What would we see at the speed of light?

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what

we

would

see if we approached the

speed

of

light

let's embark together on a spaceship that accelerates away from the Earth moving faster and faster

what

we

would

see by constantly accelerating what optical effects would be produced and if we try overcome the

speed

of

light

by bending space-time like in science fiction movies. What would we see when answering these questions? It will take us to explore many fascinating phenomena in our universe and dive into the heart of special and general relativity. Our spacecraft is initially at rest once launched.

We begin to accelerate we imagine that its propulsion system allows us to constantly accelerate for as long as we want as we gain speed we move away from the Earth accelerating more and more one would think that the speed would eventually become unbearable however this is not the case the speed It has no effect on our body when two trains pass each other it is impossible to feel if it is our train or the other one that is at rest. Likewise inside the spaceship we cannot feel its speed but only its acceleration the thrust of the reactors that press us Our seats, if this thrust is reasonable, will be perfectly bearable throughout the trip, even when we approach the speed of light, there is a risk associated with very high speeds.

In a high-speed collision, a single speck of dust would cause colossal damage if it hit. Fortunately our ship is equipped with a force field that repels dangerous objects and allows us to roam freely through space as we accelerate. A first optical effect appears. The stars in front of us that we approach seem to gradually move away. The sky contracts earlier. To understand, think about this common situation: you are in a car driving at high speed and it starts to rain, the rain falls vertically from top to bottom, but as the car moves forward, you get raindrops on the windshield facing you.

The rain. it does not appear to fall from above but from the front as if its trajectory were inclined and the more you accelerate the more it seems that the rain is coming from the front in our spaceship the optical effect is perfectly analogous the stars are the light comes from a certain direction but as we accelerate the light rays seemed to come more and more from the front their direction seems different when we are moving this is the aberration of light as the light focuses in front of us its intensity increases while behind us the sky appears to widen and Darkening light aberration results in another strange phenomenon.

Let's imagine that we move through an immense grid that represents the fabric of space. Normally we would see a straight grid made up of straight lines converging in front of us due to perspective; However, by accelerating the aberration phenomenon, it distorts the image. image of the sky around us as the days go by the grid appears to contract forward and the straight lines bend if we were to pass in front of an object it would appear to be slightly tilted in our direction, this is called the terrible Penrose rotation as it gives us We move very quickly the images of objects seem to contract in front of us and the perspective is strongly distorted.

We often hear that the more we look into space, the more we look into the past. In fact, the light we receive from a distant star must travel billions of kilometers. This trip is not like that. instantaneous and it takes some time for the light to reach us, as a result we see the star as it was in the past when it emitted this light, perhaps several thousand years ago, who knows how it might have changed since then, looking from our spacecraft in the same way. The phenomenon is underway as we move further away from Earth, the planet's light takes longer and longer to reach us.

If we could zoom in with a telescope, we would see people on Earth evolving in slow motion. This is the Doppler effect in every tick of Earth's clocks. It takes longer and longer to reach us. We receive rays of light in slow motion and their intensity seems to weaken as the image of the planet changes towards red in front of us. It is the opposite effect. The ship reaches the light and the stars seem to turn. brighter, they change towards blue and their clocks seem to speed up. With sufficiently precise equipment, we could measure aberration and Doppler effects from the beginning of our acceleration in space;

However, if we decided to end our trip and return to Earth, these effects would have had no impact, they are just optical illusions due to the way we receive light while moving after several hundred days, however, as we the reactors push us faster and faster, the ship begins to approach the speed of light at such speeds, some phenomena will no longer be mere real physical optical illusions. The effects will be activated with irreversible consequences. Special relativity comes into play. A first consequence of relativity is known as time dilation. Our universe is a huge four-dimensional fabric called space-time, made up of three dimensions of space and one dimension of time within space. moment when all bodies trace a trajectory as they all move towards their future to take off, our ship was moving in the same way as the Earth towards the future, but as it gained speed and moved away from the Earth faster and faster, our trajectory gradually deviated from that of the planet.

