You must log in or register to comment.

EmperorGeek t1_j0gf9m8 wrote

You would plot a course to an area close to where you PREDICT the destination would be. Think of it like taking “lead” on a moving target. Then about half way there you drop below light speed and refine your trajectory. You would need to do this again when closer but far enough out so that you could make a meaningful course correction and slow down to manageable speeds when you reach your destination.


zoinkability t1_j0gle14 wrote

Pretty much this. OP should consider that during the 6 months it might take to get to Mars, Mars moves considerably, yet that is no barrier to our getting there accurately. Getting to a nearby star is not dramatically different in terms of the complexity of physics. By comparison with achieving FTL travel, predicting the path of a nearby celestial body is trivial.

In terms of “what if something happens while en route,” FTL travel would make that less of a problem rather than more. 25 years is a smaller proportion of a star’s lifetime than 25,000 years, so there is 1000x less of a chance of some major stellar event — and even 25,000 years is still very little and unless it’s Betelgeuse the likelihood of a (super)nova would be almost zero for most stars.


Nejfelt t1_j0ggjz9 wrote

FTL travel is impossible for a multitude of reasons, but I fail to see this being one.

When you drive to your friends house, you assume it will be there. But there is nothing preventing it from burning down in your travel time, even if it is only 5 minutes.


Analyst7 t1_j0gf71t wrote

Pure speed will never be the solution to space travel. Finding a wormhole/jump type system might be possible but we are unlikely to achieve it anytime soon. We need to learn to move around our solar system way better first.


s1ngular1ty2 t1_j0ghvmu wrote

Wormholes don't work. We know they are impossible to use for FTL travel or communication. Unless our physics completely changes, this also won't change.


AlabamaNerd t1_j0giku5 wrote

Well, our current physics models aren’t perfect so it’s entirely possible we need to refine them- then who knows what’s possible?


s1ngular1ty2 t1_j0gjeam wrote

We know they aren't perfect but that doesn't change the fact they are very accurate about most things. Unless we discover something completely outside of what we know (very unlikely) then FTL will remain impossible.

I can say maybe unicorns will be possible one day. That doesn't mean unicorns will ever exist.

You have to have proof of a thing before claiming it is possible and we have never seen anything moving FTL and our physics says it is impossible by any means so it's likely impossible.

There is zero evidence pointing to it being possible.

If you have any evidence it may be possible then you'd have a compelling argument, but you don't, because no one does.


AlabamaNerd t1_j0gkjzw wrote

Limiting your acceptable proof to ‘seeing it happen’ is super narrow.

Black holes were theorized well before we saw one, so your argument is specious.


s1ngular1ty2 t1_j0gkr0h wrote

But we've seen one. We've never seen anything going FTL and we've done countless particle collisions and have seen countless extremely violent things in space with our telescopes that would completely blow your mind.

And nothing we've ever seen points to FTL being possible in the slightest.

We've also never come up with a method of traveling FTL on paper either using our best physics.

FTL is impossible.


AlabamaNerd t1_j0gl0bj wrote

But in 1783 when black holes were theorized, we hadn’t seen one. So, again, your argument is specious.

Plenty of things were theorized before we had any evidence of them. FTL is no different.


s1ngular1ty2 t1_j0gl7f3 wrote

We've never come up with a method for FTL even on paper chief. You are not understanding this important fact.

We have also never seen anything moving FTL, not even the most exotic particles in the TRILLIONS of particle collisions we've done in particle colliders.


igcipd t1_j0gl6r9 wrote

Quantum entanglement has entered the chat.


s1ngular1ty2 t1_j0glcro wrote

No just a person who doesn't understand quantum entanglement because they read bad click bait articles.

You can't use quantum entanglement to send anything FTL. Sorry. This is well understood.


igcipd t1_j0glhn6 wrote

Information is a thing. So yes, you can.


[deleted] t1_j0glwrm wrote



s1ngular1ty2 t1_j0gmi2d wrote

How am I wrong when I've given a link to an actual expert saying you can't use entanglement for FTL communication?

