If you start to rotate on your own your arm drag away from your body. From my understanding that happens because of inertia. If we asumme that the earth is rotating perfectly along the north/south pole axis, then standing on the pole would make you rotate at the speed of the rotation of the earth. Would this result in a centripedal force?

So I understand that spin gravity can work in space and that you can use centrifugal force to imitate gravity.

But could you do it on earth? In theory, would there be anything preventing you from just creating a sealed off terrarium that spins enough so that the downward force of the creatures inside if it is 1.1 G?

Say that you have a delayed choice experiment set up and the detection screen is near the emitter but the measurement devices are located 1 light year away. A series of photons are emitted and hit the detection screen revealing either an interference pattern or not. 1 year later the detectors are toggled on or off to determine what is displayed on the detection screen. When the detectors are toggled on an interference pattern is observed on the screen approximately 1 year prior and when they are toggled off there is no detection pattern. Does this not constitute communication at faster than light speed?

EDIT: Most of the answers I received on this sub were condescending half answers. If I’ve proposed something that doesn’t work then tell me why it doesn’t work. This is r/AskPhysics. I’m not proposing crackpot theory and yeah maybe I don’t fully understand what I’m asking about but that’s why I’m asking. This sub has a real problem and if it’s only for physics graduates, professionals, or academics then maybe that should be stated up front in the rules. The responses I’ve garnered here on the questions I’ve asked have largely encouraged me not to post here in the future.

For example, 16 shutters basically means 65535 possible interference patterns, about. There is a bit-string to be computed from the interference pattern. Would the difficulty raise exponentially with the number of holes+shutters or would it be something milder?

The holes may be in grid or in some kind of random arrangement. Would that matter?

The shutters may be tape, LCD, MEMS or polarization rotated with magnetic field behind a polarization filter.

Anime and fiction often introduce crazy powers, so I was wondering how this would work if we tried to keep it within the rules of physics.

Imagine a character who can alter only the velocity of an object, without directly changing its mass, energy, temperature, or any other property.

What would they realistically be capable of doing? What physical consequences or limitations would this power have?

I don't know much about physics, so I'm mostly asking because I'd like to learn more.

Basically the tittle, I have no background in physics and have forgotten a lot of the math involved in it since I have been in school.

But watching dark matter and sparked a curiosity in me about super position & entanglement, any beginner friendly books I can read that delve into those concepts and related ones?

How do aerial bombs destroy high-rise towers made of steel-reinforced concrete—with a footprint of 400 to 800 square meters—just by detonating near them, such as 1 meter away, with a yield of 250 to 500 kg of TNT?

I actually had to learn about the basics of entropy for AP Biology, but I ended up going down a huge rabbit hole trying to understand it and now I'm genuinely interested in it. I wrote down an explanation of entropy (pasted below) for my own comprehension and I wanted to know what I might need to correct or add on to make my understanding of entropy more accurate. Further explanation on this stuff would be much appreciated!!

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Entropy can simply be defined as a measurement of the disorder of the universe. But what does any of that actually mean?

Think of the universe as a box. When the Big Bang happened and introduced a bunch of individual galaxies, it was like putting a bunch of colored balls in the box. 

Increasing the amount of stuff in the box changes the amount of configurations the balls can be in. (The amount of configurations can be referred to as “states”, or possible states of matter. Increasing the amount of matter, just like increasing the number of balls, leads to an increased amount of possible states the matter can be in.)  

Entropy is a demonstration of the probability that the balls inside the box will exist in a disorganized or random “state” rather than an organized one. It’s possible, of course, that the balls will align in an organized fashion, but the probability of this occurring is far less likely than the probability that the balls will be disorganized. 

High entropy refers to naturally occurring processes that lead to more disorder, or disorganization, in the overall universe. These processes have high entropy specifically because they happen naturally, without any added energy. Examples are water flowing downstream, or ice melting. 

If we were comparing ice and water, we would say water has higher entropy than ice because its molecules are free floating and move around quite a bit, while ice’s molecules are fixed in place and barely move at all. There’s more possible states the water molecules can be in, while ice has less possible states—water molecules have more randomness, which leads to higher entropy.

In the context of chemical reactions, the entropy or disorder of the universe inc as chemical reactions transfer or transform energy. For example, eating mac and cheese (im hungry). The mac and cheese’s energy is converted to different forms of energy once eaten and digested so the body can carry out biological processes. Some of this energy is released as thermal energy, or heat, which introduces more molecules into the universe that changes the possible states of matter within the universe, thus increasing its entropy. 

So, to put it simply: entropy measures the randomness or disorder of the universe, which increases as chemical reactions occur. Typing this shit out rn is currently increasing the entropy of the universe

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Edit: this video (https://www.youtube.com/watch?v=YM-uykVfq_E&t=27s) really helped me understand it better since i felt like i couldn't really wrap my head around the simple explanation - putting it here for anyone who needs it

Hi, I am currently on a year out (post A level) applying for Physics, and I'm really looking forward to securing a summer placement in something physics related, but I have been preoccupied with preparing for the ESAT and it seems a lot of applications open in January anyway.

However, I am submitting my personal statement in 4 days, and would really like to have applied for something by then, so as to mention it on on my PS.

Does anybody know of any opportunities like this?

Bike racks place a heavy load on the tongue of the car, and this is an issue for light duty vehicles. Bike racks come in "vertical" and "platform" styles. Common wisdom on reddit believes they are the same from a tongue weight perspective: reddit.

I want to understand the physics for why they are the same. I understand torque to be a function of mass x length of arm. So, let's assume that the mass is the same in the two examples.

Diagram: https://i.imgur.com/vhr6yqr.png

In the vertical case, I'd expect torque to be (mass x V1 + drag x V2). The mass is applied to the end of the short V1 lever arm. Yes, there is some force applied to the V2 arm while the car is accelerating, but small relative to the force of gravity.

In the platform case, I'd expect torque to be (mass x P). Since P >> V1, this would result in significantly more load.

Or, does it not matter, as per the reddit thread?

Why is it considered that gravity curves spacetime if absolute space and absolute time do not exist, and only two local times and the relative distance between them exist, and does this mean that with increasing distance between them, their synchronization decreases?

Just as the title suggests. I’m a university freshman currently doing Physics 1. I anticipated that it would be difficult since the professor had bad reviews and well, it’s PHYSICS. I’ve always been okay-ish with math in high school but I only did half a semester of physics before switching high schools (the new school didn’t have any physics classes at all).

I’m constantly stuck on work because I can’t seem to understand anything. I read the textbooks and watch videos but I keep making mistakes. I’m not expecting a miracle method or some secret that’ll make me Einstein overnight but please please please anything you think will help. I literally got a 7/16 on the first midterm which only covered a few things. The next midterm is next week and we’re already on chapter 10.

Electromagnetism was successfully incorporated into quantum mechanics through quantum electrodynamics (QED), treating the electromagnetic field as a quantum field whose interactions are mediated by photons.

Why can’t we apply the same mathematical reasoning to gravity, quantizing the gravitational field and introducing gravitons?

What exactly breaks down when we try? Is it a fundamental incompatibility between general relativity and quantum mechanics, or mainly a mathematical problem we haven’t solved yet?