Travel Definition and 994 Threads

First I don't understand why this show is on the Travel Channel. Some stupid guy that locks himself into supposedly haunted buildings overnight and films himself screaming and pretending to see stuff. For halloween they are doing a "live" broadcast where "viewers" can posts their comments and...

Time time time Can the laws of gravity permit curving space and time in such a way as to make time travel possible. Einstein's theory of relatively states that the space/time continuum can be flat, but it can also be curved by gravitational fields. Perhaps time has three folds 1...

From what I've seen, most speculations of time travel seem to say that when you go back in time, everything else around you returns to an earlier state that it used to be. For example, if you stand outside your house and go back in time, the house will "un-build" itself and there will be nothing...

Homework Statement The starter motor of a car engine draws a current of 140 A from the battery. The copper wire to the motor is 5.0 mm in diameter and 1.2 m long. The starter motor runs for 0.95 s until the car engine starts. How far does an electron travel along the wire while the starter...

Homework Statement The starter motor of a car engine draws a current of 140 A from the battery. The copper wire to the motor is 5.0 mm in diameter and 1.2 m long. The starter motor runs for 0.95 s until the car engine starts. How far does an electron travel along the wire while the starter...

Hello, I have been lately very interested in time dilation. I have found out many information about it and it's very interesting for me. But I have few problems I don't quite understand, so I will be glad for your help. Let's start: There's a man traveling in a spaceship from point A to...

Hello all, I am new to the Forum and have no formal Physics training. I have an interest in the subject mainly due to other pursuits. I am reading Joe Haldeman's The Forever War. I would definitely recommend this book to anyone with an interest in Time Dilation or Humans vs Aliens at...

I was watching a show called "http://www.history.com/shows.do?action=detail&episodeId=373152" " on History Channel. It is claimed that someday it may be possible to travel to parallel universes. Does this not violate law of conservation of energy, mass and information? Would this action...

A spaceship becomes lighter and easier to accelerate as it burns fuel. If it doesn't literally burn fuel, but it "magically" converts mass into to momentum with 100% efficiency, you will find that the limit of v as m approaches zero is c. You may ask, "At that limit (when v=c) where did all...

How is time travel possible? i understand that we can warp and modify time but i don't understand the concept... Is there any evidence to suggest that there are wormholes? if so how are they created?

I'm having a bit of a debate on traveling to AC. I was wondering if someone can post calculatons to show how long it would take traveling at 1g accelaration, and how much energy would be needed including any relativistic influences. Thanks

First of all, my background: I am an engineer interested in physics; so I am not very well versed with the nitty-gritty details and the math of physics. These are my thoughts and would like your comments: In some sense, time travel, being able to move back and forward in time is the...

I don't know if this has been discussed before, but I offer this paradox to debunk time travel. If time travel was possible, given an infinite amount of time from the point of its discovery and perfection; then someone eventually would have traveled back in time and made its existence known...

If speed of light is the upper limit of speed in the universe, how about force? (please refer to example for the paradox) For example if there is a block of wood 50 light seconds long floating in free space, say it weights only 1 kg and I apply 1 N causing it to accelerate 1m/s^2. So does the...

I had been reading about the troubles down there and was concerned about my young nephews and niece going there. Their father replied, "If you always listened to the State Department, you would never go anywhere." So then, what is a good way to determine if a destination is safe enough for young...

As a Physicist (I was thinking mainly about those employed in academia which is why I posted this here and not in Careers Guidance) how much opportunity is there to travel? Many publications by the IoP to encourage students to study physics emphasize the international nature of a research...

Homework Statement An object with mass 10kg is dropped from a height of 200m. Given that the constant k in the equation is 2.5Nsm^-1 mv'(t) = −mg − kv(t) approximately how many seconds does the object hit the ground? Homework Equations v' + (k/m)v = -g The Attempt at...

Homework Statement A person driving her car at 56 km/h approaches an intersection just as the traffic light turns yellow. She knows that the yellow light lasts only 2.0 s before turning to red, and she is 30 m away from the near side of the intersection (Fig. 2-29). Should she try to stop, or...

Is time travel is possible?

Firstly, I must apologise if this thread is in the wrong place on the forums. I wasn't entirely sure where it might suit best. My question arises from something taken pretty much as read without much thought. That light travels through varying edia at varying speeds. I am curious as to why...

Not sure if this will have anything to do with quantum mechanics.. but... Ok so if you're traveling faster than light speed, then what do you see? I'm not talking about the whole doctor who scenario, its like traveling faster than sound, if the jet pilot is traveling faster than the sound it...

i´m new in this fisics forum but, i would like tomake some questions about time travel...is there any specific place to put that kind of questions?

How do the movement of a particle relate to the speed of light

I've been thinking about this for some time now and I wanted to get some feedback on it. If photons are supposed to travel along straight lines (for the sake of simplicity let's neglect the curvature of space-time), then how could one photon possibly be used in a double slit experiment? More...

Let's say you've got this steak and you've found a way to launch it in orbit and propel it back to Earth without any effect on the steak other than friction via air: http://a725.g.akamai.net/7/725/1095/000031/www.omahasteaks.com/gifs/big/ss031.jpg How fast does it need to go, for how long...