Where is your evidence? Or right, probably some TV show you saw once...


s1ngular1ty2 t1_j0gly2u wrote

Nope you can't even send info FTL. You don't understand this at all.

Here is a well known expert proving you are wrong and I'm right. Weird...

Look him up on Wikipedia..

You believe you can from bad articles from other people who don't understand these subjects and from TV and movies which get everything wrong.


Bucking_Fullshit t1_j0h0fn1 wrote

Yep, we got it all figured out. Pack your shit and go everyone.


Edit: Poor thing got his feelings hurt.


s1ngular1ty2 t1_j0h304j wrote

Like you have any involvement in furthering humanity lul. Keep up the great reddit comments! I'm sure you will make a difference...


NotAnotherEmpire t1_j0gfwn5 wrote

Everything we see is in the past. Betelgeuse could have gone supernova 300 years ago and we won't see it for another 342 years.

FTL has nothing to do with this besides breaking physics /causality and therefore causing paradoxes.


ILoveEmeralds t1_j0gesr9 wrote

We’re humans. We’ll just use that as motivation to make a faster one


s1ngular1ty2 t1_j0gey76 wrote

To bad it's IMPOSSIBLE. Stop believing sci-fi and click bait FALSE tech articles.


frezik t1_j0ggtdk wrote

Should BELIEVE Reddit comments with WORDS in caps, instead.


s1ngular1ty2 t1_j0gh4gt wrote

I don't care if you believe me or not because I don't need you to believe for what I said to still be true :)

This is science, not faith.


frezik t1_j0ghab4 wrote

It's science, but you're not helping your case by using bad messaging.


s1ngular1ty2 t1_j0ghcm7 wrote

Telling you the truth is not bad messaging. You are just mad you can't get your way.

FTL is never happening.


drfeelgood779 t1_j0giiih wrote

I think you mean "linear acceleration to speeds faster than light" is never happening. Even Einstein stipulated that wormholes (Einstein-Rosen Bridges) could connect two places. Assuming we figure out how to make them large enough, we could get around the acceleration cap.


s1ngular1ty2 t1_j0gita9 wrote

No I mean all FTL methods are impossible... Cause they are all impossible...Wormholes can not be used for FTL travel or even FTL communication and we already know this. You just don't know this. The experts are giving lectures on this to college kids every year.

You need to educate yourself before going around saying what is possible and what isn't.

Warp drive isn't possible either because no warp drive has a means to get to FTL. You don't just turn it on and magically travel at FTL speeds. YOu still have to accelerate from rest to FTL and none of the proposed warp drive ideas have a means of doing this. I can link you a video proving this if you want. Not like you'd watch it anyway because you are brainwashed by sci-fi and think everything is possible.


Raeandray t1_j0gj8jp wrote

No one disagrees with our current understanding of the laws of the universe the FTL travel appears to be impossible.

But its the height of arrogance to claim it actually is impossible, and it will always be impossible. The nuclear bomb would've been thought impossible 1,000 years ago. You don't know what discoveries could be made in our understanding in the future.


s1ngular1ty2 t1_j0gjupg wrote

It's not arrogance to say FTL is impossible with our understanding of physics because it is. There is also no observations of ANYTHING ever moving FTL from any experiment or space observation. This kind of implies it's impossible.

You have a laymans understanding of physics. We have a VERY GOOD understanding of most things. We can predict what the universe looked like less than a fraction of a second after the big bang and have proof of this from particle colliders.

Our physics is EXTREMELY good. There are very few questions left that would change our understanding in a such a profound way that suddenly FTL is possible.

You can hope as much as you want, but the probability of FTL ever being possible is next to zero.


Raeandray t1_j0gn5xq wrote

> It's not arrogance to say FTL is impossible with our understanding of physics

That's not what you said.

>No I mean all FTL methods are impossible... Cause they are all impossible

This is what you said.

