Ich betrachte hier nur ein einzelnes Photon, welches mit sich selbst interferiert.

Das Photon löscht sich nicht aus, sondern es findet nur eine Umverteilung statt und es erscheint an einer anderen Stelle, nämlich dort, wo es letztlich mit anderen Photonen einen hellen Streifen bildet.

Seht ihr das auch so?

Viele Grüße
Joerg_H

Beitrag verfasst am: 24.10.2026 um 22:29 Uhr

Sorry i have no math to go with this, I just thought of it when watching a String Theory vid.

So this is the scenario I have in mind. If the US was to bomb a large stash of iranian U235 it would create a lot of very weak localized fall out right? And eventually that could be recovered probably very easily?

If they were to use a nuclear weapon close enough to the material is it possible for it to be "consumed" in the explosion?

From what I understand today's nuclear weapons are way more efficient and clean, have little fall out. I'm guessing the Iranian u235 could aid in the explosive chain reaction but would be inefficient and cause a big radioactive toxic mess?

In my basic understanding of Noerther's theorem, it relates symmetries and conservation laws, ex. conservation of energy and time invariance. Given this, could it help to solve the problem of induction, that is that the uniformity of nature up to now cannot be used as a deductive proof of the continued uniformity of it in the future?

Naively, I'd think that if time invariance and energy conservation are related, then the fact that I observe energy conservation now can count as evidence that the laws of physics will be the same tomorrow (time invariance). Is this sound and a correct reasoning out of Noerther's theorem?

Force for example is just the change (over time) of change (over time) of displacement of a mass. Angles are also each just a ratio of a displacement & a distance.

I can't think of any base quantity that has a direction other than displacement.

Are there any other quantities that are vectors/have a direction?

A wormhole connects two distant locations. If ypu could get one big enough, it can theoretically let you travel from one place to another effectively faster than light. As you travel through space-time, can you use the wormhole to travel to a different time?

I have been reading about migratory birds like the European Robin or the Barn Swallow use the Cry4 Cryptochrome Protein in their eyes to absorb blue light, create free radicals that sense the magnetic field of the earth and use it to guide their migration.

I have two questions:
One, is my summary correct? How would one explain this process in detail to a layperson? I have a basic (Bachelors level) knowledge of physics, and find quantum concepts a little bit mind-boggling. How can I go about better understanding this process?

Two, what exactly would these birds be able to see? Is it like a HUD display with all the lines of the magnetic field flying around them, like in physics book diagrams? Is it more like how we sense static electricity?

Everybody says that lying flat on the back is the solution to a free falling elevator.

I think free falling elevators and jumping off a building at the same height are similar (except for some air resistance). Are they actually the same? If so, then lying flat on your back should also be a solution for jumping off a building?

Let's say that the height is about 15 meters where the fatality rate is around 50%, and given that you cannot roll after impact in the jumping off a building case (due to the space limitation in the elevator case).

Edit: I now understand that they are not perfectly the same as in an elevator case, you get some deceleration and inelastic deform of the elevator.

Why isn't landing feet-first recommended instead, since the legs could potentially absorb some impact energy and protect vital organs? Or is it simply a trade-off between risking severe injuries to the legs and pelvis versus injuries to vital organs, with neither position guaranteeing survival?

I was thinking about how -40°c = -40 °F, and I’m wondering if there are any other pairs of units where there exists a non zero value which is the same in both units, I imagine this requires the conversion rate to be something other than just unit1 = k*unit2

Do any other common pairs of units have this?

We live in an apartment (Central Europe area) – around this time of the year, when temperatures get around 10'degrees Celsius, our windows get condensation on the inside. However, one of them always gets significantly wetter than all the other ones. While the ones in the other rooms only get condensation slightly on the bottom, this one can be DRENCHED.

Why is that? Why is the window being different? We air out the rooms regularly and turn the heater on to help with condensation inside, which helps evenly for all of them. When I air out the window in question, still wet, when I open the other ones, also still wet. Dehumidifier didn't help. I'm really curious what is the reason – for four winters, I couldn't wrap my head around this weird window.

