Travel Definition and 995 Threads

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...

Homework Statement 1. Homework Statement You wish to travel to another galaxy, which is 1,000,000 light years away. You'd like to be still alive when you get there. How fast must you travel? Given enough fuel, can you do this? Homework Equations t/t(proper)=gamma...

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...

If matter were to travel the speed of light, would it convert to energy?

Homework Statement A charge of -1.8 µC is fixed in place. From a horizontal distance of 0.0450 m, a particle of mass 2.25 10-3 kg and charge -1.7 µC is fired with an initial speed of 65.0 m/s directly toward the fixed charge. How far does the particle travel before its speed is zero...

Homework Statement A motorcycle can attain a maximum speed of 55 m/s, accelerate at 5 m/s^2 and decelerate at 7 m/s^2. If the motorcycle starts from a rest, find the minimum possible time it takes the motorcycle to stop exactly 800 m further down the road. Homework Equations d=rt is the...

i would just like to know where to get some good info on possble time travel and some people personal views on it. Thanks.

Looking for clarification: FTL travel is said to imply signals moving backwards in time for some inertial frames. Is this because in certain cases, depending on how much greater than light speed one is able to achieve, someone can signal someone else's "past light cone" in the graphical sense...

Just wondering what the connection is between them, I understand that it relative to what we see but time in general? why not the speed of sound as its only another sense right? Just interested to know why light is so special? thanks guys, :smile: Sorry messed up title should be speed of...

New method would not break Einstein's Theory of Relativity -xCross Source: http://www.dailytech.com"

While SR states one can never measure a velocity greater than C, for all practical purposes one can travel 'faster than light'. Here is what I mean. . . Lets assume I have a Spaceship with the means of constantly accelerating at 1G. The fact that this is technologically unfeasible is...

Two objects lie motionless in an isolated frame. One object accelerates to a speed v, then then holds that speed for an amount of time t. This causes the accelerated object to travel a time t_s into the still motionless object's future. v=\frac{c\sqrt{t_s^2+2t_st}}{(t_s+t)} If you're...

Why does light travel at varying speeds through different materials?? why does light travel at different speeds through different materials?? for example, it travels at 38 mph through super cooled sodium. also, if light is massless, why is it susceptible to gravity?? i don't know the...

Homework Statement The length of the barrel of a primitive blowgun is 1.5 m. Upon leaving the barrel, a dart has a speed of 12 m/s. Assuming that the dart is uniformly accelerated, how long does it take for the dart to travel the length of the barrel? Homework Equations I was...

1. A 1000m long and 200m wide (when at rest) spaceship equipped with a chronometer is sent on a roundtrip to their Galactic Base, 8 light years away. (a) Astronauts start the trip after celebrating their captains 29th birthday and they want to make a round trip and return to Earth on the eve...

My knowledge of QM is far from great, but I can't figure out what I'm missing here. When looking for e.g. an electron, it has a certain probability to be at a certain location, right? So how does *not* this allow for the electron to travel faster than light? If I take two measurements, one...

im compfuzzled.

Is it possible at the start of big bang matter and energy went faster than c?

I am not a physicists, engineer or even a student of such, however, I am writing a book and so this leads me to research. Say traveling to another dimension is possible. Would the traveler lose his/her memory there, only to regain it upon return to the dimension they started from? What...

Homework Statement Show that, in the limit of large damping, the time of flight of a projectile (the projectile is fired from level ground) is approximately, t \approx \left(\frac{w}{g} + \frac{1}{\gamma}\right)\left(1-e^{-1-\gamma w/g}\right) Homework Equations The equation of...

Is it literally possible for them to be in two places at once? Is this proven; How is this possible? I mean, sure they travel very, very fast. Even if they travel faster than the speed of light, it would appear so that they are, but nothing can travel at a speed that literally freezes time...

A quick question, let's just say that my friend and I became photons, and were emitted from a light source in the same direction 1 second apart. My photon friend would never catch up to me, right? Am I correct to say that I wouldn't even be able to tell that he was following me since his...

I'm no theoretical physicist or physicist of any kind, but I have some basic grasp of how the universe works and after thinking long and hard about time travel, I don't think we have to worry about the paradoxes which are inherent to time travel when time traveling into the past. If we are to...

I've been told that as a person approaches the speed of light, time relative to others being viewed slows. when you make the speed of light ( if possible, I’m aware of distance change and mass increase and of the immense amount of energy needed to possibly reach this speed to push that mass)...

Hi, I'm new here. I got referred here when someone else couldn't answer my question. Hopefully, someone can answer the question. Thanks in advance for taking the time. I have a vacuum thermos. Somehow, a bottle cap wound up in there. I was walking with it, but I could still hear it jingling...

