Travel Definition and 995 Threads

Suppose there was a ring of some material (steel? future carbon nano tubes?) around the sun. The ring would have a diameter of 2*10^9th meters. If a solar sail were placed attached to the ring with the reflector at a 45 degree angle) then the solar sails velocity would only be limited by the...

I understand the electromagnetic spectrum travels below speed c in Earth’s atmosphere. Is there any part of the spectrum which remains at speed c, or indeed anything which travels at speed c in the atmosphere? Thanks

Hello! Sorry, I'm not not exactly sure if this post is in the right thread. But I would just like to ask what time travel theory is appropriate, and hopefully much easier to use, for science fiction? I am planning to write a semi sci-fi short story, and it involves using time travel: to the...

Hello everyone This is my first post and I am interested in the question about neutrinos... I have many questions that I would love to have answered but I'll stick to the question of whether they can travel faster than light or not... ( please bear with me as I am returning to physics after a...

I can't really bring myself to understand why time slows when you travel at high speeds. I tried to think of a graph in witch the y is time and the x is distance. This line could be at any positive slope. So the only relation is the "speed" at witch the line moves on the graph. Please help me...

So I look at the Minowski diagrams, and I can understand that moving on the y means moving in time, and moving on the x means moving in space, but drawing some diagrams of my own, I find it impossible to see why it would imply FTL travel. All objects travel either directly on the x...

neutrinos -- what is their mass when they travel so close c? I understand that neutrinos move at very near the speed of light and that they have a very small amount of mass. This being true, why do they not have a great deal of mass at that speed?

It could be possible for a driven vacuum bubble (like an Alcubierre drive,assuming that it could be possible to realize ) to travel not only many order of magnitude faster than light but even trough different vacuum phase ? like for example region of false vacuum ?

Homework Statement As an example of the manipulation of an electron beam, consider an electron traveling away from the origin along the x-axis in the xy plane with initial velocity vi hat bold = vii hat bold. As it passes through the region x = 0 to x = d, the electron experiences acceleration...

I would like to calculate the maximum distance, crest, a guitar string will travel at it's center when plucked in order to determine how high the string needs to be on the fretboard to avoid striking parallel frets and thus avoiding "fret buzz". Example: 0.762 mm string thickness with...

Question between friends! -- How long to travel 1 light year? Homework Statement Me and a few friends were trying to work out how long it would take a human to travel one light year. We were using the these variables. Distance = 9.4605284 × 1015 m Fastest speed for manned space...

Doc Brown's explanation of time travel on the blackboard, in BTTF2, the best explanation of time travel I have seen in any movie.

I was discussing with some friends, in the hypotetical case that we could travel really large distances through space at superluminal speed (or that we did not care about the trip lasting millions or billions of years), whether the risk of hitting some object during the trip might be a...

Assuming (Big assumption I know) you could create a wormhole, and using either of the relativities created the time effect needed to travel in the past, is there any way where the traveler could go beyond the inception of the wormhole. So if we made the time machine today, how could I get to the...

Do aircraft need to factor in the coriolis effect when flying?

I am a non-traditional student (35yrs old). I have a daughter and a wife, and before I finish my degree (only on 2nd year), I will probably have another child as well. As such, the though of traveling around a lot for post-doctorate work is a bit unnerving. So, I was hoping that some of you...

Homework Statement "Use the equation I=nAve to justify why charges travel faster in semiconductor than in metallic conductor. Assume that the dimensions and current are the same. " Homework Equations I=nAve I know I = current, n = number density, A= cross sectional area v= drift...

I am currently in the process of re-writing an episode for a Science Fiction television series. Currently the main character a 280 year old human scientist travels back in time to stop catastrophic events set in motion. I would like to stay away from the actual time travel of a human being. So I...

Homework Statement A spring is launched from the ground at 2.3 m/s t an angle of 78° to the ground. What is the max height of the spring? How far did the spring travel? Homework Equations ##\vec{v}_R = 34 m/s## ##\theta = 78°## The Attempt at a Solution First things first, get my...

I've heard that photons have a mass. If a photon were to be stationary, would it have mass? If not, then where does the mass of a photon come from? I know that if an object has stationary mass (forgive me if this isn't the correct term), then it takes an infinite amount of energy in order to...

Every horse travels 12 km every hour, how long will it take to travel from manila to baguio which is 500 km away? How will i write every hour? I am confused, is is 60 minutes? Ty in advance

Shuttling ball. I was told that as the two conductive plates are brought closer together the speed the shuttling ball travels between them is increased. I don't understand this as i thought because the electric field is uniform between plates the distance they are apart wouldn't affect the...

Homework Statement In a CRT tube, electrons are accelerated by a 20,000 V potential difference between the electron gun (the cathode) and the positive metal mesh 5.00 cm away. a. What is the electron’s speed when it reaches the positive wire mesh? b. How much time does it take the electron to...

Doesn't traditional time travel violate conservation laws? If I could in effect materialize in the past, then the universe, being an isolated system would have suddenly gained matter/energy out of nowhere! Also, the atoms that make up my body would then be in two places at once since they...