1.Light is moving so fast that is apparently stopped.But it ain't.Photons of light come and go. Now the question: Is light seeing us stopped?Like we arent moving? Thats a dumb question.Of course the light sees us stopped.If i ride a photon of light from Sun to Earth everything is stopped.8...

You all have heard of the paradox whereas when you travel to the past and kill your grandfather you should not have existed in the presence whatsoever because you have killed your origins. So far so good...but I thought of another case, which I believe is more interesting since so far the...

One application I can think of is that if I had an incurable disease I could go on a one week ride in a spaceship, on return 50 years have passed on earth. Of course if there wasn't a cure I could just go on another trip.

I know that relativity doesn't permits a motion at speed of light or fast, as the Lorentz factor becomes infinite and we get absurd results, but what about wormholes or something, say wrap drive and what about http://en.wikipedia.org/wiki/Alcubierre_drive" and tachyons. Also I've heard that...

Why would time stop if you travel at the speed of light?

I was considering this the other day, and I'm pretty sure I know the answer, but I want verification that I am not missing anything. Suppose you are in a rocket ship and you want to travel, say, to a star the nearest galaxy. Is there a minimum amount of time that would require? Since the...

Starting the trip off in geneva, and looking to go to germany possible austria and maybe parts of eastern europe.. 4 of us are students so budget is tight, but also looking to have fun i.e if they're any good festivals or cheap gigs going on. We're only traveling for 10 days so we're looking to...

So I was watching a video on youtube. http://www.youtube.com/watch?v=QM28eErikAo" It says that the faster you travel through space, the slower you travel through time, and that if you went faster than light, you could go back in time. Is this true? Forget about it being impossible to go...

No pitchforks please (and lay off the caps with the big 'D' on them too) Following staying up until 4am (all good stories start like this), and making small talk with a friend doing a degree in physics, we both decided to harp on about theoretical theories such as string etc, and as hours...

I have thought of an interesting property of time travel based on Novikov's self-consistency principle. I'm sure it's not wholly original, but if someone has heard of it before, I'd really like to know the name given to it so I can research it: If you find yourself next to a future version of...

I was watching the show Exodus Earth on the Science Channel, and they were talking about new methods of travel in space. Things like Ion Engines, Solar Sails, and Vasimir Plasma engines. I was reading a HALO book, is it mentioned how their Shaw-Fujikawa Translight Slipspace Engines worked. I was...

If you are traveling away from Earth on a spaceship near the speed of light, it is well known that the moving clocks on the ship run slower relative to stationary clocks on earth. I was wondering if while on the space ship, you could watch the news on TV and see events progress at a...

Someone here once said to me, via post, that "any compact spacetime must have closed timelike curves". Are there any good references out there on why that is / how that is derived? As an after thought... Isn't it true that a particle traveling in one direction in time is equivalent to its...

Would this be valid for all other planets as well?

What are your thoughts about this?

This is not a a school or college question, it is just for my interest. Homework Statement suppose I travel 605 meters North , then travel 673 meters West. I have calculated shortest distance of Sq Root(605^2 + 673^2) = 905 meters What I am now trying to calculate is direction to face...

So the other day while I was folding up some laundry I had this idea pop into my head. Now I'm not an expert or anything and I dropped out of physics in high school, but I do think quantum physics are interesting like most people. I figure this would probably be the best place to post this due...

Imagine a hypothetical large region of empty, non-expanding space whose spacetime is flat. At the start of the scenario, a rocket sits stationary relative to our galaxy at a large proper distance "x", in the common inertial frame. Then at t=0 the rocket quickly accelerates to a constant .99c...

In the movie, when superman flies near light speed, he manages to reverse time? Was the story-line just completely off from a physical perspective or is there some truth to this phenomenon? I understand that time would slow down for superman from a human's perspective. Maybe I just didn't...

I was just watching Ian Morison on Fora.tv about Time, in chapter 14 he talks about wormholes and time travel. You can see the time travel part here: http://fora.tv/2009/03/19/Ian_Morison_Its_About_Time#Journeying_Through_Space_and_Time_in_a_Wormhole Anyhow, in short he mentions opening a...

Ok, I have come up with a new theory of traveling at the speed of light. This is totally theoretical and isn't phesable at any level. That aside, here it is. Make a pole 1000 light years long. Now swing the pole like a bat. The tip of the pole should be traveling millions of times faster than...

I was wondering the feasbility of time travel. Has it been proven not possible? Has it been proven theortically possible? I have always been interested in time travel, even if it seems like science fiction, but was wondering from scientist, professors, etc, if it has been an 'unsolved'...

Homework Statement Truck brakes can fail if they get too hot. In some mountainous areas, ramps of loose gravel are constructed to stop runaway trucks that have lost their brakes. The combination of a slight upward slope and a large coefficient of friction in the gravel brings the truck...

How time Travel work ? ok i know some of the basic about speed of light... You can't get to the speed of light ... You can't reach the speed of light cause According to Einstein's special theory of relativity, and E= MC ^2 objects gain mass as they accelerate to greater and greater speeds. Now...

Hello everyone, The topic of superluminal flight has intrigued me for decades but coming from an engineering background and not a strong physics background (although I have studied physics), I am finding the notions about how to possibly achieve such a system quite difficult to accept. In...