Okay, we should probably elaborate a bit more.
There are many things in physics we are unsure of. And this question is one of those. First we need to understand what do we mean by “travelling faster than light” light travels at a speed of
299 792 458 m / s in vacuum. Now why this speed and other mind bending stuff about light will be in another post. Anyways getting back to the topic,
What do we know about, what will happen if we just try to go faster than the speed of light? First it is not a hard stop. Your engine is not suddenly going to explode, nor are you going get pulled over by the intergalactic police for going too fast.
Firstly it’s going to take an unnecessarily long time to get somewhere even near the speed of light. So your spaceship starts from 0 m / s and it has to get to 299 792 458 m / s. Now considering you accelerate at 10g (10 time the force of gravity or 98 m/s), which is the absolute maximum speed that even top fighter pilots can briefly withstand and unless you are some kind of an Erich Hartmann you stand no chance of surviving that. Okay let’s consider you are somekind of an Erich Hartmann. Even then it would take you months to get anywhere near the 300 million m / s speed of light. And the whole time you would be pressed against your seat, unable to move at all. (Not very comfortable.) And even after all that, this is what happens: You never reach that magical 300 million m / s. Yes, you do keep going faster and faster but at one point you will find that getting more speed gets harder and harder. Now why is that? you might ask. Well the reason is
E = mc2 Einstein’s famous equation that turned physics upside down. It basically states that as an object goes faster it gains more mass and thus it get’s harder to accelerate it any further. And an object travelling at the speed of light will gain infinite mass. Therefore it is impossible to travel at or faster than the speed of light.
But Maybe We Can Visit Other Stars
Travelling faster than light is an intriguing possibility, not because anyone wants to win a race against photons but humans have a fundamental desire to explore the universe around us. Visit distant stars, land on alien planets, perhaps meet aliens and make friends with their silly pets – few people will turn down the opportunity to do any of these things. Those of you eager to jump onboard the first starship will be sad to hear that we cannot travel faster than 300 million metres per second as the nearest star to earth is 40000000000000000 metres away. But perhaps we are asking the wrong questions. Instead of asking,”Can we travel faster than light?”, we should ask,”Can we travel to distant stars in a reasonable amount of time?” because the answer to that is a very intriguing “Maybe, but it is expensive” . Warp drives and Wormholes are in theory possible, but that is a story for another time.
Let’s Keep the Dream Alive
Put aside the practical considerations-the impossible energy requirements and our lack of technology to create warp drives and wormholes-because these pesky details interfere with the awesome grandiose fantasy of interstellar travel that you, diligent reader, are entitled to after reading so many paragraphs that pour cold water on faster than light (FTL) travel.
The challenges of compressing space or traversing wormholes are imensely difficult, but take heart in the fact that physicists have upgraded the problem of interstellar travel from “totally impossible” to “very difficult and monstrously difficult”, which is better than nothing.
Any predicting about the pace of technology far into the future would either be accidentally correct or embarrassingly naive, so we decline to make any. But humanity’s track record suggests that technological marvels are waiting for us in the future.And since there is not fundamental law of physics preventing us from visiting other stars, there is still hope.