

Pat

[AntonioLao]

what happens when a photon encounters another photon

To date, there still no theory for a direct description of photon-photon interactions. However, in quantum electrodynamics there are pair productions of electrons and positrons where and when the photons are annihilated (completely destroyed) in high energies particle collisions. On the other hand, the collisions of electrons and positrons create photons.

[Profpat]

To date, there still no theory for a direct description of photon-photon interactions. However, in quantum electrodynamics there are pair productions of electrons and positrons where and when the photons are annihilated (completely destroyed) in high energies particle collisions. On the other hand, the collisions of electrons and positrons create photons.

" On and on it just keeps on going..on and on..on and on.."

Thanks Antonio, I was having a dickens of a time trying to research it.

Would photons come under QED or QCD?

What do you speculate would happen if many of them converged on one going perpendicular to them?

Very Best,

Pat

[Profpat]

I thought this looked like a good picture of the double slit experiment:

Here is how the real thing looks like. In the image bellow we see the wavefunction of a single photon at three different points in time: first hitting a double-slit (observe that the photon's wavefunction is not exactly round but slightly flattened), passing through it (observe that the interference pattern has started forming), and then the complex interference pattern behind it (my previous sketch would be that of a horizontal intersection somewhere at the top of the picture).

[Profpat]

And this also from the internet may be of interest, as it reminds us that the colors we see are the reflected photons, the colors we don't see are the absorbed photons.

There are two ways to combine colors: additive and subtractive.

A TV works by additive colors: you put a red, green, and blue light and it appears white.







A crayon works by subtractive colors. A red crayon absorbs blue and green light. A green crayon absorbs blue and red light. And so on. Put all three together, and any photon hitting the surface will be absorbed by one of the three.

We usually define color in terms of what we see (what’s reflected or emitted) rather than what’s absorbed. If you want to say that a red crayon is "really" blue+green, because it’s hoarding all of those blue and green photons... well, I guess that’s one way of looking at it. But it’s really turning those blue and green photons and converting them into heat. They’re not being saved up to be emitted as blue and green later.

So we say that "black" is when no photons are reaching your eye, and a "black" surface is one that absorbs all of the photons so that none hit your eye. And space is black because there’s nothing out there putting out photons (except where the stars are).

Best to all,

Pat

P.S. Notice my subtle attempt to loop back to my An Idea. To me the photon and proton is the same. The proton is the massive particle and the photon is a tiny bit of that mass converted to pure energy.

[SteveA]

And this also from the internet may be of interest, as it reminds us that the colors we see are the reflected photons, the colors we don't see are the absorbed photons.

...

Notice something interesting in that what colors an object appears as is are in many ways the colors that it is specifically not.

A white or reflective object would not allow light inside and be equivalently dark/black internally or something seen as blue would mean that it's absorbing internally other colors (wavelengths) except blue.

Notice that many animals eyes reflect light - they're not absorbing or seeing the same light as a human and so their eyes don't appear black. People see the same colors so their eyes don't appear as reflective.

[Fredrick]

I thought this looked like a good picture of the double slit experiment:

Great image, Pat, of what happens to the photon when it hits a double-slitted wall. I particularly like the third image for it shows the result of the single separation so well; it is a varied result, yet somehow organized. The only result I do not see here is what happens to this photon-'brain' afterwards, will it move towards becoming a single photon again as shown with the first image? Will it fully regroup?

What we do know now is that even the single photon is actually a collective that can get split up. The unit of the photon is not a single entity, but a singular state maintained — until it can no longer be maintained.

Thank you also, Antonio, for joining the discussion. The head-on collision of photons is indeed interesting, yet as such it is not the norm in our universe. Still, we can use your information and ask the question again: what happens to that photon of one star that is going straight to another star? Will it reach that star? Will it have been absorbed, and if so, will that result be noticeable?

In general, the universe is fully laden with photons, and if they all decided to change directions and come towards us, the night sky would be brighter than day time. We only get to see the photons that head in our direction. Can anyone calculate what percentage of the sun's photons come in our (earth's) direction?

[Profpat]

"What we do know now is that even the single photon is actually a collective that can get split up. The unit of the photon is not a single entity, but a singular state maintained — until it can no longer be maintained."

You're right of course Fredrick. Light is a 2 dimensional transverse wave " packet "

[AntonioLao]

Would photons come under QED or QCD? What do you speculate would happen if many of them converged on one going perpendicular to them?

It would certainly come under QED. Then we would have the most powerful LASER beam as a reality of light amplifications by stimulated emission of radiation.

[Profpat]

Can anyone calculate what percentage of the sun's photons come in our (earth's) direction?
[/quote]

Sorry I couldn't find a direct answer but did come up with this from NASA which I think is interesting:




Electromagnetic radiation
Electromagnetic radiation consists of electrical and magnetic energy. The radiation can be thought of as waves of energy or as particle-like "packets" of energy called photons.
Visible light, infrared rays, and other forms of electromagnetic radiation differ in their energy. Six bands of energy span the entire spectrum (range) of electromagnetic energy. From the least energetic to the most energetic, they are: radio waves, infrared rays, visible light, ultraviolet rays, X rays, and gamma rays. Microwaves, which are high-energy radio waves, are sometimes considered to be a separate band. The sun emits radiation of each type in the spectrum.
The amount of energy in electromagnetic waves is directly related to their wavelength, the distance between successive wave crests. The more energetic the radiation, the shorter the wavelength. For example, gamma rays have shorter wavelengths than radio waves. The energy in an individual photon is related to the position of the photon in the spectrum. For instance, a gamma ray photon has more energy than a photon of radio energy.
All forms of electromagnetic radiation travel through space at the same speed, commonly known as the speed of light: 186,282 miles (299,792 kilometers) per second. At this rate, a photon emitted by the sun takes only about 8 minutes to reach Earth.
The amount of electromagnetic radiation from the sun that reaches the top of Earth's atmosphere is known as the solar constant. This amount is about 1,370 watts per square meter. But only about 40 percent of the energy in this radiation reaches Earth's surface. The atmosphere blocks some of the visible and infrared radiation, almost all the ultraviolet rays, and all the X rays and gamma rays. But nearly all the radio energy reaches Earth's surface.
Particle radiation Protons and electrons flow continually outward from the sun in all directions as the solar wind. These particles come close to Earth, but Earth's magnetic field prevents them from reaching the surface.