Travel Definition and 994 Threads

In the double slit experiment, Bohmian Mechanics http://plato.stanford.edu/entries/qm-bohm/#2s" the paths of real particles traveling from the two slits to the detector to look like something like this: The above image shows particles traveling in non-straight paths. The diagram below...

Hi! I'm sure this has been done before, but is it possible for dark matter to travel faster than light (at least some candidates for dark matter)? We know that ordinary matter is limited by the speed of light, but what about dark matter? For all we know, dark matter may not use c-limited...

I've got an interesting problem that I can solve sometimes, but not always. Say I've got a 3 sets of lat/long positions on the earth, relatively close to each other. The idea is your in a car/airplane driving along and arc between points #1 and #2, with a center point #3. The question to be...

Homework Statement Fundamental frequency of a string fixed at both ends is 256 Hz. How long does it take for a wave to travel the length of string? Homework Equations V = f (lambda) Otherwise, not really sure. The Attempt at a Solution I didn't really know how to approach...

Under the general relativity principle, If you take a wormhole, put one end into a gravitational well, then take it out, there would be a time difference between the two openings of the wormhole. But, what effect would it have on the wormhole if you keep the middle area of it near a...

Space travel is possible (or not) not more than time travel is. Do you thing that you can travel back and forward in space? You may THINK that you can, but you can't. We all travel with earth, and Earth travels with sun, and sun travels... etc. The final velocity is too high to reach with...

I'm doing a problem in thermodynamics that deals with sound waves and the bulk modulus B and it got me thinking. Since the compressional waves would be traveling far too fast to be considered isothermal, I assume you must consider them to be adiabatic compressions of air. Now if adiabatic...

Hey, I have heard that red light travels shorter than regular light. I am thinking of flashlights, where I learned that people in the army uses red light to make them less visible. Is this true?

I have been working on this problem for 30 min and can;t seem to get anywhere. Question You have a amphibian vehicle which can travel 20 mph on the water and 52 mph on the land. You must find the quickest point from point A to C. -A is 20 Miles east of point B and is all land. -C is...

Hello. This is my first post here, so I can only hope (having read the guidelines and physics FAQ), that my post is appropriate to go here. If not, and it is deleted, I'd much appreciate an explanation by PM and a suggestion as to where it would be appropriate to post. That said, the reason...

So if I'm on the moon is there a delay with the communication to earth? What is the speed of sound over satellites verses copper wires? Anyone know?, this has been on my mind. thanks

Homework Statement In the diagram below, an elementary charge (either an electron or a proton, you decide) is accelerated between two charged plates into a magnetic field. The mass of the proton = 1.67x10^-27 kg. The mass of an electron = 9.11x10^-31 kg. D. Find the distance from the...

Got an ok to do a poster presentation at a neuroscience conference in Honk Kong. I am not sure whether my budget can stretch. I heard that grants are available which will cover half these costs. Anybody know anything about these grants, if traveling from Britain ?

Hi there, I am a physics idiot, but I still want to know where my object will end up ;) Here is what I am trying to do: I have a block that is sliding on a flat surface. I know the friction coefficient, the mass of the block, its initial position, gravity and initial velocity. How...

A steel wire of length 5.0m and radius 0.300 mm is knotted to another steel wire of length 5.0m and radius 0.10 mm. The ires are strethed with a tension of 150 N. How long does a transverse wave pulse take to travel the distance of 10 m from the beginning of the first wire to the end of the...

I don't know much about physics, but I was wondering the other day whether what I was thinking was a popular theory. If time is like a one dimensional line and it starts at the orgin and it grows like a vector along the line as time progresses, then wouldn't it only be possible to travel back...

...where would you go? If a new technology allowed a spacecraft to travel at say 0.5c, and life on board this ship could be sustained indefinitely. If this ship was built tomorrow, where do you reckon it would go? Andromeda? pluto? centre of milky way? alpha centauri? Just though it...

Theres the Butterfly effect and Grandfather paradox which makes logical time travel into the past difficult. Is there any theory or anything which suggests it may be possible?

I'm doing some research into time travel for a presentation I have to give in a month or so, and I'm currently looking at the compatibility of Time Travel and the Laws of Conservation. Sending an object back in time would increase the mass - and hence the energy - in the Universe at this...

If time is a curvature in spacetime as described in relativity, then picture this. If there is a curvature in spacetime time is going in one direction (let's call this curvature 1) but then could time travel not be possible by having a second curvature in curvature 1 but going in the opposite...

Okay, I read this on a blog so I'd post it the way it ias with the link: "There is one aspect of time travel that nobody considers, whether in science or science-fiction (at least, i am not aware of it), something that has the potential of rendering time travel, even if it is possible...

Homework Statement I wish to know what is the best angle that can make an object go furthest. Homework Equations No idea... Wiki is not helping... The Attempt at a Solution I can not find anything on Google...

Homework Statement Which electromagnetic waves travel the fastest in a vacuum? a. Violet light. b. Red light. c. Ultraviolet light. d. Red, violet, and ultraviolet light travel at the same speed. ok so i thought that in a vacuum every wave traveled at the same...

Does what we as humans consider "cold" travel through space like heat does? Could a planet have moons that are cold because the planet itself is cold? I know cold is really just air, but could it somehow travel from one astronomical body to another?

