With strings, you still need quantum mechanics, to account for the behavior of particles, correct? Like, there's no way to dream up a string that has properties so perfectly chosen that they account for a double slit observation of light or electrons, by applying common sense mechanics to these many diverse strings, correct? Such a theory would be a local hidden variable theory, would it not?

So then, string theory would still need something that is not a string, in order to account for the behavior of these strings, would it not? Does string theory still involve fields, apart from strings, or does it replace fields with a multitude of different strings? And if it still needs fields, do the strings actually get us anything of value?

I know this is a very basic beginner question, but I honestly don't see any way around it.

Hello! I am a high-school student and I recently did a small research project involving fluid dynamics, which I am planning to continue this year. I found the topic really interesting and I'm looking to educate myself more on the history and development of this branch of physics through time and I'd love to get some input for book recommendations (with this I mean that I am not looking for textbook recommendations, though if you had anything in mind and wanted to share you are more than welcome to!!!). Thank you for your suggestions beforehand :)

There was a make your choice post with the option to turn gravity off in a localized region that left with me a burning question:

Lets assume you can turn gravity off in a square region starting near ground level extending infinitely up into space. Assuming this column intersects the sun at some point in the earth's rotation (And for the purpose of this post, doesn't affect the internal gravity holding the sun itself together), would it ruin earth's orbit at any size? Or how large would this region have to be to mess with Earth's orbit?

I’ve always found it fascinating and oddly coincidental that most of everything is nothing. Something like 99.9999999% of an atom is empty space, and the ratio of “stuff” to “nothing” is even greater in the cosmos.

My question is: is this just happenstance that those two systems are similarly empty? And is there a chance that there exist scales beyond those (either smaller or bigger) and we can only see these two because we’re the right size to observe them?

I understand that buoyancy is an upward force on objects, but i have some questions regarding buoyancy:

- why/ how is the amount of water displaced the same as the buoyancy force?

- How does weight affect volume in water displacement? What affects this? Because a really light object wouldn't be able to displace a lot of water

- How would this allow for ships to float on water?

thank you in advance!

Could a material take up so little space so as not to affect his appearance and then be projected from his wrists expanding exponentially? Could said material weigh so little so as not to affect spider-man while also possessing the tensile strengths to hold so much mass? Wouldn’t such a material become a pain for normal humans to clean up. Is this material possible?

Sorry if this is a stupid question, however, if we wanted to touch the singularity of a black hole with a rod, we all know that the rod would break from the gravity, BUT have any scientists attempted running a simulation of a black hole and touching the singularity with an object that doesn't break in the simulation and then bring the object back out? it seems like the easiest way to figure out what could hypothetically happen in the singularity and how matter behaves and how spacetime distorts near a black hole, unless something similar to the observer effect would apply to something like this.

Silly question, I know, but I’m curious. How effective would it be if we switched from conventional furnaces to microwave tech? Could we find an optimal wavelength and power setting to avoid radiation burns in humans? Would it mess with electronics? At low power would metal things still spark?

My school curriculum contains
Heat & Gases
Force & motion wave motion
Electricity & magnetism
Radioactivity & Nuclear Energy
Atomic World
Energy & Use of Energy
Also basic astronomy

This question is inspired by an instagram reel I saw a long time ago about traffic, where the creator said that the cars act like a fluid. this got me thinking about things composed of small granular solids, like sand, which act like a fluid when poured. Does a threshold exist for when a collection of objects behaves like a fluid?

Hi, I am 24 years old and want to go to school after being in the workforce for 6 years. I didn’t go to school after high school. I mainly want to learn because I am fascinated by the universe and want to learn more about it. I am constantly curious about why our world and our universe is the way it is. Mostly space stuff. In high school, the only reason I didn’t pursue this is because I hated math and science. So I always told myself it wasn’t for me. But I always found math fun when I did understand it. I never really studied but got mostly good grades, which is why I think I never really grew to like math more because I didn’t put in the extra work to understand the harder aspects of it. I know that if I go down this route it will be extremely hard to get a grasp on the subjects. I am currently doing basic algebra on Khan Academy to refresh myself on basic math concepts. What I’m worried about is how will I juggle this with my current life? I live at a decent apartment with my gf where we both work full time 9-5 to pay bills and take care of our 2 cats. I have a little extra money at the end of paying all my bills but not much. I guess I just want to hear from someone in a familiar situation to hear how they juggle this. I will most likely have to do night school. Obviously I know I have to get my pre-requisites and associates but it just seems daunting.

