r/AskPhysics

could you build a theoretical pyramid to an infinite size or would the physics eventually break it from its own mass or physical forces or something else?

heres the basic parameters for my question:

1. assume you have an infinite flat plane of some indestructible material so you don't have to worry about curvature or terrain
2. assume you have infinite time, funding and supply of any material you need
3. assume earth gravity, atmosphere and average temperature

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?

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?

As far as I have understood so far, observation is defined by the results of an observation (an interaction which results in a change in state), which sounds weird to me as a definition - since it doesn't describe anything about the interaction itself. I just doesn't sound like a precise scientific definition to me.

Can someone help me wrap my head around what an observation is exactly? Please? Pretty Please? With sugar on top?

Quantum mechanics theories state that information can't be created nor destroyed. It also states that there are true random phenomena such as decay patterns. But if information can't be created, then how can anything be truly random? If you somehow record decay patterns, that would be a truly random record with new information

Aside from just making use of electromagnetic induction, and transferring energy to nearby components.

If yes, is the EM radiation "detached" from the transformer and can be detected very far away?

What about other devices utilizing electromagnetic induction, like metal detectors, wireless chargers, induction heaters, etc. ?

While doing a physics homework problem the other day I got that the strength of the electric field is 10^40 N/C. I am 99% sure I made a mistake somewhere because that number sounds way higher than the other answers I've found in the past. But that got me thinking, how strong would an electric field with a mangitude of 10^40 N/C be in reality?

Hi, I'm currently learning about Maxwell's Demon in stat mech and the whole "where did the entropy go" question. I understand the whole journey to Landauers principle, but I feel like im going crazy over the general proposition in the first place?

Like fundamentally the postulate of being able to open a partition (in any manner) for ZERO energy cost, like we just handwave away the physics of opening the partition and then wonder "OMG where did the free energy go/leave to!?!??"

Like guys... we stated a physically impossible thought experiment, its there, its in the moving of the partition... The partition needs SOME physical prescence to reflect molecules and maintain itself at T of the gas (to allow black body radiation principles to work).

To me its like saying, imagine there was no friction in this water wheel, itll spin forever blah blah blah, then asking "WHY DOES THIS GIVE US FREE ENERGY!?!?"

I understand that in Newtonian physics, time is treated as absolute. The same everywhere and for everyone. But Einstein showed that time is relative and that space and time are connected as spacetime.

This is where I’m confused:

1. What exactly is spacetime? Does it mean that space and time are literally combined into one physical thing, or is it mainly a mathematical framework for describing events?

2. What does it physically mean for time to “slow down” ?? If I travel at 99.99% of the speed of light, why does my clock measure less time than a clock on Earth?

Suppose I travel through a large portion of the galaxy at 99.99% of the speed of light. If I experience only 5 days during the journey, while many years pass on Earth, have I effectively traveled into Earth's future?

3. From my perspective, my watch is ticking normally and my body feels normal. So what exactly is changing? Why does less time pass for me compared with someone who stayed on Earth?

4. Is time actually a physical dimension that can be affected by motion, or is “time dilation” simply a difference in how different observers measure the same events?

5. Finally, what is time itself according to modern physics? Is it something that actually “flows” or is it simply a way of measuring the interval between events?

I know that we always move towards higher entropy, and this is why we will eventually reach a point where all energy is converted to heat(?), and no further processes can be generated because there are no more gradients of energy to take advantage of.

Would this not be a low entropy state? I am imagining there being only one possible state of "perfect heath death".

I'm a first year university study who is taking chemistry courses, and although i'll admit for the content I'm doing, I don't have to understand how electrons work in great depth but rather just accept certain facts about them, but its always irritated me. One of those 'facts' is that electrons have an intrinsic property called 'spin' but I have struggled comprehending this concept.

Heres what I know;

- Electrons don't actually spin, but act like they do

- Electrons have a quantum spin number (1/2) and a direction (+/-), and that all electrons are either +1/2 or -1/2 spin

- That electrons have to 'rotate' 720 degrees to return to their original orientation (This I can understand, like Dirac's belt)

Heres what I'm struggling with;

- How electrons have angular momentum if they aren't actually spinning

- What is causing electrons to 'spin'

- How come 2 electrons can only occupy the same orbital if they have opposite spins (Pauli Exclusion Principle)

If anyone can help me greater understand electron spin I will be super grateful!!! 🙏

Hey everyone! I’m sure this is a super naive question.

