Slashdot Mirror
Can We Travel To That Exciting New Exoplanet?
An anonymous reader writes "The news last week that exoplanet Gliese 581g may be in the 'Goldilocks zone' and could therefore hold liquid water and alien life got everyone all excited, with good reason. A potentially habitable planet — and only 20 light years away! But to put things in perspective, here are a couple of estimates on what it would take to travel to Gliese 581g. One scientist puts the travel time at 180,000 years based on current space flight technology, while another explains that it could be quite quick if we build a matter-antimatter drive, and can figure out how to bring along 530 times as much mass in fuel as is contained in the ship and cargo itself."
That is one HELL of an assumption. Considering that the fastest space vehicles ever created took 3 months to travel a mere 8 light *minutes* (somewhere around one-16000th the speed of light), the assumption that we will ever reach even a significant fraction of the speed of light with a vehicle created anytime in the conceivable future is a bit of an overstretch to say the *least*. At the speed of the Helios probes, that journey to this planet would take over 300,000 years, BTW. So even McConville's 180,000 year estimate is a bit optimistic.
And that's not even throwing in the navigation difficulties (that's going to require some epically precise calculations), the damage such a long trip would inflict to the craft with radiation and micrometeorites, the need for braking when you get there, etc.
Interstellar space is a big VAST empty that few people appreciate. When I was a kid, all the science fiction and popular misinformation made it sound like the next solar system started right at the edge of our own. It was only when I got older that I realized that our solar system is just a tiny dot in a huge sea of lonely empty. The scale of distances between solar systems is difficult for the human mind to even appreciate.
SJW: Someone who has run out of real oppression, and has to fake it.
Well hell, if we develop wormhole technology, we can open a gateway, visit Gliese 581g, and be back home in time to watch the next episode of Fringe. Can I be quoted in the Discoblog too?
Project Orion could get us there.
Let's make sure first that it has, you know, oxygen, and not one of those 95% carbon dyoxide air content some younger planet lacking vegetation may have. Or one of those fancypants sulfuric acid atmospheres that melts your lungs.
Damn you, Enrico Fermi, and your infernal paradox. Damn damn damn!
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
How long would it take at warp 6, Ensign Chekov?
http://alternatives.rzero.com/
Just convince some corporation that it has unobtainium.
Is it just my observation, or are there way too many stupid people in the world?
Assuming it takes 100 years to build everything we need to make this flight, by the time you get there it will be 178,570 years after the group that took 1000 years to build the matter/antimatter ship finished their project.
Do really dense people warp space more than others?
http://www.telegraph.co.uk/news/worldnews/europe/france/8044599/Jerome-Kerviel-will-need-177000-years-to-repay-5-billion.html
Well - he'll have had 3000 years to enjoy his income at that point!
--------------------------------------------- "In the end, we're all just water and old stars."
Why do we want to go there ? Poor aliens if we can go there. May be there are far far away on purpose.
star gates are much faster!
more like a few seconds.
Technological limitations aside, this is the first time in several hundred years that we have had a further shore to sail to... a place where no man has gone before, as the saying goes.
That has to count for something.
For me this is the most profound discovery in the history of us. Without hyperbole. The only thing I can see superseding it is, of course, the confirmation of life itself out there.
I think we need a further shore... and I'm glad I lived to see a new one.
Years later, a doctor will tell me that I have an I.Q. of 48, and am what some people call "mentally retarded".
How about sending some targeted "Hello world" transmissions towards that object first? If they have any intelligent life and a SETI program in place, they may hear us and answer back.
Banu
Would it not make sense to communicate first? Radio at 20 light years is a 40 year round trip. You never know, somebody might answer with instructions on how to get there quicker.
