Thread Definition and 503 Threads

Why rainbow formed ?

I'm trying to determine the contact surface area of a threaded bolt so that I can make some changes to the design and maintain the same contact surface so as not to affect the performace in other ways. This presents itself as a helix, and my initial guess was that it may be best to work this...

Found this "not so little" beast flying round my garden shed today. A lower pitched "buzz" than a typical bee - it sounded a bit like a very small motorbike engine! I presume it's some sort of beetle. The wingspan was at least 2 inches. The first picture is after it crashed into the window -...

Hi, I am trying to figure out how to pass arguments to a thread via a struct. It's not really working out for me. What am i doing wrong here? #include <stdio.h> #include <stdlib.h> #include <pthread.h> #include <string.h> void *run(void *thread_arg); struct thread_args {...

Hi everyone, this is my first post on the forums :redface: OK so I want to design a microwave power transmitter and I need a few opinions before I make any commitments. I haven't made many complex circuits before, but I am going to do my homework if this is viable and break it into chunks...

Homework Statement I'm sitting down and doing somewhere around 50 problems this evening for practice, and I just got stuck. I will probably use this one thread to post multiple questions if that is okay. Homework Equations The Attempt at a Solution Edited out this problem, it was my...

EE vs. Applied Physics (different than "become an engineer thread" I think) Hello all, I read through the first few pages of the "So U want to Engineer" thread, but the gist was not quite was I was hoping. Ok, I am about to be a senior in an Applied Physics program in North Carolina. I...

Stoichiometry problem Homework Statement 1 g of H2O2 solution containing x % of H2O2 by weight required x ml of KMnO4 for complete oxidation in acid medium. What is the normality of KMnO4 solution? Homework Equations H2O2 + KMnO4 => 2KOH + 2MnO2 + 2O2 The Attempt at a Solution...

<Crackpot link deleted> Anyone have details or an opinion rooted in science?

Ok double slit experiment. Two slits send through one photon which passes through both slits due to wave/particle duality. So really we have two probability waveforms now don't we? One passing through each slit and creating a wave pattern from the start of each slit. THat's how we get an...

Hi Folks Regarding the double slit problem, I read recently a theory that suggested that the universe itself split creating effectively two particles, which can interfere. Personally I think this is imaginative but it simply doesn't sit right, it seems somehow illogical and wasteful for...

From a locked thread: 1)When the car goes forward we tend to go backward and our back is pressed into the sit, so I'd say the balloon does the same, i.e. goes backward. It would be counter intuitive if it went the other way. 2)I have to use common sense here, pure intuition would leave me...

Maybe there should be a resources thread/sticky here? This would make a good start: http://cew.georgetown.edu/whatsitworth/

Fukushima thread, June 1st, 2235.

My physics teacher is having us research random topics in advanced physics for us to get some experience with research. He assigned me Fluid Thread Viscosity, but I could not find any good sources on the web. Do you guys know of any good sites I could find some information on the topic? Thanks

Homework Statement A parent takes their child to a water slide which is shaped similar to a portion of a parabola (see diagram). There is an elevator 3m from the edge of the pool. The elevator takes the rider to the top of the slide which is 19m above ground. The rider slides down and falls...

Hello everyone, Is anyone else here planning on applying to grad schools soon? If so, please holler out! Maybe we can share resources with each other (in a place where there aren't many resources). I'm actually really into astronomy, but my area, modelling planetary atmospheres, is one...

I don't want to keep making threads when I come across some puzzling algebra concepts or problems, so I'll just use this thread as a reference point in the future when this may happen. I'm having trouble understanding the following: 1/x3 = -1 The author of my text says to cross multiply and...

Hi people new to this forum but i need some help on my thread design. I've been browsing the net for some time to try and find some help on the design of this but have not found much. My problem is i have a tubular member of 250mm outer and 100mm inner diameters that is subjected to an axial...

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nvmd. This thread can be locked

Hi, I have a maglite pen powered by 2 AA battery. I hadn't used it for years. I found out i was leaking chemical already at the rear, and I couldn't open the rear cap. I tried using wrench, pliers, hammers, nails which I insert to the hole at the rear cap and no matter how I twist and turn...

I decided we needed a thread just to track radioactive contamination. I will start it with my hometown of San Diego, but reports from anywhere are appreaciated, especially if they show the degree of contamination of the Japanese countryside and the ocean. In San Diego we have seen only a very...

Discuss your latest adventures in fast food. Me? Last night I had FOUR sandwhiches in one sitting from McDonalds. It was awesome.

Your "Dream Come True" thread Now, to be perfectly straight with you all: I honestly don't consider myself very materialistic (or at least, I didn't used to be). As a matter of fact, I seriously thought for a long time about joining the church--maybe the Franciscans (pun not intended)--and...

dears y every time i post a thread i do not find it in the website? Did the administrator delete it? and y?

Yesterday there was a thread here on a claimed violation of Lorentz invariance, but I can't locate it today. Was the thread moved? Can someone point me to its new location? (I don't remember the exact title of the thread, but the posts referred to a letter in the Sep 2010 issue of European...

