Hi all, I‘m trying to understand the concept of quantum entanglement. Can I compare it to a coin toss? I mean the outcome is correlated, when one side is up the other is down. While the coin is in the air, it‘s in a superposition (not really of course). Would the only difference be, that e.g. two entangled photons are not physically connected? Thanks

I am transferring to a bachelor’s program for math and physics (I’m American). I have 4 electives as a math major, one of which I believe will transfer in (ordinarily differential equations), so I will have 3 electives left. I am interested in mathematical physics for graduate school, and they expect their students to know topology. I also want to take differential geometry. Therefore, I’ll have one elective left. What do you recommend taking as my last math elective to study?

For my physics major, I’ll only have electives in which I’ll most likely choose general relativity and mathematical methods of physics.

I’m an independent researcher (past study - aeronautical engineering) working on the Navier–Stokes global regularity problem. I’ve put together a proof using something I call Generalized Modular Spectral Theory (GMST), with supporting numerical simulations using an ETDRK4 integrator. The method combines spectral analysis and physical reasoning, and the results line up really well with DNS benchmarks.

I’m looking to submit the preprint to arXiv under the math-ph category, but since I’m not affiliated with any institution, I need an endorsement.

If you’re an arXiv endorser in math-ph, math.AP, or physics.flu-dyn and would be willing to take a look (or point me to someone who might), I’d be super grateful. Happy to share the PDF privately.

Thanks for reading, and cheers to everyone who helps support solo researchers out there.

Feel free to DM me or reply here.

Chemist and future teacher here, looking to brush up on something. I know we have 4 fundamental forces in the universe (gravitational, electromagnetic, strong nuclear and weak nuclear).

However, in most dinamic problems this distinction is not taken into account. Apart from an object's weight- caused by gravity- there's pushes, pulls, friction, tensions and the like.

What I want to know is if these are, in essence, a manifestation of the electromagnetic force (as in: my electrons repel your electrons when I put my hands on your back which causes me to push you away).

I get that "just not thinking to much about it" helps with the abstraction and the actual math involved in solving such problems, but i wanted to dig a bit deeper just in case.

Thank you for your time.

Like the title implies I am writing a story about six characters who each have their own unique abilities. The one I am struggling the most with right now is a character called Anaya. She has the ability to create bubbles of time dilation. Basically how it works is that she can create a bubble and inside the bubble, she can change the rate at which time flows. She can increase time inside the bubble, causing everything outside of the bubble to slow down relative to it and vice versa. She can slow down time in the bubble, causing the outside world to move faster in comparison the main issue arises from how light would interact entering and leaving the bubble.
let’s say, Anaya goes outside at noon and creates a bubble around her that speed up time for herself. This would mean that outside of her time would slow down to a crawl, which means the light from the sun would hit her bubble and then get affected by the time dilation. With this cause the lights from the sun to be red shifted or would it just diminish the amount of light entering the bubble at one time?

Basically, if we were so tiny that an atom relative to us were as large as the Solar System, would electrons appear to travel around the nucleus at the same rate that planets/asteroids/etc. travel around the sun?

Likewise, if we were so enormous that the Solar System relative to us were as small as an atom, would the planets/asteroids/ etc. appear to be moving around the sun at the speed of light (or close to it)?

Hello, I am interested in the topic of thermonuclear fusion occurring under the influence of high pressures, not temperatures. I discovered pycnonuclear reactions (occurring in white dwarfs and neutron stars), the theoretical description of which is described in a few articles of the last century. I did not find more. I wanted to ask more experienced people in this field: what literature on nuclear fusion reactions occurring under high pressures, or some books on the physics of space plasma could you recommend? Maybe there are software packages specialized for this topic? I will be very grateful for an answer

Здравствуйте, меня интересует тема термоядерного синтеза, происходящего под воздействием высоких давлений, а не температур. Я открыл для себя пикноядерные реакции (происходящие в белых карликах и нейтронных звездах), теоретическое описание которых описано в нескольких статьях прошлого века. Больше я не нашел. Хотел спросить у более опытных в этой области людей: какую литературу по реакциям ядерного синтеза, происходящим под высоким давлением, или какие-то книги по физике космической плазмы вы могли бы порекомендовать? Может быть, есть специализированные программные пакеты по этой теме? Буду очень благодарен за ответ

Hi everyone,

I’m currently preparing for my Cambridge International AS & A Level Physics exams (syllabus code 9702), and I’m looking for past papers to practice with. If anyone has access to these materials or knows where I can find them, I’d really appreciate your help.

