Physics

Considering an atom within a rigid body, does the angular momentum of an electron within the atom vary when the body is put in motion?

So it's that time of year again; wintertime cyclones bring snow, then snow-melting rain, then the mixture of rainwater and meltwater can freeze in the colder temperatures that follow both. Typically I've only seen the latter on streets, not patios, though I'm not sure why if at all there isn't a risk of the same happening on patios, if for any reason marginally less so. I'm wondering what the most practical way to deal with that is. Is it better to shovel the snow off the patio before it transitions to rain, or does that just expose the rainwater to the subsequent cold temperatures? Conversely, if one were to deliberately leave the snow on the patio, to insula…

A light-hearted question... Every time I am in hurry filling up my water bottle before gym, I wonder the same thing: how much water should I pour into the bottle (then shake it vigorously and pour it out) for the best rinsing effect? Of course, I don't care much about the exact number - but I wonder how to even tackle the problem?

This literally hurt my head when I read that statement in a book, the book was trying to prove that Physics rhymes historically to the point of the rhyme itself being the science instead of the Physics that we normally would pay attention to. In the first 3 pages of the book he writes in big bold letters dramatically, “ ‘THE YEAR OF 1-DERS’ SHOWS THAT ‘PHY-6’ BEGAN IN YEAR ‘1-666’ WHEN ‘NEW-TON’ CREATED HIS ‘NEW’ LAW OF ‘TON’! ” When I went to check if that was true it checked and I was scared. Have you ever heard anything like that before? And when younger more naive people here that statement this younger generation that is into entertainment and ra…

Okay, this is a simple question, but the context is a bit unconventional. There is a claim from a man named Bob Lazar that he was hired by the government in the 80's to help reverse engineer a UFO. He claims that the fuel used by the UFO(s) was a stable isotope of Element 115, AKA Moscovium. Obviously there is a lot of unpack there about the veracity of the claim and we could easily get off track. What I want to know is how you would know what it was you had in your hand. For the sake of argument, let's assume that a materials scientist had a stable isotope of element 115 about the size of a ping pong ball. I could be wrong, but I don't think spectroscopy woul…

If it were possible to ride a photon, what would our perception of time be like?

Inspired by my own thread on forest fires. https://energyeducation.ca/encyclopedia/Betz_limit So basically, the Betz limit suggests that a theoretical maximum of 59.3% of energy could be extracted from wind at a time. That leaves 40.7% or more still in the wind. So, wind retains at least 0.407 times its maximum energy; which, by E=mvv/2, suggests it retains 0.638 of its speed. Does that mean that with a long enough row of closely-packed, highly-efficient wind turbines designed to handle hurricane-force winds, you could reduce the wind speeds from 120 km/h to about 77km/h, storing the excess energy until the power lines are repaired? …

This question is for the physicists mainly, I suppose, though there may also be a philosophical element to it. (Mods may wish to relocate the thread as appropriate). I ask as an interested layman. We're routinely told--by scientists--that there are four fundamental forces of nature, one of which is gravity. This is so commonly heard that I assume quotations are unnecessary. Gravity construed as a force seems entirely unproblematic under the erstwhile Newtonian paradigm. But times have moved on . . . Much of the lay reading I've done in this area seems to suggest that general relativity--if read literally--treats gravity not as a force at all; rather, it is…

I've been, as of late, debating with rather fringe or crackpot physicists on ResearchGate and in the process of such an exchange i've found myself forced to be rather particular about my terminology. It was a debate regarding Special Relativity and the person in question made the obvious mistake of assuming that such a theory couldn't be extended to accelerating reference frames. I came to clarify to him that in Special Relativity you could only deal with reference frames that accelerate as a result of dynamical influences or forces as General Relativity would come into the case for accelerated motions without forces. In hindsight, it is relatively true this is the case i…

From what I understand when the ionocraft or ion lifter is turned on, the corona wire becomes charged with high voltage. When the corona wire reaches approximately 30 kV, it causes the air molecules nearby to become ionised by stripping their electrons from them. As this happens, the ions are repelled from the anode and attracted towards the collector, causing the majority of the ions to accelerate toward the collector. The current is carried by a corona discharge (and not a tightly-confined arc) means that the moving particles diffuse into an expanding ion cloud, and collide frequently with neutral air molecules. It is these collisions that create thrust. …

There are plenty of explanations as to why light exists in different colors due to existing as different wavelengths, but what I can't find is any explanation as to why light exists as a variance of wavelengths in the first place. What process/force/function/whatever is it that gives rise to a spectrum of wavelengths as opposed to there just simply existing one wavelength?

