An Internet forum, or message board, is an online discussion site where people can hold conversations in the form of posted messages. They differ from chat rooms in that messages are often longer than one line of text, and are at least temporarily archived. Also, depending on the access level of a user or the forum set-up, a posted message might need to be approved by a moderator before it becomes publicly visible.
Forums have a specific set of jargon associated with them; example: a single conversation is called a "thread", or topic.
A discussion forum is hierarchical or tree-like in structure: a forum can contain a number of subforums, each of which may have several topics. Within a forum's topic, each new discussion started is called a thread and can be replied to by as many people as so wish.
Depending on the forum's settings, users can be anonymous or have to register with the forum and then subsequently log in to post messages. On most forums, users do not have to log in to read existing messages.
I am new at the forums and still getting used to writing in Latex. I found that it is easier for me to write my LateX in this editor:
http://www.codecogs.com/latex/eqneditor.php
and then copy to the physics forum.
So, I wanted to ask you guys, do you know any other tricks you want to...
I need to purchase a dress suit for some upcoming research presentations but the Men's Wearhouse in my area has terrible reviews and I don't know anywhere else that sells suits. Anyone know where in the NYC area to buy a suit or any other forums to ask about this?
This forum is ONLY for the discussion of existing science fiction and fantasy stories in movies, books, tv, comics. It is NOT for discussing personal ideas, those would go in the Science fiction WRITING forum if they adhere to the rules for that forum.
This forum is not for new ideas or...
Hi n PF,
Is there any IRC for Physics forum or similar thing... So that I can ask my doubts real time...
Also for windows7 which is the best IRC software.
-Devanand T
Homework Statement
A tank consists of two chambers, one open to the atmosphere and another closed and filled with a gas. The two chambers are connected by a sluice opening. What is the pressure in the gas, in gauge and absolute terms if the barometric pressure = 742 mm Hg. Difference in height...
I am looking for a forum that is similar to PF, except tailored for law students rather than for students of science and engineering. Does anyone have any recommendations?
I searched google. Most results give forums for either people who have questions about an actual case (i.e. they are...
I was talking to my physics teacher today about electric motors and used some information I learned here. I'm not calling you guys wrong by any means, I just would like to know what is real. He claimed two things: 1. As load on an electric motor goes up, current goes down (I know this is wrong...
The Philosophy forum will be closing in one week, Monday the 15th. All threads will be closed and merged into General Discussion. The reason is that the Philosophy forum over the past couple years has been almost impossible to moderate fairly and two out of three threads end up locked. Please...
I’m a layman new to the Cosmology Forum and just finished reading through the very helpful, “Effort to get us all on the same page (balloon analogy anyone?)” by Marcus et. al. followed by “Look 88 billion years…”. [If you’re in a hurry see the nice summary by Mark M at cosmo.pdf.]
Along the...
I'm having a really difficult time understanding limits from the graph. I don't completely understand how to find if the limit exists or not. I tried to do these for my homework but I don't know if they are right. Could someone please help me understand limits?
I've made a few efforts to learn to program in the past, but I've never lasted more than a few days.
What are ideas on ways to make it fun? Websites maybe? Or forums?
For learning science/engineering principles, this forum is great.
Do you guys have suggestions for ways to make...
Hi, I have been looking around for popular, well-used, and informative forums for alternative energy. I can't seem to find any great ones using google/bing/duckduckgo. If anyone has any suggestions it would be great!
thanks!
Hi, why is the debunking forum gone? does it have to do with the fact that after the discovery of the Higgs. Science is complete and the universe is purely nuts and bolts and humans mere flesh and blood indistinguishable from animals and there is no mystery left in the world?
Well, the title really sums it up to be honest.
Are we allowed to write our own stories and post it piece-by-piece as we write, here on this forum? If so I would love to do something like that.
I may even include some of the members as characters even ;)
In this forum, it is possible for writers to ask for help with science-fiction or fantasy stories. Since science-fiction is speculative in nature, some degree of speculation is allowed here. However:
There can be no speculation about the real world and about known science. Rather, all...
Do LaTex tables work in forum posts? I've never used them before. Today I tried copying several examples from pages on the web such as:
\begin{tabular}{ l c r }
1 & 2 & 3 \\
4 & 5 & 6 \\
7 & 8 & 9 \\
\end{tabular}
which on my browser doesn't show up as a table. I tried...
This is my first post on any message board so bare with me on any grammatical errors I make in the post. I will be heading into my senior year of high school and I plan on majoring in physics. But I live in a rather rural community and high school courses aren't considered challenging. We have...
i am new to this forum so if i do any mistakes then kindly guide me.
i didnt know where to post this question of mine.
i was wanted to go deep in physics, but in India not much importance is given to this field as a career and i was never motivated nor did i receive any help from any of my...
Hello,
I am new to the forum but figured I could ask some intelligent people about an idea that has been bugging me. Here goes...
I am trying to make a generator that is run by an electric motor but the electric motor runs off the generator head at the same time.
The way I...
I never click ads, I use adblock plus, and I assume that most other people also rarely click ads. I know that ads can still be valuable by increasing my awareness of a brand/idea though.
My question is: Do ads still pay well? I've read that online advertising is becoming less viable as...
Original Title: could you help me on this trigonometry function
Hi rlaydab, :)
\[\sin^{2}n\theta - \sin^{2}(n-1)\theta = \sin^{2}\theta\]
\[\Rightarrow [\sin n\theta - \sin (n-1)\theta][\sin n\theta + \sin (n-1)\theta] = \sin^{2}\theta\]
Using sum to product identities we get...
