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It is a bane of small scale physics (e.g. quantum mechanics) that we have absolutely no natural intuition. By natural intuition I mean something along the lines of the following. Take this question "if a ball falls down under gravity after a meter of falling does its speed exceed 100km/h". You know the answer is no because you have seen balls ...


4

Do photons take all paths or not? Yes, they take all paths. This can be seen by single photon sources and: Double slits Diffraction gratings Lenses Etc. For me, the diffraction gratings are the most convincing. the photon travels in a straight line, This is clearly not correct in a myriad of experiments. Particularly where there is diffraction.


3

Photons are not little balls of classical matter. In particular they have not a definite trajectory nor a position. Their description needs a suitable notion of quantum state in a suitable Hilbert space. In some, very special, regimes states of single photons can be approximatively described as particles moving along straight paths (para axial states). Also ...


3

First, In the unit systems used for everyday commerce, engineering and undergraduate physics, magnetic and electric field have different units, so the two amplitudes can't be equal, any more than one meter can be equal to one kilogram. There do exist alternative unit systems that allow comparing electric and magnetic fields directly. But even if you chose ...


2

This kind of depends on what you mean by "directly detected", but there is a strong case to be made that optical frequencies have indeed been directly detected. This has a large overlap with my answer to Have we directly observed the electric component to EM waves?, so I'll leave the details there, but the short answer is that via the experiment ...


2

You could think of photon creation as 2 distinct processes: 1) let's take an excited atom with its excited electron, this electron disturbs the EM field but these forces do not involve an exchange of energy (they are said to be caused by virtual photons also known as force carriers). These forces in theory extend a great distance uniformly and effect the ...


2

E and B are equal in free space in Gaussian or Natural units. Their numerical values are not equal in SI units because different units are used for E and B. It's like saying a plot of ground 5,280 feet by 1 mile is not square.


2

What's the difference between the two waves from a physical point of view? The amplitude of the higher power wave is greater. If you measured the electric field associated with the stronger wave with a field strength meter, you'd find a higher value. In the quantum view, that means you're receiving more photons per second from the stronger transmitter, but ...


1

The textbook argument against photons cancelling each draws upon conservation of energy. Our theory of particle physics is called the standard model, and photons are point particles of zero mass , in the axiomatic table of the model, and that is what the textbook is using. Yes conservation of energy is a very strict law. (In addition, photon photon ...


1

I'll assume you're talking about eletric lighters. In both cases the air ionizes and what you see is a plasma. Now the color blue/purple makes sense for the energy and the oxygen/nitrogen. Can it be white, that's a bit more difficult to answer. Let's start with why lightning is white, Lightning is also a plasma and white doesn't make that much sense based on ...


1

Even in classical electromagnetism, Huygens' principle says that you can treat each point on a wavefront as a source of new waves traveling in all directions – or to put it another way, that you can replace the classical wave picture with one in which light is pointlike and "takes all paths", including non-straight paths. The difference between ...


1

Key to effective shielding is complete coverage with no gaps or holes, using a good electrical conductor. For a cast-iron pan, complete coverage would require putting a close-fitting lid on top of the pan, which would cut off all your wi-fi & bluetooth connections and make the computer impossible to use.


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how can we see objects with the help of light if we cannot see atoms? It is easy to think of a solid material as "just a bunch of atoms", but for photons (which interact with charges), that isn't the case. Solid materials are made up of molecules, or large numbers of bonded atoms. When bonded, the positions of the (charged) electrons changes from ...


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In essence, via the concept of a coherent state: the quantum state of the EM field which most closely resembles a classical field. It has a well-defined 'central' (expectation) value of the electric and magnetic fields, with a minimal uncertainty around them coming from the Heisenberg uncertainty principle, which is often called shot noise. At low ...


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