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debeng
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what exactly is photon? chemical , physical properties? how could they survivr insppeds of light?
Photons are light, that's how they survive. Which is the easy explanation.How could they survive at light speeds?
Photons, are like little pieces of light. Quanta of light, quanta coming from quantization, meaning to express something with numbers. Turning something qualitative, such as light, into qualitative, by cutting it up, into different pieces, a number of pieces. Light/photons have no chemical properties.Dr.Brain said:Photons are not particles as in physical world. They represent the particle nature of light in the sense , they are 'bundles' of energy , since each photon is associated with some particular amount of energy , therefore each one of them has an individuality associated with themselves , thus counting them as one 'particle' , not in the sense that they are point-masses or something , they are simply 'bundles of energy' which transforms to wave-energy when we talk about wave-nature of light.
BJ
Bob3141592 said:How's this explanation?
Photons are electromagnetic energy with momentum. Since you cannot have a stable electric field without a charge to anchor it, the electric field of a photon decays, creating a magnetic field as described by Maxwell's equations. However, you cannot sustain a magnetic field without anything to anchor it either, so this also decays in it's turn into an electric field. As long as nothing absorbs these fields, the photon continues to oscillate between one and the other. Since the photon has momentum, these fields are asymmetric so the fields regenrate each other in a specific direction, giving a particulate appearance to the energy packet in motion.
Is that more or less correct?
To determine the momentum of photon, we do not use the equation momentum=mass*velocityvaishakh said:This is something that has kept me puzzles for long. How can photons that have 0 mass have mommentum-Bob
There is refraction, scattering, etc. in the air: That's why the sky is blue and the sun turns red as it gets closer to the horizon.debeng said:is there any difference between their oscillaiton in the vacuum and in the air ? when they pass through a prism, why would they disperse? and why not disperse in the air?
debeng said:is there any difference between their oscillaiton in the vacuum and in the air ? when they pass through a prism, why would they disperse? and why not disperse in the air?
Vixus said:Isn't there always wavelength = h/p?
This links in the idea of wave-particle duality.
ok, I understand all the way up to:FeynmanMH42 said:Momentum = mv
Photon energy = hf
E = mc^2, therefore mass = energy / c^2
Therefore
momentum = E/c^2 * v
For a photon traveling at C, momentum = (hf/c^2) * c
therefore momentum p = chf / c^3
so p = hf / c^2
matrixx333 said:ok, I understand all the way up to:
For a photon traveling at C, momentum = (hf/c^2) * c,
but wouldn't (hf/c^2) * c = hfc/c^2? Which in turn would equate to hf/c, right?
But from your math what I am seeing is (hf/c^2) * c/c, which would equal p = hf / c^2.
Also in the equation momentum = E/c^2 * v, doesn't v stand for a vector quantity, and if that is true, is c a scalar quantity or a vector quantity?
J
silverdiesel said:c is a scaler because it is the speed of light, not the velocity of light. Speed implies simply the magnitude, loosing any information about direction. Wikipedia comes at this questions from a different angle:
In special relativity, the energy-momentum relation is an equation which relates energy, rest mass, and momentum of an object together:Thus, p = E/c, just as Feynman### deducted.
E2 = m2c4 + p2c2,
where c is the speed of light, E is total energy, m is rest mass, and p is momentum.
If the momentum is zero (the object is in its inertial rest frame) then the energy-momentum relation simplifies to
E = mc2.
If the object is massless then the energy momentum relation reduces to
E = pc
as is the case for a photon.
A photon is a fundamental particle of light that carries energy and has no mass. It is the smallest unit of light and is responsible for all electromagnetic radiation, including visible light, radio waves, and X-rays.
The properties of photons include their energy, frequency, wavelength, and polarization. They also have a constant speed of light and can travel through a vacuum. Photons are also known to exhibit both wave-like and particle-like behavior.
Photons behave according to the principles of quantum mechanics. They can act as both particles and waves and can interact with matter through absorption, emission, and scattering. They also have a fixed speed of light and can travel in a straight line or be redirected by a medium.
Photons are produced by accelerating charged particles or by the emission of energy from atoms and molecules. They can also be created through the annihilation of a particle and its corresponding antiparticle. In some cases, photons can also be produced artificially, such as in lasers.
Photons are essential to the existence of the universe. They play a crucial role in energy transfer and the interaction of matter. Without photons, there would be no light, and the universe would be dark. Photons also contribute to the formation of stars, galaxies, and other celestial bodies.