Hey! That's given me an idea for a great film. Is Jodie Foster available for the lead?
make a ship that contained the necessary fuel and so on to get there in one human life span, vital systems in the ship would almost certainly malfunction and the crew would be stranded until they died or something. People need to realize the only way we're getting off this rock is with nanorobotic manufacturing. Nanorobot constructed ships would be smart, and self-repair, fixing any problem that arises. If congress would dedicate a small fraction of that $25 billion NASA is getting to study rocks in outer space to nanorobotics, we'd get indefinite life-spans, space ships that could travel to the Andromeda galaxy never mind a star 20 light years away, an end to poverty, disease, crime, and so on. I suggest everyone read "Engines of Creation" by Drexler, it's free to read and posted on the web. http://e-drexler.com/d/06/00/EOC/EOC_Table_of_Contents.html
"...I think the Microsoft hatred is a disease." - Linus Torvalds
You are correct, but just a mere few hundred years ago the fastest we could move was a dozen or so miles in a day. I am optimistic that if we don't manage to destroy ourselves we'll find means of providing energy and types of propulsion that would seem like magic to us today (kudos to A.C. Clarke for the reference).
Why do we need to go away when we still have to colonize about 80% of our planet?
The fantasy to live on another planet is irrational.
Love many, trust a few, do harm to none.
What I find exciting is the prospect of a lot of young minds trying to figure out how to get a probe there with the capability of communicating back (within a reasonable time frame) what it finds. And then the science, if it is a habitable planet, of trying to visit it.
We need a new catalyst to spark imagination and an intense drive to succeed in the sciences.
Even if it is impossible to venture there, the discoveries and new technologies that we _do_ develop that doesn't quite reach the goal, but is above anything we currently have... Exciting!
I bet in the next 1000 years humans could figure out how to make the trip at half the speed of light (40 years).
Everyone is forgetting about Project Orion.
...
Sounds like I'll need more than a good book for this trip...
We aren't, QA. We're hedging our bets. Have you considered that unless you want immortality to be restricted to people with the wealth of Bill Gates, we'll pretty much have to develop a means to get off this rock pretty much the day we develop clinical immortality? The oceans are big, but we went from a billion people to 6 billion people within a century or two without immortality. The oceans just aren't big enough to support a civilization of a trillion immortals.
Meantime, while someone else works on life extension, we're workin' on making sure there is somewhere to go. Easiest way to do that is have a bunch of frozen cells in the core of a space probe, and lob the probe towards the nearest suitable star, and let the robots wake the cells up in 10-20K years. A ship full of algae could go first, and a ship full of human embryos - woken and taught by robots - could show up a few centuries later.
We space nutters would also prefer if we get to see the rocks, but in lieu of that we'll settle for a scenario in which someone gets to see the rocks. If, as the Fermi Paradox suggests, we're the first sentient species capable of spaceflight, the galaxy is ours for the taking.
For now a matter-antimatter drive might as well be a pipe dream. We don't have a way to create antimatter in any meaningful quantity. Using the current process it would take 2 billion years to produce 1 gram of anti-hydrogen. Then there's storage. Anti-hydrogen has been kept from destroying itself for 10 seconds. (Thanks, Wikipedia.)
Before we start even talking about getting to other planets there are a few things we need to do. We need a space station far more robust than the ISS. One that allows manufacturing in space. Heavy-lift vehicles get all the materials we need into orbit. It's all assembled and launched from space. Needless to say, that's far easier said than done. But if we want to engage in real space exploration I think to start outside of Earth's gravity well. Too much energy is wasted just getting spacecraft into space and building them to survive launch and flight through the atmosphere. Although, I suppose even in space they have to withstand similar loads. But the point is that if you start in space you have many more options.
And I think it's high time we restarted research into nuclear propulsion.
I would like to volunteer my ex-wife for service aboard one of your algae-ships.
I understand it quite well, and I'm humble enough in my understanding to acknowledge that if we survive another 1000 years we might solve said problem.
Considering where we were a hundred years ago, it seems rather pedantic and just as dismissive for professor grumpy pants to say it's would to take us 180K years to get there. The stuff that will get us there quickly might still be sitting on grease boards, but chances are it really isn't that far off that a robotic mission will be able to reach a system this close and do it within a reasonable timeframe (i.e. decades). Liftoff before the turn of the century, I'd expect.
