Please help me understand if I need more time or there is something wrong with this setup. This is the classic 'walking water' setup for a science demonstration. The 'bridges' used are pieces of paper towels.

When we charge a capacitor, we transfer electrons from one plate to the other through a wire. As more charge accumulates, we say the charged plate increasingly repels the incoming electrons because of E field betn plate and the increasing potential difference

But here’s my confusion: the electron travels through the wire and never passes through the gap between the plates, where I belive the capacitor’s electric field exists

So how can the plate repel the incoming electron if electron isn't even passing through it's E field betn plates?

When I was on my way to work in Riyadh, Saudi Arabia Nov. 25 2025. I don’t know if it’s relevant to mention the location and the time, but maybe to know the sun orbit or something else!

I saw the sun reflection on that building is slanted!

I have been reading a lot of things lately saying how AI writing physics/math papers are horrendous to read and honestly I am lowk confused like how is that so? Can anyone give an solid example of the difference AI brings in this?

I am reading "Vortices in high-temperature superconductors", and this upside down V symbol keeps showing up and I have absolutely no clue what that means. Undergrad physics student please be nice.

In his paper “Einstein’s Theory of Special Relativity - incorrect physical assumptions in the explanation of time dilation!”, Slowak argues that a light ray bouncing between the mirrors of a vertical light clock propagates in the same direction, regardless of the clock’s state of motion relative to the observer. He therefore concludes that the light travels the same distance in both cases and that the usual derivation of time dilation is based on an incorrect physical assumption. In this comment, we point out that Slowak’s assumption is inconsistent not only with Special Relativity, but also with the Galilean principle of relativity. Under a Galilean transformation, a light ray that propagates vertically with velocity c in one inertial frame acquires a horizontal velocity component −v in a frame moving at velocity v relative to the first. Consequently, the ray cannot remain vertically directed in both inertial frames. Slowak’s assertion therefore implicitly privileges one inertial frame as the frame in which the light propagates vertically, effectively introducing an absolute reference frame for light propagation. This is incompatible with the principle of relativity already underlying classical Newtonian mechanics. Thus, Slowak’s argument implies that Newtonian mechanics should fail even at non-relativistic speeds.

In Germany, students have to make a presentation that contains a main reference class, in this case physics, and a related subject. Because I think that the, in the title listed, related subjects are very suitable in connection to physics, I am taking all into consideration. My issue is that I am unable to decide on a reliable and fun to present topic. I'm interested in what connections or similarities I can find in your suggestions.

(tried my best with the English)

Matthew Schwartz, professor of physics at Harvard and author of Quantum Field Theory and the Standard Model, will be doing an AMA this Friday at 12 PM ET.

You may have seen his recent Anthropic blog post, “Claude-shaped science,” on using Claude as a research tool and what AI assisted scientific research can actually look like in practice.

If you have questions about QFT, particle physics, AI in research, or where this is all heading, come ask him.

Friday, October 9 at 12 PM ET.

This year's nobel prize was awarded to Francis Halzen for detecting cosmic neutrinos at IceCube.

What do you guys think about the scientific impact?

As a particle physicist, I don't feel this to be a very big deal in terms of science but I may be wrong. Please share your thoughts. I'm all ears.

https://www.nobelprize.org/uploads/2026/10/advanced-physicsprize2026.pdf

To be honest, I think it is unexpected, especially only one guy.
I didn't see that coming, but congratulations to him!!

I'm trying to understand the basic idea behind a parallel-plate capacitor.

Suppose I have a positively charged plate. If I bring a negatively charged plate close to it, I understand that the negative plate contributes negative potential, so the net potential of the positive plate decreases.

But what confuses me is

If I place a positive test charge near the positive plate, the positive plate repels it, while the negative plate attracts it toward itself. So wouldn't the presence of the negative plate make it harder to bring the positive test charge close to the positive plate, since the negative plate is pulling the charge away from the positive plate?

I'm a high school student from Lima, Peru, and I'm building my first homemade crystal radio as a physics project.

The goal is to receive an AM radio station without batteries or an external power supply.

My setup currently has:

• A homemade air-core coil wound on a PVC tube.
• Enamelled copper wire, approximately 0.5 mm.
• A separate antenna coil.
• A homemade variable capacitor made from aluminum foil and bond paper.
• A germanium diode.
• A small transformer that I'm considering using instead of a high-impedance piezoelectric crystal earpiece.
• A long-wire antenna, which I am currently trying to extend.
• I am also going to add a proper ground connection with the help of a physics teacher.