The axis we call time is no longer aligned with the time axis of people on Earth, if we decided to turn around and go back, our clocks would have measured a different time and we would have aged less than Earthlings because our trajectories in space- time would have been different. Another key consequence of special relativity is called length contraction. When a body moves near the speed of light, its length contracts in the direction of its motion. From the perspective of the spacecraft, the entire universe shrinks. moves backwards for us the universe contracts along our direction of movement as such the duration of the trip to reach our destination is shorter than expected we are no longer talking about optical effects but rather a physical and concrete phenomenon if we tried To reach a distant star the journey would actually seem shorter to us - it would take less and less time the faster we moved - so contrary to popular misconception, it is in fact possible to travel thousands of light years in just a few seconds and in the If we were moving almost at the speed of light, the trip would even seem instantaneous.

For us people on Earth, however, several thousand years would have passed. Longitude contraction is a very real phenomenon. However, visually it would be difficult to understand why we imagine that we cross the orbit of a planet as it moves very quickly towards us. of the planet is contracted, but remember that the further we look into space, the further we look into the past, and from our perspective, the back of the planet is located further into space than the front of the planet that has taken the image we received from the back of the planet. It takes longer to reach us so we see it as it was in the past, even if it is contracted, the planet does not seem that way because we receive the image of its back with a delay, instead of contracting, it seems to be rotated, this is a phenomenon that we have already seen.

Terrell Penrose rotation When we move very fast and look to our side, the edges of the object around us appear shorter in the direction of movement, this can be interpreted as a length contraction or as a rotation as a change in perspective for the same. which is why a person watching us on Zoom wouldn't actually see our ship contracted but rather rotated on itself over time, our field of vision continues to contract, intensifying in front of us while turning completely black behind us as we accelerate further and more than perhaps we would expect. reach the speed of light at some point what would we see then this question could be one of the most fundamental in relativity the answer is no, even if the ship constantly accelerates we will never reach the speed of light, that is because the speed of light is Absolute, you can try to catch a ray of light, but from your point of view it will always escape at the same speed.

The speed of light, you can speed up as much as you want, even if from Earth you would appear to be approaching the speed of light. from the point of view you remain motionless and the light escapes inexorably in short it is strictly impossible to exceed or even reach the speed of light in the best of cases our ship will continue to accelerate forever and our field of vision will continue to reduce more and more until form an infinite bright spot in front of us surrounded by a completely black sky at almost the speed of light, all the optical effects would become extreme as we reach the rays of light in front of us, they all seem to come from the front, while the rays behind us can never reach us in our In a frame of reference the universe would be extremely contracted like a thin cloth that we would cross from side to side in a fraction of a second for a person on Earth we would be moving at the speed of light but To us the journey seems instantaneous moving infinitely fast to conclude that nothing can move faster than light through space, but there might be a way around this rule.

In fact, nothing prohibits space itself from moving faster than light. In fact, the theory of general relativity teaches us that the fabric of space-time. It is dynamic, it can bend in multiple ways, so we could imagine creating a bubble around our spaceship that we would propel faster than light, this is called warp drive in reference to science fiction, it would no longer be a question of making it fly a vehicle through space, but To propel the fabric of space, our ship would remain motionless, sailing on a faster-than-light wave of space-time. Such a structure may seem absurd and, in fact, is currently believed to be impossible to achieve.

To produce a warp drive, it would be necessary to bend space-time with enormous amounts of negative mass, a form of matter that does not appear to exist in our universe and which, according to mathematics, still allows us to model and calculate what we would see in such a situation. If we looked from the outside, the warp drive would seem to appear out of nowhere. The curvature of space-time deflects the path of light rays forming a moving lens that divides into two, one part advancing and the other receding in the opposite direction. the light travels slower than the warp drive itself when it approaches the light has not yet had time to reach us and after it crosses us we receive both the light that had not yet reached us and the rays that were emitted later looking from the inside From the warp drive we would see the sky contracted in front of us and very bright behind us. the universe would look extremely dark and an entire portion of the sky would simply disappear from our view the light emitted from there is too slow to reach us a cone of the universe remains permanently invisible