SPACE is big," wrote Douglas Adams in his book The Hitchhiker's Guide to the Galaxy. "You just won't believe how vastly, hugely, mind-bogglingly big it is."
He wasn't exaggerating. Even our nearest star Proxima Centauri is a staggering 4.2 light years away - more than 200,000 times the distance from the Earth to the sun. Or, if you like, the equivalent of 50 million trips to the moon and back.
Such vast distances would seem to put the stars far beyond the reach of human explorers. Suppose we had been able to hitch a ride on NASA's Voyager 1 the fastest interstellar space probe built to date. Voyager 1 is now heading out of the solar system at about 17 kilometres per second. At this rate it would take 74,000 years to reach Proxima Centauri - safe to say we wouldn't be around to enjoy the view.
So what would it take for humans to reach the stars within a lifetime? For a start, we would need a spacecraft that can rush through the cosmos at close to the speed of light. There has been no shortage of proposals: vehicles propelled by repeated blasts from hydrogen bombs, or from the annihilation of matter and antimatter. Others resemble vast sailing ships with giant reflective sails, pushed along by laser beams.
All these ambitious schemes have their shortcomings and it is doubtful they could really go the distance. Now there are two radical new possibilities on the table that might just enable us - or rather our distant descendants - to reach the stars.
In August, physicist Jia Liu at New York University outlined his design for a spacecraft powered by dark matter (arxiv.org/abs/0908.1429v1). Soon afterwards, mathematicians Louis Crane and Shawn Westmoreland at Kansas State University in Manhattan proposed plans for a craft powered by an artificial black hole (arxiv.org/abs/0908.1803).
No one disputes that building a ship powered by black holes or dark matter would be a formidable task. Yet remarkably there seems to be nothing in our present understanding of physics to prevent us from making either of them. What's more, Crane believes that feasibility studies like his touch on questions in cosmology that other research hasn't considered.
Fuel as-you-go
Take Liu's dark matter starship. Most astronomers are convinced of the existence of dark matter because of the way its gravity tugs on the stars and galaxies we see with our telescopes. Such observations suggest that dark matter outweighs the universe's visible matter by a factor of about six - so a dark matter starship could have a plentiful supply of fuel.
Liu was inspired by an audacious spacecraft proposed by the American physicist Robert Bussard in 1960. Bussard's "ramjet" design used magnetic fields generated by the craft to scoop up the tenuous gas of interstellar space. Instead of using conventional rockets, the craft would be propelled by forcing the hydrogen gas it collected to undergo nuclear fusion and ejecting the energetic by-products to provide thrust.
Because dark matter is so abundant throughout the universe, Liu envisages a rocket that need not carry its own fuel. This immediately overcomes one of the drawbacks of many other proposed starships, whose huge fuel supply greatly adds to their weight and hampers their ability to accelerate. "A dark matter rocket would pick up its fuel en route," says Liu.
A huge fuel supply hampers a spacecraft's ability to accelerate. Dark matter starships would avoid this
His plan is to drive the rocket using the energy released when dark matter particles annihilate each other. Here's where Liu's idea depends on more speculative physics. No one knows what dark matter is actually made of, though there are numerous theories of the subatomic world that contain potential dark matter candidates. One of the frontrunners posits that dark matter is made of neutralinos, particles which have no electric charge. Neutralinos are curious in that they are their own antiparticles: two neutralinos colliding under the right circumstances will annihilate each other.
If dark matter particles do annihilate in this way, they will convert all their mass into energy. A kilogram of the stuff will give out about 1017 joules, more than 10 billion times as much energy as a kilogram of dynamite, and plenty to propel the rocket forwards.
Even less certain is the detail of how a dark matter rocket might work. Liu imagines the engine as a "box" with a door that is open in the direction of the rocket's motion
Liu points out that the faster his dark matter rocket travels, the quicker it will scoop up dark matter and accelerate. Precisely how quickly it can accelerate depends on the density of the surrounding dark matter, the collecting area of the engine and the mass of the rocket. In his calculations, Liu assumes the starship weighs a mere 100 tonnes and has a collecting area of 100 square metres. "Such a rocket might be able to reach close to the speed of light within a few days," he says. So the journey time to Proxima Centauri would be slashed from tens of thousands of years to just a few.
