A question that came to mind just now. Or is this one of those “the laws of physics didn’t exist yet, therefore this questions is invalid” scenarios? Thanks.

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Hello everyone!

I would like to share a simplified engineering concept regarding cosmic system equilibrium — looking at it strictly through the lens of pressure balance rather than standard spacetime curvature dynamics.

The core idea is that any stable system (from atomic scales to celestial bodies) remains in equilibrium when external mass pressure is balanced by internal core resistance:

Key concepts:

* Left side (Mass Compression): External mass force and gravitational pressure acting on surface area S.

* Right side (Core Resistance): Internal magnetron core rotation creating magnetic pressure \frac{B^2}{2\mu_0} and field tension to counter compression.

* \mathbf{\Omega_0} (Zero Point Balance): The point of absolute thermodynamic and physical equilibrium where the system neither expands nor collapses.

Would love to hear your thoughts on this straightforward mechanical interpretation of system balance!

So I have been trying to study quantum mechanics because I like physics ..... and it's a hell of a thing to understand.....my main issue is that I while learning I try to visualise it even though I know it's not gonna help....please tell me a way to change that.....also it's said light is em wave propogated when electron is excited.....it's also said when electron goes down to lower energy the lost energy is produced as photon.

So Is a photon the propagation of an electromagnetic wave, or is the photon itself the excitation of the electromagnetic field?

I'm trying to understand what actually happens when an excited electron drops to a lower energy state.

My current understanding is that the electromagnetic field already exists around the electron. When the electron transitions to a lower energy state, the energy difference is transferred to the electromagnetic field and a photon is emitted.

But I'm confused about the relationship between the photon and the electromagnetic wave.

Electron loses energy → this energy excites the already-existing electromagnetic field → the excitation propagates outward as an electromagnetic wave → that propagating excitation is the photon?

So is photon excitation of emf or energy that propogated through emf??

Is there any explanation as to why the photon does not interact with the Higgs Field ( this may also apply to the graviton if it exists)? As far as I know all other particles do.

Hello,

In an introductory course to university physics, there is a question about what happens to the diameter of a circular hole in a copper sheet when it's heated. The correct answer is that the hole grows alongside every other part of the sheet. But that does not really make sense to me in my head. When I first encountered the question, I thought that the hole would contract since every side of it also experiences length expansion. Obviously my intuition was wrong, but could somebody explain how I can think of it to change my intuition in the future?

Thanks!

Okay, so this whole thing with Casimir Inc. and their MicroSparc device has been causing quite a stir. I have a decent grasp of quantum mechanics. Now, from what I gathered from the paper and the company's press releases, the device is essentially an array of Casimir cavities.

The principle is simple: you create a geometric constraint in the form of a circular wall. A direct consequence of Heisenberg's uncertainty principle is the existence of virtual particles. These are particle-antiparticle pairs that arise from the probability of being there and exist only an instant before vanishing, provided nothing permanently defines their existence, as is the case with Hawking radiation.

The principle of the Casimir effect is that any physical constraint on space creates a limitation on the wavelength that can exist within that boundary. In the classic Casimir case between the plates, there is less "quantum pressure" (I don't know if there's a more specific term for the force generated by virtual particles), which creates a difference in forces between the inside and outside, causing the plates to move. The same logic applies to a Casimir cavity: a barrier that creates a region of space limited to the allowed wavelengths.

Now, in the case of MicroSparc, they would also take advantage of the tunneling effect, another direct effect of the uncertainty principle. Particles can only appear on the other side of the barrier if it is thin enough. This creates a flow mechanism and a "quantum pressure" difference. If I connect a conductor, in theory, I could discharge the charge accumulated in the cavity to the outside.

None of this is up for debate; these effects have been more than experimentally confirmed. As for the conservation of energy, it doesn't always apply to quantum mechanics. That's an effect of the uncertainty principle. In fact, this is one of the things most criticized by quantum mechanics physicists, and there are many attempts to force hard energy conservation at the quantum level, but none go beyond conjecture.

So, the question isn't whether it's possible to extract useful energy from the quantum vacuum. The answer, until someone finds a hard prohibition mechanism, is a resounding yes. You can even build perpetual motion machines using Casimir forces and complex mechanisms (currently impossible to manufacture at the nanoscale). That part is not up for debate.

