Slashdot Mirror
The Three Possible Classes of Interstellar Travel (forbes.com)
An anonymous reader writes: The stars call to us through the ages, with each and every one holding the promise of a future for humanity beyond Earth. For generations, this was a mere dream, as our technology allowed us to neither know what worlds might lie beyond our own Solar System or to reach beyond our planet. But time and development has changed both of those things significantly. Now, when we look to the stars, we know that potentially habitable worlds lurk throughout our galaxy, and our spaceflight capabilities can bring us there. But so far, it would only be a very long, lonely, one-way trip. This isn't necessarily going to be the case forever, though, as physically feasible technology could get humans to another star within a single lifetime, and potentially groundbreaking technology might make the journey almost instantaneous.
here is a working link thats not thru forbes. http://scienceblogs.com/starts...
This is a decoy link to Forbes Starts With A Bang column! Anonymous submission indeed.
Let's say a single lifetime is 100 years. Well above average, but whatever.
The nearest star to Sol is a little over 4 light years away.
So you have to go over 4% of c to succeed. Good luck with that!
Slashdot getting a cut of ad revenue from Forbes? They went downhill quick ever since Steve Forbes sold it to the Chinese.
Only a blank page.
No, I'm not going to enable Javascript on two dozen sites to see this shit. Post a real link or STFU.
This poses some interesting possibilities. Let us say for example that we do find human-habitable places in the galaxy, but they are very far away so we send generation ships. Now let's say that 150 years into a 300 year journey some seriously fast FTL is invented on Earth (I more than suspect it is not possible though, hope I'm wrong). They now just have a few years journey. Would we send a ship to pickup the people on the slow boat? It would be kinda nuts to finally get there and find humans have been there for shy of 150 years. Then again if it's wormhole technology we would probably have to drag half of the device to the other planet to begin with.
Brought to you by Carl's Junior.
" with each and every one holding the promise of a future for humanity beyond Earth"
Really? Really? This is horseshit. The future of humanity is right here on Earth. Evolution is still happening, and just like there wasn't a humanity a million years ago, there won't be one in another million years.
So what?
Even on a text of a wholly speculative nature (something that a piece like this would inevitably have to be), I would expect something more definite. The author simply fled from the difficult (and interesting) part. He didn't even come close to outlining the "constraints" mentioned on the first paragraph, as well as the 'physical feasibility' aspects referred to in the original post. As it stands, the article is wholly irrelevant. (Please spare me the "a la thundercats" thing. And the image from the double-slit experiment in Bohmian mechanics would merit some context at least.)
1. Generation ships
2. Nuclear propulsion, antimatter propulsion
3. Science fiction (warp drives, transporters, etc.)
Anyway all of this seems moot to me. We can already freeze human beings for long periods of time. It's called 'embryo freezing' and it's commonly used.
A fool and his hard drive are soon parted.
So it looks like I won't be reading it. Such a shame.
Did it ever occur to you people that we could/can travel to distant locations via quantum entanglement? No?!
I didn't think so. I have to sometimes wonder just who the hell do we have working in these fields.
Randy AB5NI
First, the link goes to forbes.com which blocks any browser with an ad-blocker. http://fortune.com/2015/12/22/...
That's ironic and hamfisted, but particularly in light of Forbes own September 2015 article that says ad blockers won't hurt online adversiing. http://www.forbes.com/sites/ro...
Second, the summary of this "anonymous posting" says:
The stars call to us through the ages, with each and every one holding the promise of a future for humanity beyond Earth
No. They don't. Humans evolved to live here, on Planet Earth. Not on our own star, or on any other star, and humanity's future is right here where we have an entire planet we were built for... not on a foreign star.
How CRAZY would we think it of MONKEYS who want to live underwater? We'd marvel at why happy jungle monkeys would leave a comfortable environment free of most predators and full of food to go somewhere hostile where they can't breathe, their temperature will decay, and without machine aids would soon die.
That's no different than us claiming that other stars[sic] becon us to live there. No. There's great scientific exploration to be done, and we could even establish limited outposts where machines keep us alive despite the harsh vacuum and cold [or relative heat] of space. The ISS is a good example of one such outpost. However, there's no "interstellar colonialism" happening because the rest of the universe is inhospitable.
