Have you ever dreamed of traveling to other stars crossing the galaxy like in science fiction movies , forget it The idea of reaching the speed of light is one of those concepts that pop culture sells us as almost possible but in reality it's more like a cosmic fairy tale Even if we had the most advanced technology in the universe the laws of physics are very clear Nothing with mass can get there So why do you still believe that today let's dismantle this illusion with facts and some painful realities about the universe If you think a revolutionary engine will change everything or what is It's just a matter of time, maybe it's time to face the harsh reality [Music] Traveling at the speed of light is impossible because so many people still believe in it. It's largely science fiction's fault Movies, series and books made us think that all it takes is a super advanced engine to accelerate to absurd speeds and go out exploring the galaxy. It seems simple, right?
The problem is that most of the time these universes completely ignore the limitations of real physics. Think about Star Wars . Trek, space warp allows the Enterprise to go from one side of the galaxy to the other in minutes Interstellar Despite being one of the most scientifically accurate films, it still needs a miraculous wormhole to solve the issue of distance All of this feeds the wrong idea that the speed of light is just a technological obstacle and not an absolute limit of the universe Unfortunately, the universe does not work like a Hollywood script So what actually stops us, even the most daring projects in theoretical physics still face the same difficulties If one day we want to explore the deep space we will have to accept an uncomfortable truth There is no magic solution And to understand why we need to look at what really happens when we try to accelerate to extreme speeds Let's be clear the speed of light is not an arbitrary speed limit it is a law of physics You can't do anything about it I know this concept can be difficult to assimilate After all, centuries ago it was thought that it would be impossible to cross the ocean with existing vessels or that it would be impossible to leave Earth's orbit Humanity seems to always be discovering ways to refute what it is believed to be impossible but in this case we will see that the problem is much more complex First you need to know that as an object accelerates its mass increases This means that the faster you go the more energy is needed to continue accelerating Now imagine a ship accelerating through the vacuum of space As there is no air resistance it is easy to believe that it would be enough to accelerate for a certain time and eventually the ship would reach the speed of light But it turns out that the more it accelerates the greater its mass becomes so the more energy is needed For more energy more fuel is needed which would increase the mass of the ship even more which in turn causes us to makes you enter an infinite loop of the relationship between speed, mass and energy So guess what when you reach the speed of light your mass will become infinite which would have required an infinite amount of energy And there's no point in just reaching the speed of light You have to be able to stop too Good luck with that To decelerate an object moving in a vacuum it takes an amount of energy equal to that used to accelerate it which doubles the problem of infinite energy In other words no matter how advanced we are there is not enough fuel in the universe to take something with mass to that speed This is demonstrated in the theory of Einstein's relativity OK so how photons travel at the speed of light is because they are already emitted at that speed They do not accelerate from zero to C They are already created traveling at C This only happens because the photon is not matter it has no inertial mass otherwise it would need infinite energy to emit a single photon But let's say that by some cosmic miracle we managed to obtain this absurd energy we would still be in trouble Space despite appearing empty is full of wandering atoms that sometimes group together forming clouds of interstellar gas and dust stars and planets Other times these atoms remain isolated traveling aimlessly and without colliding with another atom for thousands of years But one thing is the probability of collision between two hydrogen atoms in 1 cm of space Another thing is the certainty of the enormous flow of particles that will collide against a moving spacecraft Particles that are practically harmless at low speeds become a deadly rain of projectiles and ionizing radiation As the speed increases this radiation would have enormous penetrating power and could seriously damage the hull of the ship and make it dangerously radioactive for its occupants A simple speck of dust colliding with a ship at that speed would have the energy of an atomic bomb Basically your ship would become a beautiful and fast fireworks display and end of trip But if we ignored all the practical difficulties of accelerating a ship to extreme speeds there would still be a fundamental problem Mass is not the only quantity that varies with speed Another factor to be considered in space travel at relativistic speeds is time dilation Contrary to what classical physics postulates that time does not flow uniformly for all observers In fact the closer to the speed of light an observer is the slower time will appear to pass to him On board a spacecraft that leaves Earth accelerating until it reaches a relativistic speed time will always pass more slowly than on the planet that was just left behind Imagine a spacecraft traveling at 95% the speed of light to a planet located 9.
5 light years away A stationary observer on Earth would measure the travel time as the distance divided by speed, that is, 9. 5/ 0. 95 = 10 years.
For the ship's crew, due to time dilation, the trip would seem to last only 3. 12 years. In other words, between leaving Earth and arriving at the destination, the crew would age just over 3 years, while for the people who stayed on Earth, 10 years would have passed .
time for your crew will pass 1. 15 times slower than on Earth At 75% the speed of light time will appear to pass 1. 5 times slower If the speed reaches 99% the speed of light time on board will flow seven times slower and so on At 99.
99% time will pass 70 times slower And if the speed reaches 99. 99999% the speed of light then time inside the ship will pass 22,300 and 300 times slower until when reaching 100% of the speed of light time would appear to stop completely These numbers that could make us hope about the possibility of traveling through the galaxy at will actually reveal something impressive They tell us in a practical way that for an observer moving with his ship at almost 100% of the speed of light his journey to any destination be it 100 light years or 100,000 light years away would seem practically instantaneous Unbelievable, well let's see a example Suppose we want to travel from Earth to the Andromeda galaxy which is about 2. 5 million light years away If the trip was carried out with an acceleration capable of taking the ship to 99.
99% of C it would obviously last about 2. 5 million years But for the crew on board the ship the perceived duration would be only 35,000 years And it doesn't stop there If we increased the speed by just 30 km/s reaching the 99. 99999% of C Andromeda could be reached in just over 11 years Impressive isn't it if it were really possible then yes we could achieve the much desired Star Trek scenario where spaceships travel with ease from one point to another in the galaxy So time dilation solves the problem well unfortunately no In this hypothetical scenario where we managed to accelerate to almost 100% of the speed of light we now have time working in a bizarre way The ship's crew would be affected by a different passage of time than the others objects in the universe On our trip to Andromeda, for example, 11 years would have passed for the crew but 2.