I've read most of the Paradox within a Paradox thread but rather than hijack it to get to my point I thought I'd start a new thread. First, if this has already been addressed from this angle my apologies, but it is next to impossible to read through all the TP threads to try and find one from...

A quick note: when learning anything, I wish very strongly to focus on things that have cross-applications. I have little interest in focusing on learning specific skills, so when I state an interest in programming or closely related subjects, I mean that I wish to learn the metaskills...

1. What does an experimental physicist do? What does a theoretical physicist do? 2. What does it take to be an experimentalist? What does it take to be a theorist? (In terms of ability, courses taken, skills, etc.) 3. Work conditions, career options, financial freedom, intellectual freedom...

This is related to another current thread https://www.physicsforums.com/showthread.php?t=426307" wherein yuiop presents a very convincing demonstration of non-reciprocal proper time differential between an accelerated system AF and an inertial system IF between two points A and B In...

I know some members like to go hiking different places, and there are various pictures posted in Nature threads. But this is for sharing information on hiking and hikes that folks have done or would like to do. Explorer 6 Days, 6 States, 6 Peaks...

Not the usual "how to get research" thread... I've worked with professors before during the academic year and am doing so currently. I've done an REU also. My question is: how does one ask a professor for a (paid) research opportunity for the summer? Simply asking a professor to work with...

I have a 15-year-old who wants to go into astrophysics, applying either quantum, or atomic/molecular/optics disciplines. My understanding, from reading Zapper's thread, is that she should get a BA degree in physics then specialize at the graduate level in astrophysics. Is that correct...

Hi there. Sorry for the lengthy thread! Please persevere :smile: I have seen that there are many of these threads - so apologies for the bits that overlap. I have tried to keep this as 'original' as possible - but with all of the help I have had so far from browsing this forum I couldn't...

I recently attended this lecture by Physicist Daniel Sheehan, any opinions about the 2nd law soon violated in Laboratory Experiments? (and we are not talking about background fluctuations, etc). Experimental Challenges to the Second Law of Thermodynamics D.P. Sheehan, University of San...

From http://star.tau.ac.il/QUIZ/ website: This problem can also be found on page 32 http://kvant.mirror1.mccme.ru/1990/05/resheniya_zadach_f1206_-_f1212.htm , but it's in Russian so might be hard to read... Can someone explain this solution? Is it always true that F=Fo/2? Don't we need...

"Ben and Jerry's 'Boston Creme Pie" Ice Cream" Appreciation Thread Truly amazing stuff going on in that container. those who know, know. I only hope to one day truly understand the science behind why this is so delicious. until then, i shall enjoy and appreciate it. - may scientific...

Rule 1) Absolutely no religious references, only spiritual and philosophical Rule 2) God may be discussed in this thread Rule 3) God is not a person, physical being, or anything with any type of anthropomorphic traits for the purpose of this discussion (i.e. does not talk and certainly does...

So after posting the blur contest, I did some experimenting with trees in the wind and the sun. Camera on tripod, telelens 70-300, all controls manual, exposure 1/4 sec while zooming in Same exposure but letting the wind do the blurring work Same exposure while making circles...

I've seen a few people posting their failures and successes in various threads, so I figured it'd be a good idea to have one combined thread where you post how you did this semester. What classes did you take? How did you do? Did you get any research done? What other trials and tribulations did...

I thought it might be fun to have a thread to show our fossils. Everyone dig up your fossil picks. I found this rock this morning. The fossils range from 400-500 million years old. I'll post more as I dig my pictures out. I'm posting the kansas fossil page for what's on this rock (from...

Another "Late in Life Physics" thread I should really say "Really really late-in-life" I'm 56. About 20 years ago, I flushed myself out of grad school (physics) largely over just being fed-up. Lately I've been reading again because of the huge number of very good books immediately...

Is there any point at all in learning Latin?? I know this is the 21st century, but there must be some little use for it right? For Mathematician/Physicists.

I was shooting some macro pix in the park today. Actually I was targetting this lichen in that pic: and this one: But it's more about the new life: Feel free to share your spring pictures.

Find an interesting article about a new technology, new design, and whatever else is related to things that fly? Post her here!

So, the time has come that grad school decisions are coming in. Anybody received any acceptances yet? I have applied to 8 schools for a master's in math and have gotten accepted to two - Miami University of Ohio and Bowling Green State University.

I drew a picture of Leonardo Dicaprio. Here's one I drew of Jackie Chan.

Whaaat? Nobody has started a first post thread? Jees. Fine, I'll be the radical bad boy and make it. Hi! I'm Joe. Nice to meet you all. I'm a Physics Major in Western Massachusetts (no e, lol) and currently attempting to find a new college because the one I'm at is just abysmal. I've...

Hi, I was just wondering why paragraphs containing inline LaTeX have extra line breaks or line spaces after the line containing the TeX image? I was also wondering why I don't always see new posts in threads I've subscribed to in "My PF" unless if I click on the link to see all subscribed...