Saturday... when an "anonymous" (friend of the editor?) posts something that makes no sense, and links to a site that's about as close to a paywall as you can get.
Ehud
In one of Lem's books, the protagonist (Ijon Tichy) picks up the Popov's first radio signal somewhere between stars.
In Soviet Washington the swamp drains you.
You can make human colonies in faraway places without humans having to travel there. In 200 years, I expect that we will be able to reproduce entire ecosystems from data alone. That data "recipe" could be packed into a rather small package and transported slowly to many distant solar systems to germinate into diverse islands of life and civilization. Once this becomes possible, I really doubt that nobody is going to get around to doing it. We will need an autonomous asteroid miner, ore processor, and a primitive 3D printer to produce other, increasingly more precise and specialized machines. To do their job, all they will need is the right software, lots of ordinary rocks, and the energy of a nearby star. The system will be able to build anything that we are able to build, including viable cells with human DNA, and the technology to gestate them. With careful planning, I suspect that the starter kit will fit inside the volume of a shipping container. Since the data/software will be stored in a very stable medium, these seeds will work even if their trips to the stars are slow. But if we spam the galaxy with these little seeds, the future of humanity will eventually be pretty grand.
Is Interstellar Travel Possible
For generations, when we looked out at the distant stars, we could only wonder whether there were planets and the conditions for life-as-we-know-it around them. The past 25 years have brought forth a revolution in planet-finding, with thousands of known, confirmed planets, including many of potentially habitable, Earth-like worlds. But could we ever get there? Reader C. Vidal wants to know:
Do you think interstellar travel is possible (by any civilization). It seems to me that all possible solutions are one way trips.
When it comes to interstellar travel, I definitely do think it’s possible. But there definitely are constraints, dependent on how we’re willing to do it.
1.) Conventional Technology. If all we’re willing to use is the technology we have today, we could, theoretically, reach another star. By building a large enough ship that we could have a sustainable mini-civilization — a “generations ship” of sorts — we could boost up to speeds of tens or maybe even hundreds of km/s, growing our own food and recycling our water along the way. An alternative would be to develop cryogenic freezing-and-thawing technology, where humans, plants and other living creatures could be transported in suspended animation (a la Thundercats), only to be reanimated and revived upon arrival.
Some “standard” concerns, like collisions with interplanetary/interstellar objects, like rogue asteroids or planets, are actually not particular causes for concern. These objects — although plentiful — are so low in density that strikes even between stars are extraordinarily unlikely, even on million-year timescales. A trip like this would take hundreds of thousands of years to reach the nearest star system, and seems to be within reach.
But this is the ultimate one-way trip, and not at all a satisfying solution.
2.) Future Technology based on known Physics. But if we’re willing to consider other technological possibilities, we can certainly do better. In particular:
Fuel improvements: rather than using chemical-based rocket fuel, which releases about 0.001% of its mass into energy which can be used for thrust, we can use nuclear-based fuel (which is about ~1% efficient), or even antimatter-based fuel, which would be 100% efficient.
Thrust improvements: if we can transport large amounts of matter-and-antimatter for fuel on board a ship, we can continue to accelerate along our journey. Since humans can withstand (and even prefer) thrusts that are similar to Earth’s gravity, we could point our ship towards our destination, fire the thrusters at 9.8 m/s2, and when we reach the halfway point, point the opposite direction and fire again, decelerating until we reach our destination.
Time improvements: because this will bring us close to the speed of light after only a few years of acceleration, we could get to pretty much any star we choose in no more than 20-40 years of travel.
This would be great, because we wouldn’t need a ship to last for generations. Sure, it’d have to survive traveling at very high speeds through the interstellar medium, but a strong enough magnetic field (and a map of neutral gas clouds to avoid) should take care of that. And if we can master the cryo-freeze technology, we wouldn’t even need to bring resources other than seeds to plant and eggs to incubate upon our arrival.
