Thread: how realistic is the possibility of star travel in the future?

first off, i have a great interest in science, but my expertise is in other areas...so i'm just testing my understanding of how things work. so i would appreciate any feedback or corrections. thanks.

it seems that we take it for granted that one day humans will travel the stars...i'm not so sure. even if we can build a spacecraft that can approach the speed of light, which i don't think will ever happen, there are still too many obstacles which seem insurmountable. first off, if my calculations are correct, it would take a year to accelerate to that speed...and another year to stop. also, you wouldn't be able to navigate a ship travelling that fast. you're pretty much travelling in a straight line. you would need to make any course corrections millions, if not billions, of miles in advance. and if you hit anything with mass at that speed...a tiny ice crystal, or a gas cloud...the results would be catastrophic. then there's building the ship itself. can't even imagine how much power an engine would need to generate...and be able to sustain that power for at least a couple of years. not only sustain, but increase in power as velocity increases. and you would need to power the ship for years, even with time compression, as well as having a complete self contained ecosystem on board. remember, there are no bus stops along the way. the hull integrity would have to be perfect and remain perfect for the entire voyage. and i'm sure there are many more challenges which would have to be addressed. but i don't see a way getting pass the ones i've mentioned...regardless of how much technology advances. the universe is just too big and the laws of phyisics are just too restrictive to allow star travel, imho. what do you think?

Originally Posted by mrjc99

first off, i have a great interest in science, but my expertise is in other areas...so i'm just testing my understanding of how things work. so i would appreciate any feedback or corrections. thanks.

it seems that we take it for granted that one day humans will travel the stars...i'm not so sure. even if we can build a spacecraft that can approach the speed of light, which i don't think will ever happen, there are still too many obstacles which seem insurmountable. first off, if my calculations are correct, it would take a year to accelerate to that speed...and another year to stop. also, you wouldn't be able to navigate a ship travelling that fast. you're pretty much travelling in a straight line. you would need to make any course corrections millions, if not billions, of miles in advance. and if you hit anything with mass at that speed...a tiny ice crystal, or a gas cloud...the results would be catastrophic. then there's building the ship itself. can't even imagine how much power an engine would need to generate...and be able to sustain that power for at least a couple of years. not only sustain, but increase in power as velocity increases. and you would need to power the ship for years, even with time compression, as well as having a complete self contained ecosystem on board. remember, there are no bus stops along the way. the hull integrity would have to be perfect and remain perfect for the entire voyage. and i'm sure there are many more challenges which would have to be addressed. but i don't see a way getting pass the ones i've mentioned...regardless of how much technology advances. the universe is just too big and the laws of phyisics are just too restrictive to allow star travel, imho. what do you think?

For many years at the University of Maryland, Prof. Bob Park would have the undergraduates in his introductory physics class look into exactly this question (or the allied set of questions): How long would it take? What is the total mass of the food and other supplies that would be needed to sustain the crew for that period? How would you shield the occupants from hazards (including radiation)? How big would the spacecraft have to be? How much energy is needed? How much fuel is implied by the energy requirement? etc.

The conclusions are always pretty depressing to those who have just assumed that we will eventually have interstellar travel for humans. It's worse than the flying-car letdown that I'm still chapped about.

I'm betting this is a subject that many people think about. One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

This may very well be an endeavor in futility, but the need for humans to have more than one planet to call home is very high, and we need to keep exploring any possibilities that come up. We also need to take the long view on capital invested. We can't just cut project funding every time some politician is trying to get elected to office and wants to save a few bucks to demonstrate how fiscally responsible they are.

The need for international funding coalitions with long term stability is an absolute must.

If we can't get this done then we will go extinct still stuck on planet Earth. That being the case I choose to believe where there is a will there will be a way. I do think it's a long shot, but I still want to support it any way I can.

Originally Posted by Bad Robot

I'm betting this is a subject that many people think about. One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

This may very well be an endeavor in futility, but the need for humans to have more than one planet to call home is very high, and we need to keep exploring any possibilities that come up. We also need to take the long view on capital invested. We can't just cut project funding every time some politician is trying to get elected to office and wants to save a few bucks to demonstrate how fiscally responsible they are.

The need for international funding coalitions with long term stability is an absolute must.

If we can't get this done then we will go extinct still stuck on planet Earth. That being the case I choose to believe where there is a will there will be a way. I do think it's a long shot, but I still want to support it any way I can.

There's no controversy about the need to succeed. The problem is converting that insight into actionable plans. Right now, with the physics we understand today, and with the fuel sources available, many orders of magnitude separate us from success. We can plan all we want, but it won't move the needle. Real progress toward practical interstellar travel will likely require new physics. At least, that's what I recall from having participated in the equivalent of Bob Park's homework exercise at my university. The whole class went from "Aim for the stars!" to "Crap; we might be stuck here until our sun turns into a red giant and engulfs the planet."

But, as Yoda said, "The future in flux always is." Maybe it'll flux the right way before we are all permanently fluxed.

I've been amused by the thought of us building a generation ship and sending it out to the stars.
A couple hundred years later, it reaches its destination only to find a colony of healthy and advanced humans there, welcoming them with an "We were expecting you" party.
During the generation ships journey, serious strides in advanced propulsion and energy were achieved on Earth and... I don't know but I think it would suck to be one of those guys hopping off the generation ship that day. Speaking of let downs...

"This is one small step for a man; One giant leap for... Wait, who the hockey puck are you?!"

Originally Posted by tk421

The conclusions are always pretty depressing to those who have just assumed that we will eventually have interstellar travel for humans. It's worse than the flying-car letdown that I'm still chapped about.

I don't believe anyone (scientist or layperson) can give a definitive answer to whether interstellar travel will ever be possible.
I think it was a prominent British astronomer (can't remember the name) who stated, in the late 1950's, that the belief we could reach the moon, in the near future, was absurd nonsense.
We will not be able to travel to the stars ten years from now, and maybe not this century, but the real arrogance comes from those who tend to set limits to what can be achieved because they appear to believe they can predict limits to scientific and technological advances far into the future.
I do believe that travel to the stars will be possible but, of course, I can't prove that. Perhaps we will never leave the Solar System but, if that turns out to be the case, I suspect the cause will be major economic, social, and political problems, here on Earth, and not because interstellar travel proves to be technically impossible.

