What is Outside: Definition and 469 Discussions

Trying to imagine what the world looks like traveling at relativistic speeds of course has a noble history, vis a vis Swiss trams etc. etc. I get the thing about passing clocks at speed and staying young by going really fast (and slowing down again). I apologise if this perhaps rather obvious...

Hi, I've seen a couple of posts in the Homework section of Physics Forums about the fields of solenoids, but neither of them seem to address the problem that I have about it. The set-up is a long solenoid that has a sinusoidally varying current going through it. We can establish that the...

Damn, I'm burnin' up here. Aren't you dyin' down there in Olympia Lisab?

Hello, I'll be getting my physics BS soon and I want to obtain my master's in some other country. I have been thinking about going to either Japan or Switzerland. Has anybody studied in any of those countries? In Japan I'm considering the University of Tokyo. In Switzerland, the EPFL Lausanne...

Homework Statement Per Maxwell's equation and my H. H. Skilling EM textbook, curl H = 0 in the absence of current density. But consider a long, thin wire along the z axis carrying time-invariant current I. By Ampere's law, at a point (x,0) outside the wire, H = I/2πx j . But curl H...

If the universe is expanding at less than the speed of light, what happens to EM radiation that is emitted from stars at the edge of the universe?

Say we have a +Q charge located inside an isolated spherical conducting body and I want to know the E field at some point P outside the conducting body. I reliase that since this is a conducting body, the E field inside is zero. So by Gauss's Law, ##Q_{enclosed} = 0##. The only way for this...

something that has had me confused: How can I calculate the time varying magnetic field produced by a solenoid, outside the solenoid along the axis of the core. I know that: inside the solenoid : apply amperes law For DC (magnetostatic) case outside the solenoid : apply Biot-savart law...

So, Voyager 1 appears to have finally made it outside of the Heliosphere, and is now encountering high energy particles, galactic wind, cosmic rays, etc. Are these likely to be more dangerous to human life than the conditions faced inside the Solar system, or would a space station capable of...

If we consider the common electromagnet that is made by passing current through a wire coiled around an iron core, I wonder what effect produces more magnetic field: 1. The field produced outside the solenoid due to the current in the wire 2. For this effect I don't insist that the object is...

Homework Statement A metal sphere of radius 10 cm carries a charge of +2μC uniformly distributed over its surface. What is the magnitude of the electric field due to this sphere at a point 5.0 cm outside the sphere's surface? 8.0 x 109 N/C 4.2 x 106 N/C 8.0 x 107 N/C 4.0 x 109 N/C 4.0 x...

I use the ternary operation in web development all the time, eg: x = y > z ? a : b Which reads, if x > y then a, otherwise b I realize that it is just a shorthand for if...else statements, but even still, are there any mathematical properties associated with it? I know inequalities have...

A conducting spherical shell of radius 11.0 cm is charged to a potential of 5.00*10^4 V. What is the value of the electrostatic potential 5.0 cm outside the surface of the sphere? V=(1/[4*pi*(epsilon naught)])*(Q/r) <-- outside of the shell V=(1/[4*pi*(epsilon naught)])*(3Q/2R) <-- inside...

I have a 36" OD aluminum drum within another 48" OD aluminum drum creating 6” channel between the two diameters. The total height of the drum assembly is 16” This design project that I am working on requires me to fill this channel up with 12” of water which equates to about 342.5 lbs of water...

Homework Statement http://home.phys.ntnu.no/brukdef/undervisning/tfy4155/ovinger/Ov03.pdf Hi. Take a look at the picture under assignment 2 ("oppgave 2"). Let's say there is a charge +q inside the cavity of the conducting metal ball. The problem is: "How will (free) charge be distributed...

With the advent of the internet, and the fact that a theorist's work does not require access to expensive laboratory equipment, it would seem that there should be a vibrant community of ex-academics performing research outside of the traditional environment. But if there is such a thing...