I agree our current understanding of physics suggests its impossible.


s1ngular1ty2 t1_j0gnboy wrote

Yeah and our physics is not likely to change to make it possible.


frezik t1_j0gjysh wrote

No, I fully accept that FTL isn't happening. Your messaging is bad, equivalent to a scummy Free Energy ad.


s1ngular1ty2 t1_j0gk6j4 wrote

Nope, you are just mad you can't ever have FTL.


gaybraham-lincoln t1_j0gj5d4 wrote

“Fifteen hundred years ago everybody knew the Earth was the center of the universe. Five hundred years ago, everybody knew the Earth was flat, and fifteen minutes ago, you knew that humans were alone on this planet. Imagine what you'll know tomorrow”

Science is ever changing, and we are always learning more new things that we didn’t think were possible


s1ngular1ty2 t1_j0gklfg wrote

I don't care what you believe. I'm telling you facts. FTL is impossible and just because you don't understand this doesn't mean it isn't true.

We have an extremely developed understanding of physics that hasn't changed dramatically in 100 years when it comes to FTL travel. It is not likely to ever change either.

FTL is just impossible.


X2Starbuster t1_j0h6c79 wrote

These two statements are irreconcilable. “It is not likely to ever change either“ and “FTL is just impossible”.

Scientific consensus is that FTL in the ways currently discussed is extremely unlikely, outside of some limited potential wormhole scenarios that either require exotic materials, science, and massive energy that renders it pretty speculative.

Any change to that would be a pretty significant scientific revolution, but those have happened before and will almost certainly happen again.


FedRCivP11 t1_j0gi3l6 wrote

Because, as everyone knows, physics has already coughed up her last secrets to us. There’s nothing we have yet to learn about.


s1ngular1ty2 t1_j0gi9u9 wrote

Unless our physics completely changes, which it hasn't for the past 100 years, then it's very unlikely FTL will ever be possible because with our current physics it is impossible.


Gatrigonometri t1_j0gj5sp wrote

You’re meaning to tell us that people 200 years ago had the innate understanding of the mechanism of splitting atom?


s1ngular1ty2 t1_j0gkd6w wrote

You are again equating something we didn't understand to something we do understand and know is impossible. Splitting the atom wasn't impossible because it happens naturally in nature all the time. Fusion also happens in stars naturally all the time and we can see it.

NO ONE has ever seen anything moving FTL in any experiment or anywhere in nature.

It is impossible.


mf9769 t1_j0gq383 wrote

Dude, I think everyone understands that FTL is impossible. What you're not doing is not leaving the possibility of being wrong, however minute, open. That's not science. That's bigotry.


[deleted] t1_j0gqaij wrote



mf9769 t1_j0gsdfx wrote

Maybe we don’t have the ability to see things moving at FTL until we prove the theory behind them moving at FTL being possible. In that case, we just don’t know what to look for. If you were blind and didn’t know what the color blue was and i tried to explain it to you, you wouldn’t have the frame of reference to understand what the heck i’m talking about.


[deleted] t1_j0gsrqi wrote



mf9769 t1_j0gudat wrote

This is where you’re partially wrong. I won’t say my understanding of math and physics is at the level of a PHD or anything like that but 30 years of dinner table discussions with someone who’s understanding of it IS at that level, as well as a personal interest in the subject and multiple college courses has given me a good backround. His belief, like yours and mine, btw, is that it’s impossible, precisely for all the reasons you’ve stated. At the same time, even that guy doesn’t have the brazen overconfidence to say that we understand enough to completely rule anything out.


s1ngular1ty2 t1_j0gvkeq wrote

Bro, provide evidence you are right or keep learning. YOu can't just say things are possible with no evidence. This is how science works. You need evidence.

There is NO EVIDENCE that FTL is possible. NONE. ZERO. We've never witnessed it.

Our best math says it's impossible also.

If you can't accelerate to FTL you can't move FTL, and General Relativity says you can't accelerate anything with mass to light speed. It requires infinite energy.

Since infinite energy is IMPOSSIBLE then FTL is IMPOSSIBLE.

