Often regarded as one of the most influential scientists of all time, Albert Einstein had remarkable insights into the laws of nature. However, his work has a very disappointing outcome, especially for science buffs who hope to one day travel to distant stars. His theory showed that there is the fastest speed in the universe: the speed of light. This means that the shortest round-trip to the nearest star would take nearly a decade.
But how does that work? Even the most enlightened science enthusiasts often have a wrong, or at least incomplete, understanding of why you can’t move faster than light.
This speed limit is a strange fact and one that totally runs counter to our common intuition. After all, if you’re zooming in on your car and stepping on the gas, it’s going to go faster. And while your car has top speed, we know faster things like fighter jets and bullets.
However, the acceleration eventually stops working. No matter how hard you try, you can’t go faster than about 186,000 miles per second (about 300,000 km/h).
The most common explanation for this cosmic speed is that as an object moves faster and faster, its mass increases. This explanation makes sense. After all, pushing a mountain is harder than pushing a pebble. If the mass of objects becomes infinite as they approach the speed of light, it stands to reason that you can’t break the speed barrier – it would take infinite energy to get it done.
There are a lot of merits to this explanation, and it is often explained this way even in undergraduate physics classes. (Heck, even I’ve been taught that from time to time.) But it’s not Better Answer.
Everything travels at the speed of light
To really understand why you can’t move faster than light requires that we learn a basic idea from Einstein’s theory. While our shared experience tells us that space and time are two different things, he realized that they are more alike than different. Instead of space and time, there is one thing called space-time.
Perhaps this idea is more intuitive by analogy. Look at any map of the world. We can define a location on a map as two numbers: latitude (the north/south number) and longitude (the east/west number). Although there are some slight differences (for example, it gets hotter or colder as you move north/south), there is no difference between the two directions.
In spacetime, it’s much the same. Individuals can move through time or space, just as travelers can decide to move east/west versus north/south.
Now for the main insight. One of Einstein’s professors, a mathematician named Hermann Minkowski, looked into Einstein’s theory of relativity and realized that at its deepest, most fundamental level, the theory said that any object was simply traveling through spacetime – partly through space and partly through time. . When Einstein’s theory was pushed further, it was revealed All Goal It travels through space-time at the same speed – light’s speed.
To understand this more easily, suppose you’re somewhere big and flat, like the Bonneville Salt Flats in Utah. Further suppose you are in a car with the throttle locked so that it can only travel at one speed, 60 mph (100 km/h).
Now, let’s get behind the wheel and drive. If you go east at 60 mph, you won’t move at all in a north/south direction. Likewise, you can drive north at a constant speed, but you will never travel east/west. Or you can choose to drive northeast at 60 mph, thus moving east-north at about 42 mph (69 km/h).
If you are moving at a constant speed, the bottom line is that you can move in any direction you want, but you cannot move in any direction faster than that constant speed.
They are identical in spacetime. Objects move in space-time at the speed of light. A stationary object does not move through space at all, so an object moves through time at the speed of light. Furthermore, any object moving through space at the speed of light has no velocity left to move through time.
Thus, the absolute maximum speed at which an object can move through space or time individually is also the speed of light. Note that this idea also explains the strange features of relativity, such as the slowing down of time for an object as its speed becomes faster and faster. An object that travels the most through space travels the least through time.
The speed limit is a harsh reality
The reason it’s so difficult to travel through space at the speed of light is because you have to push the object away from moving in the direction of time to move further in the direction of space. And it turned out to be difficult. But, even if you’re successful, you can’t beat that single speed.
That’s it. The real reason you can’t travel through space faster than light is because you’re always traveling through spacetime at the speed of light. The best you can do is transfer all your effort to moving through space; But once you push all of your movement toward space, there isn’t any speed left. Just like a car can’t go faster than 60 mph, you’re over it.
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Does this mean that the day we finally get out into interstellar space, we are doomed to travel Not faster than light? The round trip to the galactic center and back takes 50,000 years to travel at the speed of light. Can we do better?
Unfortunately, the answer is no — at least not without a new scientific discovery. The warp drive, hyperspace, and all the faster-than-light options from familiar science fiction aren’t real — or at least unknown to our better understanding of the laws of nature. Keep in mind that scientists have discovered previously unknown things, such as radio waves and radioactivity, so it’s conceivable that the discovery will change everything. So I think there is hope.
On the bright side, now that you know about space-time, the next time your boss takes on your case just for sitting there, you can tell them they don’t make sense. You are moving as fast as you can.