Original Title: Please Need an help on this integral!
Hi chamilka, :)
\[\int_{0}^{1}x^{a+b-1}(1-x)^{c-a}(1-x^b)^{d-1}\,dx\]
Using the Binomial series of \((1-x^b)^{d-1}\) we get,
\begin{eqnarray}...
Hello... I'm trying to figure out how many magnets I need to put on one side of a piece of sheet metal in order to sufficiently magnetize all the surface area of the other side to a specific attractive force to other pieces of steel in contact with the sheet. It has been too long since...
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
Title: how do i show something is a solution without solving it? 2nd order DE
Hi ouchimdead, :)
The only thing that you have to do here is to find the second derivatives of \(y(x,t)\) with respect to \(x\) and \(t\). Then it could be easily seen that they satisfy the given differential...
Title: Website/Article of use for solving this?
Hi trig108, :)
I think a good place to start with is Paul's Online Notes: Differential Equations. It gives a very simple introduction which is easy to understand. Also "A First Course in Differential Equations by Dennis Zill" is a nice book...
Title: How do you do this problem?
Hi mortifiedpenguin1, :)
I presume what you meant by a "closed triangle" is in fact to show that the given three points are non-collinear; so that a triangle is uniquely determined.
You can show that the points are not collinear by showing that the two...
Title: Find a standard basis vector
Hi saqifriends, :)
We can use the determinants to see which standard basis vectors are linearly independent with the given two vectors.
\[\begin{vmatrix} 1 & 0 & 0\\-1 & 2 & 3\\1 & -2 & -2 \end{vmatrix}\neq 0\]
\[\begin{vmatrix} 0 & 1 & 0\\-1 & 2 & 3\\1...
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...
Hey, I'm Cameron and I live in Florida. I graduated from HS in 2008. After a few years of "exploring" my options, I'll be attending college this fall semester. My ultimate goal would be to get involved in anything to do with commercial space programs. Right now I'm pondering which major and...
How do I write X bar with the bar over it to denote a vector?
I discovered that if I compose a Latex equation here that I can copy it into a Word file. Is this true of all the symbols? Same for sub and super scripts.
Is there a software tool that I can use to write Latex outside the realm...
One of the great benefits for me during discussions and debates here on Physics Forums, Politics & World Affairs (P&WA) is that I gain personally from participating. Questions on controversial issues get posted and then the ideas, beliefs, and opinions of our members begin to accumulate for...
At least as far back as the Greeks people have been trying to understand things by looking at lower and lower levels to find the first principles which determine all things. We break things into their components, and then into materials and then into compounds and then into atoms. This works...
What's REALLY wrong with this Forum...
Logged on this morning, and noticed that Evo, had once again, mercilessly, locked an apparently well meaning thread.
Was it posted in the wrong section?(Looked like a philosophy topic to me) Were there no "reliable" sources for the information?
What...
Maths is a precice science*, but when using maths in the real world most people, including many mathematicians, generally take 'short cuts' which result in specifications of a problem or descriptions of a solution which are strictly incomplete. This has a number of advantages:
it is quicker...
1. There should be a separate (sub)forum for NT. ... and one for abstract algebra, for that matter!
2. Show that there are infinitely many n such that both 6n + 1 and 6n - 1 are composite. Without CRT, if possible.
My work... let n = 6^{2k}.
Then 6n \pm 1 = 6^{2k + 1} \pm 1...
Hmm. Having a...
I have to admit I'm a newbie to this forum.
My background is computer graphics and physics simulation.
I'm not a student but have 20 years of professional experience and an academic background (phd).
Here some realtime inteactive physics simulations that may be interesting to you.
Could...
Homework Statement
CD is playing for 74 min, starts at angular speed of 480 rpm then slows to 210rpm. what's the magnitude of the angular acceleration
Homework Equations
angular acceleration =ω/ t
The Attempt at a Solution
i converted the rev to rad then min to sec then divided...
Long story. Not a homework question, tho sometimes I think the person running the contest would think to use a forum contest to do his coursework. But it's not.
Topic: Linear algebra.
If no one gets it right after 3 days then we can use any means to get the question right, now becomes a race...
Hi,
I am trying to come up with a formula that will generate a price based on its cost. The only trick is that it can't be something constant like 20% or 30% more than the cost. It has to be a formula that adds a bigger profit on smaller numbers and lower profit on bigger numbers.
So on a...
Hi people, as you can see i am new in this forum.
Sorry if i am posting in wrong section.
Im going to try to traduce the problem.
" f(n) is the sum o n terms of a arithmetic progression. "
Show that :
f(n+3) -3f(n+2) + 3f(n+1)-f(n) = 0
I just want to know if
-3f(n+2)...
Hi everyone,
I'm having some issues understanding how to approach (conceptually) a problem
where there is a box with a ramp with static friction. The scenarios that are problematic to me
are when you are pushing with a force horizontally and perpendicular to the surface.
It's not a...
PForums,
I am a writer working on a novel and as part of my job is to research the science behind any idea, I have to make sure is it plausible in real life. I did some research about three years ago for the novel I am writing and got the opinion from scientist and medical experts in regard...
Hi all
I use Lyx v1.65 for creating LaTex.
Obviously it displays OK in Lyx. It also displays OK with an online editor I've tried
http://www.codecogs.com/latex/eqneditor.php
But invariably when I try to post LaTex to this forum it does not work. I've tried the sandbox which the reason...