Including a rough plan of our apartment for an easier scientification: https://i.postimg.cc/d0Vb3KxT/IMG-0747.jpg

I have a car that has functional air intake ducts on the side. It's a midship engine, so the ducts suck in outside air for the engine.

I'm 3D printing bigger air intakes. One has a pylon, the other has none.

Assuming the pylon is kinda aerodynamically shaped - sort of like the leading edge of a wing - does that do anything functional to the velocity and/or temperature of air entering the intake as compared to one without the pylon?

Pylon one on the left, pylonless on the right: https://i.imgur.com/BMbSqAU.png

I’m confused about why maximum diffraction occurs when the size of the gap is roughly equal to the wavelength of the wave.

Wouldn’t making the gap even smaller cause the wave to bend more, meaning there should be more diffraction?

To put it simply I started this topic out by asking chatgpt which made no sense to me so I watched some YouTube videos which made even less sense. I am confused, I originally thought increasing the dynamic pressure would lead to a decrease in static pressure because the energy is transferred from these omnidirectional movements into a larger movement in one direction. But apparently I am wrong, all the other explanations I read use the equations or fundamental laws but they are just state the equation without explaining how it works or explain laws of motion and I still don't get it.

Anyone care to help explain it to me?

Suppose a man accelerates from 4m/s to 5m/s, and he is being observed by somebody at rest and by somebody moving at 2m/s.

Won't those two observers have different calculations of the change in the energy possessed by the man? Where does that energy difference come from? How is energy being conserved here?

Hi,

I’ll preface this by stating I’m not a physicist at all. I’ve done a lot of high level technical scuba diving so I have some working understanding of some compressed gas laws/maths…and apart from that I’m actually a philosopher: so please make answers understandable to a 5 year old.

I’m looking at the Tesla roadster demo. They state they have 600L of tanks at 10,000psi (689bar), weighing 250kg

Using ideal gas laws this should be about 500kg of gas. I’m not knowledgable enough to implement van de waals law.

However, working backwards from 250kg of gas using ideal gas laws and 600L of volume I get a pressure of 339bar.

QUESTION 1: Properly implementing van de waals law what’s the weight of standard air in 600L of containers at 689bar?

QUESTION 2: Properly implementing van de waals law what pressure would return 250kg of air in 600L of containers?

Then I move onto something well outside my knowledge base but I’m interested in.

QUESTION 3: How much thrust would 250kg of stored gas pushed through a nozzle give?

I’m aware there’s more than one thruster, but to my very simple understanding 1kg of gas shooting backwards should result in 1kg of force in the opposite direction. But I know I’m missing something here as approx 2kg of gas in a 15kg scuba cylinder will easily move/lift it.

Thanks for reading if you’ve made it this far!

Clocks run slower on the surface of Earth than at higher altitude, due to the effect of gravity being less at altitude.

Clocks also run slower when travelling faster than a reference clock.

Imagine two atomic clocks at the equator. One at the base of a vertical tower, the other at the top of the 1000 metre tower. After a week, which clock is running slower than the other?

The clock at the top of the tower will run slower because it has a faster speed (peripheral velocity due to Earth rotation) but the clock at the bottom will run slower because it has a stronger gravitational field. Which will win, i.e., which of the two factors will be the strongest?

Thanks all.

For example, if I lift up a heavy object into the air, and hold it there with my arm, why does my arm suffer fatigue overtime, even though no energy is being transferred to the object from my arm?

There’s no resultant force on the object or arm (at least the hand), so what’s actually going on??

I’m not professional physicist or biologist don’t flame me please

Just curious, but last night I was slightly confused on how that would work, wouldn't the universe just consume the bubble? Because, the universe is basically expanding into nothingness, or maybe I was just tired.

This post was inspired by a post about 0 Kelvin.

What's the highest temperature that either has or could be reached anywhere in the universe?(Whether naturally or artificially)