The downside, though, is that a one-way journey might only take a few decades from the perspective of the person on the journey, but that’s due to special relativistic time dilation. If we’re visiting a star hundreds or thousands of light years away, then hundreds or thousands of years pass here on Earth. Even if we make this journey, our prospects of communication with anyone still on Earth (assuming there is still anyone here on Earth that far in the future) will have to be with their distant descendants. The journey need not be one-way for the people who go,
And by solution I mean completely eliminating any and all references to Forbes pages from your browsing experience.
If you have Adblock Plus and the element hider add-on, create an Element Hiding rule as this,
##A[href*="index"]
In case that gets mangled by the post processor, that's the following all on one line, no spaces:
PoundSignPoundSign
Capital A
LeftSquareBracket
href
asterick
Equal sign
Double quote
forbes dot com (the usual way)
Double quote
RightSquareBacket
That will completely obliterate any Forbes links.
The only method we could have access is generation ship. And access is a big word seeing how much resource we would need and some problem at the moment seem quasi intractable. The rest, is speculation as we have no way to create anti matter and store it in meaningful quantity and speculative tech is just that : speculative. This is just a fluff piece from forbes. Probably something they have in stock for long holidays while writers are away.
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
You don't aim for technology to travel to another star within a human lifetime, you extend human lifetime. It's a hell of a lot easier to make humans live thousands of years than it is to bend the laws of physics and pack enough energy into a small enough package to travel 20 trillion miles. The human system is a lot more finite than the laws of physics, therefore it's almost certainly an easier puzzle to solve.
Extending human life and using stasis is the way we will travel to other solar systems, not warp drives and space folding.
http://abcnews.go.com/Technology/story?id=99113
https://www.youtube.com/watch?v=1dZveoBfiww -- 1:34
4I2C
What worthless blog spam. I remember when /. had long interesting articles. Not short boring b.s.
FWIW the only validated method is slower than light, and, due to energy considerations, at considerably less than 1G. There are, IIUC, speculative ways around the light barrier, but they're all quite dubious. Perhaps one of them would work, but not with any foreseeable technology.
That said, there could be some kind of breakthrough, eventually, but it hasn't happened yet. Were I to bet, I'd bet on ion rockets with around 100-200 pounds of thrust as the way most likely to succeed. And this might be doable with fission power, but may well require fusion. (Light sails require either an even lower thrust, or trusting someone back home to keep your engine running for several centuries.)
For various reasons I don't expect any group to set out aiming to reach distant stars, but rather aiming to live off the Oort cloud, and eventually deciding to make the jump to another one. Or via a series of loose planets. When resources are rich, build a second ship and then the two of you go your separate ways. Eventually some of them would end up on other solar systems, but this would just be because that's where resources were thickest, and nobody was defending them. (Sort of "life as a von Neuman Probe".)
N.B.: For various reasons these ships would need to be quite large. A question that hasn't been answered is "What is the minimum number of people required to maintain a technological civilization?", but presumably laser communications would be possible and cut down the minimum number. So say a stable population of 100,000 or more. And not too crowded, as that causes increased unrest...and it's already going to be stressed as there's going to be needed a firm limit on the size of the population. Virtual reality is also going to need to be well developed to defuse social stresses.
P.S.: Don't suggest suspended animation. Interstellar space is where these people are going to live. Planets will only be occasionally visited for special reasons. And will probably only be visited by robots.
Now give me a magic space drive and all this changes, but I'll believe it when I understand that it can actually be built.
I think we've pushed this "anyone can grow up to be president" thing too far.
Seems Forbes found out about getting around the clickbaits. The scienceblogs link now just has a longer version of the summary with pictures added, and a link to the clickbait version.
If you insists[sic] on using a plugin that makes your browser non standards compliant...
I'm sorry but the standards you speak of don't require anyone to load all content. That's the choice of
the user and his/her browser. There a standard for HTML https://html.spec.whatwg.org/.
There is no standard on "how to browse a web page".
Specifically, it's not required to load the main page ("index.html/php"). (You can deep-link instead).
It's not required to load everything linked to by that main page. It's not required to load anything at all.
It is assumed when one visits a site with a web browser one will load up the index page and all subsequent
referenced links, but that's not in ANY standard; a browser that doesn't do that is NOT out of compliance
with standards, and further more if we go by de facto standards then the standards IS not loading ads.
