If we could travel near the speed of light

In summary, if we had a spacecraft that could travel at 0.5c, many people would think it would be a good idea to explore the nearby stars, as they are 'nearby' in our galaxy.
  • #1
Rocketjj
9
0
...where would you go?

If a new technology allowed a spacecraft to travel at say 0.5c, and life on board this ship could be sustained indefinitely. If this ship was built tomorrow, where do you reckon it would go? Andromeda? pluto? centre of milky way? alpha centauri?

Just though it would be fun to see thoughts on what you guys believed would be the most promising destination.
 
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  • #2
Rocketjj said:
...where would you go?

If a new technology allowed a spacecraft to travel at say 0.5c, and life on board this ship could be sustained indefinitely. If this ship was built tomorrow, where do you reckon it would go? Andromeda? pluto? centre of milky way? alpha centauri?

Just though it would be fun to see thoughts on what you guys believed would be the most promising destination.

Alpha Centauri or Pluto would be the most feasible
Centre of Milky Way inadvisable owing to the black hole that I believe is lurking there and although I don't know where Earth sits in relation to the centre, it's probably a long way even at 0.5c.
In the case of Andromeda (I'm no astronomer) but isn't that seriously millions of light years away? It wouldn't be a case of where would you go so much as where would the ship go, no-one starting the journey would live to get anywhere near the destination, let alone the return leg; it would need to be a generational ship which likely would still be doomed to failure through obsolescence. Imagine one or two generations into the journey, technology back on Earth has pulled up and you find yourself being overtaken with contemptible ease by a ship that left 20 to 40 years after you.
If you're suggesting we're all in stasis then we just won't see ourselves being overtaken, unless they're polite enough to come aboard, wake us up and take us with them.

While we're stuck with 0.5c technology, I'd do the local rounds
 
  • #3
Traveling at the speed of light is impossible.
 
  • #4
Chronos said:
Traveling at the speed of light is impossible.
What was your point in writing this? No one said anything about traveling at the speed of light.
 
  • #5
Yes Proxima and Alpha Centuria would probably be quite good candidates considering the possibility of a planet in the system due to a slight stellar wobble.

Perhaps some of the closer stars that exhibit possible planets would be interesting to visit. A lot of these stars are 'so to say' in our back yard.
Two interesting ones being 18 Scorpii and Gliese 581.

Andromeda, would be out of the question at 2.5 million light-years unless traveling very close to the speed of light.
I think time dilation would have to really kick in here.

However, on the bright side the Andromeda Galaxy is 'headed' in our direction and will eventually collide with our galaxy.
So, if we wait long enough the trip will be substantially shorter.
 
  • #6
Yeah I think you guys are right. Going to the nearest galaxy is simply too far away. I can't imagine people wanting to begin a voyage to a destination that was millions of years away. In fact, there is probably a better chance of waiting for wormholes!
 
  • #7
I can't help but suggest if we had a single ship capable of 0.5c we could use it to launch lots of probes (just go top speed in a certain direction and release them). Although I guess this isn't really keeping with the spirit of the question. Next I have think we could just use it as a ferry, and set up orbiting stations around all the planets and major satellites in our solar system, which would allow parallel study of most of the solar system at once.

However, if I limit myself to only being able to visit and study anyone place at any time I'd have to say we use it for the solar system first, spending about a year here, then move on to the near stars. While visiting a completely new star would certainly be amazing I can't overlook how insanely quickly we could get around our solar system, most of which we really haven't studied up close at all (mainly the outer planets satellites). Although I suppose acceleration would greatly limit the ability to make short trips. But hey, this is fantasy anyway right?

As for if people would be willing to visit very far away places (other galaxies), I think they would. I don't think it should ever be that high a priority. But if building a large ship capable of near c speeds becomes possible for relatively cheap (and I think it will, in a few hundred years), then I don't see any reason why not. Sure the people leaving would never see the other galaxy, but they won't see it sitting here either. Their chances aren't that great, but if we never come up with some way to cheat the speed limit of light (worm holes, warp drive), which is a very likely possibility, then it means once we are capable of even 0.5c we might as well start making these long journeys. It's unlikely that we'll be gaining much more. I suppose you could argue that we should wait until we can reach a high enough speed to make the journey in a single lifetime (due to the slower passage of time for the people on board). Sure millions of years would have passed here, and millions more before any news could be transmitted back, but at least the people who set out could actually be alive for the arrival. That would also help with the problem of a generation ship losing all memory of the culture that sent it, as well as the very real problem of how to keep a ship running for millions of years.
 