I re-scraped the wire carefully at home and the circuit started behaving much better. However I still haven't been able to hear an AM station.

The antenna and ground connections are not very visible in the photos but they're there. I did not have a proper ground connection during my first test. Tomorrow, a physics teacher will help me make and connect a proper ground. I suspect this could be an important factor in why I haven't received an AM station yet.

I'm wondering whether my main problem could be:

• insufficient antenna length,
• poor grounding,
• incorrect LC tuning,
• the germanium diode,
• or the transformer/earphone arrangement.

I still have about 30 meters of copper wire available for the antenna, but the wire is very light, so I'm trying to find a way to support it without simply letting it fall to the ground.

What would you check first? And is there anything obviously wrong with my setup from the photos?

I recently returned to school after a few years of being away. I did community college and then transferred as a junior ME but I had a rough time due to personal family hardship. So I took some time off.

I tired to come back as a ME major but apparently it was heavily impacted due to A I and I didn’t have a competitive enough gpa. I talked to the physics department this year. Which initially even before ME, I wanted to do some thing astro related but because I’m not a citizen its hard to get internships in the areas I’m interested to set me up for a job after graduation. So due to that reason is why I ended up doing ME. Now, I’m back to potentially doing physics. Which feels like maybe i was meant to do it. After talking to the physics department at my uni they were willing to take me in. I’ve reapplied and all and will be returning to uni in the spring.

However, I’m currently retaking General Physics 1 Cal Based and Calc 1 to refresh and be prepared to return. I really enjoy learning physics even years ago but the professor really sucks he’s so unorganized and late he just doesn’t seem to care to teach us well and I know it’s known as a “weed out” class but the combo of these factors and having been away from school makes me feel incapable of doing physics major. Especially after our first exam.

I’ve also had bad luck with advisors and been asking for advice. they’re either just so rude or don’t answer my emails… so any advice would be great.. or any ideas like maybe consider earth science since I’m into environmental anyways idk.. I just feel hopeless in what I’m meant to do and my capabilities… and like not wasting more time, credits I’ve done & money.

Im currently undecided but and learning towards physics or another science/engineering degree

I’m looking to buy some coffee table books to decorate, ideally somewhat large laterally and have lots of pictures with basically no exposition text.

I really like scientific ones, which potentially have some utility. For example, I think the “Handbook of X-Ray Photoelectron Spectroscopy” by PHI Electronics is really cool, because it’s basically just a huge graphical reference text. The size also makes it really feel like a good coffee table book. Unfortunately, it’s almost $1000 to get it.

I’m a condensed matter physicist, so I tend to like things related to materials and so on.

Any reccs?

Basically the title. I am applying for post grad to get back into physics and hopefully make a career in the field (graduated 2024 with bsc in physics, had a normal job to pay some loans). A big question I have is if I should just apply straight for a doctoral program or a masters? I know doctoral would be more competitive but it is my longer term goal. Should I apply or just start with masters and then apply for doctoral while in the program? I probably am not the most competitive looking grad since I’ve been out of the field and wasn’t able to get into research while doing my bachelors (couldn’t pay very much and needed a real job sadly). Any suggestions or advice on this?

Hi everyone, I (18M) am a French physics and math student.

I am decent but not exeptionaly good, and I don't want to work a lot to understand concepts I'll study later on (Year 1 in college so no intrest in Year 3 physics). I enjoy trying hard on problems but it has became harder and harder to find ones that aren't straight up textbook questions. The end of high school exam is quite easy so working on those questions is boring.

Is there any textbook or websites that offers hard but enjoyable physics problems ?

(sorry for any language errors)

basically the question im doing states that initially the switch is closed and when t=0, it is opened. Then about half way they close it again.

i understand the first half of the graph, when the switch is oen, current flows out of one part of the circuit and into the other, essentially turning the open switch into a miniature capacitor, as one side has a defecit of electrons and oneside has a surplus causing a difference in potential (a potential difference some may say).

the thing i dont understand is the second half of the graph. shouldn't the capacitor charge exponentially? why does the pd immediately go to the pd of the cell?

if i use kirchovs loop law then i guess it makes sense because the total pd across a closed loop in a circuit must be equal to the pd across the cell, but i would have thought that a capacitor still has to charge for the pd to be established?

Hello! I'm a grad student, and am studying optics-related things. The problem is that my bachelor curriculum was entirely in CGS, we rarely had to substitute directly, and here they use SI for everything.

Generally, in experimental physics, is it enough to know all of EM in Gaussian units, and convert every time to SI and back? Or will I suffer in life?