Have a happy browsing day. Don't confuse "standards compliant" with "being required to load an
entire page and all its referenced links."
E
How did this get posted the the /. main-page? Forbes is a magazine about money, with a known editorial slant. The article's author apparently discovered science fiction novels, and then perused Wikipedia for all of his sources (except for a pic or two from NASA/JPL, which are public == free).
WP is great, but for some bozo to lazily summarize a few WP articles, all written by many volunteers, including their fair-use images, and then selling it in a for-profit magazine w/website is disgusting.
It's totally against everything that Wikipedia is about. Ah, but it is also everything that Forbes is about. So there is that.
Only for those not using web protections.
Everyone else gets either the Forbes welcome/login page which nobody with commonsense will use just to read some random article, or else a completely blank page which highlights the incompetence of Forbes devs who can't even make static content render in all browsers.
It would be funny, if it weren't so sad for Slashdot. What little reputation remains is plummeting because of the stream of unreadable Forbes articles. It's a perfect illustration of how not to design a website, assuming you want to attract readers instead of strongly repulsing them.
Due to the fact that elements are uniformly distributed throughout the universe, only luxury goods will be of any value in interstellar trade. http://www.costik.com/inttrade... This means that no company or government will ever see any point in interstellar travel.
By interstellar medium, does the author mean "space." That is, dimensional space but a very hard vacuum.
Isn't interstellar space somewhere around 10^-25 Torr, or roughly one atom per cubic meter? (I did not check my math for the conversion, so go easy on me.)
For comparison: On Earth, we can build usable vacuum chambers that go down to about 10^-13 Torr, at room 'temperature'. Lower than that, hydrogen just seeps through your chamber walls as if it they were a sieve. And a single fingerprint can out-gas for a month.
There is NO interstellar "medium". It is called space; void.
First Class
Business
Coach
It seems to me that the biggest bugaboo of space travel is conservation of momentum. A consequence of that is that the center of mass of a closed system (and that 'closed system' might be the whole universe) remains the same. To send a ton of mass to Alpha Centauri, you have to send the equivalent of a ton of mass 4+ Light years in the other direction (or more mass for a shorter distance or less mass for a greater.) This is what rocket exhaust does, and the only time I've ever seen anyone talk about it is in Isaac Asimov's novel "The Gods Themselves", which is what made me start thinking about it.
I have imagined a space faring civilzation creating something like a space equivalent of a cable car system, where draggers would be racing back and forth between solar systems, and snagging cargo to go in one direction while other cargo got snagged to go in the opposite direction, to maintain the center of mass. If you depended on reaction mass and wanted a lot of travel you'd end up with supernova style explosions of mass out of your patch of space.
On a completely different topic, I saw a video of Vint Cerf where he talked about developing a communication protocol for interstellar space, something that might not be realized for 100 years. I thought that was an interesting thought. Ultimately, I reckon it's going to be mainly information that goes back and forth, if anything.
PS!
(Is anyone else having a problem that everytime they post or moderate, even though they are logged in, they get turned into an anonymous coward? That's what's been happening to me the last few days. If I click on 'yell for help' I'm an anonymous coward again and have to create an account. Bah!)
Class 1 also includes sending frozen people, etc., but the article doesn't put any more detail into it. It also doesn't include the fact that we don't have a clue how to build a long-term stable ecology that a generation ship or even a Mars colony would need.
He also doesn't include Class 4 - Robots/AIs instead of canned meat humans. That's the most likely option, and building a drive that will ever get to another star is still in the "sufficiently advanced technology" category, not actually conventional technology.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Before going speculative about teleportation and work holes, but past antimatter propulsion is a miniature black hole power source. A million metric ton black hole would radiate about three terawatts (with less mass dramatically raising the radiated power) and you could use magnetic fields to pump in material from in front of the ship. It would eat anything even photons and nutrinos. It should be able to power a decent sized ship and would be the most ideal power source known to modern physics.
And with the quantum vacuum thrust engine, which would not require the mass of any fuel to be brought on board, the kind of lengthy accelleration times involved to get up to such speeds should be entirely feasible.