1.\int { x } dx=x\int { 1 } dx\\ 2.\int { t } dx=t\int { 1 } dx\\ 3.\int _{ x }^{ x+1 }{ x } dt=x\int _{ x }^{ x+1 }{ 1 } dt Which of the equations are correct?

Hi, Homework Statement I am trying to compute the volume bounded by the sphere x2+y2+z2 = 4 and outside the cylinder x2+y2=2x. Homework Equations The Attempt at a Solution The cylinder's equation is obviously (x-1)2+y2=1, but I am not sure how to formulate the integration for the...

Hello fellow aerospace engineers and physicists, I am currently working on a project and trying to figure this out. I was wondering if you guys could help me out. Here is the problem statement: A nuclear waste disposal spacecraft is to be sent from Earth in order to carry radioactive waste...

So I've started a doctorate in corrosion and through the last 2 months of reading and experimenting I've become interested in a type of corrosion (scc) that my supervisor has no interest in (they mainly look at atmospheric corrosion). I went into the PhD being told that the project would...

if such a place exists how would someone reach "outside of time and space"? and what would be there when you arrive?

Instead of the usual B = μ0NI for field inside solenoid... how should i go about finding the field let say... 10cm away from one end of the solenoid 1. directly at the z-axis 2. not directly at the z-axis this is assuming the solenoid has finite length, finite number of turns ,finite...

You hear this phrase sometimes. Movies and video games have sometimes used this visual gimmick for a comedic or surreal effect. But what about reality? Is there something quantum mechanical that could allow a surface to literally take up more volume inside than outside? Perhaps this is possible...

Hi, It seems that there is no much examples of this particular case. OK, we all know how to write the general solution to Laplace equation in spherical coordinates in terms of Legendre polynomials (when there is azimuthal symmetry). There are a lot of cases here but I would like to know...

Hello, I would like to know what can do theoretical physicist who don't get a job in academia, after a phd in theoretical physics or after a postdoc for example. I am thinking about people working in theoretical high energy physics, cosmology or things like that. If we compare the number of...

Possibly I'm misinformed, but adrenal glands make us feel excited, sex glands (whatever their name) makes us feel the appropriate (or not, depending on your situation) emotions. Maybe to rephrase, how emotional is the brain on its own? And possibly, how important are these emotions or...

Homework Statement Charge density: σ(θ)=w*sin(5θ) (where a is a constant) is glued over the surface of an infinite cylinder of radius R. Find the potential inside and outside the cylinder. Homework Equations s is a point inside or outside of the cylinder, and θ is the angle between...

In relativity, it says that faster you approach the speed of light, the more things slow down. Is this on a sensory level, or actually, physically slow down? I mean, if light were "outside" time, then it wouldn't truly move, would it. We couldn't say light had a speed because it does not have...

Homework Statement f(z) is analytic for |z|≥1. Let C be the unit circle. Show that the integral \frac{1}{2i\pi}\int_C\frac{f(w)}{wz-z^2}dw is 0 if |z|<1, is \frac{f(z)}{z} if |z|>1 Homework Equations The Attempt at a Solution For |z|<1 case, I tried to write the integral as \frac{1}{z2\pi...

After an analogy with air and water waves, which are limited in speed by the density of the medium in which they travel, I was wondering if there were variations in the "density" of the vacuum of space which might cause light, or any electromagnetic waves for this matter, to vary in speed...

The first thing that we should notice is that the leading coefficient $a_n = 1$. I was thinking about considering the factored form of p. I googled, and there is an algorithm called the "Schur-Cohn Algorithm" that is suppose to answer exactly this, but I can't find any information on it or...

Space: So far for me it's 3D along with Time T. say 3D+T=4D (spaceTime), from the bigbang we have considered Time (t sub I) as well, considering Time from the start of bigbang to 13.7 Billion years after the bigbang. Since our universe is accelerating due to Dark energy, expansion is speeding...

