Idea Definition and 803 Threads

  1. daniel_i_l

    Undergrad Where Does the Extra Energy Come From in a Gravitational Field?

    Lets imagine that there is a gravitational field and you are in a position that if you fall a meter your g increases by 2m/s/s (I'm pretty that that's possible). In this case, the more you fall the more P energy you get and you get more K energy. In order for this not to contradict the...
  2. M

    Graduate Is Time Truly the Fourth Dimension or Something Else Entirely?

    I'm just curious to see what other people in this group have to say about this theory I have. I used to think that time was the fourth dimension. It seemed pretty logical due to the way dimensions are built up. The zero dimension is a point, the first dimension is an infinite number of...
  3. Ivan Seeking

    News What Idea Shapes Your Political Philosophy?

    What do you consider to be the basis or roots of your political philosophy and opinions? Is it Plato, the plight a certain group like the Palestinians, a cause such as environmentalism, national loyalty and basic patriotism, a greater concept or ideal such as world peace, an economic ideal, or a...
  4. L

    Trouble Understanding Idea: Searching for Resources

    I'm having a bit of a hard time getting my head around this idea. Can anyone provide some links to good references, or offer an explanation here? Thanks.
  5. ZapperZ

    Einstein's Big Idea: Oct 11 on PBS

    If you are in the US, or have access to Public Broacasting Station signal, you may want to mark your calendar or your TIVO for Oct. 11 next week. http://www.pbs.org/wgbh/nova/einstein/ Zz.
  6. S

    How Does Transforming to Moving Coordinates Simplify a Hyperbolic PDE?

    define L[u] = a \frac{\partial^2u}{\partial t^2} + B \frac{\partial^2 u}{\partial x \partial t} + C \frac{\partial^2u}{\partial x^2} = 0 Show that if L[u] is hyperbolic and A is not zero, the transofrmation to moving coordinates x' = x- \frac{B}{2A} t t' =t takes L into a mutliple...
  7. O

    A question and no idea what to do

    determine the inital velocity of a projectile that is luncked horizantaly and falls 1.5m while moving 16m horizantaly i tried everything all i figerd out is that they r displacmednts the accelaration is 9.8 and nothing i don't have enogh info to do anything please help me
  8. J

    NASA NASA's Crazy Mars Idea: Interplanetary Ship in Orbit

    surely building a craft to go to Mars without any infrastructure is pretty pointless & will end up being as beneficial as the moon. Wouldnt developing a petrol station in orbit be a better idea, and then a interplanetary ship that doesn't land but stays in space & a way to get up & down to it...
  9. N

    Graduate Is there a connection between antimatter and the expansion of the universe?

    Hi all, New member here, found the forum when lurking around the 'net last night. A very brief disclaimer: I've a Chemistry degree, I work with computers in the IT security field, but I am NOT a Physics expert... far from that. I've read a lot of "popular" literature, and from my humble...
  10. Lisa!

    Which PFer is most (est) in your idea?

    You can name more that 1 person and add more of your own. o:) 1)witty: 2)humorist: 3)kind: 4)cute: 5)helpful: 6)thoughtful: 7)wise: 8)hot: 9)cool: :cool: 10)strange: --------------------------------------------------- Threadholic: Mr Wolram, yomamma Gentleman: TSA, Astronuc
  11. Mk

    Breakfast - Good idea or otherwise?

    People tell me I should, I say why? I figure if my body doesn't tell me to eat then I won't (unless loss of appetite from illness or something). When I'm sleeping I hardly lose any energy, just my brain, stomach, and heart! I usually end up eating it more often than not, but I do NOT like...
  12. T

    How Much Does a Plumb Bob Deviate at 40 Degrees North Latitude?

    I have this problem here. Let's say: A plumb bob does not hang exactly along a line directed to the center of the Earth's rotation. How much does the plumb bob deviate from a radial line at 40 degrees north latitude if we assume that the Earth is spherical?
  13. L

    Blog idea - What Physicists Do - Opinions?