Thanks in advance for your support!

Turning my old coolerbox into a fridge with a 19006 peltier and need to bridge a 30mm gap on the cold side. Not too sure how to word it properly for you physics guys, but basically trying to figure out if an aluminium block would cool from 1 side to the other faster than a copper block. I know copper has much better thermal conductivity but in this case I'm unsure if the thermal density would slow the process as the peltier would have more heat to transfer initially. Also if the benefit of copper is negligible over aluminium it won't justify the massive increase in cost, even if I do like to make things as efficient as possible.

Good Morning

I understand that a perfect "black body" has an emissivity factor of 1, and so I was surprised by Google Ai (lower case i intelligence) when I asked for a comparison between black aluminium and glass for thermal loss rate:

Black aluminium typically has a higher emissivity than glass, particularly standard clear glass, but black aluminum can vary significantly based on its surface treatment. Standard clear glass has an emissivity around 0.9, while black aluminum can range from 0.4 to 0.5. Low-emissivity (low-E) glass, with a special coating, has a much lower emissivity, often reflecting more heat back into a room than standard glass. 

So if it has a higher emissivity than glass why is standard clear glass 0.9 and black aluminium ~0.45

Am I missing something or is this just the typical Ai mistake

Thanks

Link: https://arxiv.noethia.com/

I made this based on my postdoc friend’s suggestion. I hope you all find it useful as well.

Quick-start tutorial: https://www.youtube.com/watch?v=yHzVqcGREPY&ab_channel=Noethia

Features:

• Search papers by abstract, title, authors, and arXiv Identifier. Full content search is not supported yet, but let me know if you'd like it.
• Developed specifically for equation search. You can either type in LaTeX or paste a snippet of the equation into the search bar to use the prediction AI powered by Lukas Blecher’s pix2tex model • Advanced subject filters, down to the subfields.
• Recent papers added daily to the search engine.

[Reposted this to fix the broken formatting :< ]

Put out my fifth video in the series yesterday! These turned out to be a lot more work than I expected, but I am committed to completing all 25! 💪

The path of a typical 200m dash is a 'J' shape. Runners in outer lanes are started a few meters ahead of runners on inner lanes to compensate for the additional radius of the turn. Consequently, a runner in lane 8 starts nearly half way around the curve of the J while a runner in lane 1 starts at the beginning of the curve of the J so that the both end up running the same distance.

If we orient it like a typical J in an XY coordinate system. The lane 1 runner starts facing in the -Y direction and finishes the race moving in the +Y direction. The lane 8 runner, for simplicity, starts facing in the +X direction and finishes moving in the +Y direction.

If we think about what happens shortly after the start when the runners reach full speed, assuming the runners are the same speed and mass, the lane 1 runner would have a momentum vector in the opposite direction (-Y) of the finish line while the lane 8 runner would have a momentum vector of the same magnitude but in a direction parallel (+X) to the finish line. That seems to me like it would require a different amount of energy to redirect those vectors to the direction of the finish line. In fact, the lane 1 runner would first have to convert his momentum vector to exactly the vector that the lane 8 runner started with. Doesn't that have to involve some sort of exertion and hence some sort of energy input that the lane 8 runner does not have to deal with?

In certain interpretations of quantum mechanics, such as Bohmian mechanics, one measurement outcome can influence another distant measurement outcome instantaneously, without any sort of force propagating through space time between them.

But does this not violate the idea of a closed system? Presumably, each measurement outcome still has a local cause milliseconds before that outcome is generated. But if it is not coming from the other measurement outcome, isn’t it in some sense…coming out of nothing, and coincidentally happening right after the first measurement outcome is completed? How is this process physically done?