Can an ellipse's focal points be outside the ellipse? I have tried googling this, but without any good explanations or answers. According to my calculations, the focal points of the ellipse defined by x^{2} + \frac{y^{2}}{4} = 1 are (-\sqrt{3},0) (\sqrt{3},0)) . I maybe wrong of course...

Homework Statement Imagine the following. You and your best friend are at sea on your ship. Your ship is designed to withstand seas during 120 knot winds. You measure the winds outside your ship at 30 knots. From satellite images and Global Positioning System (GPS) data, you pinpoint your...

If I have a bladder (or balloon) that is charged with 300# of a nitrogen gas at a normal atmospheric pressure outside the bladder, and I then enclose the bladder and subject that bladder to a liquid pressure of 25# on it's outside surface area but inside the enclosure. Assuming a constant...

I'm trying to figure out if the Helmholtz & Gibbs free energy are ever used outside of chemical reactions (I suppose they could be used in nuclear reactions in a plasma as well.) It seems to me that they are not, as I can only recall using them for chemical reactions in my thermodynamics course...

Hello. I'm currently coding on a physics engine. To do so, I looked up some code from open-source engines. I noted that there is a function where you can apply a force to a rigid body, outside it's center of mass. It goes something like this: ApplyForceAPosition(vector force, vector...

Greetings, this is my first post here. I just graduated with a B.S in Physics and will be attending a university for a M.Sc program (Terminal degree there). I will be receiving a state university grant, additionally there are TA/GA positions that I am applying for. I will also...

Optics-Lenses -- image outside the mirror? A question in my book asks what are the images formed in this diagram: http://www.flickr.com/photos/80147355@N05/7362964734/sizes/m/in/photostream/ I thought there was only one, inside the mirror. But it turns out that there is another one...

Is it possible to see galaxies/clusters/astronomical-objects "outside" our own galaxy without use of a telescope or equipment, other than our eyes? Thanks;)

Hello, If you can get me a hint for solving this matter it would be much appreciated. I have the 3D coordinates of three points on a plane A, B, C. There's another point G and we know AG, BG, CG. My problem is to find the coordinates of point G:cry: Thanks in advance!

how does this change with introduction of another charge in its vicinity suddenly..and how does this vary as both charges repel each other after introduction of like charge.. btw I even wonder whether a electron which is outside a atom is in form of wave or particle..hope my questions are...

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...

Homework Statement Hi everybody i have a problem please help me (sorry for my bad english) Homework Equations volume of the space region inside sphere outside coni z^2=x^2+y^2 coni x^2+y^2+z^2 =1 sphere The Attempt at a Solution I am new in this forum , I search question like this...

On a warm day, why do droplets of water appear on the outside of a cold glass of water? I don't really understand partial pressure and saturated vapour pressure, but I know it has something to do with this. Like when partial pressure = SVP, the water will boil, but at what point will water...

Homework Statement One step in one of the problems in my book (involving calculation of the Poynting vector) asks to find the electric field outside a wire. This wire is resistanceless and the current is steady. Homework Equations Maxwell's. The Attempt at a Solution Stared at...

Homework Statement A conductor with inner radius R and outer radius 2R. A charge q is kept at a distance d<R but it is not at the centre. What will be the electric field outside the conductor? Will the charge distribution be uniform? Homework Equations The Attempt at a Solution i...

Homework Statement I am supposed to design a control system with feedback and disturbance feed-forward, with all relevant transfer functions. The system consists of an oven where the temperature T is controlled by an electric heater that dissipates power P_{in}. The temperature outside...

Is spin of electron taken into account when people accelerate electron in LHC?

Homework Statement Suppose w is not in the interval [-R,R] show that the equation z+\frac{R^{2}}{z}=2w has one solution z with |z|<R and one solution z with |z|>R Homework Equations none The Attempt at a Solution the book mentions that the quadratic is left unchanged by the...