My YouTube/Undergraduate (decades now ago 😂) physics knowledge lets me know Dark Energy is the force that is pushing far away things. Galaxies/things we see far away, further and further away, are getting faster/speeding up.

So my problem in understanding…this is light measured having been emitted many billions of years ago? Back when of course a giant event happened. Of course the further back you looked the faster things are going to look like. Of course the event was “pushing” things…the earlier you looked the faster it will be.

How do we know/assume that’s still happening?

I’ve been thinking about a speculative idea and I’d like people with a background in physics or mathematics to criticize it.

Imagine a world containing intelligent beings that can understand and mathematically describe everything within their own physical system. Now imagine that their entire world exists inside a higher-dimensional system that they cannot directly access.

A simple analogy would be a video game.

Imagine that the characters inside a 3D game become genuinely intelligent after thousands or millions of years. They could discover the physics of their world, develop mathematics, study matter, space and time, and eventually understand their universe extremely well.

However, the programmer exists outside their system.

The characters might observe unusual events caused by the programmer. They could potentially detect the effects of an external influence, but they might not be able to directly measure the programmer, represent the programmer mathematically, or even understand what "outside their world" means using the mathematics developed inside their world.

This leads to my main question:

Could something similar theoretically happen with dimensions?

Suppose there is a higher level of existence that interacts with our universe. We might not be able to directly observe or mathematically represent that higher level, but we could potentially observe its effects if it interacted with our universe.

I'm particularly interested in the distinction between:

Detecting an effect
and
measuring or representing the source of that effect.

For example, a 2D observer could potentially observe the cross-section of a 3D object passing through its plane, even though the observer cannot directly perceive the complete 3D object.

So perhaps a lower-dimensional observer could detect consequences of a higher-dimensional interaction without being capable of describing the higher-dimensional structure itself.

I'm not claiming that this proves a sixth dimension exists, and I'm not claiming that unexplained events are evidence of higher dimensions.

I'm asking whether the underlying concept has a valid mathematical or physical analogue.

Is there an established concept in physics or mathematics that describes this kind of limitation—where an observer can measure projections, intersections, or effects of a higher-dimensional structure but cannot fully represent the structure itself from within the lower-dimensional framework?

I'd especially appreciate criticism and examples of where this analogy breaks down.

This is an idea I've been thinking about, and I'm curious whether there is already physics that addresses it.

From our perspective, electrons are incredibly tiny, while galaxies are unimaginably enormous and distant. We tend to think of these as two completely different scales of reality.

But what if "size" and "distance" are partly dependent on the frame of reference from which the universe is being observed?

For example, an electron might appear incredibly small and localized to us, while a galaxy appears enormous and incredibly distant. But could there be some other frame of reference in which those scales are perceived very differently?

I'm not suggesting that an electron literally contains a galaxy, or that galaxies are simply giant versions of atoms. I'm wondering whether there could be some deeper relationship between the different scales of the universe that isn't apparent from our particular perspective.

Is there an existing concept in physics that deals with something like this? I'm particularly interested in ideas involving scale, reference frames, spacetime, quantum mechanics, or cosmology.

I'm approaching this as a genuine question rather than claiming I've discovered a new theory, so I'd be interested in hearing where the idea does or doesn't fit with established physics.

Mostly whats in the title, I have always viewed thermodynamics under the lens that if it were possible to describe the system totally, from start to end, an identical system would be identical at any point in time to another system under the same conditions.

Meaning that regardless of the number of particles, most of thermodynamics still assumes that the changes occurring within a system are governed by some (incomprehensibly complex) multi particle interaction.

Is this, at least generally, the correct interpretation? That thermodynamics, as it was initially formulated, still assumes that the movement of particles within the system is completely deterministic, and that all the statistics used is necessary because it simply is not possible to solve or even write out the trajectories of n particles?

Consider a positive charge Q placed in a dielectric substance. The molecules of the dielectric substance will polarize in such a way the the negative end of their dipole will point towards the charge Q and positive end will point radially outwards.

If this is the case, then should the electric field of the dipoles not be in same direction as of electric field of Q, hence it should, like, amplify the electric field of Q. But in reality the dielectrics reduce the electric field on a charge, so how does that happen.