Let's say there's a stick, and two persons are holding the extremities: Person A ----------stick---------- Person B Both are pulling the stick with equal forces. At a certain moment, Person B releases it and instantly Person A knows it becase he can now pull the stick to himself. Why...

Space ship Alpha travels at t = 0 and v = 4/5 c to the star Sirius which is 8.6 light years away. One year later spaceship Delta starts at v = 9/10 c to the same star. Question 1: When does Delta overtake Alpha, as measured from Alpha's, Delta's and Earth's perspective? Question 2: At which...

I have a question which relates to the physics of light. I hope I can explain it well enough for a proper answer! Let's say there is a 15 feet tall light pole 50 feet from my door step. The light pole has a 300W light bulb. Given these info, is there anyway to calculate the amount of...

The Light Speed has been proved to be around 300.000Km per second. So, Before continuing to expose my real thread, i need to know if it is really impossible to an object to travel faster than Light Speed.

Light can be left or right polarized (circularly or elliptically). This is achieved by passing unpolarized light through various polarizing crystals which are optically active (ie chiral). My paired questions are: 1. When we consider the photons before they strike the polarizers, can we...

We consider light is made up of material particles (photon), and we know photons travel at speed of light having zero rest mass so we say photons travel but how can something travel at this speed , we say electric forces are experienced by a test charge due to some other charge , the field...

This Question begs an answer and that is impossible but I'm sure we can agree on one 'unified answer' I Know from a lecture about energy needed to travel at the speed of light and found: E=(Gamma)Mo(Mass In A Stationary Postiton)C2 (Constant/Speed Of Light) Now according to this formula...

All right, so here it is! Archer Enterprise states that they have a theoretical device (in process of proof of concept) that can reach speeds near that of light. Looking at the description of the theory of the device, it looks like this could work, at least in electrically propelling space...

Homework Statement A spacecraft with its astronaut has a total mass at rest of 10^5 kg. The astronaut is to travel to a star 10 light years away at a speed such that she only ages 1 year in her frame of reference a) the quantity 1-v/c where v is her speed with respect to Earth is? b)...

When releasing two different objects at the same time, the objects will travel at a constant speed towards the Earth no matter the mass. I have a hard time believing this. If I were to release a brick and a feather at the same time, the brick will reach the ground before the feather. I know...

A spaceship with empty mass MSS(?kg), start its journey from A to B which distance is RAB(?ly). The amount of fuel the spaceship initially carry is MFUEL(?kg), which energy per mass is EPM (?Joule/kg). The spaceship engine efficiency is SEP (?%), and the engine is capable of burning FPS (?kg/s)...

Sorry for bringing up this subject again but I'm really just looking for some answers. This is strictly hypothetical. Suppose, for a moment, that humanity could somehow overcome these problems (disease, war, global warming, terrorism, etc) and advanced to a stage where it was limited only by...

Hi this is my 2nd post so pls be kind guys. Let me know of any other cool cosmology forums out there as they seem hard to find with google. So to my idea! Instead of waiting for some hyper-drive to be invented (I read of pushing spaceships with lasers?) how about we use our own star, the...

A 1000.0 kg car experiences a net force of 9500N while decelerating from 30.0m/s to 23.4m/s. How far does the car travel while slowing down? I do not even know how to start to setup the problem. I know that W=Fd but I do not know how to apply this with the velocities. Any help would be...

Homework Statement A cylinder (R= 0.11 m, I (center of mass)= 0.015427 kg*m2, and M= 1.48 kg) starts from rest and rolls without slipping down a plane with an angle of inclination of Theta= 26.3 deg. Find the time it takes it to travel 1.51 m along the incline.The attempt at a solution...

You are visiting a new planet with radius of 5000km. You set up a seismic network and detonate a test chare at the north pole at time T=0. At time T=24minutes your instruments detect S-waves at a latitude of -60 degrees. No S-waves are detected south of -60 degrees. what is the size and...

I think I know why we can't time travel backwards. I have been researching like mad at my skool and I think i have the answer. If I'm wrong, PLEASE tell me. This is for a research paper, and I am trying to navigate my way out of the math and stuff: We are in the present, while physical...

Direction of travel in glass...please please HELP! Homework Statement A 0.95-cm-thick layer of water stands on a horizontal slab of glass. A light ray in the air is incident on the water 58° from the normal. What is the ray's direction of travel in the glass? (Give the answer in degrees.)...

This is my first post, so if I am in any way out of line for the the norm on this site please forgive and instruct me. That said, I found this site while trying to comprehend a physics issue I just cannot seem to get my head around. That would be the claim that faster than light travel woudl...

I am beginning a textbook on SR and I have come across the introductory example of disagreement regarding simultaneity. John is in a lab and Mary flies through the lab's corridor on a rocket. The rocket has an antenna. The antenna strikes John's pen in his shirt pocket and creates a spark. 2...