Unless we overhaul General Relativity, which hasn't changed in over 100 years, then FTL is a pipe dream.

The best minds have been trying to improve GR for 100 years and have failed. It has also been proven to be EXTREMELY accurate over those 100 years.

It is the MOST advanced understanding we have and the culmination of the pinnacle of our achievements and it says you can not go FTL because of having to accelerate to get to FTL velocities.

Warp drives do not solve this problem. They specifically ignore this problem because of how impossible it is. They do not work.

Wormholes also do not work.

Nothing we have ever thought of works. They all fail.

You are relying on a complete overhaul of everything we understand to make FTL possible.

It's not happening.


Demiculverin t1_j0giu8k wrote

In the 1800s they said the same thing. And with the discovery of XRays that has changed dramatically.

Arrogance in science gets you nowhere.


ILoveEmeralds t1_j0gmldj wrote

The Alcubierren warp drive is the future. Also people have also said similar things to powered flight, traveling across the equator, and that washing hands helps prevent diseases from spreading.


[deleted] t1_j0gmzk8 wrote



ILoveEmeralds t1_j0go1og wrote

Bro, we’re humans. We’ve built enormous stone monuments with a couple slaves and some string as a calculator. We can figure it out bro.


[deleted] t1_j0go7i2 wrote



jadnich t1_j0ghckz wrote

The first thing to consider is that there is no such thing as “faster than light”. The speed of light isn’t just the speed the fastest thing can go. It is the speed of causality. It is the rate at which time moves forward. As you approach that speed, time itself appears to slow down, and at the speed of light, it stops completely. It isn’t just extremely difficult to exceed the speed of light, it is physically impossible in our universe.

But let’s consider your question from the point of a wormhole. Say you are looking at Sirius (brightest star in Canis Major) and you are seeing what it looked like 8,000 years ago. Then, let’s say you step into a wormhole which transports you to that location instantly. The place you transport to will be 8,000 years later than the star you looked at at the start of your journey. If something happened in those intervening years (say, a supernova), the star won’t be there. But if you go back through the wormhole to return to earth, you would still look up and see Sirius.


JerryWasARaceCarDrvr OP t1_j0gsmn8 wrote

The whole “you step back through the worm hole and you will still see it” is just so awesome.

I think about space and space travel all the time and I just have to laugh.

It is ssssssooooooo big. Man we are insignificant. Hah.


lowtideblues t1_j0gkn5r wrote

I never thought about it that way. Travel only to find the destination is gone, then travel back to earth and still see in night sky. Kinda blew my mind there for a few min. Crazy to think about!


alphex t1_j0gg9ep wrote


We won’t go to Canis Major first. We will visit the hundreds of stars in side the immediate 10 or 20 LY

But you’re right. Even at 10x C. It would take a year to go 10 ly. So as someone else says. You predict where it will be. And lead the target.


JerryWasARaceCarDrvr OP t1_j0gsw8o wrote

For sure. But as the distances get big. I mean space big your chances of things being way different than your prediction get way bigger.

Not like Joe Montana leading Jerry Rice for a touchdown big. Or even is leading mars for a River landing big.

Like really really big.


[deleted] t1_j0girgo wrote

25 years of travel in space is absolutely nothing. If you can see a planet before traveling, I would almost guarantee you that we could calculate where it will be in 25 years with a very, very small margin of error. We can see where it came from, and because objects in space pretty much never change trajectory unless acted upon, we would know exactly where it's going to be in 25 years UNLESS it had a change in trajectory. That being said, things in space don't move that quickly, so we would likely be able to see any bodies or objects that could interact with our destination in such a way as to change trajectory.


Regardless, I would be willing to bet, that if we picked a random planet in the sky, we could predict where it will be 25 (earth) years in the future with almost 100% accuracy.