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Have your say
google, wikipedia and even MS Word (though it did not know the correct answer) knew that you had misspelled the name of a star:
Promixa Centauri
should actually be:
Proxima Centauri
This comment breached our terms of use and has been removed.
This comment breached our terms of use and has been removed.
Who cares if it's spelt wrong!? People who point these kinds of things out are no fun to be around....great article.
Spell Checker
Thu Nov 26 11:41:56 GMT 2009 by Michael Marshall
http://www.newscientist.com
We missed that typo, apologies for that. It's fixed now.
I'm a bit disappointed that they left out the line "you might think its a long way to the corner shop, but thats just peanuts in space" which rounds the whole description of space off perfectly. Maybe theres a limit to the size of quotations before you have to pay royalty?
Yes, and what happened to "It's really big," without which the punchline about "You won't believe how vastly...etc" falls a little flat?
T'cha.
I am sure that other similarly curious people like yourself are very grateful for the correction.
It is a shame that you have been criticised for trying to help others find out more information on items included in this topic.
I guess there are blinkered people everywhere - even on NS
I think you spelled even wrong - It's spelled 'especially'.
An object traveling at 2/3 the speed of light has a kinetic energy equivalent to the rest mass of said object. Translation: the energy required to travel the stars in a timely fashion is comparable to the energy it takes to make the object out of nothing.
It's even worse than keep under 2/3 c for efficient travel Newton's third law and E=mc squared combined with the desire to stop at your destination. Produce a very dangerous combination cutting the maximum effective speed down to about 1/10 c, even with antimatter fuel.
The problems are with our accepted understanding of the universe, not with the universe itself.
Ask yourself, why is a black hole a special case? A Singularity? It forms from the same gases as all the other stars. The larger a star is the quicker it burns out and more likely it is to become a "black hole" rather than a white dwarf or "neutron star" but it starts off the same as the rest.
The idea of a black hole being a singularity, a special case, is right up there with the special case planets and their need for epicycles.
Extended Heim Theory can explain the "black hole" phenomenon and it makes intuitive sense. Under certain conditions photons can be transformed into gravitophotons, light energy into gravitational energy.
The stronger the magnetic field and the faster the matter rotates, the more photons get transformed into gravitophotons. A black hole star spins so fast and has such a strong magnetic field that all of its light energy is transformed into gravitational energy which is why a black hole can't be seen yet has a massive gravitational field.
Using a very powerful solenoid coil and a high speed flywheel we humans can replicate this natural phenomenon and travel amongst the stars for ourselves.
P.S. The American Institute for Aeronautics and Astronautics gave an award in 2004 to the team that sent in a paper on Extended Heim Theory and the proposed solenoid/flywheel experiment. That team has been giving presentations at the AIAA ever since.
Excuse my pea sized brain (I am an exchange student in first year from Promixa Sentoree) but if light can travel only at the spped of light and the ship is nearly at that speed, how will it's Star Trek sensors fare? Whill there be enough time to handbrake turn around a black holel in it's path? Who will have right of way? Will the sensor beam be travelling at 1.9 times the speed of light or will this just alter it's frequency?
I think it would be safe to assume that if we managed to build such a spacecraft, we would also be able to plot a course without flying directly into a black hole.
Which would be truly mind boggling, when you would have to develop a model replicating the relative movement of every object that could possibly cross your path on such a massive journey.
Subscribers can find a New Scientist feature about Heim theory here
(long URL - click here)
I thought most particles would go through the materials we can produce, what would we use as a reflector.If you can reflect 25% you need 4 times the power,and we would need very good shielding - or have a radiation burnt crew.
We need new science -ie force fields.
Force fields aren't new science.
http://science.nasa.gov/headlines/y2005/24jun_electrostatics.htm
Plus, I think this would be rather trivial considering the complexity of the spacecraft!
"1 million-tonne artificial black hole" as the power source. Well, nobody asked about the fuel wight. It a ship has to carry such atom core sized black hole to ensure propellant, this actually means that, although it carries only an atom core sized fuel, it drags 1 million-tonne of fuel. With such mass of any fuel, we could go pretty far away on a steady acceleration right? What is the required energy to push let's say 1000 tons of ship's mass in addition of at least 1 million-tonne weight black hole at the speeds near the speed of light? I doubt that even such micro black hole with is Hawkins evaporation will be sufficient for this.