Hey guys, Why you think time travel will be or won't be possible either now or in the future?

I hope this isn't a common question, and that I'm not breaking any rules of posting - please let me know if I am, as I'm new here. So, to describe what I'm trying to ask: Picture a very long rod, say, one light-year long. Imagine it's in space, and is free of gravitational interactions (and...

This is my first post so let me know if I'm posting this in the wrong section. I read somewhere that if we are ever able to travel faster than the speed of light that fact would automatically enable us to travel back in time. I don't see how those two things are connected. Even if we travel...

Yeah, all of those things, multipled by five thousand, and there we have the current cosmic predicament for human beings. Is there any way in which we can do something about this? Or will Schopenhauer have the last laugh?

I'm just learning the basics of electromagnetics and am a bit confused as to how ac works. From my understanding, a rotating conductive wire in a magnetic field create a current that changes direction from positive to negative flow, modeled in accordance with the sine function. But i was...

Using the given information, is it possible to solve the new travel direction of the smiley face? To clarify, I am casting a ray using the Möller–Trumbore ray-triangle intersection algorithm.http://http://en.wikipedia.org/wiki/M%C3%B6ller%E2%80%93Trumbore_intersection_algorithm by casting the...

At Stewart airport in Newburgh New York a small commercial commuter jet leaves and lands in Philadelphia, Pa one hour later. The total distance is about 150 miles. Can small commercial jets travel at an average speed of only 150 miles/hour?

Hey guyies, can i get some really interesting and crazy paradoxes, except the grandfather one, thank you

Homework Statement Hi, Please help me to identify the materials required for a large travel suitcase and the properties which are required for it too. Homework Equations The Attempt at a Solution I was thinking of nylon as one of the materials for a travel suitcase. Properties...

I'm not sure if this is the right area of the forums. If it's not. Tell me which area would be better and I'll post this there. Time Travel- Would have to be space travel... and possibly faster than light If the time traveled and the time it takes to travel took less time to travel...

Homework Statement I have to calculate minimum travel time between two points. I already have cycloid equations in parametric form: x=r*(t-\sin t) y=r*(1-\cos t) Homework Equations For calculating time i want to use following formula: \int_{0}^{a} \frac{\sqrt{1+{y'}^2}}{\sqrt{2g\,y}}dx My...

Is it possible at all to merge with the tachyon field for a while to obtain FTL travel. Or do I have to go back to the good old standard warp drive?

Homework Statement A traveller with mass m = 66,5 kg travels with a velocity of 0,82 c to the Andromeda galaxy which is a distance of 2,55·106 lightyears away. Light with the wavelength 459,4 nm is emitted from the galaxy. assume the galaxy doesn't move and use the exact speed of light. How...

I have a conveyor that travels radially. I need to calculate the HP needed to move it. It works on a concrete slab. The Motor RPM is 1750 and a reducer of 180:1. Any help would be great. Thanks

This article is based on information from the Canadian Department of Foreign Affairs. Strangely, Canada itself is not classified, I guess because it's information for Canadians. One surprise is Japan which is ranked two levels below the safest, indicating some areas are unsafe. I always thought...

Hi, I'm trying to find out the time it takes to travel a known distance, but with a capped speed. For example, let's say a train has an acceleration rate of 0.8m/s/s, and a top speed of 72km/h, ie: 20m/s. It's going to make a 12km journey, accelerating to it's top speed from rest. How...

If a photon does not experience space-time does that mean it cannot "degrade/fray"? Is there a way to reconcile the, say, eight minutes, time the photon (approx) took to travel from sun to Earth with the zero time that passed in the (frame of reference of) photon? Where was the photon, in a...

After looking at where the isogravitational point between the Earth and the moon was, I thought about practically what sort of speed you would want to cross it at. Of course, if time is not a factor, I imagine you would ideally want to expend as little fuel possible in getting from planet to...

I'm looking for as much information as possible about time travel to the past and ideas for hoe to make it a reality. Thanks in advance!

I recently found an interesting read on the mysteries of quantum mechanics, here : Don't know about you, but I am personally confused by this result. How can a photon travel faster than itself? If it can travel faster than itself, than what does that mean for the universal speed limit? My...

Light doesn't have mass so what's stopping it from going infinitely fast ?

My guess is that this topic has been covered somewhere at some point. However, I have not recently seen a general, more non-technical treatment of the subject, so I thought this may be the thread for it. In any case, for discussion purposes, I'm going to make the bold statement that time...

Homework Statement a beam of charged particles is emitted from a very small opening called an "orifice" from the source. Above the source, a set of parallel plates is used to create a uniform electric field E. The distance between the two plates is D = 20 cm. The charged particles enter the...

Let me ask a strange question. is it posible to atract the gravitational pull of an object in space and some how use it to accelerate your spaceship thrue space. Like reach out to Jupiter and lock in on its gravity and magnefie it for acceleration.

I can't figure this out/find the answer. Why are acoustic phonons very low loss (i.e. earthquake P and S waves), but optical phonons die out rapidly? Thanks, Joel

So basically if you were on Mars, you cool look back and see yourself traveling to mars?