What's more likely to stall this is dollars and ability for a project of this scope to survive multiple successive administrations across multiple international boundaries. And a good reason too, hopefully better than "all hands, abandon ship".
...to be found near us, wouldn't "they" have identified Earth as a potential harborer of life and a) attempted communication, b) sent robots, or c) tried to visit? Any meaningful discussion on getting to this place is useless without the technology to actually get there.
There goes next years vacation plans.
A man on a good horse can maybe cover 30 miles a day unless he wants to kill the horse. A man on foot maybe 20 if he's in top shape. My comment stands. Maybe I should have said "A dozen or few" but still, you're just being pedantic.
When I first read this, and someone saying it would take 180,000 years to travel there, I thought, "Maybe we can bring that planet to us!"
But then the various issues with this, not least of which that location matters when discussing habitability, struck me and I thought, "Okay, that wouldn't work."
Even if you made a spaceship sized tunnel between here and there, essentially pulling some section of their solar system across the light years to meet with a section of ours...a wormhole if you will...
Just had to mention Heim Theory here:
http://en.wikipedia.org/wiki/Heim_Theory
Current space-travel technology, even accounting for an Orion ship powered by every nuke on Earth, would take so long to get there as to receive a warm welcome by the travelers' own great^N-grandchildren, whose ancestors stayed behind long enough to develop Dilithium Crystals, Warp Drives, and/or whatever technology will whisk travelers there on the order of a few hours.
Can we get a "-1 Wrong" moderation option?
If you haven't read A Short History of Nearly Everything by Bill Bryson, do yourself a favor and pick it up. It's wonderful read about pretty much everything. He opens with a chapter on space travel which he says, ...
The point to remember, of course, is that when considering the universe at large we don't actually know what is in our own solar system.
Now the other thing you will notice as we speed past Pluto is that we are speeding past Pluto. If you check your itinerary, you will see that this is a trip to the edge of the solar system, and I'm afraid we're not there yet. Pluto may be the last object marked on schoolroom charts, but the system doesn't end there. In fact, it isn't even close to ending there. We won't get to the solar system's edge until we have passed through the Oort cloud, a vast celestial realm of drifting comets, and we won't reach the Oort cloud for another - I'm sorry about this - ten thousand years. Far from marking the outer edge of the solar system, as those schoolroom maps so cavalierly imply, Pluto is barely one-fifty-thousandth of the way.
Of course, we have no prospect of such a journey. A trip of 240,000 mils to the moon still represents a very big undertaking for us. A manned mission to Mars, called for by the first President Bush in a moment of passing giddiness was quietly dropped when someone worked out that it could cost $450 billion and probably result in the deaths of all the crew (their DNA torn to tatters by high-energy solar particles from which they could not be shielded).
Based on what we know now and can reasonably imagine, there is absoulutely no prospect that any human being will ever visit the edge of our own solar system - ever. It is just too far. As it is, even with the Hubble telescope, we can't see even into the Oort cloud, so we don't actually know that it is there. Its existence is probable but entirely hypothetical.
Sure, chucking a probe 20 lightyears away would be awesome, and if we could scrape together the international will and resources necessary to do that I would be all for such an effort. But what about exploring some of the more exciting areas in our own celestial backyard, if you will?
To date we have only had landers on a few of our planets. We only have functioning rovers on one. We had an impact probe on only one of the moons circling the gas giants. We have rendezvoused with one asteroid, and we have gotten two probes into the Kuiper belt. So, before we go dumping trillions of dollars (and it will cost at least that much) into a tiny (and it will be tiny) scientific payload to another solar system, can we start funding some serious exploration here first?
