Physics

CPT symmetry (charge, parity, time) is at heart of modern physics: However, it seems treated seriously only in scale of Feynman diagrams with a few particles - is it still valid for macroscopic physics? Feynman diagrams of Avogadro's scale numbers of particles? In other words, if preparing CPT(initial conditions), should they lead to CPT(their evolution) ... including time reversed causality direction? While it seems technically challenging to prepare CPT(initial conditions), in theory general relativity allows to prepare T(initial conditions) - by hypothetical Klein-bottle-like wormholes ( https://en.wikipedia.org/wiki/Non-orientable_wormhole ) e…

I was thinking... if something had a strong and far enough magnetic energy, enough to pull a human, then we could use magnets to move between point A and point B. Stupid idea? Probably.

How much important physics in science?

Hi Everyone, I ended up here today while studying all the ideas that have come up about why James Webb has looked back to within 1/2 billion years of the big bang and found fully formed Galaxies that usually take longer than 1/2 billion years to form? I'll spare you all the crazy madness what that I've read going down this rabbit hole. I just want to ask something specific to this thread regarding the speed of light being invariant. Because in this article today: https://www.sciencealert.com/the-entire-universe-could-be-twice-as-old-as-we-thought they're dusting off Zwicky's tired light hypothesis. So my question is how can we be certain that the behavior of p…

What does 'emergent' mean to you in a physics context, such as spacetime?

The thought of extracting sound from objects brought up some other questions When two or more electromagnetic waves collide they mix with each other And form a result wave @ the point of collision and then they continue to go as they were before the collision right ? Is it possible that after the collision they each hold information about the collision like the place ( distance from the point of observation ) of collision or the characteristics of the other waves it had collided with ?

How do you think about it?

Does can age really stop or slow down theoretically or realistically? Is time affected by aging?

They say it is impossible to manufacture a ideal engine. First what we require is a source with a infinite thermal capacity.So to keep its temperature constant we can add external heat to it. By that way though we take heat from it its temperature will remain constant. Similarly for the sink we can use a coolant constantly to keep its temperature very low. Is it possible to do that. I am just 15 years old. So please dont mistake me if my question is ridiculous

We know that if something is fixed to the ground and we give force to it, then it will give reaction force in equal amount. How about if "something" isn't fixed, e.g. a toy truck? When we push it for an instant, does the toy truck at the same time give reaction force back to the us? Does it only give reaction back for the time they touch each other? Is my concept correct?

Hi. Please no not merge to a similar thread. A laser beam travels trough air, enters glass, then a rhodamine+ dye, changing its green wavelength to yellow : If the dye is a thin layer, should the green beam pass trough it as yellow ? Or, if the dye is 'sandwiched' between glass 'slides' , would it exit the second glass as yellow ? Will it be coherent and monochromatic ?

Good day. What is the name(s) of crystals that divide or multiply the wavelength on incident light, and light exits them at doubled (or halved) wavelength ? Any examples beyond DPSS lasers ?

It seems that a particle can be completely described by 1) mass, 2) charge 3) spin (or angular momentum) It seems that a black hole can be completely described by 1) mass, 2) charge 3) spin (or angular momentum) Is there a reason for this similarity ?

Unlike other sciences, physics can be hard to define. For instance, if we want to give other sciences definitions or short descriptions we could say this, biology is the study of squishy stuff that might smell bad, chemistry is the study of stuff that goes boom, geology is the study of rocks and stuff from the ground, astronomy is the study of the stuff that dots the sky, but what exactly is physics?

I have a question, born of necessity : I believe that simplicity should always be at the center of everything : complexity becomes a poison for intuition and truth, when it is a mental masturbation apt to feed the ego of scientists who do not seek universal truths, but elitist beliefs to feel superior regardless( or, simply, the need to feel important, which in itself is an understandable need, but not at the cost of truth and justice ); the ego must not be developed without putting truth, courage, justice, the critical and rebellious spirit, as its foundation; otherwise it will be moved by the need to lie, to omit, to adapt reality to his oasis of certainties that have n…

Neutrinos are ghostly subatomic particles existing in quantum superposition. Right now 100 billion neutrinos are passing through your thumbnail every second. 8.5 minutes ago they were in the heart of the Sun.

Hello. A helium filled mylar balloon, loses pressure as the small He atoms sieves trough any envelope, as far as I understand. Sent aloft, when the He pressure inside the balloon equals the atmospheric, the balloon stops rising, as far as I understand. At certain altitude the differential pressures of gas filling the balloon and the atmospheric outside its envelope, nearly equalizes, reducing the He leak. But there is still some weight of the balloon. Do helium balloons last much, much longer aloft at high altitudes than at low altitudes or there is a factor am not considering ?

Hello, in my opinion objective reality exists and is the result of all science. I wanted to know or have opinions on the question whether it is valid to define material things in a way that is unusual but does not interfere with scientific facts i.e. contradict them and thus become invalid in objective reality. For example a defitiniton such as : "an atom is a molecule" would be invalid because it contradicts science. Now let's say I see an apple on a table. Would it be valid to say the following? "The apple I see also consists of the upper most atoms of the table". I think it is valid as a subjective opinion because it does not contra…

We know that convex lens converge light at a point, Is there any other shapes that could also converge light? What if a convex len has only one side circular while the other end is flattened, when the incident light enters the circular side, what will be the transmitted light?

Hello. A weather radar operates at location R and emits to/receives and displays bounced signals from snowing points S. Beyond the snowing there is rain or sleet at E or more snow in the same direction. R----------------------S---SS---------SSS--------EEEE---E-EE--------SSS------ > If the radar signal bounces from the precipitation back 'reporting' the signal; how are the beyond places detected, if the outgoing signal is severely attenuated/bounced/impeded after crossing trough large distances with precipitation ? If relevant, take each - as a mile.

Stern-Gerlach experiment is often seen as idealization of measurement. Using strong magnetic field, it makes magnetic dipoles (of e.g. atoms) align in parallel or anti-parallel way. Additionally, gradient of magnetic field bends trajectories depending on this choice. Magnetic dipoles in magnetic field undergo e.g. Larmor precession due to τ=μ×B torque, unless μ×B=0 what means parallel or anti-parallel alignment. Precession means magnetic dipole becomes kind of antenna, should radiate this additional kinetic energy. Thanks to duality between electric and magnetic field, we can use formula for precessing electric dipole, e.g. from this article: Using wh…

How can electrons of a circuit accelerate the LHC protons to the velocity of .99c when the max velocity of an electron is 10^6 m/s.

Is it considered that there is a minimum parcel of time, or can it be divided infinitely to zero ?

Hello: I am "No-One" (named Ben, the "no-one is based on the idea that in the whole of time, 100 years is nothing. We are nothing, but what we leave for the future generations.), and "I am not me (more philosophy: One ends different than when one is born, evolved through the things the person experienced). I am 52 years young, Belgian, married now 30 years with my first and only love that I met at age 23, resulting in 4 daughters and a son (in that order). Blessed with severe Asperger's and severe ADHD, my life always evolved around the logical and rational, and I live to prevent issues by fixing these before these happen. Something I am decently skilled in,…

When I try to answer this question, I think of light traveling through the vacuum of empty space as photons. But if light is both a particle AND a wave, when light travels through space, it is a wave of WHAT? There is no medium, no ether, to transmit a wave.