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Johnny Helium
DAYONE: Posted 6 weeks of work to invite resonance.
10 hours later: Removed for violation—flagged as “unpublished.”
May similar shared works be reviewed with equal rigor.
Now publicly available on GitHub Gist:
[Unaceptable reference removed by the Mentors]
Johnny Helium
Johnny Helium
a forum about physics, where spacetime bends and particles tunnel, yet your birthdate is immutable unless you beg an admin.
MrApple12
Learning Python, C++, SQL! Any recommended books is appreciated! Thanks!!
berkeman
berkeman
Welcome to PF. That question is best posted in the open forums in the Textbooks sub-forum. That should get you some good replies. :smile:
TensorCalculus
Gold Member
Leading a hackathon tomorrow... so scared... but also super excited :)
berkeman
berkeman
Awesome! You will do great -- have fun! :smile:
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TensorCalculus
TensorCalculus
Thank you so much!!! Now there's only 2 hours till the hackathon the nerves are hitting me: 12 hours of managing 60 teenage nerds... welp...
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TensorCalculus
TensorCalculus
Update: everything went very well! It was chaos but it was amazing, and not so chaotic that we had any problems. Some of the most fun I've ever had!!!
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dlbruce0107
I was reading Anderle's TQB and they mentioned wives and their husbands' skid marks and I got distracted thinking about the probability of a grown man . . . Well, anyway I started thinking about the physics of skid marks — obviously I googled.
Hi! Looking forward to understanding the calculus of skid marks!
berkeman
berkeman
Some parts of your Profile post are problematic, but let me take it at face value. Please post your questions about friction and skid marks in the Classical Physics forum and post links to your reading that you've been doing about friction and tire skid marks. That will help us to try to help you understand what you are asking about.
dlbruce0107
dlbruce0107
Just what I wanted to know.
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Baakii
Let's Talk Big Bang and the Start of Our Universe! (Help Needed: My English is Basic, So Let's Make This Fun!)"Hello everyone! 🌌 I'm from Mongolia and super excited to chat with anyone who loves learning about the Big Bang and how our universe began. But honestly, my English is not perfect – it's a little bit broken sometimes. 😅 So, please be patient if I make mistakes, and let's help each other out!
berkeman
berkeman
Welcome to PF. :smile:

Please read through our Insights articles about the Big Bang: https://www.physicsforums.com/insights/?s=big+bang

and if you have questions about that reading, start a thread in the Cosmology forum. We do not generally discuss science questions in Direct Messages (DMs). Thanks.
SarcasticSkot
Hello everyone I’m Skot. I’m an amateur wannabe physicist, a father, inventor, writer, guitarist, music producer, Photoshop aficionado, audio engineer, and retired TV and Radio Broadcast Engineer for the NFL and MLB.

I’ve been writing down a lot of the crazy ideas I’ve had rattling around in my head and finally decided to see if they hold any value to the scientist community. I want to help push humankind forward into a future I know we can achieve.
berkeman
berkeman
Welcome to PF, Skot. Please keep in mind that we do not allow personal speculation at PF. Discussions have to be based on science as published in the professional scientific literature (peer-reviewed journals and mainstream textbooks). Please have a look through the PF rules (see INFO at the top of the page). Thanks.
SarcasticSkot
SarcasticSkot
All of my concepts are expanded from published particle physics, quantum mechanics and other sciences. Are you saying this site doesn’t encourage theoretical discussions within the current sciences?
berkeman
berkeman
We welcome discussion of published articles (modulo the Clarivate list mentioned in the rules), but likely would not allow proposed extensions to those published works (until those extensions themselves have also been published).
TensorCalculus
Gold Member
I've had 6 coffees in the past 2 hours so now my physics is turbocharged :woot:
sophiecentaur
Science Advisor
Homework Helper
I just discovered this messaging facility. Message: Keep posting questions and don't worry that they may sound daft. It's PF's fault if you don't get proper answers to put you straight.
Cheers
:smile:
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C
A graduate student, interested in algebraic quantum field theory (AQFT), axiomatic quantum field theory, and mathematical physics.
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Starknakdfopsy
New here and looking for like minds.
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AlexB23
AlexB23
Welcome to the forums. Also, nice avatar of a thunderstorm and red sprite from the ISS.
Starknakdfopsy
Starknakdfopsy
Just found the curt response in my email sent to me. Free minds or even friendly minds are not allowed here. I will not return.

Thankyou for responding without banning me.