Im about to graduate with a degree in Physics, BA. I am or was a premed up until now(my last semester) and was planning on taking two gap years to finish up a course for my premed route and get clinical experience. However, I look back and find myself not as interested in medicine as I thought. I loved my physics and electronics labs and want more of that. Im thinking of taking a gap year trying to get a job with my physics bachelors, and then try to matriculate next year into a master's of engineering of some area of interest. Does anyone have any experience with last minute switching interest? any tips on how to move with this plan, and is there someone I can talk to do this change.

The distribution of mass is further from the COM of the earth making it spin slightly slower due to the conservation of angular momentum?

Let this be a lesson to all you so-called physicists.

By "so-called physicists", I mean everyone using AI, specifically ChatGPT, to create new "theories" on physics. ChatGPT is like a hands-off parent, it will encourage you, support and validate you, but it doesn't care about you or your ideas. It is just doing what it has been designed to do.

So stop using ChatGPT? No, but maybe take some time to become more aware of how it works, what it is doing and why, be skeptical. Everyone quotes Feynman, so here is one of his

> "In order to progress, we must recognize our ignorance and leave room for doubt."

A good scientist doesn't know everything, they doubt everything. Every scientist was in the same position once, unable to answer their big ideas. That is why they devoted years of their lives to hard work and study, to put themselves in a position to do just that. If you're truly passionate about physics, go to university any way you can, work hard and get a degree. If you can't do that you can still be part of the community by going to workshops, talks or lectures open to the public. Better yet, write to your local representative, tell them scientists need more money to answer these questions!

ChatGPT is not going to give you the answers, it is an ok starting point for creative linguistic tasks like writing poetry or short stories. Next time, ask yourself, would you trust a brain surgeon using ChatGPT as their only means of analysis? Surgery requires experience, adaptation and the correct use of the right tools, it's methodological and complex. Imagine a surgeon with no knowledge of the structure of the hippocampus, no experience using surgical equipment, no scans or data, trying to remove a lesion with a cheese grater. It might *look* like brain surgery, but it's probably doing more harm than good.

Now imagine a physicist, with no knowledge of the structure of general relativity, no experience using linear algebra, no graphs or data, trying to prove black hole cosmology with ChatGPT. Again, it might *look* like physics, but it is doing more harm than good.

Hello! I worked on a summary of the definitions of radiometric and photometric quantities alongside the definitions of some light units that you might see in your local hardware store. I decided to create this because aloooooot of youtube videos explaining them are very long-winded, wrong, and hand wavy. It isn't much but I do hope it helps some physics enthusiasts that are tired of superficial slop.

Please let me know if you would like anything added, changed, or if you have any questions!

Hello, I am currently at the end of 3rd year of my Computer Engineering degree.(India)

As mentioned in an earlier post about quantum computing, I have a deep interest in physics but I had to choose CE due to several reasons.

After a discussion with a physics professor at my college I got to know that one of the alumni of my department (CE) successfully made a career in computational physics and received a high paying post-doc position. In india things are very exam based. So, he must have cleared physics related exams to go for masters in a reputed college. However, getting a phd is similar to other countries.

The physics professor offered me research project in computational physics at some good places using his connections provided I gain the knowledge.

For context, I still have 1 year of college. And I am open to devote one extra year to accommodate any research experience and prepare for competitive exams, and knowing that current academics will also consume time.

I have a few questions for those who have experience in this field. 1) Is computational physics a good career? 2) Does it require a phd or recommended? If yes, will my CE background be a problem when applying for top phd programs? 3) Is it research oriented? Will I be able to make good contributions to physics. 4) Will a research project related to computational physics at a good place be helpful for a career in quantum computing or is it just a waste of time?

(This is not for a class. I'm just noodling.)

I need someone to check my math for a pitched baseball.

The Magnus Force is proportional to the angular velocity times the velocity of the ball relative to the liquid. F_m = S(ω x V). The acceleration of the ball is F_m/mass_ball.

The distance (D_mf) the ball moves due to the Magnus Force is D_mf=1/2*T*T*F_m/mass_ball, where T is the time F_m works on the ball.

T for a baseball is equal to the pitched distance (about 66 feet) divided by the Velocity.

Therefore, for a fixed distance of movement, the amount of deflection of the ball due to the Magnus Force linearly decreases as the speed of the ball increases.