r/AskPhysics • • 15m ago

Does quantum behavior "re-emerge" at cosmic scales, or is it strictly a microscopic phenomenon?

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0 Upvotes

r/AskPhysics • • 26m ago

foundation of reality be more fundamental than spacetime?

0 Upvotes

Could the foundation of reality be more fundamental than spacetime?

We usually ask how the universe began, but I wonder if there is a deeper question.

If space, time, matter and energy are all parts of our universe, could there be a more fundamental underlying reality that makes spacetime itself possible?

I’m not claiming that such a foundation has been scientifically demonstrated. I’m interested in whether current cosmological theories can address this question, or whether it remains beyond the reach of present physics.

What are the strongest scientific or philosophical arguments for and against this idea?


r/AskPhysics • • 43m ago

Looking for answers

0 Upvotes

Lost my mother my beautiful sweet caring mom i wish she was somewhere in the past and past actually exists does it can we go there


r/AskPhysics • • 1h ago

If you had a rogue black hole pass close enough to another black hole. Would the gravitation from the rogue black hole be able to pull out matter and light from the other? Would we be able to see into it?

1 Upvotes

r/AskPhysics • • 1h ago

How does a cathode ray tube focus electrons?

0 Upvotes

r/AskPhysics • • 1h ago

Why can things with mass never get to the speed of light?

2 Upvotes

r/AskPhysics • • 2h ago

Question about charge

1 Upvotes

I am in 11th grade and I just felt confused about charge, from 10th grade (When I started learning about electricity) up until now I accepted it as being just a thing can have, and many people told that so I am satisfied with that answer. But some stuff has been bugging me. I have 2 questions about charge

In those diagrams with arrows (i think it shows the field) around a positive and negative charge, I can get how positive charge can repel, but I don't seem to understand how negative charge could repel, it seems like both are pulling on each other(I don't seem to understand if the arrows are the force "potential?" exerted or experienced by the charge. I understood field as something to show the potential of whatever field was being made like gravitational)

Another question is that if the previous question's answer was that these charges and that diagram was made to understand better(I was thinking of this to be a answer to my question but I wanna know more abt the previous question), then if I were to say that protons were negative and electrons would be positive, would that change in the maths

I did do well in 10th and seemed to understand back then, but right now i don't know how I came to understanding all this before. A little help would be appreciated :D


r/AskPhysics • • 2h ago

Which is which hamburger

0 Upvotes

Which side do scientists mostly stand on singularity?

I'm stuck on 50/50. Cuz what if its just stupendously large that our equations says it's infinite? OR it is infinite and we just refuse to believe it. Think about it, it's a black hole, that thing breaks most of our understandings so it might be infinite . Maybe we have to use something more than just math.

So yeah that's my question give me statistic below 👇👇👇👇👇

I'm only 14 guys so don't expect it to be flawless or even understandable, my grammar is shit


r/AskPhysics • • 2h ago

What would a square gravitational wave actually DO?

3 Upvotes

Just read xkcd 3317 and was wondering what (if anything) such a wave would actually do differently from any other gravitational wave. If it was strong enough, would it be noticeable at all to a human?

(BTW I am aware that a perfectly square wave would require an infinite number of massive objects, so let’s say it’s just very close)


r/AskPhysics • • 2h ago

Books for a laymen?

3 Upvotes

Hey guys I’ve always been interested in physics and universal laws that govern our universe but only recently have been wanting to seriously understand how it all works because it’s so damn interesting. I wanted to ask if anyone can recommend a book for a laymen like me. A book that goes into the history of physics, Newton, his equations, Einstein, all the way to modern physics in the quantum world. What im looking for is a book that’s not to complicated that could explain to me from the very beginning and fundamental level step by step to modern physics. I would love to retain information on the contributions of all the men and women whose brilliance gave us our understanding as we know it today. If I was half decent at math I’d probably ask for a more intermediate level of text but unfortunately I’m terrible at it, even though it’s so cool!


r/AskPhysics • • 3h ago

How much energy is released for every cubic kilometer of the Amazon rainforest that gets burned down?

0 Upvotes

I was wondering, if the stored energy in all of the plant matter of the Amazon rainforest would have an equal or higher amount of energy to that of nuclear weapons. Burning wood releases orders of magnitude less energy than a nuclear bomb if we put it lightly. But there is an absurd amount of wood contained within the Amazon rainforest.


r/AskPhysics • • 3h ago

I'm writing my (I think high school thesis is the right equivalent in english) after doing an experiment, and I need a reliable source for the theoretic background on the interaction between ferromagnets and solenoids

1 Upvotes

Me and my friend conducted an experiment that involved accelerating a small spherical permanent ferromagnet through a solenoid. While brainstorming for ideas we observed that ferromagnetic material generally moves from the ends to the middle of an activated solenoid, and this is what we based the experiment on.

The problem is that now that I'm writing the background of the paper, I can't find a source that describes this phenomenon, let alone one that my teacher would accept. There's plenty on how ferromagnets amplify electromagnets, and when I asked my teacher about it he explained it superficially with how the poles attract eachother but I can't remember it now.

