Why have we ruled out the possibility of finding something faster when we’ve only scratched the surface of space exploration and understanding?
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For something to go faster than light, it would have to go backwards in time.
Space and time are linked according to our best model for the universe. The faster something moves, the slower time passes for it relative to everything else. When we take 2 very accurate watches and send one to space to orbit the Earth for a while, it will be behind the one left back on earth. Time stops entirely for something traveling the speed of light. Light takes 1.3 seconds to travel from the earth to the moon from our standpoint, but from the light’s standpoint the trip happened in an instant. Any faster than that and it’ll move backwards in time.
It may be possible to go backwards in time for all we know but that seems highly unlikely. Causality starts to break down if that were allowed to happen.
What if I said “If I see someone on the moon light a green light, I’ll send a faster than light signal for him to light a red one.” while the moon light operator has instructions to keep it green unless instructed to turn it red. If the message gets there faster than light then it goes backwards in time to before I actually send it. Meaning when I look at the moon it’ll already have a red light. But if it has a red light already I’d never send the instruction to turn it red, meaning it should have stayed green. Which is it? Maybe such an event would create it’s own fork into two separate universes, one for each outcome. It seems much more likely that it just can’t happen.
It could very well be that our best model for the universe is missing some key piece of information that allows faster than light travel. I don’t think it’s fair to say the possibility is ruled out completely. Someone would have to put forth a new model of the universe that fits all the observations better though. Since our current model has withstood a lot of tests for a while now, that doesn’t seem likely.
If you draw a straight line on a sphere there is some maximum length this line can be. Why is that? It is just the geometry we choose. The speed of light is the same thing but less intuitive, it is the fastest speed possible due to the geometry of our universe. If we had a different geometry this speed could be different.
It is also worth noting that anything without mass travels at c in a vacuum so this isnt something only special about light.
As for could there be something faster? No, not really. You would have to invalidate so much evidenced backed theory to make that work and there is no reason to believe that it is at all possible in our universe.
It isn’t ruled out. But current theories cannot be based on unkowns or hypotheticals, and so far light is by far the fastest thing we can observe. Also there is good proof of the “speed of causality” which is the same as the speed of light, c. There is a lot of math and many years of experiments that re-enforce the idea that c is the speed limit of our universe
Space can expand faster than light, particles with no mass can travel at the speed of light in a vacuum, slower if not a vacuum, and any particles with mass can not reach the speed of light.
If there was something in the standard model of physics that disobeyed that we’d know about it. If there are any other areas does not obey this speed restriction, e.g. dark matter, then it is also likely it would never have any application in the everyday matter that we CAN interact with.
For something to go faster than light, it would have to go backwards in time.
Space and time are linked according to our best model for the universe. The faster something moves, the slower time passes for it relative to everything else. When we take 2 very accurate watches and send one to space to orbit the Earth for a while, it will be behind the one left back on earth. Time stops entirely for something traveling the speed of light. Light takes 1.3 seconds to travel from the earth to the moon from our standpoint, but from the light’s standpoint the trip happened in an instant. Any faster than that and it’ll move backwards in time.
It may be possible to go backwards in time for all we know but that seems highly unlikely. Causality starts to break down if that were allowed to happen.
What if I said “If I see someone on the moon light a green light, I’ll send a faster than light signal for him to light a red one.” while the moon light operator has instructions to keep it green unless instructed to turn it red. If the message gets there faster than light then it goes backwards in time to before I actually send it. Meaning when I look at the moon it’ll already have a red light. But if it has a red light already I’d never send the instruction to turn it red, meaning it should have stayed green. Which is it? Maybe such an event would create it’s own fork into two separate universes, one for each outcome. It seems much more likely that it just can’t happen.
It could very well be that our best model for the universe is missing some key piece of information that allows faster than light travel. I don’t think it’s fair to say the possibility is ruled out completely. Someone would have to put forth a new model of the universe that fits all the observations better though. Since our current model has withstood a lot of tests for a while now, that doesn’t seem likely.