Think of it this way. How many times in the history of our specific solar system has ANYTHING changed course? not a once. This is also something that we pretty much never observe in space as well. Correct me if I'm wrong, but I don't think we've ever witnessed a planetary body change course. We've seen things like black holes or stars going supernova, which undoubtedly would affect the planets around them, but these would all be super predictable if we are actively looking for it at our destination. Likewise, even if a planetary body did change course slightly, chances are it wouldn't break orbit from its star. That means that even if we miscalculate, we'd still end up very close to where it is.


I don't think this is all that much of a problem. I think that if we are able to get an object moving at 1000x FTL, this will be a non-issue. Mind you! I am also making the assumption that with 1000x FTL, we'll also have technology that allows us to SEE FTL as well. IE, we'll be able to look at a planet 25k light years away and see it at its present state, not what it looked like 25k years ago. Even so, 25k years is not that much in space terms and likely wouldn't change anything.


Vishnej t1_j0gjmth wrote

This level of uncertainty doesn't require FTL, only a lack of faster-than-you communications. When you crossed the Atlantic in the early 1800's to visit an ailing grandparent, you didn't know if they'd, say, die during your trip, until you got there. Or if they'd moved to another city with a better hospital.

There are scenarios that are specific to FTL information transmission though; If we believe FTL is possible, under our current model of relativity we have to believe that FTL messages can travel backwards to earlier on our timeline, breaking observed causality:


produit1 t1_j0ggukt wrote

We still cannot explain gravity in fundamental terms. We know how it effects things and where to find it but cannot describe at a fundamental level what it is. Once we can learn how to effect/ manoeuvre gravity for/ around man made objects then we’ll see developments in actual travel and speed.


ExtonGuy t1_j0gh0w3 wrote

We have a very good fix on the speed and direction of Canis Major. There’s no real problem in figuring out where it will be in 25,000 years.


Laser-Brain-Delusion t1_j0gh6l8 wrote

FTL travel would be time travel. If you exceed the speed of light, you exceed the speed of causality. If you travel 1000x the speed of light towards a distant destination, then you will also arrive there when light emitted from that object was from a time before when you observed it at your departure. I don’t think FTL or even a large portion of light speed will ever be possible. Even at 99% the speed of light, in the forward direction, everything will be blue-shifted to an enormous degree, possibly to the point that even the cosmic background radiation becomes essentially gamma rays blowing holes through you and your spacecraft. God help you if you ran into a small particle or even a gentle solar wind, as the front of your ship vaporizes in a nuclear explosion.


JerryWasARaceCarDrvr OP t1_j0gtqh0 wrote

See that is where my thinking is off. The FTL being time travel hits home.

Thanks man.


rbrucejr t1_j0gj5fy wrote

It's only impossible until it isn't. In 2022 - 2023 it's absolutely impossible. 2070? Who knows... Humanity and science have a really fun way of making the impossible possible. I doubt I'll see it happen, but I think something like it will happen.


FGM_148_Javelin t1_j0gjnw8 wrote

I’m more concerned with the one time someone is gonna make a mistake and FTL straight into a planet killing billions


MajorTallon t1_j0gg7xr wrote

In dune they solve this by using dust to see the future.

If we have the ability to create wormholes or other space warping technology, then maybe we could send light first to confirm but otherwise yeah we would be flying blind.


CarRepresentative843 t1_j0gi76h wrote

I think you misunderstand what FTL means. If you travel faster than light, you already know where you’re going, because you are faster than the light is to get to you. You obviously would’t have any problems arriving somewhere where you already know where it is, because you saw the light from its past. The light that left there already reached you so you know exactly where you are going.

Like everyone said, that’s definitely not the top problem with FTL. It wouldn’t be in the top 100 issues with FTL travel. For instance: collisions with any particles. I recommend XKCD comic


JerryWasARaceCarDrvr OP t1_j0gtay1 wrote

Thanks man. That’s what I love about this sub. You can learn things without too much hate. Haha.