    I was thinking about creating a blog that would make regular posts about what a particular physicist does. The aim would be to provide a resource that would show how diverse the areas of physics study are, give details on what physics is being done and provide a little insight into what...
  14. P

    Could a hybrid F-15/SR-71 space plane reach orbit with added PAM rockets?

    I don't know if this would work or not. What if you used one engine bay of an F-15 for a scramjet, the other for an SR-71 engine. That takes you to mach 10 and the edge of space. If you strapped PAM rockets to the missle racks on the wings and belly, could you make it to orbit velocity...
  15. M

    Graduate Idea of increased mass at relativistic speeds

    I would like to clarify that this idea that mass increases at relativistic speeds is an explanatory tool only (usually to explain why you cannot exceed the speed of light). It comes from the fact that in some equations, the factor gamma = 1/sqrt(1-v^2/c^2) multiplies the mass. However, I think...
  16. quantumdude

    Graduate Logic, Metaphysics, and the Idea of an Expanding Universe

    This thread is an offshoot of https://www.physicsforums.com/showthread.php?t=83978&page=1&pp=20. Hmmmm, OK... ex·pand v. intr. 1. To become greater in size, volume, quantity, or scope: Air expands when heated. This critic's influence is expanding. 2. To speak or write at length or...
  17. G

    High School Is A Always Equal to B? Understanding Equality in Math

    ( 1 / 1 ) = ( B / A ) = ( A = B )
  18. S

    Holy bad idea Batman Problems with caffeine

    Well to begin I should say that I used to be a caffeine freak. I averaged 2L of Diet Dr Pepper everyday for the past four years. About three weeks ago I ran out of pop and, being extremely busy with college, I was unable to get to the grocery store for anything other than a few bags of food...
  19. R

    Quantum Mechanics & Mind-Body Problem: Tempting Idea or Crap?

    tempting idea, but crap? The universe is quantum mechanically. But no one understands quantum mechanics, as Feynman put it. On the one hand the pivotal role and accuracy of QM in describing nature. On the other hand the inability to interpret QM (1. quantum reality- what is a superposed state...
  20. Adrian Baker

    How Can Punctuation Change the Tone of Online Communication?

    Sometimes on PF people use words and phrases that CAN seem aggresive without smiley faces or similar to 'disarm' them. However, as an alternative, we could use 'different' punctuation' to really be aggresive, without anyone knowing actually knowing, so also avoiding upset! Here, take a...
  21. B

    Can a Hypothetical Object Exist if it Does Not Satisfy a Universal Rule?

    Consider some hypothetical universal rule which everything (including nothing) must satisfy. Then take that some hypothetical object that does not satisfy this axiom. What can be said about that object? Certainly it can not be said that it doesn't exist.
  22. P

    Help With Problem Setup: No Idea What the Hint Says

    I have no idea what the hint tells me to do...please help me set the problem up...
  23. W

    Undergraduate Student Ideas: New Discovery or Rediscovery?

    In following up one of my idiot ideas that usually turnout to be absolotley stupid, I may have discovered, or rediscovered, an actuall result that I think might be worth publishing in arxiv. Since I am only a undergraduate student I am wondering what I should do. Should I talk to a doctor at my...
  24. S

    Weird Project Idea: Help Needed for Report Container

    Don't know what forum to put this in. In what must be the most retarded step I know, we have been told to hand in a report in a "decorative container" worth a mind bogglingly large percentage of the mark. Considering my report is on the anthropic principle and its relation to cosmology...
  25. L

    Graduate The Mysteries of Dimensions: A New Theory with 11 Dimensions Explained

    First I called it an idea, not a theory. One might call it an hypothesis, though I do not think it is at that stage. I have posted it so someone who works on demminsions can help see it, maybe test it. To start off with, the string theory says that there must be 11 deminsions. I know this...
  26. recon