If we neglect hypothetical journeys using wormholes, black holes, extra dimensions and other highly speculative theories, I can see only matter-antimatter annihilation propulsion system as more or less plausible solution.
Although connected to the great technological and scientific issues, there is nothing here which is theoretically not possible and it is only matter of our advance in science and technology to achieve this goal. Everything else is still more in the domain of fiction or science fiction than science itself.
Maybe LHC with its possible new discoveries about the very nature of the matter will in reasonable time offer some new possibilities, but so far, annihilation propulsion seems to be the most plausible solution for interstellar journeys.
Oh, and in addition to previous- Dark matter as propellant for star ships? We even do not know that dark matter exists. It seems to be there but are we sure?
For decades scientists were trying to find out the geometry of our Universe? is it flat, curved, open? Will it expands forever or should it collapse due to its own overall matter gravity pull? Before "dark matter" become widely accepted as the fact, we was assured by cosmologists that there is slightly less matter in the Universe than needed to start its contraction and collapse. So curved geometry which will bring us a new Big Crunch was ruled out.
What is now with estimated quantity of dark matter? It seems that there are out there some 6-10 times more dark matter than visible matter, so what? Do we change our opinion about geometry of our Universe? With such amount of visible and dark matter, the geometry of the Universe should dramatically change, bringing us close to curved, closed universe which could eventually collapse in a Big Crunch. But other observations indicate that it is still expanding? Where is the glitch? Do dark matter really exists? Or galaxies keep rotating without dispersing their material due to the strange geometry of space around them, not by the gravity pull of the dark matter. The idea of the dark matter which do not interact or weakly interact with the normal matter and interact only gravitationally looks pretty like pure mathematical construction and fiction in order to fulfill missing knowledge, and gaps between our theories and observations.
Offering idea of the star ship using dark matter which existence is not confirmed and is still speculative is also pure science fiction, not a science.
A 1Kg object traveling at 2/3c "I used around 67% c" would only have 31,999,279,384,000,000 joules in the form of kinetic energy.
The rest mass energy of that object going by E=mc^2 would be 89,875,517,800,000,000 joules.
It's total mass energy would be increased by a little over 1/3.
The kinetic energy will not exceed the rest mass energy until 86.7% c.
Even then this is not an upper limit for an anti matter rocket as the vehicle could have stages.
In the case of the dark energy rocket it's not carrying it's fuel.
Even fusion can top 10% c as in project Daedalus who's goal was to get a probe to 12%c.
this type of speculation is completely aimless. a 1 million-tonne black hole created by humans using a gamma-ray laser powered by solar panels 250 km across? and that's the only FEASIBLE way this guy sees as being able to travel the stars?
wow...just...wow.
Well, when would you build such a star-ship?
For colonizing an earth-like planet after we
had spoilt our own (thru for example global
warming)? That would mean it would be
worth-while, but would we be welcome,
if there were other civilizations abound where
we got...
Are you a telephone sanitiser, by any chance?
I don't know about him, but as a marketing student I am getting a bit afriad of this talk of interstelar colonisation and global warming. Next I might be told to take the first ship out with the hair dressers and store clerks to make sure we can get a hair cut and buy a coat when we get to this new planet.
We just have to get out there and find these other civilizations so we can have fun drawing crop circles and such.
What The Hell?
Wed Nov 25 20:52:40 GMT 2009 by Dave
http://d
so what did YOU come up with Mr. Feasibility? Wow...just...wow.
Well, obviously he isn't stupid enough to make idiotic hypotheses that we would never achieve unless our species survived for at least 1000-2000 more years (which is seriously unrealistic). Oh, and also, people who exert such ideas onto the fragile (yet simultaneously powerful) nature are either idiots, people who take hallucinatory drugs (metaphorically speaking), or people who have an above average imagination (which is a bit rare in our present time).
I thought you knew this by now.
Wow...just...wow...
"people who have an above average imagination (which is a bit rare in our present time)."
Approximately half the population have an above average imagination.
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