Submitted by Crazy-Sundae-5141 t3_z9iksu in science
JonesP77 t1_iyh73id wrote
I know, this is not yet real with our technology. But why do so many scientist still believe that traveling faster than the speed of light is impossible even though we have no idea what space and what gravity really is? I dont think we know enough to exclude traveling through space with wormholes or something else we even dont know exists. We have sooo many unknown unknowns. I hate it if scientists say "nah, thats impossible, if we cant do it no advanced species will ever do it"
Like really? As if we cracked all the secrets of the universe. Get more humble, in the past being humble was important for scientists. Now they feel like they know anything and saying something that is not within the consense is in principle stupid because our scientist cant be wrong, no thats impossible...
KiwasiGames t1_iyhbnod wrote
Because we like causality.
Faster than light travel plus relativity means time travel. You would literally be able to travel backwards in time. Full on Michael J. Fox fall in love with your mother time travel.
Time travel introduces so many logical paradoxes that most scientists reject it out of hand. Even if you don’t reject it and allow time travel to be a thing, every known law of physics breaks down.
It’s not just a “go faster” thing. The speed of light is a fundamental limit to the universe.
Extension-Ad-2760 t1_iyhsslb wrote
See, the thing is, quantum physics and just relativity also introduces a heckton of things that humans would call logical paradoxes. These are actually real. How do we know what is a true paradox and what isn't? The universe doesn't care about our perceptions. Time travel could just create multiple realities. Moving at close to lightspeed already does similar things
supercalifragilism t1_iyil0lx wrote
So there's no experimental results to clarify what's going on with quantum mechanics and gravity, but we've also never seen anything travel faster than the speed of light. It has never been observed, ever. Every time we think there's an FTL phenomenon, it turns out to not be FTL. Energy levels are vastly higher in cosmological situations, so it stands to reason that FTL, if possible, would occur in nature. While absence of evidence is not proof of absence, it informs theories. Likewise, proving a negative is difficult or impossible.
The real problem with FTL are the implications it has for the rest of physics. There's a saying: "FTL, relativity, causality, pick two." Built into the logic of relativity is the idea that <c is the maximum velocity for anything with mass, =c for massless particles and >c for negative mass. It's unclear if negative mass is physically meaningful, it has also never been observed.
More than that, built into the logic and math of relativity is the idea that information can only travel at speeds less than c; there are a number of situations in relativity that can arise with superluminal travel that would undermine causality completely; even at near c, time dilation will never alter the order of events, causes will never follow effects and information can never arrive at a listener before the speaker says it.
Relativity is a very well researched and experimentally supported theory. It's only exceeded in predictive power and experimental agreement by quantum mechanics. But neither of them is anywhere near as important to science, logic and reason as cause and effect.
Basically, without proof of FTL that is ironclad, there's every reason to believe that all the rest of science is more accurate, because thre's no explicit experimental proof of FTL and the implications of FTL conflict with all other observations of basically everything.
tl;dr because of the implication
Extension-Ad-2760 t1_iyixd2t wrote
The specifics of causality were invented by humans. For example, we don't like the grandfather paradox, but a multiverse just ignores that problem.
Personally, I think that we assign too much value to our own human experience. In our own experience it is possible to exactly know the velocity and position of an object. In our own experience things are solid, not wavelike. In our own experience it is impossible for time to warp based on speed. And in our own experience it is impossible for cause not to follow effect.
supercalifragilism t1_iyj54s1 wrote
I'm sympathetic to this interpretation, and I agree that human experience is centered too often when dealing with these kinds of notions. The trouble is that causality is necessary for any and all science, including the science that's leading you to doubt causality. The nice thing about experiment is that it can allow you to get out of the human experience.
coffeecofeecoffee t1_iyiyozv wrote
I feel like "we like causality" is not good enough for me. Just because we can't understand a universe that breaks causality doesn't mean it doesn't exist. We know n o t h i n g.