Sean B.
AlexB23
AlexB23
I was not the guy who did that.
TensorCalculus
Gold Member
Doing Physics :-)
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View previous comments…
.Scott
.Scott
If you really want to be an astronaut and you're willing to trade your well-being and perhaps your life for wonders and glory, make sure you let SpaceX know. It is reasonable to expect that they will be sending hundreds to Mars over the next decade or two.
In school, I was also "abysmal" in sports. But even then, I could climb a tree like a monkey and easily bike 40 miles any day. Since then I have tried out several aviation "sports" and I walk 6 miles a day.
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.Scott
.Scott
Despite my age (71), my fitbit says my resting heart rate is that of an athlete.
In a hypobaric chamber exercise (years ago), I was able to outlast 15 other pilots (mostly military) before I needed to put my oxygen mask back on. The exercise involved trying to answer test questions at 40,000ft with no supplemental O2.
So I wouldn't use that "abysmal" as a serious yardstick for your astronaut potential. First in football is more likely to get you into elected office than into a space craft.
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TensorCalculus
TensorCalculus
okay that is very impressive...honestly I can barely bike 5 miles let alone 40 though :(
For now the path is astrophysicist BUT you have made it seem a bit more feasible now! And giving up my life for going into space... well... as of right now - I'm more of a fan of trading my life and every last scrap of my sanity for studying and knowing more about space instead XD
AlexB23
'Sup sir. I like the Danish products you guys have over there. One of my tables is made there (got it second hand at a US consignment shop, as I am in the US), and is high quality. Beautiful architecture and history in Denmark as well. Also, Lego is cool. Gonna get some off my cousin who is downsizing her collection.
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AlexB23
AlexB23
Thank you. The table was made in the 1970s, and did not have any IKEA branding. The technics Lego were cool. I did that for a Lego club after school in 2010 or 2011.
sbrothy
sbrothy
If you have any furniture designed by Poul Henningsen, popularly called PH (as is his design, "PH-lamps", "PH-chairs"), you're basically (literally in the former case) sitting on a small fortune. The word "fungible" actually sprang to mind (although I had to look it up subsequently to confirm it's meaning). :smile:
AlexB23
AlexB23
I am not sure what mine is
E
Gold Member
Equation Sheet:

$$ 0 = \frac{ d}{dt} \int_{cv} \rho d V\llap{-} + \int_{cs} \rho ( \boldsymbol {V}\cdot d \boldsymbol{A} ) \tag{mass}$$
E
erobz
$$ \sum \boldsymbol{F} = \frac{ d}{dt} \int_{cv} \rho \boldsymbol{v} d V\llap{-} + \int_{cs} \boldsymbol{v}\rho ( \boldsymbol {V}\cdot d \boldsymbol{A} ) \tag{Momentum}$$
E
erobz
$$ \dot Q - \dot W_s = \frac{d}{dt} \int_{cv} \rho \left( \frac{V^2}{2} + gz + u \right) d V\llap{-} + \int_{cs} \left( \frac{V^2}{2} + gz + u + \frac{p}{\rho} \right) \rho \boldsymbol {V}\cdot d \boldsymbol{A} \tag{Energy}$$
berkeman
berkeman
Hi @erobz -- do you still need this? It's probably better to store such LaTeX helper sheets locally on your computer.
Jay222
ChatGPT isn't always right, I agree with that !! But it and others like it, are well beyond the early "chatbots" and can be successful in many applications. Vetting is clearly always needed rather than just accepting everything ChatGPT says without review and careful proofreading/copyediting. This URL links to discussion of ChatGPT as compared to early "dumber" chatbots. https://research.aimultiple.com/chatbot-vs-chatgpt/
Jay222
Jay222
Also of course, ChatGPT and similar AI systems are improving VERY rapidly, so their potential future abilities shouldn't be underestimated. That's just obvious.
W
6 years ago you asked about the origin of the (-) in the differential equation for the RC Circuit. I felt compelled to make an account & tell you that the last lecture note that my physics professor posted for the year was based on this question, and he used it as lesson on perseverance and the desire for learning. There was even a heading titled Simpcar: an Internet Hero. I disclosed the lecture note in a private message to you; I added this post just to increase the likelihood of you seeing it
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A
Gold Member
Hello Raul welcome to PhysicsForums,

Firing a neutron and a proton at each other in a tube and have them hit sounds very very difficult to do.

I think it will be impossible to convince anyone your idea can work until you are better educated in physics. I think you should continue with your education. As you learn more you may want to change the design.