CarRepresentative843 t1_j0hxmcc wrote

I think I'm wrong. You don't know where you're going cause the light hasn't left. but technically speaking FTL is impossible for various reasons. it breaks time travel and causality. But also any collision at speeds close to the speed of light would create nuclear fission or fusion. Check out this video as well from spacetime


hymen_destroyer t1_j0gj0ta wrote

Because of relativistic time dilation, to an observer on the spacecraft, the journey would be nearly instantaneous.


YourFatherUnfiltered t1_j0geq0i wrote

Simple. we dont and i don't really think this confuses you as much as you feel like it should.


JerryWasARaceCarDrvr OP t1_j0gu0ui wrote

I think it is that I don’t look at this in the terms of relativity. Some good comments here that have made me a bit more enlightened.

While no astrophysicist I am smart enough to get it when pointed in the right direction.


ChaoticJargon t1_j0gh62u wrote

From my perspective, the amount of technology we'd need to make that kind of space flight viable is staggering, and simply not something we'll have in our lifetime.

We'd need a warp drive that can nullify space-time so that we can travel to any other point in the universe instantly, we'd need a light-speed drive so that we could use the warp drive, because the warp drive will likely be extremely dangerous to use near any celestial object. We'd need a way of discerning how to exit the warp drive safely away from dangerous celestial objects. We'd need a light-field generator outside the ship to push away debris while using the light-speed drive. We'd need way better materials science than we have today. The ship's life support would need to be completely self-sustaining. We'd need an anti-gravity drive to traverse planets.

That's not to mention all the other considerations we'd need to make everything work together. I don't believe its impossible, I just don't believe we'll get to that level of technology within our lifetime.

I'm an optimist about these kind of things though, I think we as a species will solve these problems, if we try.


s1ngular1ty2 t1_j0ghoub wrote

Warp drives don't work and never will. They are pure sci-fi.


ChaoticJargon t1_j0gmy39 wrote

We don't really know what will or won't work, not until science has a complete understanding of the universe, which is not likely at this point in time.


s1ngular1ty2 t1_j0gn66x wrote

We have enough of an understanding at this point to say FTL is extremely unlikely and probably impossible...


ChaoticJargon t1_j0gnxet wrote

We have an understanding that it is impossible, right now, but paradigm shifts have happened in the past and until the day scientists can say there's nothing left to study (unlikely any time soon) I will believe such things are possible.


s1ngular1ty2 t1_j0gotcs wrote

Nothing remotely this significant has ever happened in the past. Discovering FTL would be the single most important thing we've ever accomplished in human existence by an extraordinary magnitude. It so far beyond likely as to be practically impossible.

You seem to think our physics is bad or something. We have an extraordinary understanding of matter, energy, and the history of the universe. There are very few things left that will dramatically change this picture.

General relativity hasn't changed since Einstein and has been proven right, again and again. That's over 100 years ago.

There is nothing even hinting at the fact that FTL may be possible from any experiments we've ever done.

It is just not something that is not likely to ever be possible. You can hope as much as you want. I have hope but I also know the odds, and the odds are almost zero.

It sucks, but that is where we are.


ChaoticJargon t1_j0grbpa wrote

I mean, I don't doubt that its an impossibility in our lifetime, I just wouldn't say its absolutely impossible at all, given that we still don't have a complete understanding of the universe and its fundamental properties.

If you can imagine a sphere containing all the knowledge we have about the universe, and a sphere outside it containing all the possible knowledge we'd need to have for 'perfect knowledge' of the universe, I'd say the distance between these to concepts is more vast than the size of the universe to our own planet, well, I can't say that for sure, but I imagine there's quite a large gap there. In any case, I don't think that gap will be closed anytime soon either. Who knows what sort of discoveries await us, but I can bet they will be things we once considered impossible.


[deleted] t1_j0grntt wrote



ChaoticJargon t1_j0gsjl6 wrote

You're saying there's nothing left to study, nothing left to learn? I don't buy it.


s1ngular1ty2 t1_j0gtf46 wrote

I never said that. I'm saying, the things that are left that we don't understand will not likely lead to FTL because there are some basic laws of the universe you can not overcome no matter how much you learn.