File under 'M' for 'Manic ranting'
And the winner is...
the one that got the most "likes" on Facebook!
Happy light new year, in a galaxy that never even heard of a pageant called Miss Universe, and yes, the winner was whats-her-planet again oh don't bother it's Mostly Harmless
WARNING: Smartphones have side effects--most of them undocumented.
This poses some interesting possibilities...
Sci-Fi writers have been looking at these paradoxes from the beginning.
The short answer is that interstellar emigration implies that your back is against the wall. It is now or never kind of thing --- with a very good chance you will doing everything you can to conceal your true destination.
Methuselah's Children (1941, 1958)
Rescue Party (1946)
Battlestar Galactica (2004)
The quantum vacuum thruster might be a dead end - right now it's just a few interesting results that are likely just the result of experimental error. It's going to need a lot more confirmation yet. Even those few interesting results haven't made peer review journals. Even if it does pan out though, and the physics actually works, it's still not fuelless. It's propellentless, but it does need energy, and a lot of it. Solar panels are essentially useless in interstellar space, so you'll still end up slowly burning through a stock of whatever power source you bring along - probably something radioactive.
... is non-biological survival, as described in Arthur C. Clarke's Rendezvous with Rama. (1973) Rama is also a reminder that you don't need true "artificial gravity" or even a "space drive" if you can build on the grandest of scales and don't particularly care how long the journey will take or that it will almost certainly be a one-way trip.
I click on the link using IE 10 with AdBlock Plus with EasyList enabled which takes me directly to Ethan Siegel's blog for Forbes. Loads instantly with all images. No adds. No problems.
Fuck habitable planets. Seek out Nebulas. If you have developed the technology to live in deeps interstellar space, why the fuck would you ground yourself again to lazy terrestrial living when you could instead continue to construct massive space platforms for your existence using the gravity-tax-free materials of nebulae?
It makes no fucking sense, other than, "Herp, lemme keep thinking like a land lubber 'bout life on the sea". Just literally retarded thinking which has been obsolete for hundreds of years.
and we will be able to go anywhere we want. Develop a machine that can scan an object or living creature and store all the necessary information needed to recreate what was scanned.
We would be able to send all the equipment and AI controlled robots to terraform and convert distant planets into suitable habitats for humans. A replicator is then setup and the speed of light is the only delay in the arrival of humans.
How we get to that point before destroy the planet and blowing ourselves up with nukes, I cannot say.
I dearly hope so. For those who can barely tolerate the rest in steerage, imagine decades with your fellow man!
Come to beautiful Alpha Centauri, and stay at the Holiday Inn. It's within walking distance to McDonald's, Wendy's, and Wal-Mart.
The writers are also forgetting that to even get to the point where such travel could ever be seriously considered, humanity will have to pass through a transition perhaps as equally debilitating as warping space-time, namely a solution to the human induced global warming and biodiversity crises. Given that solutions to these problems at the current rate of warming will have to take place within the 1-200 year period we may still have left to resolve the most devastating consequences that will almost certainly cause human extinction. Because the window to solve such issues is rapidly closing, it is virtually certain that the biological constraints are going to be far more serious than those presented by the potential physics making interstellar travel infeasible.
It is more than a bit ironic that the worry about crashing into some lifeless deep space object that is either in the way or just ultimate destination is given more concern than the problem of actually turning planet Earth into one of those lifeless deep space objects before potential space travelers could even leave the ground.
Even if you can get up to speed, how do you dodge all the comets, and space gases which would rend your ship when you're at high speed? Interstellar travel is harder than a lot of people think.
It's at best lightspeed, according to all known physics.
at the current rate of warming will have to take place within the 1-200 year period we may still have left to resolve the most devastating consequences that will almost certainly cause human extinction.
If the worst case predictions happen the earth will not support more than a small fraction of the 7 Billion people, but certain human extinction? Tone it down a little. Life and certainly a number of humans will survive, the earth has been through much worse changes.
You're wrong, you just made something up that aligns with your expectations. The document you linked to has a section discussing "User agents with no scripting support", and it also briefly mentions that image loading can be disabled, but otherwise it's completely prescribing how the browser should behave. Just search the page for "the user agent must" and see how many matches you get.