  • #8
HallsofIvy said:
What was your point in writing this? No one said anything about traveling at the speed of light.
My error. I misread the op.
 
  • #9
Well if it was just me in it, and can only go 0.5c, I'd set the ship on a course to get a long series of gravitational boosts from stars in our galaxy. Keep doing that for awhile until I get super close to c, where hundreds of millions of years are passing out in the universe relative to me inside the ship. Cruise around like that and periodically wake up to watch the evolution of the universe on the largest scales through to the end of time. Maybe? I may need some special Doppler-effect compensating windows.
 
  • #10
Chronos said:
Traveling at the speed of light is impossible.

it technacally is, but we could use wormholes. And i would use the device to get to the heliopause (i think its called that) of the sun.
 
  • #11
Travelling near the speed of light is difficult. The energy required is enormous, and the results are not good. Light in the direction of travel is extremely blue shifted [you fry].
 
  • #12
At 0.5c the blue shift is not that big. Of course, the down side is that it takes a long time to get anywhere.

As far as stellar gravitational assists, you would need thousands of them to get to anything like a substantial fraction of c. And thousands more to slow down when you got to where you were going. It's far from clear you wouldn't be better off just flying to where you wanted to go.

Finally, there is no evidence that there are wormholes.
 
  • #13
Considering that space is a vacuum, all you need is a little push and a lot of time, and your speed would increase. You wouldn't need to slingshot yourself on other stars gravitational field. But the problem comes that at a certain speed molecules start to separate. So in theory, you, and your ship would disintegrate. *sigh*… that is why scientists are trying to develop a “plasma” shield.
 
  • #14
seetherage said:
But the problem comes that at a certain speed molecules start to separate.

This is not true.

seetherage said:
So in theory, you, and your ship would disintegrate. *sigh*… that is why scientists are trying to develop a “plasma” shield.

I don't think this is true either. Which scientists?
 
  • #15
Vanadium 50 said:
As far as stellar gravitational assists, you would need thousands of them to get to anything like a substantial fraction of c.
I think is is not possible even in principle. There's got to be an upper limit on how much of a boost you can get.

I think anyway...

If you were approaching Jupiter at .1c could you still get any boost from it?
 
  • #16
seetherage said:
But the problem comes that at a certain speed molecules start to separate.
It seems like you don't understand the basic principles of relativity, at a certain temperature they start to separate but it have nothing to do with uniform speed.
 
  • #17
Klockan3 said:
It seems like you don't understand the basic principles of relativity, at a certain temperature they start to separate but it have nothing to do with uniform speed.
What are you talking about? Relativistic speeds cause molecules to separate? No. Or are you simply referring to high temps causing materials to vapourize? Yes.
 
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  • #18
Originally Posted by seetherage
But the problem comes that at a certain speed molecules start to separate.
This is not true.

At the speed of light, your mass is converted into energy.


Originally Posted by seetherage
So in theory, you, and your ship would disintegrate. *sigh*… that is why scientists are trying to develop a “plasma” shield.

I don't think this is true either. Which scientists?

I honestly don't know. I read it in a magazine somewhere. They were trying to make plasma cold enough to not damage a vessel, but yet extremely hot on the outside. Thus - > "Shield". It could be bs, or not. But it was pretty convincing.

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  • #19
seetherage said:
At the speed of light, your mass is converted into energy.
No it isn't.

Your mass will not reach the speed of light. Ever.
 
  • #20
DaveC426913 said:
No it isn't.

Your mass will not reach the speed of light. Ever.

If it did, in theoretical terms, that is what would happen.
never say never. ; )
 
  • #21
seetherage said:
If it did, in theoretical terms, that is what would happen.
never say never. ; )

No, not even in theoretical terms. You have been reading the wrong books.

No object with mass can attain the speed of light. Ever.
 
  • #22
DaveC426913 said:
No, not even in theoretical terms. You have been reading the wrong books.