No offense meant. I think before I STAR TRAVEL, I really need to see what is already here and experience it. Will it happen? I would think so, though probably not in my life time.

I am pinning my hopes on the Alcubierre drive. Won't happen any time soon if it does, but if it does, we could potentially go anywhere...

with all due respect...i do believe that the laws of physics and the vastness of space do act as limits to technological advances. and, as a side note, i was trying to point out that even if we can overcome the technology hurdles and build such a craft, it still would be too dangerous to fly, and have just about no chance of reaching its destination (i would imagine fwiw).

Well it certainly might be possible one day given that scientists such as Dr. Harold White and his team have been working in the NASA Johnson Space Center Eagleworks trying to find instances of microscopic warp bubbles using an instrument called the White Juday Warp Field Interferometer. So far what they have managed to find are loopholes in some of the mathmatical equations that govern our current understanding of physics which have indicated to them that the warping of space-time fabric is indeed actually possible.

Whilst this discovery may seem small now, Dr. White firmly believes that this may on day lead to a real life working warp drive.
What they one day hope to do is use one of these warp bubbles, so a spaceship's engine can compress the space ahead and expand the space behind, moving it to another place without actually moving, and carrying none of the adverse effects of other travel methods. Simply put in his own words Dr. White says "by harnessing the physics of cosmic inflation, future spaceships crafted to satisfy the laws of these mathematical equations may actually be able to get somewhere unthinkably fast and without adverse effects."

He also goes on to explain how if everything is confirmed in the practical experiments, we would be able to create an engine that could get us to Alpha Centauri in two weeks as measured by clocks here on Earth. Also that the time would be the same in the spaceship and on Earth, he claims, and there will not be any tidal forces inside the bubble, no undue issues, and the proper acceleration would be zero. When you turn the field on, everybody doesn't go slamming against any bulkheads.

One of the more fascinating aspects of the their work has been a potential way around the energy problem, team has discovered that the energy requirements are much lower than previously thought. If they optimize the warp bubble thickness and oscillate its intensity to reduce the stiffness of space time, they would indeed be able to reduce the amount of fuel to manageable amount, instead of a Jupiter sized ball of exotic matter for example, you will only need 500 kilograms to send a 10 meter bubble (32.8 feet) at an effective velocity of 10c.

Certainly what I would consider encouraging for our long term space faring prospects.

Originally Posted by mrjc99

with all due respect...i do believe that the laws of physics and the vastness of space do act as limits to technological advances. and, as a side note, i was trying to point out that even if we can overcome the technology hurdles and build such a craft, it still would be too dangerous to fly, and have just about no chance of reaching its destination (i would imagine fwiw).

I would sign up in a heartbeat.

Originally Posted by Neverfly

I've been amused by the thought of us building a generation ship and sending it out to the stars.
A couple hundred years later, it reaches its destination only to find a colony of healthy and advanced humans there, welcoming them with an "We were expecting you" party.
During the generation ships journey, serious strides in advanced propulsion and energy were achieved on Earth and... I don't know but I think it would suck to be one of those guys hopping off the generation ship that day. Speaking of let downs...

"This is one small step for a man; One giant leap for... Wait, who the hockey puck are you?!"

I read that SciFi story too. It was about 30 years ago and I can't remember the title of it. But it's not a new plot.

Originally Posted by Halliday

I don't believe anyone (scientist or layperson) can give a definitive answer to whether interstellar travel will ever be possible.

That's why what Yoda said is important to keep in mind.

I'm an optimist at heart, but optimism isn't sufficient. It will require major breakthroughs, a lot of hard work, a lot of money, and the will to sustain the project over a long time, and despite the many inevitable setbacks that will be encountered. But, as lottery promoters remind us, "You can't win if you don't play.'

Originally Posted by Neverfly

During the generation ships journey, serious strides in advanced propulsion and energy were achieved on Earth and... I don't know but I think it would suck to be one of those guys hopping off the generation ship that day. Speaking of let downs...

"This is one small step for a man; One giant leap for... Wait, who the hockey puck are you?!"

That's a definite possibility -- "First in" need not guarantee "first out." There was an old Twilight Zone episode based around that notion, as I recall. It was one of the better ones...

thanks for the feedback, everybody. my takeaway from all of this is that for star travel to happen, it would probably be by manipulating space rather than travelling through it. regards.

In the future can be a long time from now. Looking at technology development over the last 100 years, I suspect that it would be very hard to predict what will be possible just 100 years from now, much less 1000 years from now.

From the perspective of 1913, could any of these be imagined - nuclear energy, man on the moon, earth satellites for all kinds of applications, battleship obsolescence, etc.?

Any starship that is prepared for interstellar travel...would probably need a least one or possibly two magnetic shields surrounding the starship; in order to avoid any small cosmic collisions with the main hull of the flying craft.

Originally Posted by Erno86

Any starship that is prepared for interstellar travel...would probably need a least one or possibly two magnetic shields surrounding the starship; in order to avoid any small cosmic collisions with the main hull of the flying craft.

I think the kind of magnetic shields you are talking about would require more energy than the current entire out put of our planet. Not sure how we could generate it and then put it into a package small enough to be in a spaceship. If you have any ideas about that, lets hear it.

Originally Posted by Erno86

Any starship that is prepared for interstellar travel...would probably need a least one or possibly two magnetic shields surrounding the starship; in order to avoid any small cosmic collisions with the main hull of the flying craft.

How sure are you that any cosmic debris is magnetically polarised?

I think there are plenty of interesting things to do right here in the solar system. I don't get what the big deal is with wanting to go to other stars. Whats going to be there? More floating rocks and stuff like we already have here.

Originally Posted by danhanegan

I think there are plenty of interesting things to do right here in the solar system. I don't get what the big deal is with wanting to go to other stars. Whats going to be there? More floating rocks and stuff like we already have here.

I wonder who said that to Magellan et al?

