Welcome Definition and 177 Threads

Hi there I am new to this site but I have been reading on it for a while. I have a question, I am building a loading ramp for my box truck to load my lawn mower in. it will be about 12 feet long and 6 feet wide I was wandering what size steel box tubing would be best used for this the...

Howdy y'all, I posted a ways back about an interest in science policy, concerning internships. Now I'm more or less asking about possible classes to take. I am in the process of a political science minor and I need a few classes to take and I'd prefer them to be useful or interesting. If...

HI! i am new to this PF, discovered this site few days ago. After seeing the brilliant people here i decided to join. I know very little math/physics(i'm 16) so i thought that if i am in good company at least i'd improve with time.(i hope)

Hi, I was thinking of something: How are one supposed to calculate the moment needed for a scoop to scoop up a sample of e.g. sand? Does the classical p=mv work? Any ideas or comments?

Hi, I'm new to this forum. I came here because I was told by a friend that the forums are great for getting help on classwork/homework. Aside from that, I came here to learn more about science. I always thought that science was about experiments and wearing white lab coats and growing long...

Hello. I have a question regarding the p-n junction. When I look at figure B here: http://en.wikipedia.org/wiki/P-n_junction it looks completely wrong to me. Take the E-field. It is going to be positive outside the depletion region, which in turn will make the voltage tend towards zero...

Well although the thread topic speaks for itself I want to introduce myself here. I created an account in this forum a while ago and I've been checking it a bit So yes! I want to participate but I know no one, I tried to find the topical section in which newbies introduce themselves but I...

Hi PF members! I've recently been working on an image (see attached thumbnail) in which I try to include the most important/influential steps in the history of science. Now, I am very well aware that this is not easy (!) :smile:, and it will always be debatable and not without controversy...

Greetings to all, I know activity for a Am-Be neutron source. I want to compute strenght source in neutrons/s. Yours advices are welcome. Thank you!

HI : good to see you everybody ,I am a new comer on this board Being a math teacher ,I always trained my students with various difficult problems from now on I am going to post a sequential challenging questions for people to share most of them I know the answer and the solution of it , maybe...

Hello! I'm a third year student studying physics. My spring semester has begun and I believe I'll be frequenting this site more often. I suspect the classes that'll give me the most trouble are quantum, EM and solid state. I hope this can be the place to get assistance along with helping...

Criticism of small "bridge" design welcome. I live near a park that has two large hiking areas divided by a stream. If those areas were linked by a bridge the number of possible hikes that could be taken would be increased. The stream at one "crossing" is about 30 feet wide and normally has a...

Hi all! BLUF: I'm starting school rather late (I'm 25) and I'm very interested in Physics and Computer Science. Logically, CS seems like a better fit for me due to my hobbies, but my heart is set on Physics. BACKGROUND: I'm just now starting school at 25 after being in the Air Force for...

Hello Physics Lovers, I was working and suddenly got this question. What external forces have effects on electron spin, like slowing down/speeding up? Is that a possible thing in the first place?

How man of you preread for a math class? All members welcome, mods, homework helpers etc... Talking specifically about math classes. What if an instructor doesn't give the sections to read. When I do preread, it helps a lot to focus in class and gain more from lecture. Almost always otherwise I...

Hi folks, I am new to the group. I was willing to know what is the importance of polarization and also wave number? What idea does angular wave number and general wave number provides? Hope to hear from you guys,soon. Thanks in advance.

I'm Sammy I've been lurking through the physics forums for a while and finally decided to start posting. I enjoy the good advice and humor I've seen throughout the forums. I'm glad to see that there's a forum community just for our kind of crazy. :P

It seems to be project time. This used to be my little front yard: So it was decided to redo it after Myrthe's birth. This was taken yesterday: https://dl.dropbox.com/u/22026080/project1.jpg and this at lunch time today. Dinand wants to help too...

Here are a couple of pictures of a gate at the back of my house. The previous owner didn't paint it. When I bought the house, I should have done so, but I didn't and over the years, it deteriorated. It no longer swings right and the stationary part is falling off.

Congressmen, Why have you allowed such a massive budget deficit to persist? I can only see three outcomes for such a course: 1) Unprecedented budget cuts. 2) Unprecedented tax increases. 3) If neither above, the destruction of the value of the dollar as an international currency. So what...

Hi there. Mime here from Poland. It's really pleasant to meet you all :) Have a Nice day. It's just for introduction. Mod. Please close it after week. If it's not a problem.

Hello all, I am a mechanical engineering major who is fascinated with control theory. At my school you can specialize in controls as either a mechanical major, or an electrical major. Does anyone know if being a mechanical major is a disadvantage at becoming a control system engineer? My...