5 million years would have passed for everyone else, including Earth If we went back, 5 million years would have passed in total and we would find a planet completely different from when we left or in the worst case scenario a world completely in ruins And the worst part is that despite the speed of light being the absolute speed limit of the universe it is not even that fast. After all, to reach the system to be installed closest to the Sun it would take more than 4 years traveling at the speed of light Even though for the ship's crew the time perceived during the trip was much shorter, for the rest of the universe time passed normally So if we discovered a habitable planet for a few tens of light years with observations made from Earth and we tried to send a ship there at a relativistic speed the time it would take to reach the destination could be enough for there to have been a drastic change in the conditions of this planet making it completely uninhabitable which would have been a trip completely in vain So even if at some point in the future of our history we mastered a way of traveling at speeds close to that of light this would only be useful for exploring the surroundings of our own star system We could never go very far with this Of course for travel within from the limits of our solar system reaching relativistic speeds would make everything much easier and faster But even so, trips very close to the speed of light, although theoretically possible, are not viable There are energetic and economic factors that are already totally impediments But let's ignore this and skip to the practical part What would happen to an astronaut's body as the speed of the ship increases for this we have to take into account the G force which represents gravity A G represents the gravity of the Earth which is what the human body is used to and can sustain without problems Above that things start to complicate In current manned missions like the ships that send astronauts to the international space station for example astronauts can experience a force of 3 to 4G during the acceleration phase They can only be under such a high gravity force for a few minutes And this is because they have extensive training and the aid of pressure suits But being under a gravity force greater than 1G for a long time could be fatal even for the most resilient and well-trained human being So here we come to a problem For a manned spacecraft to reach a speed of say 10% of C it would have to maintain the acceleration under a force of 1 G for 35 days Manned missions currently have an acceleration phase of approximately 10 minutes Enough for the ship to reach escape velocity and exit the Earth's atmosphere There is no engine fuel source of energy or form of propulsion in the world capable of sustaining an acceleration for 35 days Now let's say that new form of miraculous propulsion has been discovered It is capable of sustaining an acceleration for a long time and very efficiently Enough to move a ship with several tons of mass and without exhausting all the fuel whatever it may be in this process Perfect We can reach 99% C eventually and explore the entire solar system in moments We wouldn't get anywhere near this Let's imagine that a manned ship would be sent to the limits of the solar system at the inner edge where the horte cloud begins at about 1000 astronomical units Remember that the ship needs to slow down to reach its destination, which will take the same time and the same energy expenditure as it did to accelerate So it will need to accelerate constantly for 45 days until it reaches the inversion point and take another 45 days decelerating to reach its destination Do you know the maximum speed it will reach only 38,000 km/s About 12% of the speed of light There is not even enough space within the solar system to reach the speed of light In this hypothetical trip Naver would need to accelerate continuously for months of course assuming it is a round trip And if we shorten the time with a greater acceleration, well then we would have that abandon the idea of manned travel since the crew would not withstand prolonged exposure to forces greater than 1 G. The speed of light in practice is not an objective, it is a limit imposed by nature that even if it were achieved would have unsustainable consequences for any traveler Still not convinced so I'll make a small analogy Take a piece of paper or a blackboard Drw three points on it Now connect the three and you will have a triangle The sum of the three angles will be 180º Always Place these points wherever you want on this flat surface It will always be 180º If you insist on placing the points in a line but you will no longer have a triangle If you move any of the three a little bit outside the line of the other two you will have a triangle again And no matter how small this deviation is, the sum will return to 180º A line is a single angle of 180º Time distance speed three points They always add up metaphorically speaking to 180º 180º is the limit of the triangular The speed of light is the speed limit of the universe The faster you move the slower time passes for you the more massive you become and the shorter the distance you travel They are interconnected like the angles of a triangle What happens when you try to make an angle of for a triangle to reach 180º it never does It would have to turn into a line What happens when you try to make a massive object reach the speed of light it never does Only objects without mass can travel at the speed of light Just like lines are not triangles and objects without mass do not exist below the speed of light What happens when you try to cross a line with your triangle it remains a triangle The largest angle decreases and one or both of the others increases What happens when you try to break a fundamental law of the universe well you can't It's impossible That's why that speed C can theoretically be approached but never achieved Well I imagine you're thinking that we don't need to reach the speed of light to explore interstellar space What if we invent the warp drive what about wormholes and if aliens have already done that time to get back to reality Warp engines In 1994 the physicist Miguel Alcubier proposed the idea of contracting the space in front of the ship and expanding behind it creating a bubble of spacetime The problem mathematics requires exotic matter with negative energy something that has never been observed in nature In 2021 a study in Classical and Quantum Gravity concluded that even if the necessary amount existed it would be equivalent to the mass of Jupiter and we haven't even gone into the energy cost of controlling this Wormholes Wormholes are valid mathematical solutions in general relativity but are unstable A 2022 study in Nature Physics simulated theoretical wormholes and found that without exotic matter to stabilize them they would collapse into milliseconds Furthermore, even if there were radiation inside them, it would be lethal to any ship Alien technology If aliens are traveling between stars they have either broken the laws of physics, which is unlikely, or they use methods that our minds can even understand But as the astrophysicist Seigan said, absence of evidence is not evidence of absence Until proven otherwise, we follow the rules of our universe The idea of traveling through space has always fascinated humanity After all, who has never dreamed of exploring the farthest reaches of the universe by jumping from star to star like in fiction films?