I like the Star Trek "Beam Me Up Scotty" idea. Sure would beat flying.

to dan's point, hate to be a further pessimist here, but to find another habital planet, like some have mentioned, would be like finding a needle in a haystack the size of mount everest, where the individual hay stalks are trillions of miles apart...and then having to terraform that planet whose many lightyears away. just one little criteria...like the fact that oxygen is extremely rare in the universe, and requires massive amounts of photosynthesis to occur on a planet over eons...really dims our hopes of finding another earth. and there are many more requirements on top of that. so put me in the camp that we're stuck here until the sun turns red and destroys us. sorry for being such a downer.

on second thought, maybe its not being a downer. maybe it just makes us appreciate how special and important our planet is...and we better take care of it.

Originally Posted by mrjc99

to dan's point, hate to be a further pessimist here, but to find another habital planet, like some have mentioned, would be like finding a needle in a haystack the size of mount everest

Yeah, but in this case we're allowed to use a magnet to find the needle.
http://news.nationalgeographic.co.uk...e-kepler-nasa/
We're already finding planets - and we're constantly refining the technique so that we know what they're like before we even consider setting off to visit.

just one little criteria...like the fact that oxygen is extremely rare in the universe

Is it?
Apart from the link above, you're guessing.
Since we don't know how many planets out there actually do have oxygen then we can't state with any certainty whether it's "extremely rare" or not.

Originally Posted by mrjc99

to Dan's point, hate to be a further pessimist here, but to find another habitual planet, like some have mentioned, would be like finding a needle in a haystack the size of mount Everest, where the individual hay stalks are trillions of miles apart...and then having to terraform that planet whose many lightyears away. just one little criteria...like the fact that oxygen is extremely rare in the universe, and requires massive amounts of photosynthesis to occur on a planet over eons...really dims our hopes of finding another earth. and there are many more requirements on top of that. so put me in the camp that we're stuck here until the sun turns red and destroys us. sorry for being such a downer.

Any planet that has free O₂ in the atmosphere already has life on it. Oxygen is highly reactive and can only remain in any atmosphere if it is constantly being supplied, and that takes life as we know it. So we will know before we ever start out if the planet supports life and I for one wouldn't want to make a very long trip knowing it didn't support life.

[QUOTE=Bad Robot;441807]

Originally Posted by mrjc99

to Dan's point, hate to be a further pessimist here, but to find another habitual planet, like some have mentioned, would be like finding a needle in a haystack the size of mount Everest, where the individual hay stalks are trillions of miles apart...and then having to terraform that planet whose many lightyears away. just one little criteria...like the fact that oxygen is extremely rare in the universe, and requires massive amounts of photosynthesis to occur on a planet over eons...really dims our hopes of finding another earth. and there are many more requirements on top of that. so put me in the camp that we're stuck here until the sun turns red and destroys us. sorry for being such a downer.

Any planet that has free O₂ in the atmosphere already has life on it. Oxygen is highly reactive and can only remain in any atmosphere if it is constantly being supplied, and that takes life as we know it. So we will know before we ever start out if the planet supports life and I for one wouldn't want to make a very long trip knowing it didn't support life.[thats my understanding as well. but i was even being less picky in my analysis and including planets that could support life as we know it but didn't have any life yet...or planets with life without photosynthesis...in which case we would have to terraform. including these types of planets would increase our odds, but they would still be extremely rare. but there are other requirements as well, such as radiation levels, toxic componds, atmospheric pressure, gravity, magnetic field, both oceans and dry land, minerals available, etc. etc. very difficult to measure all these things from afar.]

Originally Posted by danhanegan

I think there are plenty of interesting things to do right here in the solar system. I don't get what the big deal is with wanting to go to other stars. Whats going to be there? More floating rocks and stuff like we already have here.

I do believe that eventually we will travel beyond the Solar System. If that time comes it does not mean we have to ignore interesting places within our own planetary system.
It takes a special kind of mindset to dismiss the exploration of the rest of the Galaxy as simply looking for "floating rocks and stuff like we already have here".

Originally Posted by danhanegan

I think there are plenty of interesting things to do right here in the solar system.

Not on a rainy Thursday afternoon. It gets quite dull and boring.

Originally Posted by mrjc99

to dan's point, hate to be a further pessimist here, but to find another habital planet, like some have mentioned, would be like finding a needle in a haystack the size of mount everest, where the individual hay stalks are trillions of miles apart...and then having to terraform that planet whose many lightyears away. just one little criteria...like the fact that oxygen is extremely rare in the universe, and requires massive amounts of photosynthesis to occur on a planet over eons...really dims our hopes of finding another earth. and there are many more requirements on top of that. so put me in the camp that we're stuck here until the sun turns red and destroys us. sorry for being such a downer.

Even given the highly unlikely possibility the Earth is the only planet, in the Milky Way Galaxy, capable of supporting life it is perfectly possible to list a number of points that could be used to justify exploration outside of the Solar System.
On reflection, I'm not certain this thread should be in the physics sub forum.

Originally Posted by Halliday

Originally Posted by mrjc99

to dan's point, hate to be a further pessimist here, but to find another habital planet, like some have mentioned, would be like finding a needle in a haystack the size of mount everest, where the individual hay stalks are trillions of miles apart...and then having to terraform that planet whose many lightyears away. just one little criteria...like the fact that oxygen is extremely rare in the universe, and requires massive amounts of photosynthesis to occur on a planet over eons...really dims our hopes of finding another earth. and there are many more requirements on top of that. so put me in the camp that we're stuck here until the sun turns red and destroys us. sorry for being such a downer.

Even given the highly unlikely possibility the Earth is the only planet, in the Milky Way Galaxy, capable of supporting life it is perfectly possible to list a number of points that could be used to justify exploration outside of the Solar System.
On reflection, I'm not certain this thread should be in the physics sub forum.

Humans need incentive to make progress. With the next generation of instruments we should be able to tell the composition of any planetary atmosphere out to about a thousand light years in every direction. Sure that's far enough out that we would need some kind of FTL traveling abilities, but we will know if there's any life as we know it anywhere inside a nice section of the galaxy. Any proof of exolife will be a great deal of incentive. While I can't know for sure that we will find it, I do believe we will.