How to fairly divide the contingent payout of \$25,000 (sum insured/face value) as part of total insurance payout \$35,913.33 (balance was from dividends and bonuses)? 1. A paid 8 yearly premium @\$348.25/year (total=\$2,786) inclusive for a relative C(the life insured person). 2. A's...

Hello everyone, I would like to ask you question related to PWR 1000MWe, in the event of Station Black Out SBO there is a safety system called TD AFW to supply steam generator with enough water so that can remove the heat from the primary side indirect way as a heat sink. My question...

Hey everybody! I used to visit physicsforums a long while ago when I was in high school/undergrad (if anyone remembers!) and grew to love it immediately. I have been away for a long while since then due to lots and lots of work, but things have worked out quite well so far and I'm now well...

Welcome our new tigons! Just before last Christmas, a lioness gave birth to 3 tigons, her off-spring after an affair with a tiger male. The tigon is much rarer than the liger, less than 10 tigons are believed to exist. But, they are mighty cute! :smile:

i have just joined in...what are you guys doing?

But couldn't find one. I just wanted to say hello and I really enjoy what I am reading so far. I have been running through tons of pages on a lot of these subjects on the internet and was hoping to find something with more conversations and am glad I have found it in this forum. Lots of...

Hi to everyone :-) I'm new to this forum. I'm an engineer working in a core field. I need to design brush less dc motor of 30 W power, Inout voltage-13.5 V. I'm struck in winding design . Could anyone help?

(A long drawn out introduction) I thought id post a hello since I've been reading this forum for some months with little or no post activity, it's a very intimidating place to post if you haven't a clue :D. Im Martin from South wales (uk) a 24 yr old Carpenter by trade (5 yrs) having been to...

I used to post here on PF quite regularly, but life got busy and I've been inactive for about a year. So, to everybody here who were active a year ago, hello again. :smile:

In the nowadays posh Oslo suburbia of "Bærums Verk" (where there previosly was a an iron works plant, founded in 1610), a moose family, on the third year in a row, has become a welcome sight. This article has a few photos of them...

Welcome to the world of Handwriting technology, where we work on the science of handwriting. At Annant Institute of calligraphy Right we Analyze repair, add speed and style to handwriting.We analyze handwriting for children, individuals & corporate, & we expertise in professional Calligraphy and...

These pictures are incredible. http://www.wellcomeimageawards.org

hello I am a new member in this forum , and I want to learn well with you...sorry I speak little English,so I use google traductor , i speak french , but with french unfortunately there is a little information! now what is a cavity resonant ? and how to write equations for field within...i...

hey everyone

I'm looking to build a new computer for myself but it's been a while since I've done so and I find the market to be more confusing now than ever. Are requests for such advice welcome on these forums? I figure a question on forum protocol would be more welcome than a blatant violation of...

hey guys, We have a design project where we are supposed to design something cool to machine and later auction it off. My group has already come up with a plan to build a small stirling engine. I've been thinking if there could be anything we can add on to it, like a useful/fun addon...

Hi Everyone! I'm new here and like this forum. Can anyone tell me how the electron moving roundly in atom doesn't emit EM waves while changing it's speed?

Hello everybody this is Clarke new to the forum , hope u all welcome me :)

I'm just new to the forum

Postcard club members have already seen it (or they will see it once they finally make that trip to their mailbox).

Tonight's episode of Naked Science on the National Geographic Channel.

Realizing the RD Experiment. Troubleshooting/bug fixing. Some of you may remember the experiment, that I've proposed a few months ago. The idea was to make a {laser/symmetric beam splitter/photo-multipliers/counters} setup, make one branch 'more entropic' and see if that would make any change...

I am a new member to this forum, happy in joining here and hope that I will get all your support to share and get the valuable information from you all.

Hi all Can someone tell me what is meant by an "MC Vertex"? I'm coming across it in some analysis code. Thanks.

Simple yet challenging calc problem - please help! http://img252.imageshack.us/i/en8t.jpg/ a searchlight is located at point A 40 feet from a wall. The searchlight revolves counterclockwise at a rate of π/30 radians per second. At any point B on the wall, the strength of the light L, is...

Hi all I read in a book that coherent means when two waves are monochromatic and have a definite phase relationship. What is meant by a definite phase relationship?

Hello, I am new :) Hello, I'm Rohan I am 13 years of age and think it's time to start a physic's career much to my utter disgust since there's not much opportunity for me since I'm from Australia :rolleyes:. I have had a long thought and decided that i think physic's is a good career for me...

Welcome to the game of doors! Anchor: Alright then, you have three doors in front of you, A, B, C. Two of these three contain nothing, one contains the proof of the unified theory yet unknown to man :biggrin:. You can choose anyone door, which one do you choose? You: Uhmmm.. I think I'll go...