I want to see landers, rovers, and submersibles on Europa, Enceladus, Titan, Ganymede, Io, and Callisto. I want to see regular sample return missions to near Earth asteroids. I want to start a ferry program between LEO and the Earth's surface for more than a handful of elite astronauts. I want to see experimental habitats on the moon, rovers on Venus, probes on Mercury, orbiters around Jupiter, Saturn, Neptune, Uranus, and even Pluto, and I want to have at least ten more robots actively exploring Mars. Don't get me wrong, Gliese 158g is one hell of an interesting planet and we should study it as best as we can with out long range sensors and, as one 'dotter even suggested, perhaps we should try communicating with it. I see no reason to evens start thinking about sending a matter-based payload to that planet, however, until we really take some time and effort to start exploring our own solar system. For as much as we have done here, we still really don't know all that much about our home system. I, for one, am not convinced that there are not colonies of methane-based life on Titan and a whole city of icy fish people swimming under the crust of Europa. Let's not even start talking about the possible cloud people of Venus or the cave-dwellers of Mars...
Motorcycles, Robots, Space Gossip and More!
From TFA: "3 million years to collect on earth if the entire surface were covered with solar panels" We NEED a frickin Dyson sphere NOW! GODAMMIT!
A lot can change on a planet in 180,000 years. In only 100 or so, we've pretty well toasted this one. Besides, putting all the money, effort and resources into a trip which will take that long just isn't worth the risk vs. cost. There is too much we don't know about the universe to embark on something like that with our current knowledge level.
boycott slashdot February 10th - 17th check out: altSlashdot.org
And go tell said children that curing cancer isn't "forward thinking" enough. I'm curious to see what kind of response you'd get.
That other planet had just called me, and it told me it cant wait for this civilization going there and shitting, polluting and ravaging itself too. it just cant wait !!
Read radical news here
Woven into the plot of Kim Stanley Robinson's trilogy beginning with Red Mars is a pretty good argument that, even with multiple space elevators running nonstop, it might not be feasible to move enough people off the Earth to offset increased longetivity and high birthrates.
As it is, even if we set off to the Gliese 581 system today, when we finally got there we would undoubtedly find life - ourselves. As Larry Niven points out in his fiction, by the time our current technology takes to get there, someone will have invented / discovered a faster way of travelling and will therefore overtake our 21st century probe en route.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
Develop it? Can't we just use the Stargate under NORAD?
Assuming it takes 100 years to build everything we need to make this flight, by the time you get there it will be 178,570 years after the group that took 1000 years to build the matter/antimatter ship finished their project.
This is what I see happening: The first colony ships will leave for a newly-found planet using then-state-of-the-art technology and when they arrive the first thing they'll see is a McDonald's putting up a sign advertising their new "Colonist Combo Meal Deal".
How fast was a boat a few hundred years ago?
Magellan's expedition went around the globe in 3 years.
Isn't mars in our 'goldilocks zone'? But because it doesn't have a magnetosphere it can't sustain an atmosphere against solar winds? (Not sure, just something I remember reading about). If so, how do we know the odds of habitability of planets in the zone? Couldn't it be that, yes, they do need to be in that zone to support life, but only 1% of planets in that zone have other factors that contribute to that support? (Like a magnetosphere)
After all, it's only and astronimical hop, skip, and a jump away at only 20 light years. Of course that's the equivalent of telling a 4 year old in London that they can have all the free ice cream they want in New York City if they just walk/swim there. For an adult, it's not a trival thing to do, but still possible, and in the analogy, our race and society are still wearing metaphorical diapers.
We currently don't have the technology or resources to pull off a 20 light year trip, even if it's one way.
And if we did, what would we find when we get there? A planet with higher gravity, and otherwise a completely unknown environment. It may have no water, atmosphere, oxygen, or something else we desperately need to live. On the off chance it has an ecosystem, is it one that is even compatible with us, or would we have to totally destroy it before we could supplant it with our own? What if it has intelligent life? No matter how you look at it, colonizing that place would be a tricky proposition, assuming we were even able to get there in the first place.