I want to learn how to calculate what distance a fluid will travel up a small tube if a large piston is used on one side, and no piston on the other side. [SIZE="4"]Example Diagram (Consider everything is square instead of round, for easier measurements.) Assume there is a 10kg mass placed...

Homework Statement I don't know if 'hops' is the correct English term, but that's the term my assignment uses in Dutch. The assignment is about the reflection of radiowaves by the f1-layer in the atmosphere and a hop is defined as one such reflection. The question is, what is the minimum...

if it is possible to travel faster than the speed of light will we be seeing the future or the past?

First of all, (following Einstein's theory of Gravitational Time Dilation (I'll just call it GTD,)) objects (such as us) age slower near strong gravitational fields than in empty space. The higher the local distortion of spacetime due to gravity, the more slowly time passes. So according to GTD...

I found a decent page explaining this but it's a little deep for my understanding. I think I understand the basics of special relativity where the speed of light remains constant regardless the velocity of 2 observers, the laws of physics do not depend on location or motion, and that length...

Since I only learned special relativity but not yet general relativity, please bear with me that our discussion will be limited to the scope of special relativity, that is, suppose we would not utilize special spacetime topology, such as worm hole and black hole. I ran into some video about...

[b]1. The problem statement, all variables and given/known Is it true that nothing can travel faster than the speed of light? Can't all electromagnetic waves travel at light speed. Also, if the speed of light is a constant, is the speed of the other electromagnetic waves a constant such as x...

This is the last part of the question. I already found the frequency to be 9.7 GHz and the wavelength is .031 meters. It's just this last part of the question that I can't seem to figure out. I really don't even know where to begin, I checked my book and online and can't seem to find any...

I had a thought that I wanted to run by physicsforums so all of you can tell me that I'm wrong and make me feel better. One of the main issues with the concept of time travel into the past is that we don't know whether is breaks any physical laws in the process. Here is what I believe...

Say I was embarking on a journey to Neptune at 95% the speed of light. Neptune has a minimum distance of 4.3 billion km from Earth. If I was traveling at 2.85 x 108 m/s, I would take 4 hours 11 minutes and 38 seconds to get there. Is this even possible? 1)What would I see of my...

Why does light travel so fast? I want to know about the speed at which light travels. Why can light travel so fast? is it the weight of the photons or what? And what accelerates the matter to that speed. Everything is propelled by some force so what is lights force? Thank you. Questions4all

Since, light is always traveling at a constant velocity with respect to everything else, does it also mean that everything else is also traveling at a constant velocity with light? As in, since light is always traveling at C irrespective of our velocity, then does it not also mean that we are...

if it were possible to send a message or travel at speed's higher than light what would happen? i know that at the speed of light time would stop.but beyond...?

Homework Statement A 30.0m steel wire and a 20.0m copper wire, both with 1.00mm diameter, are connected end to end and stretched to a Tension of 150N. How long does it take a transverse e wave to travel the entire length of the two wires? Homework Equations Voulume of Rod = pie r^2(L)...

Homework Statement Car: mass = 200g Moving at 30 m/s Braking force of 10000N. How far does the car travel before stopping? Homework Equations W=m x N w = F (delta x) The Attempt at a Solution I found work, (2000)(10000) = 20,000,000 Then rearranged the second equation to get...

Is time travel possible quantum world?

Hi, I want to know from proffesionals if time travel is physically possible. Thanks, Tony

Link: http://www.santafenewmexican.com/HealthandScience/LANL_scientist_makes_radio_waves_travel_faster_than_light Is this true ? Can radio waves or light really be send faster than light using a rapidly spinning magnetic field ? Sorry if there already was a thread about this, I couldn't...

Homework Statement Identical twins Speedo and Goslo join amigration from the Earth to Planet X. It is 20.0 light years away in a reference frame in which both planets are at rest. The twins, of the same age, depart at the same time on different spacecraft s. Speedo's craft travels steadily at...

If we have two balls, a red and blue ball, and the red ball passes the blue ball at 99.9% the speed of light, would "time" for the red ball pass slower than it does for the blue ball? If it does, and if speed is just relative, couldn't we say the blue ball is passing the red ball at 99.9% the...

Homework Statement A celebrity holds a press conference, which is televised live. A television viewer hears the sound picked up by a microphone directly in front of the celebrity. This viewer is seated 2.9 m from the television set. A reporter at the press conference is located 5.2 m from the...

1. A girl coasts down a hill on a sled, reaching a level surface at the bottom with a speed of 7 m/s. The coefficient of kinetic friction between runners and snow is 0.054, and the girl and sled together weigh 749 N. The acceleration of gravity is 9.8 m/s2 . How far does the sled travel on...

What makes light travel so fast? Is light its own energy?

first, I would like to apologize for my lousy english second,I hardly know anything about relativity (well I understand why you can't travel faster than light, and i understand a few concepts,so I get the simplfied big idea , but I don't know the fine stuff of it) me and a friend were discussing...

Homework Statement Algebra based physics: A 23 kg mass is suspended from the bottom of a rope of length 2.4 m and mass 17 kg. The acceleration of gravity is 9.8 m/s^2. Find time for a transverse wave to travel the length of the rope. Answer in units of sec. Homework Equations u= mass...

Would it be possible for a human being or any other solid matter to be encapsuled or exist in a sort of "Vaccum" which distorts space and time around the object that would make it have zero matter? If so, would it be possible for light or protons to somehow be captured and propel that object...