Seems impossible!
No, most stars don't have earth-like worlds around them. We think we might have found four within 1500 light years that might be in habitable zone, but whether they have water or atmosphere is unknown. We may find there are zero habitable planets within 1500 light years of earth
The three classes are...
First class, Economy, and Cargo.
Where wine and spirits are at a premium in First Class, space is at a premium in Economy, and air is at a premium in Cargo.
And, all of them are too expensive for you :)
lol quantum vacuum thrust? wtf is that, oh right, EMDRIVE, basically a radiation wave motion engine, and its needs fuel, power, but its very efficient, the only problem is not that it's not feasible, but that it upset the poor academics who can only ascribe to a probabilistic quantum theory, because shit the maths for describing the pilot waves is difficult like. Broglie and Einstein were right. God doesnt play dice. I wonder when people will notice that just because a mathematical model can predict n-th dimension, doesnt mean that your model exists as a physical manifestation. Its a freakin statistical model at best to predict the motion of so called "quantum" particles, but for error correction always assumes the invention of new particles. There is a way to describe the full mechanism for the motion of something, but it turns out that it's alot more difficult then predicting the probability of position. What Schrodinger realized is that in the current model you cant calculate the position and velocity of something because you cant derive classical motion from a friggin statistical model. lol 1/10000 chance that something will be at position X with a y% certainity tells you very little about the velocity, more properly you cannot derive a formula for velocity from a formula of probabilitic position .... TL:DR i need more liquor
who pays to have their shit endlessly posted on slashdot logs in as an AnonymousCoward to submit yet another StartsWithABang story, Is it still garbage that doesn't belong here?
Yes. The answer is yes.
And how do you accelerate black hole together with a ship? Attach few sticks to it and push it as rest of spaceship accelerates? Plus, if you count million tons in the mass of spaceship, it is not 'decent sized' anymore...
I have a question thats's been bothering me for a long time now. It's obvious to me that a collision with a large object in space is easy to both predict and avoid, but what about small pieces of debris? How does a spaceship detect and avoid collisions with miniscule pieces (say 5-10cm in diameter), since even such a small piece of rock could most likely cause critical damage when it hits a spaceship at something like 20km/s.
Any ship embarking on interstellar travel in the near future using any of the first two methods (a generation ship using conventional propulsion or a hyper speed ship using fuel, thrust or time improvements) is likely to be beaten to the destination by a explorers leaving earth hundreds of years later using superior interstellar travel technology.
Although a generation ship carrying massive amounts of fuel and a gigantic solar sail could boost up to speeds of hundreds of km/s, it could still be thousands of years before such a ship reached even the nearest star system... and then it would have to expend vast amounts of stored fuel to slow down, slip into a suitable orbit around the local sun and commence a search for potentially habitable planetary bodies, with no hope of ever being able to generate sufficient thrust to move on to a further star system, should the first prove to have no suitable planets to settle on.
Consider the rate of communications, propulsion, etc. advancement that would have taken place in the intervening 5000- odd years between the departure of interstellar explorers leaving earth over the next 100 years and those leaving earth, say, 2-3000 years from today. How would our present day explorers even communicate with earth using 5000 year old communication technology - heck, it would be tough to communicate with just 100 year old technology, let alone 5000 year old relics. And suppose the mission was successful... later and technologically more advanced departures travelling in the same direction would have to make first contact decisions not too dissimilar to the ones we make today about isolated peoples such as isolated tribes in the Amazon rain forest - only it would be more similar to travelling back 5000 years to the bronze age - round about the time when Stonehenge was built and Papyrus invented.
Future propulsion technologies, would not fare much better. The more efficient the propulsion technology, the faster the rate of travel. This might appear to be the answer, except that special relativity would mean that while time slowed down for the travelling explorers, hundreds or even thousands of years could pass here on Earth for a few years of time for our hyper-speed interstellar travellers. So, while interstellar travellers travelling at hyper-speed could reach their destination in a single life time, they too could be beaten to the punch by a later departure hundreds of years later (or just a months days later in time passed aboard the interstellar ship).
That special relativistic time dilation thingamajig can be a bitch!