Originally Posted by Bad Robot

Originally Posted by Erno86

Any starship that is prepared for interstellar travel...would probably need a least one or possibly two magnetic shields surrounding the starship; in order to avoid any small cosmic collisions with the main hull of the flying craft.

I think the kind of magnetic shields you are talking about would require more energy than the current entire out put of our planet. Not sure how we could generate it and then put it into a package small enough to be in a spaceship. If you have any ideas about that, lets hear it.

Based on my otherworlder starship sighting, back one night in November of 1976, approx. 40 miles west of Washington D.C.; has given me plenty of time to theorize how starships might tick. I'm a firm believer in the reality of black hole starship's. The power output of such a craft...can easily generate huge power outputs, due to the heart of the photon engine itself, which might possibly be a small mini black hole, that can generate huge magnetic fields. The photon engine would not rely on Hawking gamma photon radiation, but on regular starlight photons...such as distant stars in our galaxy---but also...fusion plasma generated from the starship itself {in places where regular starlight is lacking} --- contained by two magnetic fields surrounding the starship. The starship collects the starlight with a photon receptor --- funnels the photons into the heart of the mini-black hole photon engine --- with the black hole exiting the photons at one or both of it's magnetic poles into a thruster port and exiting the starship with tremendous thrust; increasing speed exponentially squared into the superluminal {faster than light} realm.

Originally Posted by Erno86

Based on my [totally unsupported speculative claims about something I couldn't identify], back one night in November of 1976, approx. 40 miles west of Washington D.C.; has given me plenty of time to [guess wildly] how starships might tick. I'm a firm believer in the reality of [things that don't have any evidence for their existence]. The power output of such a craft...can easily generate huge power outputs, due to the heart of the [speculative waffle generator] itself, which might possibly be a [load of meaningless double talk]. The [made up thingy] would not rely on Hawking gamma photon radiation, but on regular starlight photons [because that sounds more impressive]...such as distant stars in our galaxy---but also...fusion plasma generated from the starship itself {in places where regular starlight [and common sense] is lacking} --- contained by two magnetic fields surrounding the starship. The starship collects the starlight with a photon receptor --- funnels the photons into the heart of the mini-black hole photon engine --- with the black hole exiting the photons at one or both of it's magnetic poles into a thruster port and exiting the starship with tremendous thrust; increasing speed exponentially squared into the superluminal {faster than light} realm. [Where it eventually goes so fast it disappears up its own arse]

Corrected (most of) that for you.

"Exponentially squared" is about as good as the "10,000%" claim in that other thread...

I always find it amusing when someone goes into great detail (regardless of scientific [or otherwise] double talk) on the power plant/ propulsion system of something they glimpsed fleetingly on a dark night at a distance.
I wonder how many would be capable of watching a video of, say a warship, and accurately working out whether it's diesel or gas turbine powered (or both or either - CODOG/ CODAG), or even electric?

It's strange that the last poster's didn't even ask what the UFO, that I had a visual sighting of --- even looked like --- or the approx. size, speed, etc, etc. Its hard for some people to understand, who have trouble grappling with the unknown...yet you may understand more if you google: black hole starships & black hole saucers. If you don't care...the scientists from the Cern collider might care, since they might be the one's to actually create a mini black hole here on Earth; and I guess you might fathom where they'll probably be sticking it.

This one registers high on the crank-o-meter.

sorry...double post

Originally Posted by Erno86

It's strange that the last poster's didn't even ask what the UFO, that I had a visual sighting of even looked like

That would be largely irrelevant, since you couldn't identify it.
What relevance does its shape have?

approx. size, speed, etc, etc.

Now, here's the fun part:
How do you know what size it was?
Presumably you knew exactly how far away it was.
Because unless you know one or the other then all you have is guesses.
If you don't know how large it was then you have no method of judging its distance (or vice versa).
If you don't know the distance then you can't judge the speed.

Its hard for some people to understand, who have trouble grappling with the unknown.

No, what IS hard to understand is why people feel qualified to comment on "propulsion methods" when they haven't got a single f*cking clue what they actually saw.
And nearly as hard to understand is why people thank that meaningless Star Trek-style technobabble is worth posting as an "explanation".

yet you may understand more if you google: black hole starships & black hole saucers.

Ah, got it.
It's the usual hand-waving excuse.
You can't be bothered to (or, more likely, are utterly incapable of) provid[e/ing] an actual explanation of what you mean.

If you don't care...the scientists from the Cern collider might care

Unlikely. But that's only because they're interested in real science.

since they might be the one's to actually create a mini black hole here on Earth

Er, right.
Why did you not bother with an education? (Just asking...)

Anti matter is the most compact way to carry energy isn't it? It puts uranium or hydrogen fusion to shame because, in theory, all of the mass could be converted into energy, instead of just part of it. In practice I don't know. Maybe too many positrons would fail to find their way to an electron, unless it was done in tiny bits at a time or something.

But my point is, we kind of have an upward limit there. Nothing's going to exceed it.

Originally Posted by Ascended

One of the more fascinating aspects of the their work has been a potential way around the energy problem, team has discovered that the energy requirements are much lower than previously thought. If they optimize the warp bubble thickness and oscillate its intensity to reduce the stiffness of space time, they would indeed be able to reduce the amount of fuel to manageable amount, instead of a Jupiter sized ball of exotic matter for example, you will only need 500 kilograms to send a 10 meter bubble (32.8 feet) at an effective velocity of 10c.

Certainly what I would consider encouraging for our long term space faring prospects.

In theory, traveling a distance could have a zero net energy, if all the energy used to accelerate was recovered at the point of deceleration.

In practice, that probably won't happen.

Just saying if we discover a super, sci fi, power ranger, star trek, mighty drive - it makes sense that it wouldn't necessarily be power costly. If we're lucky, anyway, and if it should turn out that the universe decided to make it easy on us. Unfortunately we don't know what the universe has decided to do yet.

Originally Posted by Erno86

Any starship that is prepared for interstellar travel...would probably need a least one or possibly two magnetic shields surrounding the starship; in order to avoid any small cosmic collisions with the main hull of the flying craft.