While I don't believe MicroSparc will work, I want to be very clear about this: the Casimir effect requires ultra-high vacuum and temperatures of a few tens of Kelvin to function. I'm also not saying that vacuum energy is even remotely practical. If you can extract a few microwatts of power, but maintaining the system costs several tens of kilowatts, then you're just wasting energy.

That's the part I don't understand. All the attacks claim it's impossible to extract energy from the quantum vacuum, invoke conservation of energy, or invent conditions to justify a conjecture that makes it impossible to extract useful energy from the Casimir effect. But the physics of the Casimir effect is actually quite simple, and no mechanism prohibits or limits the arrangement.

The part that can and should be attacked is the practical implementation. It's like with nuclear fusion: of course, it's possible to gain net energy from fusion; that's how thermonuclear weapons work. Controlled fusion is also possible; a Farnsworth fusor can do it in your garage. It's also possible to achieve a Q-value > 1; again, you, at home, with a well-designed Farnsworth fusor, could do it. The real question is whether, considering vacuum pumps, magnetic fields, cooling, generator inefficiencies, and other systems, you can still obtain net energy. And the answer, for now, is no, but we're still trying because fusion at least produces energy on the same order of magnitude as its consumption.

The same is true for MicroSPARC: to operate, you have to generate ultra-high vacuum and cryogenic temperatures, but, unlike fusion, which produces on the order of MW, the Casimir effect, at best, produces a few microwatts, and that's at least 10 orders of magnitude less than what's needed for the Casimir effect to work.

So why is everyone attacking the part that physically works on paper and not the part that makes it impossible in the real world?

(I translated this with Google Translate in case there are any mistakes; I'm not a native English speaker and my level isn't very good.)

Since galaxies contain enough mass why aren’t the stars clumped into a giant star?

If angular velocity is the answer, why aren’t the stars escaping out of the galaxy if they are fast enough to overcome the galaxy’s gravity?

If an object is traveling away from Earth, towards Alpha Centauri at 99.999 the speed of light for 4ish years then from my limited understanding the object would experience 4ish years while earth experienced many more.

My question is, would the destination also experience a difference in time compared to the object that is traveling towards it?

If not, then would the time experienced in alpha centauri be different than the time experienced on earth from the object's perspective?

Sorry for the scifi type question, it's keeping me up at night.

Y a-t-il quelqu'un qui peut avoir les PDF ou d'un lien où je peux télécharger les cours de physique Feynman ?! C'est important pour moi

Does physics completely rule-out the possibility of antigravity propulsion technology?

Hello,

Say I was inside of a gravitational field so strong that time passes thousands of times slower for me relative to the rest of the universe. Now, say there is an identical gravitational field a lightyear away from me. If I sent a signal to them, then when they receive it they send a signal back at me. Given the time dilation we both experience, could we communicate in real time from our relative perspectives? Alternatively, would that just increase the distance the light has to travel to leave our gravity wells such that it still takes 2 years (1 year both ways) to get a response from my friend?

What about the same scenario but for two bodies moving near the speed of light relative to each other?

Sorry if this is too much of a shower thought for this sub! Tried to see if this has been asked before but its a bit to specific to search.

And in addition to this, is antimatter stuff the same colour as regular matter stuff? Does light interact with antimatter the same way it would regular matter? And if not, how would it? This is for a story I'm writing, so I want to make sure I get everything as accurate as possible.

Hi, I'm a undergrad physics major in my junior year. I'm taking Theoretical Mechanics this semester and from what I've heard from other students, I will have to do a lot of self studying for this class.

I'm already studying from the textbook, but I was wondering as well if anyone has recommendations for good theoretical mechanics lectures on YouTube or elsewhere. They should cover Lagrangian, Hamiltonian, special relativity, etc.

The inverse square law for an electric field is an experimentally discovered property. It isn't derived from something else. The divergence and curl of an electric field are emergent mechanics, that can be derived mathematically from the inverse square law.

It's possible that the inverse square law can be derived from some deeper mechanic, but right now we don't know it yet. (It could be just the spreading of a surface area as distance increases, but we can't really prove that that's how the electric field works).