What I learned in physics about visible light is that the shorter the wavelength the more energy it has, thus red which has the longest wavelength is the outermost color on the rainbow because it bends the least, colors with longer wavelengths bend less and also have less energy. Likewise, violet has the shortest wavelength and that's why its the innermost color on the rainbow, because it bends the most with its short wavelength. Also since it has the shortest wavelength it has the most energy so therefore violet lasers are the most powerful. So this being the case I would like to say that Samuel Jackson is smart. Samuel Jackson who played Mace Windu wanted a purple…

Some words associated with the entropy definition as looked up: disorder randomness uncertainty energy dispersal I know that the consequence of entropy is irreversible, but which one of these associated words fit the entropy definition best?

I store my DVD discs inside the black dvd box in vertical position and inside the cardboard box, also inside the cardboard box next to the dvdbox I have a bag with papers and screwdrivers, on top of the cardboard box I have another one cardboard box with dvd casebox, the cardboard boxes are on top of a clothes closet and if I open the clothes closet door it shakes will this balance damage the DVD discs?

Hello. Before making a hypothesis, I would like to know if anyone are already familiar with a physical and/or mathematical approach to a junction between Coherent States and the Second Quantization? Thanks. References: [1] [2]

The dishwasher, after it has ran, is a warm, humid environment. The cupboard, or at least most cupboards most of the time, is comparatively cool and dry. Yet in my hometown I recall often taking glasses and coffee cups straight out of the dishwasher immediately after it has ran and placing them inverted in the cupboard, without ever noticing any dew forming inside of them. (Though since living on my own, I've given them some time to dry out before putting them away just in case.) How does this happen? Does water vapour concentration between the surface of the glass or mug immediately decrease to approximately that of the surroundings within the sec…

Hello, question regarding the way convex lenses bend and refocus the light; will it refocus the light from two different light sources to the SAME point? OR will it refocus each light source to a DIFFERENT point? (please see picture). thank you!

this is a video i made. url deleted

why earlier scientists could not guess about the gravitational force?

I remember asking this somewhere on the internet and people said that Einstein had a lot of help from other people in formulating his theories (that's all I remember). Is this true or not? Can't find much information online or don't know exactly what to search for.

I wonder if experiments have been conducted to test whether an electrophor machine (the Wimshurst electrostatic generator) will work in a vacuum. In theory, such experiments should have been carried out, because this question interests not only me, but I did not manage to Google or Youtube anything on this issue.

I have previously appealed to this forum's moderating staff who were involved in a thread which was closed, citing that I was not arguing in good faith. Nothing could further from the truth. I'm going to prove that the moderating staff willfully ignored accepted science in favor of staff opinion. This was the moderator's claim: "If equilibrium exists, is a matter of the second law. Not the third." This claim was the basis of repeated variations used in a discussion against me. The claim fails. Newton's Third Law is fundamental to static equilibrium. Here are two examples that acknowledge that fact: Here's a video by Dr. Hanson abou…

I don't know why this isn't making sense to me, maybe I'm burned out. The idea is this: a pump rated to 1,000 psi. A cylinder head of 100 sq inches. That cylinder can move 100,000 lbs. What prevents the same tiny 1,000 psi pump from moving a 1,000 sq inch cylinder head, a 1million^2? An infinitely sized cylinder head with any amount of weight on it? The goal of this question is I want to determine what is more efficient to provide pressure onto my hydraulic ram. Basically how to design the darned thing with the pump in mind. If my pump can do X then I can have an X-sized cylinder head. Would I ever want my pump to do 1/2X but my cylinder head be 4X in …

Taking a breather from my thought-experimenting with deep sea stuff. A little background - in Apollo the inertial guidance system was instrumented through what's called the Flight Director Attitude Indicator (FDAI) or 8ball. The FDAI shows your pitch, yaw and with a ring around it, your roll. But you can think of the roll as the axis on which the pitch and yaw translate. Over time the inertial guidance system would deviate and need to be corrected using the optics. Now it is possible to find the deviation over time by simply observing the new roll axis of the FDAI as it shifts off the poles that were at 90 deg yaw. But I haven't been able to confi…

Optical photon is produced e.g. during deexcitation of atom, carrying energy, momentum and angular momentum difference. So how is this energy distributed in space - what is the shape and size of single photon? Looking for literature, I have found started by Geoffrey Hunter, here is one of articles: "Einstein’s Photon Concept Quantified by the Bohr Model of the Photon" https://arxiv.org/pdf/quant-ph/0506231.pdf Most importantly, he claims that such single optical photon has shape similar to elongated ellipsoid of length being wavelength λ, and diameter λ/π (?), providing reasonably looking arguments: Is it the proper answer? Are there other reasona…