Just my thoughts and observation
I'm not claiming to know how to build one but I do have some basic ideas as to how it would work. Black holes conserve electrical charge so you could electrically charge the black hole for one. Also material falling in tends to generate extreme magnetic fields, you would likely use that principle as well in conjunction with the extreme surface gravity which is too short range to work on the order of meters effectively.
But you left off the more important one and that is how do you keep it fed when the radius of the horizon is 10^-17m and the surface temp is 10 billion degrees? I'm not entirely sure but I would think there is a way using the magnetic fields to confine material/particles until they get within an extremely close distance and gravity takes over.
1. You ain't gonna see it (generation ship)
2. We ain't gonna do it (radical improvements to current technology)
3. Sorry, no magic (bullshit)
Time dilation isn't a bitch, it's slowing down time for the traveling explorers which is *helping* compared to Newtonian physics.
I don't even travel to the clothes- or food-shop anymore.
I think I'll wait until Amazon.alpha_centaury delivers.
What the article says is that there are three possible ways to do interstellar travel.
#1 is a generation ship. This travels at a speed well below light and takes hundreds of years to reach nearby star systems. The duration of the trip means that the people who originally board the ship die on board; it's their descendants who reach the destination.
#2 is a near-lightspeed (NAFAL) ship. Relativistic time dilation makes it possible for the original crew to reach the destination, and some form of hibernation might be used to stretch that farther. But the trip still takes hundreds or thousands of years from the point of view of an Earth observer.
#3 is future technologies or loopholes: warp drive, wormholes, etc.
Nothing new here for science fiction readers. All three possibilities have been done many times in the literature.
For Christ sake.
This would also assume that those "later generations" in fact still exist on Earth or any other body in the Solar system. That may not be the case, due to either a man-made (environmental, genetic, "singularity", war, religious "I kill you!" craziness) or natural disaster that wipes out humanity.
When the copyright term is "forever minus a day", live every day like it's the last.
Was this slashdot submission just a glorified "hey let's talk about space again!" attempt?
If we violated known physics we could do foo. If we could teleport we could do bar. If we could travel FTL we could do baz.
Well if I farted gold dust I could be rich. Next let's get a slashdot post about what we could do with a BAJILLION GAZILLION dollars, world piece, and flying puppies.
Trips measured in thousands of years are non-starters. Assuming your civilization is making progress, at say 1-2% a year, then it does not make sense to plan trips much longer than their inverse, or 50-100 years. Using the 2% example, in 35 years you expect to have a ship twice as fast, which in another 35 years will pass the slower ship (traveling 35 years at 2v, while the slower one went 70 years at v = same distance). So judge the pace of technology, and if it is improving, wait until you can build fast enough ships. If technology plateaus, then you might as well go ahead and launch with what you have.
The best propulsion system I know of (and I wrote a wikibook on the subject: https://en.wikibooks.org/wiki/... ), is using the Sun as a gravitational lens to focus a very powerful laser on the ship. The ship uses the energy to power a particle accelerator. This has better performance than matter-antimatter propulsion because:
* Antimatter annihilation is theoretically 100% conversion of mass to energy, but storing the antimatter is likely to require massive overhead. So the system level matter to energy conversion is going to be much less than 100%. I'd be surprised if you could reach 10%.
* If the energy is coming from an outside source like the Sun, there is no upper bound to how much you can use, even more than 100% matter to energy conversion.
* If your fuel is accelerated to relativistic speed in a particle accelerator, then thrown out as exhaust, it will gain mass according to Relativity. So you can eject more mass than you start with in your tanks.
We know that gravitational lensing works, astronomers use it all the time. Since the Sun makes an enormous lens, it can focus on a small target, even at interstellar distances. To slow down at the end of the trip, keep your beam collector pointed at the Sun, but flip the particle accelerator to point forward,
Both black hole and antimatter can in principal get you near mass energy equivalent (not better of course), but both have serious technical issues:
Antimatter is much easier. Still it seems impossible to produce with high efficiency (> around 1e-4) because anti-protons are unlikely to emerge from any interaction . Mostly you get mesons which decay away. Once you have anti-protons its very difficult to convert to anti-hydrogen and collect the atoms. Positrons can in principle be produced with good efficiency, but there is no neutrally charged, stable way to store them (positronium doesn't last). Even for antimatter atoms, storage is problematical, One can imagine storing frozen anti-hydrogen or something, but it seems difficult to manipulate, and difficult to cool enough to keep the vapor pressure low enough to avoid unwanted heating.