Or in the alternative, the ship could just have a really really really thick hull. In space there is no requirement for the ship to be aerodynamic.

The hull could be made up of whatever it is the space ship is ejecting behind it. Once it reaches its final cruising speed, there will (hopefully) be plenty of ejecting material left (assuming the designers also planned for the decelerating part of the voyage .... one hopes.)

Probably the ejecting material will be many times over more massive and take up many times more volume than the ship itself.

Ya know....many many years ago....my sis's and I were in the Mohave Desert...sleeping outside....and we swore we saw a spaceship ....however.....closer to Edwards AFB, could have been a lot of things....thank goodness for imaginations...it creates a part of those that do science's minds. If not for their imaginations to make things people see as unreal to prove to be reality....where would they or we be?

The road goes both ways. Respect does also.

Originally Posted by Erno86

. I'm a firm believer in the reality of black hole starship's. The power output of such a craft...can easily generate huge power outputs, due to the heart of the photon engine itself, which might possibly be a small mini black hole, that can generate huge magnetic fields. The photon engine would not rely on Hawking gamma photon radiation, but on regular starlight photons...such as distant stars in our galaxy---but also...fusion plasma generated from the starship itself {in places where regular starlight is lacking} --- contained by two magnetic fields surrounding the starship. The starship collects the starlight with a photon receptor --- funnels the photons into the heart of the mini-black hole photon engine --- with the black hole exiting the photons at one or both of it's magnetic poles into a thruster port and exiting the starship with tremendous thrust; increasing speed exponentially squared into the superluminal {faster than light} realm.

Fascinating. Could you show me the math for that please.

According to an online calculator, a 1000 metric tonne black hole would release 356 millon terrawatts of hawking radiation over its 84 second lifetime.
I'd increase it to a 10k tonne singularity releasing 3,563,442 terrawatts over 84,071.83 seconds.

Originally Posted by TheUnknowable

According to an online calculator, a 1000 metric tonne black hole would release 356 millon terrawatts of hawking radiation over its 84 second lifetime.
I'd increase it to a 10k tonne singularity releasing 3,563,442 terrawatts over 84,071.83 seconds.

There's a couple major problems with your ideas.

1. Your acting like Hawking radiation is a proven fact. It's just a theory.

2. Creating black holes by the tonne to order, is not even a theory let alone much of a possibility for humans ever to do.

What are you thinking about?

Originally Posted by Bad Robot

2. Creating black holes by the tonne to order, is not even a theory let alone much of a possibility for humans ever to do.

Rubbish.
You just get a hole, take away all the colours that aren't black and then add weight until it's the mass required.
What could be easier?

Originally Posted by Bad Robot

1. Your acting like Hawking radiation is a proven fact. It's just a theory.

What did you just say...?

In my humble opinion- BULLSHIT -we ain't going there

Originally Posted by Neverfly

Originally Posted by Bad Robot

1. Your acting like Hawking radiation is a proven fact. It's just a theory.

What did you just say...?

Sorry but no repeats. If that went over your head your on your own.

Yes, creating a black hole would require manipulation of gravity. Couldn't this be done by increasing the local density of the higgs field? (at least theoretically). I know we haven't even locked down exactly what a higgs-boson is, but we know that it gives objects and particles what we call "mass".

Originally Posted by TheUnknowable

Yes, creating a black hole would require manipulation of gravity. Couldn't this be done by increasing the local density of the higgs field? (at least theoretically). I know we haven't even locked down exactly what a higgs-boson is, but we know that it gives objects and particles what we call "mass".

There is nothing known or surmised that we could do with the Higgs that would affect gravity, other than accumulate a LOT of them in a very small space. It would be a lot easier to make that accumulation with a particle that is stable, like say an atomic nucleus.

Originally Posted by mvb

Originally Posted by TheUnknowable

Yes, creating a black hole would require manipulation of gravity. Couldn't this be done by increasing the local density of the higgs field? (at least theoretically). I know we haven't even locked down exactly what a higgs-boson is, but we know that it gives objects and particles what we call "mass".

There is nothing known or surmised that we could do with the Higgs that would affect gravity, other than accumulate a LOT of them in a very small space. It would be a lot easier to make that accumulation with a particle that is stable, like say an atomic nucleus.

So carrying around a chunk of neutronium is better than a device to temporarily increase gravity?
Also, would pushing Higgs particles away effectively work as an inertial dampener?

The sun is 1.989e30 kg (1.989 e27 tonnes). the minimum mass needed to collapse into a black hole is 15 suns, so 2.9835 e28 tonnes. So increasing the mass of a 1000 tonne object to that would require a field which amplifies mass by a factor of 2.9835 e25.
Better go with a bigger object, like the moon. Compressing it into a black hole (mass 7.3476 e 22 kg or 7.3476 e 19 tonnes) would only require increasing it's mass by a factor of 406 million.
Um Ok, Jupiter. 1.898 e 24 tonnes, so a factor of 15,720.
Good enough.

Originally Posted by TheUnknowable

Originally Posted by mvb

Originally Posted by TheUnknowable

Yes, creating a black hole would require manipulation of gravity. Couldn't this be done by increasing the local density of the higgs field? (at least theoretically). I know we haven't even locked down exactly what a higgs-boson is, but we know that it gives objects and particles what we call "mass".

There is nothing known or surmised that we could do with the Higgs that would affect gravity, other than accumulate a LOT of them in a very small space. It would be a lot easier to make that accumulation with a particle that is stable, like say an atomic nucleus.

So carrying around a chunk of neutronium is better than a device to temporarily increase gravity?
Also, would pushing Higgs particles away effectively work as an inertial dampener?

I don't think you could push Higgs particles away either. Particle mass is generated by virtual Higgs and/or the Higgs-field vacuum expectation value, not by pre-existing Higgs particles. I don't expect that it would be possible to affect either interaction. That may be just as well. If the opposite were true, it might open up the possibility of doing some really nasty things.

I think interstellar travel is realistic enough, but I would expect this to be of the "classic" variety. This means decades or centuries of in-flight time through the empty void between stars, on board a habitat vessel that can support several generations of settlers in near-zero gravity. Not pretty, but it would get you there eventually.