    Proving No Positive Integer Solutions for 1/x^2 + 1/xy + 1/y^2 = 1

    Prove that there are no positive integers x & y such that \frac{1}{x^2} + \frac{1}{xy} + \frac{1}{y^2} = 1 . I really have no idea where to start. I tried rearranging the equation, but I could not see anything useful in any of the rearrangements.
  27. S

    Graduate A Brand New Idea in Supersymmetry

    Aaron Bergman has just called attention on science.strings to the new paper hep-th/0503249 which discusses the new idea of "split supersymetry". From the abstract: I don't know if this messes up current plans at Fermilab and CERN for hunting the Higgs. but it does look like it could give...
  28. J

    Graduate Studying special relativity and using the idea of four vectors

    We are currently studying special relativity and using the idea of four vectors. The position 4-vector has been defined in class as \vec{X} = (ct, \vec{r}) \ \ \ \ \ \ \ where \ \vec{r} = (x, y, z) \ \ (ie: the usual 3 space position vector) and the velocity 4-vector is then...
  29. S

    High School Place i can get a basic idea about physics

    I don't understand half of what is being said here but that's ok with me. When i understand something it is only because I've read Stephen Hawkin's A Brief History of Time (I acutally understood soemthings in the beginning and in the end) . I'm just wondering if anyone knows i a place i can get...
  30. M

    Can anyone give me an idea on these probs

    Hello. Our instructor gave us 2 sets of problems. Deadline is on monday. If anyone can share his / her idea, I would really appreciate it. Here are the problems: 1. Two positive point charges q and q2 are moving relative to an observer at point P; P measures the forces on the charges...
  31. T

    Currents and resistors and series and parallel you get the idea

    So this problem asks you to determine the magnitudes and irections of the currents in the resistors. I definitely understand how to determine directions, using Kirchhoff's Rules. But here is where I get stuck: the batteries have emfs of E1 = 9.0 V and E2 = 12.0 V and the resistors have vlaues...
  32. B

    An idea about consciouness and materialism

    Ok so I was sitting by my computer, and I suddenly thought "um this image I am seeing when I look at the monitor, or the sounds of cars I hear outside, where are they in the physical world exactly?" To better explain, let's think about it logically.. What components are part of creating this...
  33. T

    Undergrad General idea of what Maxwell did with electromagnitism

    I have a general idea of what Maxwell did with electromagnitism, but I'm writing an essay for an Electronics class and need some information on how he directly or indirectly affected affected this topic.
  34. J

    Undergrad I have no idea how to integrate by parts

    I don't think anyone in class understands it, we went over it so quick. The only thing I seem to get is that uv - (integral) vdu = (integral) udv. You are supposed to assign u, v, dv and du, but how do you know which is u and which is v? What is the difference between du and dv? Are you...
  35. B

    Rotational Motion. Apparently, I have no idea what I'm doing.

    ok... We were given the following question... (I apologize for it's length... please bear with me) A thin long cylindrical rod (mass M radius R and length l) is initially rotating about its long axis with angular momentum L. There are no external forces or torques however interestingly Ke is...
  36. C

    Matrix Movies: Unpacking the Theme, Story, and Idea

    I've never understood most of the English movies. Matrix lies in the top ten(The Sixth Sense leads it) of my ununderstandable movies. Can anyone explain to me the theme and story and idea of the Matrix movies?
  37. U

    Proving Momentum Conservation with Basketball & Tennis Ball

    Hi, I'm doing a project when I drop a tennis ball and a basketball at the same time they hit the floor and try to show conservation of momentum after the separate. of course the V(initial) would be the same before the objects hit the ground and after they hit, the Tennis ball would receive the...
  38. D

    Convincing Your own Self of a False Idea

    If say, there is a false premise 'x'. Am i capable, psychologically, of convincing myself that this false premise 'x' is true? Therefore, can i cause myself to reach the point at which false premise 'x' becomes a true premise only in my private world? Is there a name for this?
  39. E