Black holes are a LOT worse. Small black holes - say the mass of a mountain - radiate a lot of power, but that radiation increases very slowly, then suddenly increases until they explode. The radiation is so strong that there is no way to get matter into the black hole - its gravity isn't strong enough.
Once you get to planet mass black holes you can generate power, but they are rather awkward to carry around (being the mass of a planet!). Its also not at all clear how to build a small black hole. (one that doesn't evaporate almost instantly). Below ~solar mass, kilometer scale black holes, it isn't at all obvious how to get high enough densities.
I'll bet I can sum up the "Three Possibilities" without even reading the article.
1. Ion Thrusters - work nicely, in widespread use. Lovely tech. And if they have twin engines, you can technically call them TIE fighters.
2. EmDrive (or the "Microwave Thruster") breaks a few of our preconceptions, but seems to work. Will probably get installed all over satellites to keep them on station, and advanced ones might slowly push probes around the system, once the arguments about how they work are over with.
3. Alcubierre Drive (the famous "warp drive") which assumes that since spacetime is bendable, then one day we might get the tech to shrink it in front of us, while expanding behind, and we'll 'ride the wave' at >C. Current lab experiments use big capacitor arrays to move lots of energy around quickly and see if perhaps the metric tensor goes wibbly more easily than we expected. So far, No.
Sadly, this omits a couple of novel and really quite achievable techs, like VASMIR, solar sails, and 'magnetobubble' drives.
Howd' I do?
Jeremy Lee | Orinoco
Even a hundred million ton black hole only produces 3 thousand watts, planet sized ones generate far far less than a watt. It is not a linear relationship as you said.
Yes it is a challenge to feed it as I have posted above, with a surface temp of 10 billion degrees in the above case. It's true in a low pressure medium the temperature will overcome gravity. However, you may be able to use a combination of magnetic fields and charged particles to feed it, similar to a particle beam at the LHC, overcoming the thermal radiation. Theoretically you could even feed it neutrinos or anything and it would radiate 100% efficiently.
Its a pretty tricky feedback: I think the power goes as 1/m^2 , I'm too lazy to figure out what sized black hole generates enough power to accelerate at say 0.01G, but its going to be pretty small and really hot. You will need a beam of low energy matter (where low energy means C) that can be focused into the black hole. Its not clear even neutron star material is dense enough.
Well as you say "it should go without saying" but then you went ahead and said a bunch of stuff like self-sustaining other planets and that's just plain old science fiction. As for humans evolving to chase antelopes, well we now chase after cows, pigs, and chickens. Dogs in some parts of Asia. Sometimes we make it less sporting by raising them in areas easier for us to kill them in. We're still chasing the animal meat tho.
If man were meant to fly he would have been born with wings. However, through technology we put him in the air for a short period of time at a great cost of natural resources. That actually has a purpose -- to get said man from point A to point B in a short amount of time.
None of that applies to colonizing every single other planet in the world where we can't breathe, can't drink, can't eat, cran't grow food, and while we could get around some of that with technology (much like we fly today despite lacking wings) it wouldn't be for any purpose other than science. If you think that some global catastrophe on Earth means man would create a "self-sustaining" life somewhere else, I suggest you go back to your "go without saying" because what you're saying isn't going.
To be fair you can get back all of your energy of the beam including kinetic so to me it isn't clear you need it to be low speed particles. Anyhow it would be hard to feed and certainly far far harder to produce one in the first place. Agreed it's much harder than antimatter propulsion but definitely easier and far far less energetic than wormholes or other questionable stuff.
They suggest movement of matter through quantum entanglement. Which ignores all current understandings of how quantum entanglement works. It's like suggesting that since we can fire rockets we can travel faster than light.
Niven had a similar idea. Of course, the scale was a bit larger.