Just a note, we currently don't have any form of life support systems that can sustain human life for 6 years without getting occasional fresh supplies, something which can't happen on an interstellar voyage. So even if you could travel at 92% light speed, you'd still die before you got there. I love sci-fi, but I also know a bit about the reality of our current developmental situation. We have a long ways to go before we can explore the stars.
My mistake.
Circumference of the earth = 24,000 miles / 3 years = 1,095 days
= 22 miles/day
I used to work at a place that made antimatter (Fermilab, and it was anti-hydrogen ions to be precise). the creation of antimatter is incredibly energy intensive and inefficient- to produce one gram would cost $100 quadrillion. The idea of making ten thousand metric tons or so of the stuff is ludicrous. we might make antimatter bombs someday, but not starship engines.
a fusion starship might approach 0.3 % of the speed of light, taking decades to go to the near stars. That would be taking 100x the mass of the cargo as deuterium or boron fuel.
see my other post on why antimatter won't be used for starship fuel, just too damn expensive and energy intensive to make.
I think it'll be a bit different. The colony ships will take off, and slowly build up to something approaching c over a great length of time. Thanks to special relativity, the faster they go the faster time is passing on Earth (relative to them). That means soon after they set off, relatively speaking (no pun intended) they'll be intercepted by FTL craft from Earth. Obviously we might not make FTL craft, but if we ever do, all those who left Earth before they were built will be picked up along the way by one. If I was on an interstellar ship, and arrived at my destination unmolested by human kind, I'd start worrying.
... they can't even agree on what they want NASA to do in our own little space area. Traveling to Gliese 581g will depend on the current party holding office, and whether Gliese 581g constituents make it a "Red" or a "Blue" planet.
So the question will not be about technology, but politics.
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
It's nicely re-assuring to think we might not be a fluke in a planetary sense, at least not in our 'neighbourhood'. But surely terraforming has to be the realistic way forwards?
It would be easier to build a telescope that could resolve the surface of the planet, than it would be to travel there.
Request your free CD of my piano music.
Why is fuel a problem? Wasn't that solved with ramjets?
Now shielding to block the radiation from that is another problem entirely.
...send our politicians there.
Table-ized A.I.
What's the benefit of stopping to pick them up when you can instead be the very first people to the new planet and get to place your armies in Australia?
"Deleted by poster". Damn annoying. But then again this is the wrong thread.
char*f="char*f=%c%s%c;main(){printf(f,34,f,34);}";main(){printf(f,34,f,34);}
If we had a telescope large enough you'd see people there standing in lines to see Total Recall right now.
Whatcha wanna do here is send small self replicating molecules.... accelerate them at the speed of light toward habitable planets in some kind of accelerator gun... let them land on the distant planet and start evolving... wait a billion years or so and voila... they start sending radio signals announcing their arrival.
It will be "us", but perfectly adapted to wherever "we" land.
In fact, that may be how we got here. We may be the aliens finally reporting back to the mother planet right now.
http://en.wikipedia.org/wiki/File:TI_SpeakSpell_no_shadow.jpg
Remember to maintain your supply of
Chekov supposedly has a Russian accent. However, he pronounces /v/ as if it was /w/. Russian has a /v/ and lacks a /w/. So we are basing our most famous Russian accent on someone who has a speech impediment?
Or is it just Americans who can't recognize some sounds properly (the way they think us Canucks say "oot and aboot" which we do not. Up here its "owt and abowt" if anything).
"The first time I got drunk, I got married. The second time I bought a chimpanzee, after that I stayed sober" Arian Seid
Thanks to special relativity, the faster they go the faster time is passing on Earth (relative to them).