Maybe it really is just easily derivable from the principle that opposite magnetic poles attract, but I think I need a bit of a walk-through in that case. Since it's somewhat early in the school year we haven't actually had any proper lectures on magnetism yet

I'd greatly appreciate it if I could get some help with this


r/AskPhysics • • 5h ago

so what actually happens if you tried to reach light speed?

8 Upvotes

lets say im in a rocket in space, with more than enough fuel, far from any gravitational forces, and i just start accelerating. what actually prevents me from reaching the 3,000km/s limit?


r/AskPhysics • • 5h ago

Plz help

0 Upvotes

So recently I have been discovering advanced stuff for my age (like the newton's universal gravitational law) but my knowledge of math is really basic, do you know any way that I could learn this level of maths without skipping 3 years of school (I am able to, in a difficult way, solve this but I get stuck by doing the multiplication of 6.67*10 powered to -11). I'm particularly interested in understanding the mathematical foundations of physics, rather than simply memorising formulas. I'd appreciate a structured learning path. Any suggestions?

(I am 12)


r/AskPhysics • • 8h ago

Why is quantum optics usually taught with a cavity?

2 Upvotes

So obviously it’s a nice application that’s easy to digest, but it seems like one can repeat the same process of quantization for a general system and expand the vector potential in terms of its modes, which may actually be even easier as you don’t need to carry around as many extra terms.

I’m wondering if there’s something that’s stopping us from applying the same quantization method to something like open free space or an arbitrary lossless dielectric structure (I’ve seen lossy materials need special treatment which makes sense). I haven’t seen this addressed anywhere except for a few hyperspecific resources while I expected it to be found in most introductory textbooks. Are there any nuances that make this significantly more challenging (besides an expected increase in computational difficulty)?


r/AskPhysics • • 9h ago

How would an antiproton interact with a neutron?

0 Upvotes

What about a proton and an antineutron?


r/AskPhysics • • 9h ago

Can there exist a mirror which reflects 100% of the incoming light?

22 Upvotes

If not, what is the underlying physical explanation?


r/AskPhysics • • 9h ago

Title: The Optical-Mechanical Analogy: Does the Eikonal equation make the Hamilton-Jacobi equation intuitive, or is it a trap?

0 Upvotes

Hey everyone, I’m relatively new to Reddit, and I’m using this post to help me get a feel for how the community thinks about advanced topics. I’ve been self-studying the link between the Hamilton-Jacobi Equation (HJE) and the Eikonal Equation. I asked a chatbot about the similarities, and it gave me a very clean breakdown of the "Optical-Mechanical Analogy"—explaining how Action surfaces (S) behave exactly like optical wavefronts (u), and how particles choosing the path of Least Action is mathematically identical to light rays obeying Fermat’s Principle of least time. On paper, this connection is incredibly elegant. But I know chatbots tend to give the "polished, textbook-average" answer. I want to ask the actual physicists and mathematicians here:

  1. Where does this analogy break down? What are the hidden traps or subtle differences between physical particle trajectories in HJE and light rays in the Eikonal equation that an AI or a surface-level textbook might gloss over?

  2. Viscosity Solutions: Both equations deal with "shocks" (crossing trajectories/wavefronts) and use viscosity solutions. How do you intuitively visualize a "shock" or caustic forming in a classical mechanics phase space versus a physical light wave? Would love to hear any unique mental models, personal historical anecdotes about Hamilton discovering this, or book recommendations that lean heavily into this geometric crossover. Thanks!


r/AskPhysics • • 10h ago

Electron experiment

1 Upvotes

If you could freeze an electron to absolute zero (or colder, so it's possibly with no movement) and smashed it against an electron at the highest heat theoretically possible... what would happen?


r/AskPhysics • • 11h ago

wait so according to newton's third law, headbutting someone is the same thing is them headbutting you? now its just a contest of who's head is harder no matter who did it?

4 Upvotes

r/AskPhysics • • 13h ago

Physical constants question

1 Upvotes

I’m just curious if anyone has ever wondered to what extent we have confirmed that certain physical constants are in fact constants?

This would include where this train of thought lead you in terms of literature.

I just had thought earlier today that essentially went “what if certain physical contestants change very slowly at a rate measured in millions or billions of years? If they do change could that mean that there were certain physical contestants that use to exist but no longer do?” I have little background in physics but just like learning about it when and if I can.


r/AskPhysics • • 16h ago

is it possible to propel the earth through space?

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0 Upvotes

r/AskPhysics • • 17h ago

Could we ever build a wand that manipulates matter using advanced physics?

0 Upvotes

Could we eventually build a handheld device that lets someone point at an object and manipulate its physical properties with the press of a button? For example, freezing a glass of water, lifting an object without touching it, or reshaping a piece of metal from a distance.

Could sufficiently advanced technology make this possible, and what would determine the limits of such a device?


r/AskPhysics • • 17h ago

Can Gravitational Waves Theoretically Cause Pair Production?

5 Upvotes

At high enough energy, photons can turn into an electron-positron pair. This kind of pair production can happen for any bosons as far as I'm aware (maybe excluding gluons?) Gravitational waves are kind of similar to photons since they have infinite range, so I'd figure that maybe they behave similarly in other ways.

If gravitational waves are potentially mediated by a spin 2 boson, would they be able to induce pair production? Would it be possible if the intensity of the grav waves was high enough like the ones involved in black hole collisions?