KiwasiGames t1_iyj9pqv wrote
Come on. This is a science sub.
We have never seen a FTL particle, ever. And we have looked for them.
We have no gaps in our theories of physics that would be effectively explained by allowing FTL.
And every known law of physics would turn out to be wrong if FTL was a thing.
None of that suggests that we will ever get to FTL.
coffeecofeecoffee t1_iyjolmc wrote
Yes, but models aren't truths, they are tools. Velocity A + Velocity B = Velocity (A + B) was a good enough model until we needed a more complicated one to account for relativistic speeds.
It doesn't mean the first model is wrong, just that it's not the full picture. I refuse to believe that Einsteins theory of relativity is the full picture.
I wonder why the speed of light is the speed of light? I feel things that are once thought of as "physical intrinsic laws" are really just results of a more complicated mechanism. So what's to say the speed of light, and velocity and spacetime in general is just the observable symptom of something more fundamental?
I don't expect us to find something faster than light but I'm not convinced the entire concept of velocity and spacetime is as fundamental and solid as it feels now.
odoc_ t1_iyhuxll wrote
Some theories suggest time doesn’t exist (Order of Time by Carlo Ravolli). The way we understand time is a human extrapolation, and fundamentally time in physics it is irrelevant. In such a case a time paradox would not be a paradox at all.
Tortugato t1_iyjj4ow wrote
Scientists prove themselves wrong all the time.
That’s precisely what makes it science.
Science has to be falsifiable.
Regarding the speed of light, the way you speak about it shows you don’t actually know much about the topic.
The speed of light being the speed limit of the universe is an observation and a supposition. Scientists didn’t just decide on it.. Firstly they realized that the speed of light was constant. i.e. it never changes. It took Einstein’s special theory of relativity to show why and how it never changes. The mathematics of relativity also show us that it would take literally infinite energy to accelerate an object to the speed of light. That’s when we first codified light speed not only as constant, but also as the “speed limit” of the universe.
But guess what.. Scientists are constantly coming up with tests and experiments to try and prove Einstein’s relativity wrong. But so far, relativity still remains to be proven correct.
So yes, according to the our best working theory of understanding the universe, we cannot travel faster than light. But scientists acknowledge that the theory is incomplete, and are constantly trying to find the next step in understanding.
[deleted] t1_iyh9n30 wrote
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WitsAndNotice t1_iyimcls wrote
The speed of light is essentially a mathematically calculated cosmic speed limit, the fastest anything can go without huge swaths of our mathematical understanding of the universe being wrong, including quite a lot that we're pretty damn certain is correct.
Wormholes are not truly examples of FTL speed, they're more like shortcuts through space time. Essentially taking a shorter path between two positions, allowing you to arrive at your destination much faster than you could have if you traveled through space at the speed of light.
My layman's perspective is that yes, scientists do seem to be a little too married to their current understandings of what is and isn't possible, but that's nothing new. The world's smartest people throughout history have tended to draw a line in the sand and say that they are certain of what they know, only for the next generation of scientists to confirm that they didnt get everything right. It's equally important to acknowledge, however, that without understanding the math of fundamental physics (which I definitely do not) we can't truly understand what scientists actually do and don't know, we can only understand very generalized conceptualizations of it because the math simply does not have a complete english translation. There's information that's lost when trying to express the most complex mathematics in just words that precludes us from really understanding why things like the speed of light seem so absolute.
neotericnewt t1_iyinuoa wrote
>Like really? As if we cracked all the secrets of the universe.
We don't need to crack all the secrets of the universe, just some, and then we build from there. As far as we can tell FTL travel is impossible. For that to be incorrect would mean some of our most well tested and supported theories are also totally incorrect.
That's just not at all likely, because yeah, they're really well supported. FTL travel just doesn't make sense with the rules of the universe as they are.
coffeecofeecoffee t1_iyiy27c wrote
I agree, every physical law and experiment shows observable patterns in the universe but let's not forget the inconceivably confusing existence of the universe to begin with.
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