That's exactly backwards. Thanks to special relativity, the faster they go, the slower time is passing on earth relative to them. And vice-versa. Time is passing slower for earth relative to them, and slower for them relative to earth. The colony ship would only find themselves to have experienced less time than what had passed on earth if they decided to turn around and come back.
http://en.wikipedia.org/wiki/Twin_paradox
If fate makes you a motorcycle, you become a motorcycle.
http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=world+population
world population 6,697,254,041
http://www.google.com/#hl=en&expIds=17259,23756,24472,24692,24878,24879,25566,25984,26095,26562,26714,26792,27006&sugexp=ldymls&xhr=t&q=+6697254041-++99.999999%25+of+6697254041+&cp=13&pf=p&sclient=psy&safe=off&aq=f&aqi=&aql=&oq=+6697254041-++99.999999%25+of+6697254041+&gs_rfai=&pbx=1&fp=c6affe93747c32d0
6 697 254 041 - (99.999999% of 6 697 254 041) = 66.9725409
66.97 people? I'm guessing it's more like 6,697 who give a shit-- so that would only be
99.9999
every day http://en.wikipedia.org/wiki/Special:Random
It's estimated to be roughly 3 times more massive than Earth. This means its gravity will be at least double ours (depending on the radius). I doubt humans can live long under such gravity. Our spines already fail at 1g. Well, maybe rolling beds? At least sex will be easier. And you don't have to get out of bed to go to work. Just wake up and drive using a horizontal monitor. Sign me up!!!!
Table-ized A.I.
Maybe everyone is just trying to get away from YOU? :p
Remember to maintain your supply of
As long as you're into science fiction...
Your scenario is described in "Songs of Distant Earth" by Arthur C Clarke. In that book, the root of the solar neutrino problem was that the Sun was burning out. Light from the core takes 1000 years to get to the surface, but neutrinos get out practically immediately. The information that the hydrogen-burning life of the Sun was over hadn't made it to the surface yet. So we figured it out, and realized that we had some 900 years (Evidently the solar neutrino problem had barely started when we discovered it.) to find a new home. Interstellar travel became a top priority very quickly. First ships were slower, later ships were faster. The story takes place when an earlier ship stops over at a planet which had already been colonized by a later ship.
Or take "Hitchhiker's Guide" by Douglas Adams or "Those Gentle Voices" by George Alec Effinger. Put all of your non-productive people on the first slow ships. Then those that are left can work faster/better on newer, faster ships. In a twist, safe flight for the first slow ships is optional, as are intentional crashes.
The living have better things to do than to continue hating the dead.
Does anybody else reading this discussion find new appreciation for this life raft that we all share?
Brian Williams said, “It’s just nice to know that if we screw this place up badly enough there is some place we can all go.” Tell NBC News how dumb and upsetting this comment is at http://www.msnbc.msn.com/id/29104230/
Or is it just Americans who can't recognize some sounds properly (the way they think us Canucks say "oot and aboot" which we do not. Up here its "owt and abowt" if anything).
When I used to live close to the Canada - US border, we used to watch CBC, and they did indeed say oot and aboot in a boot, although it may have been as a joke.
I always thought it was odd that no other Russians pronounced V as W as Chekov did. But then, Picard spoke with an English accent but was from France. Patrick Stewart said Picard was more European than French, in that Europe had become united. Perhaps a similar thing happened with Russia and whatever countries are nearby, causing their accents to change over the next couple of hundred years.
Do you think the Russian pronunciations of today are the same is it was a few hundred years ago? English certainly wasn't.
Putting moderation advice in your
increased longetivity and high birthrates
That's the issue. I wouldn't be surprised if my generation is given this as a choice - indefinite life extension or children (possibly with the option of having your genetic material stored for IVF at some point after your death from accident or violence). Bad luck to those who already had children...
I am TheRaven on Soylent News
I like your logic that curing cancer in children only gives them "10 years" of life added, instead of y'know, an actual human lifespan. Maybe one day, you'll be able able so snort a line of nanorobots, and they can relocate your logic circuits from your anus to your brain; we can only hope, right?
That's kinda what PC's are like: you boot up your shiny new 64-bit PC, and the first thing you see in its browser is an ad for the 128-bit 3D model.
Table-ized A.I.
If we can communicate with them, and send over our DNA sequences, then they can grow copies of humans, bring them up in their own society, and train them for the invasion force to conquer Earth.