    Carbon Nano Tube Pipeline to Space: A Revolutionary Idea

    Pipeline To Space? A carbon nano tube pipeline from the Equator to geo. orbit could pump massive amounts of H2 and O2 to space to be stored as rocket fuel. The pipeline would only have to be 1/4 inch diameter. http://www.newmars.com/cgi-bin/ikon...;f=5;t=198;st=0
  40. T

    Good Idea? 60 Minutes Show - CBS News

    http://www.cbsnews.com/stories/2004/05/11/60minutes/rooney/main616858.shtml I was watching this yesterday on 60 mintues and thought... wow that seems like finally a smart thing to do. I had thought of something very similar to it at one time, just never elaborated it to the point of the...
  41. M

    This problem confuses mecan anyone give me an idea on how to do this problem

    Potential Difference Problem..Help! :smile: Problem: Two parallel plates having equal but opposite charges are separated by 12mm. Each plate has a surface charge density of 36.0 nC/m2. A proton is released from rest at the point near the positive plate. Determine: The potential difference...
  42. check

    Holographic projector? Any idea how it works?

    “Holographic” projector? Any idea how it works? I saw this a couple of years ago. It’s a projector that’s able to display 2D images or simulated 3D video into the air. Here’s the manufacturer’s site: http://www.io2technology.com/ The site has a few really neat videos. Any idea how this is done?
  43. W

    Graduate Idea find black holes using grav. lensing

    Ok I have this idea and i need you all to bash it so i can see what's wrong with it. Ok imagine a very very large black hole at distances like 10 billion light years, imagine that there could be black holes larger than we can fathom and imagine how many stars would lie behind such an anomaly...
  44. B

    Solving Heat and Energy Problems for Monatomic Ideal Gas | Expert Tips

    I am sick of these problems. I just cannot grasp these ideas at all and I'm really trying. But it's no use. And in the end, it's always something minor I'm overlooking. I am having issues with the following problem: Three moles of a monatomic ideal gas are heated at a constant volume of 1.90...
  45. M

    Undergrad Help whit a problem. (I have no idea)

    Calculate e^A if A = \left(\begin{array}{cc}0 & -2\\1 & 3\end{array}\right) Maybe using that e^x = \sum_{n=0}^\infty \frac{x^n}{n!} , then e^A = \sum_{n=0}^\infty \frac{\left(\begin{array}{cc}0 & -2\\1 & 3\end{array}\right)^n}{n!} but i don't know if this is the right way for...
  46. E

    What is realy the idea of damped simple harmonic motion?

    i am finding damped SHM difficult to understand can anyone give sugestion as to what coul .do
  47. wolram

    Graduate Why Do We Seek a Universe Born from 'Almost Nothing'?

    I came across this in the AandC reference library posted by Marcus http://www.astrosociety.org/pubs/mercury/31_02/nothing.html My question is,Why do we seem to want a universe that started from "almost", nothing, or reduce our existence and our Us existence to as close to 0 as possible?
  48. E

    What is the Connection Between Consciousness and Quantum Physics?

    I was just wondering... It sounds like a silly question but I ask it with all seriousness. Given the nature of all the particles, waves, sparks, quarks, wimps and what-nots that exist in the quantum realm I am curious as to what type of material an idea consists of. If I share a thought or...
  49. wasteofo2

    News Colorado Amendment 36 Voting Date: When?

    I'm sure most of you have heard that there's a proposition in Colorado (Amendment 36) that their electoral votes should be split proportionally among the presidential candidates. So if Bush gets 55% and Kerry gets 44%, Bush gets 5 votes and Kerry gets 4 votes. Anyway, I was wondering if anyone...
  50. S

    What are some easy projectile experiments for 11th grade physics projects?

    hi...im new here... im in 11th grade and need to submit a project and report (physics) for my internals... pleez give me easy to make experiments which is suitable for my grade... thank u nimmi