Like the 2nd law of thermodynamics. You can never make a perpetual motion machine because of this law that was discovered a very long time ago. Nothing we come up with in the future will change this.

I doubt you comprehend how much we know and have verified about the universe so you don't even have a base of understanding to be skeptical about in the first place. I suggest you learn more and conjecture less.


ChaoticJargon t1_j0gukfe wrote

I know what it means to be a skeptic, and to me, its always been a non-starter. Its one thing to look at our current understanding of the universe and from that believe what can be accomplished has been decided, but rarely ever do I hear a skeptic question their own beliefs, which is to say, whether or not those beliefs are valid. I won't believe what's impossible until everything is settled and we have perfect knowledge of the topic. Which we don't currently have in any area, whether its material science, genetics, or particle science.


[deleted] t1_j0gw7n8 wrote



ChaoticJargon t1_j0h136g wrote

Well, we're just disagreeing with the principle of perfect knowledge, we both agree that FTL is currently impossible. You don't believe in any such notion that perfect knowledge has paradigm shifts contained within it, where as I believe there's always the possibility once perfect knowledge is attained, which may not be in our lifetimes.

Its fine to stop dreaming, but scientists who want to push the boundaries of our understanding will be the ones doing all the dreaming and making the impossible a reality.


s1ngular1ty2 t1_j0h2uel wrote

Nope, FTL isn't happening. I don't care how you "Feel" about it.


iluvfupaburgers t1_j0ghexa wrote

If we put it practically, FTL would be impossible, as calculating velocities close to light speed would require mass close to null. Meaning to go FTL, you’d require a negative mass. But if possible, there is time dilation, for the people on the ship, the travel would seem nearly instant, so the people on the ship would be basically as when they left.

As for the destination not being there. We can’t be sure any place really is there, no matter how long it takes us to get there


drfeelgood779 t1_j0ghy9f wrote

You are correct that we wouldn't know what is there, or even if the star is still active.

However, from a practical standpoint, we wouldn't bother heading straight to a destination 25000 ly away, even at 1000 times C. There's plenty of real estate closer by that we'd colonize first, then use those as staging points for the next closest stars, etc.

There would have to be some event (intelligent signals, artificial dimming of the star, or something else extraordinary) that would cause us to skip over everything in the middle.


FlyingSpacefrog t1_j0gih13 wrote

We do the same thing as what we do with interplanetary travel. You use your knowledge of orbital mechanics to determine how long it takes for you to get there, and model the motion of the target body to predict where it will be after that much time has passed, and then you use this information to plan your flight.

Stars have a much more complex orbit than planets do as they are affected strongly by nearby stars and not just circling a single center of mass like planets do around stars. So you need a lot of computing power, and a lot of data about the initial positions and speeds of each star. Then because with interstellar travel we are often contemplating journeys of many centuries or even longer, you have to worry about any inaccuracies in your initial data compounding on each other. In the FTL case you’re only dealing with decades of travel, so the calculations actually require less precision than those longer slower than light trips would.


Howard_Ratner t1_j0giryx wrote

FTL: full truck load. Wtf rabbit hole did I go down?


Kobethegoat420 t1_j0giyah wrote

You have to think, what you just said doesn’t make it impossible, it’s just a factor of ftl travel


Donut_of_Patriotism t1_j0glcrj wrote

Have you ever gone skeet shooting? If you haven’t it’s when you shoot clay pigeons with a shotgun. Anyway, the trick is to aim where the clay pigeon is going to be, not where it is now. If you aim directly at it, you will miss, but if you aim in front of it a little bit, the shot will intercept the clay pigeon.

Basically the same principle applies here. Aim for where the Star will be, not where it is. Account for both your and the stars relative speed, and calculate the coordinates to “aim” for. So actually it kinda would be a calculation done by the nav computer


arebee20 t1_j0gmjq1 wrote

My problem with FTL travel has always been how do you avoid hitting anything on your way to your destination? Sure space is pretty empty but you’re going so goddamn far you’re basically playing Russian roulette everytime you travel that there’s no object that you can hit in your path.


