Why doesn't an airplane traveling in the opposite direction of the Earth's rotation move faster than one traveling in the same direction of the Earth's rotation?
Contrary to what everyone else is saying, it does take longer to fly east that it does to fly west.Its called the Coriolis effect, and it only applies to rotating reference frames.This is why examples of driving in a car and tossing a ball, or walking the length of a ship while its underway, dont apply. Those aren't rotating reference bodies.The air mass of the atmosphere does spin in relative synch with the earth, which is why your airspeed doesn't register differently, but it has nothing to do with the length of the trip.Ignoring things like the jet stream and assuming you were flying in a perfectly static air mass, a trip from NY to LA would take less time than the return trip from LA to NYC if the pilot were flying the same airspeed. But the ground speed will be different in those cases.When you fly west from NYC, LA is physically getting closer to you due to the rotation of the earth while you are in the air. The reverse is true flying east. NYC is constantly moving away from you while you are en route to it.The reason you dont notice is that the pilots have a schedule to keep and a flight plan to stay on. If its supposed to take them 4 hours each way, they adjust the speed of the plane so they get there in 4 hours. They do this because gates have to be empty and waiting, air traffic control is expecting you at a certain time, you have to meet other connecting flights……ect.Compound this in the real world with things like moving air masses and the jet stream, which over N America can sometimes make it faster to fly east ( or much more fuel efficient) and the effect of the Coriolis force is lost in the noise. But it is still there and very real.So real in fact that snipers have to account for it when taking long shots. A sniper shooting while facing N, E, S or W has to account for the fact that the target will have moved several feet due to the spinning of the earth during the few seconds the bullet is in the air. A few feet is not much, but its enough to make you miss if you dont factor it in.
Special relativity, time dilation :?
The speed of light is the absolute speed limit in the universe. You can't go faster than it (c = 3x10^8 m/s or 300,000,000m/s). However this applies to all the dimensions - the three spatial dimensions, and the fourth which is time.The sum of your speeds through all four dimensions must equal the speed of light. So what's happening here is that the faster you travel in the spatial dimensions, the slower you age. So photons, the small massless particles of light, actually never age since they travel at the speed of light. All their speed is through the spatial dimension, leaving none to travel through time and age. So to answer your question, we can't go 300% or 1000% the speed of light. The theoretical max is 100% the speed of light. However, that is really unachievable. The closer you get to the speed of light, the more energy required to accelerate you further because you begin to gain mass. Ultimately, it would take infinite amounts of energy for any being of mass to reach 100% the speed of light.
How long would it actually take to travel 40 light years, given time moves differently at high speeds? Would it actually take generations for the people on board, or would time move slower for them due to their speed?
Robert A. Heinlein, in his book Have Space Suit—Will Travel has characters traveling from Earth to the Moon in nine hours. They accelerate at 1 G for the first half of the voyage, then decelerate at 1 G for the remaining half. Later in the story they reach Pluto in about a week using the same method.Isaac Asimov, in his book Asimov on Physics (a compilation of previously published work) uses the same method to get from Earth to the center of the galaxy in about 22 years, except with no deceleration, just accelerating at 1 G (subjective) all the way and whizzing past the center. Using the same method, Asimov says you can get to the Andromeda Galaxy in about 27 years, even though it's 2 million light-years away.The reason it works is because of time dilation.The reason it doesn't work is because we don't have spaceships that can maintain that kind of acceleration for that long. Yet.
If you were traveling at the speed of light how long would it take you to travel one light year?
1 year! A light year is described as how far light will travel in one year, and since you’re asking how long you will travel for the time of us on Earth will take to travel once around the Sun, the answer is one year.However you may experience a different reality all together can you imagine going from here to the Moon in just over 1 second.The truth is we don't know what this reality is because we never experienced it, we come up with some well thought up hypothetical ideas but never any clear evidence of how you will experience time:Maybe time will stop, you will see light coming at you as fast as you are going at it, therefore you precieve the universe as standing still.Maybe you will experience what's coming at you in fast forward, and what you're leaving behind looks still because you are traveling with those photons, maybe if you were traveling slightly faster you would see time going backwards because you are getting ahead of the photons.However these are merely speculation of the great minds of today.I do know however it would take so much energy to cause you to travel that fast it would turn you into energy itself. I do not know if you could survive the trip or what you would look like if you stopped.I want to leave you with a thought what if there is no such thing as time and time is realative to the observer?
If you are on a plane, walking from back to front. How fast are you walking?
All measurements must be taken under a certain reference frame....some reference which you measure against. There are no absolute speeds in the universe, so you technically need to specify whether you are measure the speed of the person with respect to the ground below, with respect to the plane, with respect to the sun, ..... That said, what your question is probably getting at is how fast the person is walking with respect to the ground. Since the plane has some velocity v and the person is walking with some velocity u in the same direction, the over all speed at which the person is traveling with respect to the ground can be found as the sum of v and u. Speed with respect to the ground (assuming v is the in the direction is u) = v + u *we assume that neither the plane, nor the person walking, is traveling at any significant percentage of the speed of light so we can use simple galilean relativity to answer the question.
Why do so many people think that easy interstellar travel will always be impossible?
Those who make this common assertion are missing something, just as people in the Dark Ages couldn't have imagined how to get to the moon with their knowledge and technology the same applies to us and our physics and interstellar travel. A far more advanced physics would show the "limits" of reality in a whole new way. As we probe deeper into the nature of reality we find that our old understandings of the limits of reality become obsolete or not quite accurate, as is the case with Newton's theory of gravity as compared with Einstein's etc., or what will the speed of light limit really look like if we learn how to combine quantum mechanics with relativity (which our physics doesn't know how to do yet) or discover new laws of nature or new aspects of nature to make use of which is inevitable. Suddenly new things always become possible. "Limits" and "laws" are not so definite as people like to say but are nature's way of telling us that things simply have to make sense. We simply have to be smart enough to discover and/or figure out new possibilities, this is part of evolution like life learning how to walk on land or fly. Of course we don't yet see it until it finally happens. How often in history has this happened, again and again indeed. The "impossible" is not really so impossible but is more the reflection of the limits of ones imagination and intellect.