If you draw a straight line on a sphere there is some maximum length this line can be. Why is that? It is just the geometry we choose. The speed of light is the same thing but less intuitive, it is the fastest speed possible due to the geometry of our universe. If we had a different geometry this speed could be different.
It is also worth noting that anything without mass travels at c in a vacuum so this isnt something only special about light.
As for could there be something faster? No, not really. You would have to invalidate so much evidenced backed theory to make that work and there is no reason to believe that it is at all possible in our universe.
Space can expand faster than light, particles with no mass can travel at the speed of light in a vacuum, slower if not a vacuum, and any particles with mass can not reach the speed of light.
If there was something in the standard model of physics that disobeyed that we’d know about it. If there are any other areas does not obey this speed restriction, e.g. dark matter, then it is also likely it would never have any application in the everyday matter that we CAN interact with.
Space can expand faster than light, particles with no mass can travel at the speed of light in a vacuum, slower if not a vacuum, and any particles with mass can not reach the speed of light.
If there was something in the standard model of physics that disobeyed that we’d know about it. If there are any other areas does not obey this speed restriction, e.g. dark matter, then it is also likely it would never have any application in the everyday matter that we CAN interact with.
I want you to forget about speed for a minute. Lets talk about time. Look at your clock or a watch, its moving forward. You are traveling through time! Pretty cool huh. Well this weird thing happens with time, it turns out time is not just kinda weird, its super weird. You and I see time the same way, things are happening at the same speed and such, but when you start moving faster (ok we’re back to speed a little), time starts moving slower. There is a relationship between speed and time. More speed, less time.
Yeah, but you’re gonna say, no, I live here, time doesn’t move slower, and you’d be mostly right. This isn’t noticeable to us because for it to start to be really noticeable you need to be going a lot faster, like on a spaceship.
Now the faster you travel, the slower time goes. Think of it like a line or curve on a graph, the faster you go, the line edges slower in time…it gets slower, and slower, and you keep going. But what happens when you go so fast, that time goes to 0 on our graph? You go so fast, you hit a point where you aren’t traveling through time anymore? Fucking weird right? I’m telling you, that there is some point where something can go so fast that time stops for it? Yes. Thats is what is happening.
That speed, turns out, is the speed of light. You hit a wall, you can’t go any faster since there is no where left in the time graph to go, you’re at 0 it ends there.
This is how you should think of it from an easy standpoint, the better explanations are far more complex and far more accurate (and in fact there are multiple versions such as one from particle physics that is quite accurate, but explained completely differently!), but this is a good way to conceive one method of seeing it
I want you to forget about speed for a minute. Lets talk about time. Look at your clock or a watch, its moving forward. You are traveling through time! Pretty cool huh. Well this weird thing happens with time, it turns out time is not just kinda weird, its super weird. You and I see time the same way, things are happening at the same speed and such, but when you start moving faster (ok we’re back to speed a little), time starts moving slower. There is a relationship between speed and time. More speed, less time.
Yeah, but you’re gonna say, no, I live here, time doesn’t move slower, and you’d be mostly right. This isn’t noticeable to us because for it to start to be really noticeable you need to be going a lot faster, like on a spaceship.
Now the faster you travel, the slower time goes. Think of it like a line or curve on a graph, the faster you go, the line edges slower in time…it gets slower, and slower, and you keep going. But what happens when you go so fast, that time goes to 0 on our graph? You go so fast, you hit a point where you aren’t traveling through time anymore? Fucking weird right? I’m telling you, that there is some point where something can go so fast that time stops for it? Yes. Thats is what is happening.
That speed, turns out, is the speed of light. You hit a wall, you can’t go any faster since there is no where left in the time graph to go, you’re at 0 it ends there.
This is how you should think of it from an easy standpoint, the better explanations are far more complex and far more accurate (and in fact there are multiple versions such as one from particle physics that is quite accurate, but explained completely differently!), but this is a good way to conceive one method of seeing it
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