Daflehrer1 t1_j0go0af wrote

Yes. There would need to be some kind of super-computer, a kind of trail blazer in a sense, which could a) predict obstacles & confirm a clear path; and, b) be 100% accurate in predicting motion, including the motion of the spacecraft. Intellectually, it's daunting.


EmmaKat102722 t1_j0ggd93 wrote

Difficulty and uncertainty has never stopped humans before.


s1ngular1ty2 t1_j0ghsea wrote

Nothing even remotely close to FTL has ever been done before... It's not physically possible...


HashtagBarnes t1_j0gj46t wrote

Its not physically possible yet. Our ancestors probably looked to the skies and said "We'll never fly, thats physically impossible for humans." and now look at us... flying all over the place.


[deleted] t1_j0gjpeg wrote



s1ngular1ty2 t1_j0gk4ou wrote

Equating FTL to flying is the worst possible argument and often cited by people who have to clue what they are talking about. A child can fold a piece of paper and make if fly. It is that easy.

We know FTL is impossible and wormholes can not be used for FTL travel. Professors give lectures on this to college kids. It is that well understood at this point.

General relativity hasn't really changed much for over 100 years and it limits FTL travel and how wormholes work.

It's not changing. FTL is impossible.


santasnufkin t1_j0gl9qd wrote

With our current understanding of physics what we know is that we can't accelerate to the same speed as light in vacuum.

What we currently do not know is if it's at all possible for something to travel faster at all in vacuum.

I specify vacuum due to the existence of Cherenkov radiation.


s1ngular1ty2 t1_j0glg7s wrote

Nothing travels faster than light. There is no known radiation that travels faster than light...



santasnufkin t1_j0gp5cr wrote

Cherenkov radiation. Look it up. And understand why I specifically talked about in vacuum in previous paragraphs.


[deleted] t1_j0gplhx wrote



santasnufkin t1_j0hvubc wrote

Nothing known travels faster than c (speed of light in vacuum).
In a non vacuum medium, light does not travel at c.
Try studying if you don’t believe what I said.


s1ngular1ty2 t1_j0koinz wrote

I don't need to study because I already know it LOL. I ignored you because I knew you were trying to act smart by posting trivia you just learned and thought no one else knew which wasn't relevant to the discussion. No one cares about light speed in a medium in the discussion we were having because it doesn't matter. I'm glad you learned something though! Good for you.


MarSc77 t1_j0ghvat wrote

very much true. discoveries always have costs. and thankfully there were always people willing to pay the price.


Legojoker t1_j0gjt8k wrote

The speed of light isn’t just a difficulty or minor inconvenience, it’s a physical fundamental of the universe, in the sense that the minimum amount of time something could travel from Earth to Alpha Centauri and back to Earth would be 8.5 years in Earth time, and there’s no getting around that. The objects/people aboard the ship/the ship itself could experience that entire trip in as little as 0.00001 seconds, but from Earth’s perspective, this ship would be traveling at 99.99% the speed of light there and back.


EmmaKat102722 t1_j0h0wgn wrote

Obviously, but unless I misunderstood, your premise is that these things have been solved.


nine8whatwhat t1_j0ggzhg wrote

i've always combined space travel with breakthroughs in life extension, so 25 years might become 25 months or even shorter one day


siskulous t1_j0gibao wrote

You're mostly correct. It's one of those details that we gloss over in science fiction because we're too busy telling a story to bother with details that don't contribute to the story, but yeah. The thing we're going to will have moved by the time we get there.

One detail that you forgot about, however, is the contraction of space. Granted, that may not be a thing at FTL since we wouldn't be traveling through flat space if we were going faster than light, but it may still matter. As you approach light speed space contracts from your frame of reference. I'm too lazy to do the math and get the exact figure right at the moment, but in the scenario you laid out you'd cover that 25,000 lightyears in significantly less than 25 years (from your perspective) thanks to this phenomenon.