The true question is - why would anyone want to do such a thing, given the uncertainty of what the destination will really be like ?

P.S. A Star-Trek style Warp drive is simply not a realistic expectation given current scientific understanding. Of course we can't rule out that we are still missing a fundamental piece of the puzzle which might permit some form of effectively superluminal travel, but personally I wouldn't bet on it. You can't cheat nature; there will always be a price to pay, magic simply doesn't exist.

I have no idea what the formula is

HOWEVER

if it works like "BEAM ME UP SCOTTY"

Dang I hope that happens....flying is the shits anymore

The best idea I have ever heard of for faster than light travel is an Alcubierre Warp Drive. Unfortunately, it uses exotic matter, matter that is pushed by gravity, as fuel. As far as I looked, but found there is no experimental or theoretical evidence that exotic mater exists. If we magically found some, it would be destroyed as soon as it touched matter. This leads to the question of, "How are we suppose to store it in the ship". Also, we would need HUGE amounts of energy with very precise control to activate the Drive. If somehow, all that happened, there is a theory that while traveling random radiation and particles that flood space would be "caught" by the Drive. If this is true, when the drive turn's off all that energetic stuff will be released in a massive explosion, most likely destroying everything around you. Please note, this is the best idea I have heard of for faster than light travel.

I do keep one small ray of hope. Maybe some new guy will appear out of the blue and rewrite all of physics as we understood it. In other words, he would need to do what Einstein did. Until that happens, I don't think its happening.

Originally Posted by Jewish-Scientist

The best idea I have ever heard of for faster than light travel is an Alcubierre Warp Drive.

Apart from the fact that it wouldn't work even if we could build it you mean?

If we magically found some, it would be destroyed as soon as it touched matter.

Citation needed.

Originally Posted by Markus Hanke

I think interstellar travel is realistic enough, but I would expect this to be of the "classic" variety. This means decades or centuries of in-flight time through the empty void between stars, on board a habitat vessel that can support several generations of settlers in near-zero gravity. Not pretty, but it would get you there eventually.

The true question is - why would anyone want to do such a thing, given the uncertainty of what the destination will really be like ?

P.S. A Star-Trek style Warp drive is simply not a realistic expectation given current scientific understanding. Of course we can't rule out that we are still missing a fundamental piece of the puzzle which might permit some form of effectively superluminal travel, but personally I wouldn't bet on it. You can't cheat nature; there will always be a price to pay, magic simply doesn't exist.

One way or another interstellar travel is a realistic possibility for the future.
Nobody can predict future scientific and technological developments and it is not possible prove this kind of travel will happen by "peering" into the future, but does anyone seriously believe that in 1000, 10,000 or 100,000 years humans will lack the will and/or the ability to journey way beyond the Solar System.
I go with Arthur C. Clarke when he said we will be able,eventually, to achieve just about everything we can imagine.

Originally Posted by Halliday

One way or another interstellar travel is a realistic possibility for the future.
Nobody can predict future scientific and technological developments and it is not possible prove this kind of travel will happen by "peering" into the future, but does anyone seriously believe that in 1000, 10,000 or 100,000 years humans will lack the will and/or the technology to journey way beyond the Solar System.
I go with Arthur C. Clarke when he said we will be able to achieve just about everything we can imagine.

I see your assuming the human race won't have any major setbacks? Such as out of control climate change, maybe another ice age, an asteroid or comet that makes our day, even an overdue super volcano and never mind what we might do to eachother. But then why not be optimistic?

Originally Posted by Bad Robot

I see your assuming the human race won't have any major setbacks? Such as out of control climate change, maybe another ice age, an asteroid or comet that makes our day, even an overdue super volcano and never mind what we might do to eachother. But then why not be optimistic?

I did qualify my optimism, in an earlier post, and I usually use the phrase "if we survive as a species" if I post in threads of this type.
I believe humans will survive, but I concede that the technological civilisation we have created faces real dangers and its continued survival is by no means assured.

Warp Drive Feasible? Relativity Loophole Means 'Star Trek' Device Might Actually Work, Physicists Say

Originally Posted by TheUnknowable

Warp Drive Feasible? Relativity Loophole Means 'Star Trek' Device Might Actually Work, Physicists Say

I really really just want for "Beam me up, Scotty".

or down....

Originally Posted by babe

Originally Posted by TheUnknowable

Warp Drive Feasible? Relativity Loophole Means 'Star Trek' Device Might Actually Work, Physicists Say

I really really just want for "Beam me up, Scotty".

or down....

Yes beaming technology is something to look forward to. But one of my favorites is the food replicators after I've worked up an appetite in the holodeck.

rip van winkle

Originally Posted by sculptor

rip van winkle

Is that you?

Originally Posted by Bad Robot

Originally Posted by babe

Originally Posted by TheUnknowable

Warp Drive Feasible? Relativity Loophole Means 'Star Trek' Device Might Actually Work, Physicists Say

I really really just want for "Beam me up, Scotty".

or down....

Yes beaming technology is something to look forward to. But one of my favorites is the food replicators after I've worked up an appetite in the holodeck.

Well I am getting tired of cooking.....sounds good to me....

Originally Posted by Bad Robot

One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

Originally Posted by Adirondack-Bob

Originally Posted by Bad Robot

One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

I would like to think that children born in space on a generation ship would grow up thinking it was very natural, and I would think ordinary education rather than brainwashing would be all that was needed. Humans are a very adaptive species and can live happy productive lives in a wide variety of environments. So I don't see this endeavor as condemning anyone as things might actually be better on the ship than the earth at that time in the future. Also, everyone going would be selected from volunteers which I suspect will greatly out number those who are able to go.

PS - Welcome to the forum.

Originally Posted by Adirondack-Bob

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

Thinking of a movieplot along these lines and pillaging a bit from life and 'Prometheus'.

Spreading the human race across the cosmos is simply an exercise in patience and time. We do not actually need to solve 'abiogenesis' or significantly ramp up technologies to speed up travel before we entertain such a mission of terraforming our travel route through the cosmos. Just good old evolutionary theory and the knowledge of planetary conditions that could support a carbon based 'tree of life' to emerge.

