Recent content by LarryS

Given two independent photons. The position-momentum commutator for particle 1, [x1,p1] is ih/2π and the commutator for particle 2 , [x2,p2] is also ih/2π. Also, [x1,p2] = 0 and [x2,p1] = 0 because the 2 photons are independent. But what if the two photons are in the same quantum state or...

All elementary particles have an intrinsic spin/angular momentum. The fact that particles spin at all is due to Special Relativity. How MUCH they spin, half-integer multiples of reduced Planck's Constant, is due to Quantum Mechanics. Right? Apparently, the reason particles spin at all is...

Given a DC circuit consisting of a battery, a switch and a parallel plate capacitor and no resistor. The wires are relatively thick copper. Also, the copper wire leads into the capacitor are each, say, about one meter long. Now when the capacitor is fully charged, the negative plate will contain...

In classical EM, according to the Lorentz Force Law, a magnetic field can change the direction (momentum) of a moving charged particle but not its energy. Yet magnetic fields like those in solenoids or EM plane waves are said to contain energy. How can this be? What am I not seeing? Thanks...

I think I see where you are going. I probably need to read/study this subject a little further.

Many descriptions of tensors define them to be these kind of multidimensional arrays of numbers, as generalizations of vectors and matrices, that transform in a certain way. But, mathematically, tensors are functions whose domains are these multidimensional arrays and whose codomains/ranges are...

I should have said that the shape of the wave becomes a Plane Wave, in the limit as the distance from the source increases. Never heard of an extended phased array antenna until now. Looks like it could generate an almost perfect plane wave.

The (covariant) product of the EM Field Tensor with itself is basically the Lagrangian Density for the EM Field. It leads directly to Maxwell's Equations. If there are no charges or currents present, Maxwell's Equations lead directly to an equation of motion for an EM Plane Wave. Now all EM...

In classical mechanics, the potential energy stored in an elastic stretched string is the work done by the tension during the stretching process. Is this concept and formula the same in Special Relativity? Thanks in advance.

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Not familiar with the term "super relativity". Did you mean to say "special relativity"?

Not sure. What if the speed of light was one millimeter per second? I would think that would have a profound effect on our everyday, classical/macro world. Would Newtonian physics, as we know it today, ever have been developed?

Does the product of Planck's Constant and the speed of light, hc, have any significance in physics other than an arbitrary product of two constants? I noticed that it appears in one formula for the fine structure constant. It also appears in Planck's formula for black body radiation. Thanks...

The Lagrangian Density for the EM field can be derived from Maxwell's Equations (via the EM Field Tensor). Also, from Maxwell's Equations, the electric and magnetic energy densities of an EM plane wave are equal. So, if you focus only on the EM plane wave, the Lagrangian Density for that would...

Under the RELATIVISTIC definition of Action, is the Action for a beam of light always zero? Thanks in advance.