No object with mass can attain the speed of light. Ever.

Remember that in the case of great speeds, Newton law don’t apply with the new(er) concepts of space and time.
Most of the theories/laws were developed under the condition that speed is small. Such as Newton’s second law, Where a constant force acting upon matter for certain time, can give it a speed as fast as it wants. But in reality the speed of light in vacuum is limited, and can never move in speeds greater or equal to that of light. - > thus converted into energy. Einstein estimates that the greater we approach the speed of light, the larger the mass becomes. Considering that light is composed of….no mass? it’d be impossible for us to get at that speed. The energy of movement is converted into mass. That is where the famous little energy = Mass x Constant² comes from. We would always be getting closer and closer. But never actually get there.. So in THEORY, you would not have any mass at the speed of light.


My point is that in theory it would work. It just depends on how you choose to look at it.
Sorry for my poor English.

Regards.
 
  • #23
seetherage said:


Remember that in the case of great speeds, Newton law don’t apply with the new(er) concepts of space and time.
Most of the theories/laws were developed under the condition that speed is small. Such as Newton’s second law, Where a constant force acting upon matter for certain time, can give it a speed as fast as it wants. But in reality the speed of light in vacuum is limited, and can never move in speeds greater or equal to that of light. - > thus converted into energy. Einstein estimates that the greater we approach the speed of light, the larger the mass becomes. Considering that light is composed of….no mass? it’d be impossible for us to get at that speed. The energy of movement is converted into mass. That is where the famous little energy = Mass x Constant² comes from. We would always be getting closer and closer. But never actually get there..

This is all essentially correct.

Except for the part where you say "converted into energy". Accelerating objects to the speed of light does not convert them into energy. Partly because you cannot accelerate objects to the speed of light.

seetherage said:
So in THEORY, you would not have any mass at the speed of light.


My point is that in theory it would work. It just depends on how you choose to look at it.
Sorry for my poor English.

Regards.
This is incorrect.

Objects with mass will never reach the speed of light. No matter how much you accelerate, the object's speed will always remain below c, even as its mass approaches infinity. Its mass will never approach zero.

There is no 'choose to look at it'.

And there's nothing wrong with your English.
 
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  • #24
I think you're trying to reason that if an object with mass were to accelerate to the speed of light (impossible) it would have to obtain a zero mass (because all objects traveling at the speed of light have zero mass). However, the 2nd point is intimately tied to the first so you cannot discount one without discrediting the 2nd.

As DaveC has said multiple times, mass increases with increasing velocity (which is the only case since light speed is unattainable). The point is that it's a moot question to ask because it's impossible. If you're unclear that it is absolutely impossible, you should study relativity in greater detail before claiming it is possible.
 

1. How does traveling near the speed of light affect time?

According to Einstein's Theory of Relativity, time slows down for objects traveling near the speed of light. This phenomenon is known as time dilation. As an object's speed approaches the speed of light, time for that object appears to slow down from an outside observer's perspective.

2. What happens to an object's mass when it travels near the speed of light?

As an object approaches the speed of light, its mass increases. This is known as mass dilation and is also a consequence of Einstein's Theory of Relativity. The faster an object moves, the more energy it has, and this energy contributes to its mass.

3. Can we ever reach the speed of light?

No, it is not possible for any object with mass to reach the speed of light. As an object's speed increases, its mass also increases, and it would take an infinite amount of energy to accelerate an object to the speed of light. Additionally, as an object approaches the speed of light, the amount of energy required to accelerate it increases exponentially.

4. How does traveling near the speed of light affect the perception of distance?

As an object's speed approaches the speed of light, distances appear to shrink from an outside observer's perspective. This phenomenon, known as length contraction, is also a consequence of Einstein's Theory of Relativity. The faster an object moves, the shorter it appears to be in the direction of its motion.

5. What are the potential consequences of time dilation and length contraction for space travel?

Time dilation and length contraction have significant implications for space travel. As an object travels near the speed of light, time passes slower for that object, making it possible for astronauts to age less than those on Earth. Additionally, the perceived distance to a destination may be shorter, making it possible to travel further in a shorter amount of time. However, the amount of energy required to travel at these speeds is currently beyond our technological capabilities.

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