Let's consider a move to use 'reverse panspermia' with our knowledge of the stars, gravitational slinshots and protective spores to spread the seed of life through the Milky Way and then the cosmos. The quest being that given enough time and setting in train deliberate mechanisms to creating habitable systems in our cosmos that what we really are creating is possible habitation posts along a path of cosmological colonisation. The tyrrany of exploration are the risks of travel associated with 'not knowing' your ultimate destination, what lies in wait at your destination, the journey itself where you are reliant on the supplies you have on board your ship etc. What this approach would do would be to hopefully reduce the risks of travel and at the same time provide 'designed' habitation points to at least give the human race a chance if they stuff this planet up too much. Sure, you might say, what about the universal inhabitants? How would they feel about us spreading ourselves across the cosmos like a virus?.....good point....but I say stuff 'em all. If they raise concern, then just nuke 'em from orbit /TIC

Let's 'artificially create complexes that mimic a meteorite that are teeming with robust microscoping lifeforms (that come from a wide variety of extreme niches eg. thermophiles etc.). With nanotechnology, let's impregnate these lifeforms with tracking detection technologies that ideally are powered through the biochemistry of the organism itself. Furthermore incorporate technologies into the genome that trigger notifications upon mitosis/meiosis events (the notification that possible habitation is commencing). Better still, let's see if we can mimic replication with these technologies themselves so they can follow the progeny as well. Let's then bundle these lifeforms up into packages encapsulated in extremely durable and heat resistant spores and include technologies that register impact events which trigger spore 'disintegration' to spew the contents around upon impact.

Then lets assemble these complexes up in space stations and then shoot them off into the cosmos using our knowledge of travel trajectories and ways to accelerate speeds using gravitational slingshots......then we just use our monitoring technologies and wait and listen. At least it gives something useful for SETI to do./TIC

When we receive notification of our first successfuly colonised 'way point' then work out the calcs of distance and the length of time and method to send our best transport devices to this 'way point'. We might find that it is still to far and may require multiple generations to reach this way point. Ok point taken but we can always send Jim and his family and relatives on their way as he was always the most unpopular at school but he did like gardening....but just also give consideration, if you like Jim, to possibly determining other potential locations along the way that we may be able to easily terraform to make life a bit more easier for him and his ilk. You might want to invest a bit of time and effort here as maybe I just don't like Jim. You can always decide at a later date to send one of Jim's grandchildren.......sorry Jim.

Anyway the film would be more like 'How the West was Won'. Let's think about ways to make the path easier with way points and inns as opposed to worrying about the more difficult speed and time issues......Oh and watch out for Indians. :-))

Originally Posted by Adirondack-Bob

Originally Posted by Bad Robot

One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

It's moot point, the fuel considerations prohibit trips to other galaxies. Unfortunately, for the forseable future.

Originally Posted by Bad Robot

Originally Posted by Adirondack-Bob

Originally Posted by Bad Robot

One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

I would like to think that children born in space on a generation ship would grow up thinking it was very natural, and I would think ordinary education rather than brainwashing would be all that was needed. Humans are a very adaptive species and can live happy productive lives in a wide variety of environments. So I don't see this endeavor as condemning anyone as things might actually be better on the ship than the earth at that time in the future. Also, everyone going would be selected from volunteers which I suspect will greatly out number those who are able to go.

PS - Welcome to the forum.

Thanx!

I could see a movie in which few kids start to rebel against their planned life and try to escape. LOL!

Originally Posted by xyzt

It's moot point, the fuel considerations prohibit trips to other galaxies. Unfortunately, for the forseable future.

It certainly puts a dampener on things. But never say die. That's quitter talk. :-))

Originally Posted by Implicate Order

Originally Posted by Adirondack-Bob

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

Thinking of a movieplot along these lines and pillaging a bit from life and 'Prometheus'.

Spreading the human race across the cosmos is simply an exercise in patience and time. We do not actually need to solve 'abiogenesis' or significantly ramp up technologies to speed up travel before we entertain such a mission of terraforming our travel route through the cosmos. Just good old evolutionary theory and the knowledge of planetary conditions that could support a carbon based 'tree of life' to emerge.

Let's consider a move to use 'reverse panspermia' with our knowledge of the stars, gravitational slinshots and protective spores to spread the seed of life through the Milky Way and then the cosmos. The quest being that given enough time and setting in train deliberate mechanisms to creating habitable systems in our cosmos that what we really are creating is possible habitation posts along a path of cosmological colonisation. The tyrrany of exploration are the risks of travel associated with 'not knowing' your ultimate destination, what lies in wait at your destination, the journey itself where you are reliant on the supplies you have on board your ship etc. What this approach would do would be to hopefully reduce the risks of travel and at the same time provide 'designed' habitation points to at least give the human race a chance if they stuff this planet up too much. Sure, you might say, what about the universal inhabitants? How would they feel about us spreading ourselves across the cosmos like a virus?.....good point....but I say stuff 'em all. If they raise concern, then just nuke 'em from orbit /TIC

Let's 'artificially create complexes that mimic a meteor that are teeming with robust microscoping lifeforms (that come from a wide variety of extreme niches eg. thermophiles etc.). With nanotechnology, let's impregnate these lifeforms with tracking detection technologies that ideally are powered through the biochemistry of the organism itself. Furthermore incorporate technologies into the genome that trigger notifications upon mitosis/meiosis events (the notification that possible habitation is commencing). Better still, let's see if we can mimic replication with these technologies themselves so they can follow the progeny as well. Let's then bundle these lifeforms up into packages encapsulated in extremely durable and heat resistant spores and include technologies that register impact events which trigger spore 'disintegration' to spew the contents around upon impact.

Then lets assemble these complexes up in space stations and then shoot them off into the cosmos using our knowledge of travel trajectories and ways to accelerate speeds using gravitational slingshots......then we just use our monitoring technologies and wait and listen.