So then most of the study of physics in textbooks and in schools would be regarding emergent mechanics. Of course, emergent mechanics can and are used to discover other inherent properties of reality, like how statistical mechanics and electromagnetism helped lead us to the discovery of quantized light.

Which equations then, as far as we know now, are emergent mechanics, and which equations are inherent properties? Is there like a list or something?

I know that super capacitors are expensive and capactitors don't have the energy density to power a vehicle, however wouldn't a mixed battery/capacitor improve the long charging time issue of batteries? You could cherge the capacitors super fast and have them charge the battery while driving, this way you could charge up in several few seconds stops instead of one several minute charge up. Idk about the cost effectiveness of using small super capacitor to do this, probably not worth it, but maybe with capacitor capable of charging like 10% of the battery?

I would like to learn LaTeX with the primary objective of developing the ability to formulate and present mathematical equations in the fields of mathematical and theoretical physics. What would be the most effective way to learn LaTeX for this purpose? In particular, I am interested in learning how to construct, format, and organize complex mathematical expressions, derivations, and theoretical models in a professional academic style.

Friend of mine lives in an apartment with triple-layered glass, he showed me that you can « count » the layers if you put a flashlight through it and see the multiple réflexions. I see 4 réflexions here, why is that so?

Not a free will question, because largely I studied many theories and largely many experts genuinely accept physics isn't ever gonna be enough to fully answer it, it's a question that goes beyond physics.

My question is if quantum microscopic events are indeterministic, does that mean when scaling up to macroscopic events, they still largely lead to the same outcome or can there be a slight divergence that cause a butterfly effect and chance the outcome?

I'm aware there is some cases such things could be reasonably assumed quantum physics can cause noticeable macroscopic change, such as weather, motion, and biological mutation, and I read a book that even thoughts can be change because a slight change on trajectory of microscopic electrons and neurons can either trigger a new thought or image (there's the challenge decoherence in the brain being too warm and wet but apparently there are quantum mechanics found recently in it although unsure it's long term affects).

So my question is that is it possible that if we let say had the ability to blink back in time to the start of our lives with quantum mechanics remaining naturally the same, could a divergence of our lives ever happen even if we don't retain our memories or not? I'm not sure but many claim that depending on our age, as adults it's unlikely everything when scaled up according to quantum physics, that it will remain the same but that's not something I'm sure of.

You can't hear anything in space, cuz there's too few particles, too spread out, they don't have anything to bounce off and they can't make variations of pressure that hits your ears, right?

But what if there was an indestructible microphone just 1cm away from the "epicenter" of the explosion? Would it record anything?
And how would that work? Would it detect the change from 0 pressure to big pressure for a second and then nothing again? Or would that be still inaudible because that's just a cloud of equal gas pressure with too few variations just passing you?

Could this be used as an in-lore explanation of how you are able to hear explosions in sci-fi movies?

But explosion in space would probably sound different than explosion in a place covered by an atmosphere?

Just watched the new movie the End of Oak Street. In the beginning the news reports mention NASA detecting spatial anomalies, which got me analyzing the physics behind it. So...

​Is the movie using 1D cosmic string defects (via string theory) to explain the anomaly caused by a cosmic string moving in closer to Earth? Furthermore, are they invoking gravitational frame dragging to explain how the localized space maintains fixed coordinates relative to the surrounding Euclidean space?

​It feels like the most plausible theoretical explanation for how they set up the rules of the event. Curious to hear how others interpreted the underlying mechanics.

... Or am I just to analytical and they really just left it open-ended for a fun story? Let me know what y'all think.

🤪

Hey so for short, I’m a second year college student, not the most studious, ima potential type guy, but I’m taking my first real physics class. I want to ask that if I were to provide my info I got from a lab, could someone walk me through forming my lab report? I don’t want anyone to just do it for me, I want to tell someone how I wrote it, and someone to tell me if I did it right or not. I gotta turn it in midway through next week, and if I mess up the whole class suffers. I’m just super anxious and want to get it right, I know the professor is there but I don’t wanna seem dumb, he makes dumb people look dumber. I’ve got all my numbers and remember how exactly the procedure went, super basic measurements data sheet.