I wish you luck.
Gabriel Mwamlima
I am Gabriel Mwamlima A member of Physics Forums. I joined the Physics Forum in December 2023. I am Privileged to learn so much from you guys. As you all know, technology is advancing and changing each day. Different scientists coming up with new ideas and new ways on how things can change. I am one of the persons who needs so much in technology so that things that were difficult before should be easier for us.
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Telescopic
I might switch to every week because i can NOT keep up with one per day, I'm forgetful
berkeman
berkeman
FYI, Profile Posts are not really meant to be user blogs. They are more for one-time announcements or pings to other members to see if they are up for a DM conversation. If you look at other Profile Posts, that is what you will see. :smile:
Telescopic
Telescopic
I know that but I think Its nice just having some fun facts and stuff that I learned on my pf, you know.
Hop-AC8NS
I am an 80+ years old ham radio operator (AC8NS) working on a "bucket list" project. Visit optical-eme.groups.io if interested.
berkeman
berkeman
73. KI6EGL here; it's good to have you here at PF. :smile:
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Hop-AC8NS
Hop-AC8NS
Thank you. I need help with an optics design using a laser diode, such as the Nichia NDG7H75, which emits in multi-transverse modes with wavelengths of 532nm +/-10nm. I want to get rid of the adjacent emission lobes with a spatial filter, expand the remaining TEMoo main lobe to fill a 102mm diameter, 1000mm fl lens and produce a collimated laser beam.:cool:
berkeman
berkeman
You will probably get the best responses to that question in the Optics forum under the Physics area of PF. Start a thread there with links to the datasheet(s) and links to any other useful information that you've run across while working on this project. That should help you to get good responses there. :smile:
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Telescopic
Day #3 Black Holes Warp Space itself in a sort of spiral (Sorry for missing a day)

~Telescopic
Telescopic
Day #2 Today I learned that if you teleport to the center of the sun you will die in around 1 femtosecond (which is 1/1000000000000000000 of a second)

~Telescopic
Telescopic
Day #1 Today I learned that in my favorite scene from Interstellar (The 5 dimensional scene) the 5 Dimensions are 1st, 2nd, 3rd, Time, and Gravity

~Telescopic
Telescopic
I'm new to the forum but want to learn astrophysics and physics in general.
phinds
phinds
Then you should do an intro post IN THE OPEN FORUM, not here in your very own profile posts
E
Integrated circuits are referred to as ICs, chips, or microchips. The integration of large numbers of tiny transistors into a small chip replaces the manual assembly of circuits using discrete electronic components.
AlexB23
Hello sir. Are you the guy that programmed Falstad, the electronics applet that I used in physics class a few years ago?
Hans de Vries
Hans de Vries
No, that wasn't me. I do have a pretty common name
:smile:
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AlexB23
AlexB23
Cool. I just saw your website, and you linked it to Falstad. So, you like electrical physics?
luankeanu
Good evening sir, I was exploring the concept of a flywheel for a rocket I'm designing and I stumbled upon a posting from 2012 made through your account on this thread. I was wondering if you had a minute to chat about the concept? All the best.
P
Congratulations on your new trophy (which I presume is for best “newest member poster”)

I for one am happy to have you here and apparently many others are as well.

All the best!
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AlexB23
Hello sir. It is cool that you play the violin. How old is your violin? Apparently, older violins sound better for some reason to do with wood and resonance.
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AlexB23
Hello sir. Is everything going well in California, given the news about the 2025 wildfires?
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AlexB23
AlexB23
Hey, at least you are far away from the fires. Reminds me of an episode of Star Trek Picard where LA was on fire. Prayers and hopes for California that these fires end.
Paul Colby
Paul Colby
There have been several fires like this in our area last year. Once the wind kicks up, it goes house to house. Wind events are relatively rare in my town. But likely just a matter of time. Maybe we’ll be lucky.
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AlexB23
AlexB23
Just stay safe, brother. There has to be a way to reduce these wildfires. Carbon emissions are leading to more of these disasters.
G
Hi Gary, I am responding to your closed forum: Like a claw fossil or something. Your picture is upside down. Clean up your rock with a steel welding brush to remove the mineralized dirt and oxidation. This will bring out all the colors. I can see from your photos that the inside of this rock where it is exposed is agatized. A product of fast fossilization. From what I can see, you don't have a claw, rather, you have a turtle's front flipper. Hope this message finds you. Greg
berkeman
berkeman
Hi Greg, and Welcome to PF.

Gary has not been back to PF since 2009, so it's pretty unlikely that they will respond. Thanks for trying though.
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