When we receive notification of our first successfuly colonised 'way point' then work out the calcs of distance and the length of time and method to send our best transport devices to this 'way point'. We might find that it is still to far and may require multiple generations to reach this way point. Ok, then send now we send Jim and his family and relatives on their way as he was always the most unpopular at school but he did like gardening....but just also give consideration, if you like Jim, to possibly determining other potential locations along the way that we may be able to easily terraform to make life a bit more easier for him and his ilk. You might want to invest a bit of time and effort here as maybe I just don't like Jim. You can always decide at a later date to send one of Jim's grandchildren.......sorry Jim.

Anyway the film would be more like 'How the West was Won'. Let's think about ways to make the path easier with way points and inns as opposed to worrying about the more difficult speed and time issues......Oh and watch out for Indians. :-))

I think you missed your calling as a script writer.

Originally Posted by Adirondack-Bob

I think you missed your calling as a script writer.

Na, I just hate Jim. Did I mention it would also star Paris Hilton and would be available in 3D :-))

Originally Posted by xyzt

Originally Posted by Adirondack-Bob

Originally Posted by Bad Robot

One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

It's moot point, the fuel considerations prohibit trips to other galaxies. Unfortunately, for the forseable future.

Well, like their food, they would have to grow/manufacture more as go.

Originally Posted by Adirondack-Bob

Originally Posted by xyzt

Originally Posted by Adirondack-Bob

Originally Posted by Bad Robot

One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

It's moot point, the fuel considerations prohibit trips to other galaxies. Unfortunately, for the forseable future.

Well, like their food, they would have to grow/manufacture more as go.

Sorry, not possible.

Im good not going to the stars. If it is even possible. I do not see it happening within my lifetime. Thus, no need for me to worry about it.

There is also more than enough stuff on this small rock for me to explore and enjoy for 10 lifetimes. I will never be able to experience it all but I will experience all i can. After i die, im gone and thats it so. My advice, enjoy the years you got. Life is very fleeting.

Originally Posted by GoldenRatio

Im good not going to the stars. If it is even possible. I do not see it happening within my lifetime. Thus, no need for me to worry about it.

There is also more than enough stuff on this small rock for me to explore and enjoy for 10 lifetimes. I will never be able to experience it all but I will experience all i can. After i die, im gone and thats it so. My advice, enjoy the years you got. Life is very fleeting.

Good way to look at life. Try never to harm another and live life to the fullest.

Mahalo.

Let's 'artificially create complexes that mimic a meteorite that are teeming with robust microscoping lifeforms (that come from a wide variety of extreme niches eg. thermophiles etc.). With nanotechnology, let's impregnate these lifeforms with tracking detection technologies that ideally are powered through the biochemistry of the organism itself. Furthermore incorporate technologies into the genome that trigger notifications upon mitosis/meiosis events (the notification that possible habitation is commencing). Better still, let's see if we can mimic replication with these technologies themselves so they can follow the progeny as well. Let's then bundle these lifeforms up into packages encapsulated in extremely durable and heat resistant spores and include technologies that register impact events which trigger spore 'disintegration' to spew the contents around upon impact.

sounds like a variation on the von Neumann probe idea

Self-replicating spacecraft - Wikipedia, the free encyclopedia

Originally Posted by xyzt

Originally Posted by Adirondack-Bob

Originally Posted by xyzt

Originally Posted by Adirondack-Bob

Originally Posted by Bad Robot

One project that is being worked on is called the generation ship. It's a 100 year project to build a ship that people could live on for many generations of humans being born and living their entire lives traveling to a destination with a very high percentage of being able to support human life.

I've always thought this was a Lost In Space type idea. I've never seen anything written on the ethical considerations of this idea. i.e. Do we have the right to condemn future generations to live their entire lives on this spaceship? Would this require some kind of brainwashing program to keep future offspring dedicated to the mission? This would make a good movie plot.

It's moot point, the fuel considerations prohibit trips to other galaxies. Unfortunately, for the forseable future.

Well, like their food, they would have to grow/manufacture more as go.

Sorry, not possible.

I know what you're saying but hey, they used to say we couldn't fly or walk on the moon. We don't now know what we don't know.

Originally Posted by Adirondack-Bob

Well, like their food, they would have to grow/manufacture more as go.

They could only do that by having the mass (whatever they want to use to turn into fuel) already on board.
It would be far more efficient, from both an energy use perspective AND available volume (how much space is a fuel refinery/ factory going to take up?), to carry any mass intended to be used for fuel AS fuel from the start.

Originally Posted by Chrispen Evan

sounds like a variation on the von Neumann probe idea

Self-replicating spacecraft - Wikipedia, the free encyclopedia

Nice Chrispen :-))

Originally Posted by Dywyddyr

Originally Posted by Adirondack-Bob

Well, like their food, they would have to grow/manufacture more as go.

They could only do that by having the mass (whatever they want to use to turn into fuel) already on board.
It would be far more efficient, from both an energy use perspective AND available volume (how much space is a fuel refinery/ factory going to take up?), to carry any mass intended to be used for fuel AS fuel from the start.

We all think of space as a vacuum, but it's not totally empty. There are hydrogen atoms floating around even in the space between stars. Even if the density is very small, say one atom for every 10 cubic yards of space. With a scoop you will be able to gather quite a bit of it, and the faster you are moving the more you'll be able to gather. So fuel can be replenished as you go.

Bussard ramjet?
It does have problems.

Originally Posted by Dywyddyr

Bussard ramjet?
It does have problems.

Doesn't everything have problems. I think the concept is sound and where's there's a will there's a way.

Originally Posted by Bad Robot

Doesn't everything have problems. I think the concept is sound and where's there's a will there's a way.

Except that one of the problems is that the drag created in acquiring the fuel happens to be more than is compensated for by the fuel thus acquired.
We can't re-shape the universe.

Originally Posted by Dywyddyr

Originally Posted by Bad Robot

Doesn't everything have problems. I think the concept is sound and where's there's a will there's a way.

Except that one of the problems is that the drag created in acquiring the fuel happens to be more than is compensated for by the fuel thus acquired.
We can't re-shape the universe.

How are you thinking that fuel will be used? I'm thinking a fusion reactor which should supply more than enough energy to compensate for any drag in acquiring the fuel. We may not have fusion power yet, but I'm confident we will have before to many more decades go by.

There's a practical limit to exhaust velocity: that limits possible impulse regardless of available power.