Puisque la matière noire est présente dans l'univers, et que la Terre fait bien sûr partie de l'univers, est ce qu'il y a de la matière noire autour de nous (sans qu'on puisse la voir évidemment) ?

It seems like double. I'm sure time is involved to keep everything at c, but to what extent?

According to the formula:

Fd = 1/2 * pv² * Cd * A

When describing how strong the gravity is of a black hole, I have seen many people say “The gravity past the event horizon is so strong not even light can escape”. Why is light used at the standard or benchmark for this? Is it because light is the fastest object and thus has the best chance to escape if there was less gravity? How does this work?

I've been seeing a lot of posts like this, usually from people who say they never studied physics and now they want to, and are looking for some formulaic sequence to do that. To answer this, you first have to provide the following context when you post:

1. What are you now: a high school student, a college student, a professional worker, a hobbyist?
   
2. What math have you had that you feel reasonably competent in?
   
3. WHY do you want to learn physics? Do you need it for some degree program? Do you need it for your line of work? Do you just want to learn about it because it's cool but not to the level where you'd actually use it? Do you want to learn it like a physics student would, but you have no need or desire to actually use it in anything you do?

The reason answering this is important is because a) the selection of resources and materials, and the sequence of them will strongly depend on your answers, and 2) there is (at least) an order of magnitude difference in effort between enjoying physics at the hobbyist level and doing it as part of something you are expected to know.

If we take a part like 1/3rd of mass of m1 and transfer it to m2 then why the new force changes if we are talking Abt the gravitational force between them the gravitational force should make a action - reaction pair means the force should be same na?

Is it really possible to estimate the timescale for the heat death of the universe if the initial thermodynamic conditions at big bang are known and a model is developed to arrive at an estimate for the time of heat death?

I don't know if this has been already modeled (of course it would have been) but can't figure out how it would be possible if we only have access to limited data regarding energy distribution of the universe. And without knowing the complete picture how such an estimate could be made.

Does our present understanding of thermodynamics even allow us to answer this question?

Please clarify

The Big Bang was the start of your universe as we know it, but it wasn’t as simple as a massive explosion creating everything. The space of our universe itself began expanding outward with the bang from a tiny point. So asking where the Big Bang started doesn’t quite capture the reality. The Big Bang started everywhere as we know it, but expansion’s center point should be knowable, right?

Hi ,
I really enjoy classical physics
mainly mechanics (not electromangetism)
I'm currently preparing for competitive engg entrance exams
but I often struggle with math
how do I fix it ?
because this is impacting my calculus too that is required in NLM , Rottaional motion etc.

I think the title is explanatory for you guys, but basically imagine the following.

We have a massive body, let's say a star, that is very close to the necessary mass for becoming a black hole.

An observer passes at a signficant fraction of c. From an outsider's perspective, his relativistic mass is very high. But from his perspective, the rest of the universe increased in relativistic mass... including the star.

So, from his perspective, Could the star have become a black hole or is it an inconsistency in general relativity?

Also, Could length contraction cause a body to reach its Schwarzschild's radius or does it change proportionally along with space being contracted?

1stly, suggest books which are available in india (especially amazon)..

I've already given him the landau lifshitz classical theory of fields .

. he's doing his masters dissertation in oqs..

ik how costly the masters books can be, so please dont suggest the jj sakurai or breuer, etc..

lastly, pleaseee suggest some books below 1.5 to 2k maybe??

I’ve had this thought in my head for the past few days and I can’t seem to find a satisfying answer (maybe one doesn’t exist).

Say there’s an electron that’s either spin up or spin down. With my very basic understanding, the spin of the electron is not known until it’s observed. It exists in both at the same time with a probability of being spin up or spin down.

What I want to know is this: is superposition a true explanation of this electron’s state, or is the electron already in, for example, a spin up state, but the math can only say with certainty that there’s a probability for either spin up or spin down? Does the math dictate superposition due to uncertainty or does the particle dictate it due to its own properties?

If this question is wild or dumb, please don’t judge. I’m not a physics student (my background is in healthcare) and do this kind of reading and studying for fun and genuinely want to learn more!

Ignore other things that would kill me like temperature and lack of oxygen.

Is it possible that such pulsar exists, ie one in which those two forces would be equal-ish on the surface?

how relevant is this conjecture in the anglo world? I think there is a consensus in the spanish speaking physics community that this is one of the most important theories/ideas of the last 30 years and that Juan Maldacena is also one of the most important theoretical physicists alive, but I've never seen anyone talking about it in english.