-- Tigger warning: This post may contain tiggers! --
SInce it was a character from the 60s, we can't really expect a lot.
I really enjoyed the new movie, except for Chekov. Really, you have a computer that can understand almost every language in the universe, but it can't figure out a Russian accent?
And of course having him run to get to the station while people fall instead of transferring control to his station was also lame.
The Kruger Dunning explains most post on
Canada is not a monolith. There are places in Canada where people say 'aboot' and consequently all Canada is mocked through them. Just as "American" accents are mocked through those prevalent in the Deep South, or the Valley Girl "dialect", when most of the country sounds like neither. (Being from Washington State, people sometimes think *I'm* Canadian, which happens to many who live in border states, though especially to those from ND, MN, WI, MI and ME.)
P.S. People who pronounce 'both' like 'bolth' need to be slapped until they stop. There is no goddamn 'L' in that word.
I support the Slashcott and will not be reading or commenting from 2/10/14 to 2/17/14. Beta is steaming pile of dog shit
That's exactly backwards. Thanks to special relativity, the faster they go, the slower time is passing on earth relative to them.
No you have it backwards. As they approach c their time slows down so that c stays c. Meanwhile on earth time is moving along at 'normal' rates which is much faster than on the ship that is going near c.
The colony ship would only find themselves to have experienced less time than what had passed on earth if they decided to turn around and come back.
Yes because all relativity effects are only felt on the way back. Facepalm. perhaps you meant they would only realize (as in see it firsthand) the time difference when they returned to earth, but they have indeed experienced less time regardless of whether they go back or not.
People in cars cause accidents....accidents in cars cause people
Read Mayflower II, an award-winning, excellent short novel by Stephen Baxter, probably the best contemporary hard Sci-Vi writer. The topic is, indeed a generation ship (one where multiple generations have to pass before the destination is reached). It's absolutely perfectly and vigorously on topic for this entire thread and your post in particular.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
it says it needs me to get some stones. Now a need to get a towel to wipe off my forehead.
The Kruger Dunning explains most post on
I haven't seen anyone mention vasmir yet http://www.nasa.gov/vision/space/travelinginspace/future_propulsion.html
Wouldn't this be the ideal drive type to power a probe? Extremely efficient and can basically accelerate continually, then flip around and begin de-accelerating (or maneuver near other objects to let gravity slow it down). Wikipedia says that Nasa is going to test it in space in 2011 or 2012.
Ok, if we had an engine that could produce 1G of accelleration over a large number of years.
Does anybody how long would it take to get there?
Half the trip would be accelerating, and the other half decelerating. (Actually it's accelerating the whole time, just in the opposite direction at some point.
1G of acceleration should solve the muscles atrophying problem as well.
Listen, this stuff is not easy to articulate, so I will grant that I may not be saying it clearly. But you are leaving out important information in your description, which makes it meaningless from a special relativity standpoint, namely -- relative to what?
As they approach c their time slows down relative to the rest of the universe, earth included so that c stays c. Meanwhile on earth time is moving at at 'normal' rates relative to its own inertial reference frame. That is, as described from the Earth's reference frame, the ship has experienced less time than the earth. However, As described from the ship's inertial reference frame, it is the earth that has experienced less time than the ship.
There is no universal privileged frame of reference. You are treating the ship as moving close to light speed and the earth as stationary, but it is equally valid to treat the ship as stationary and the earth moving close to light speed. Each reference frame sees the other as having experienced less time. Seriously, read the link. It will do a far better job of explaining than I can.
If fate makes you a motorcycle, you become a motorcycle.
As exciting as the idea is to me of exploring another world, I think if there are other intelligent beings out there they should stop us from leaving our world until we can learn to take care of it properly. Otherwise, we will just spread our destruction in search of profit.
await, but we are trapped on our little planet. To paraphrase Admiral Kirk:
EINSTEIN!!!!
There is no universal privileged frame of reference.
There is no privileged inertial frame. Everyone on this site reliably talks about special relativity when this subject comes up, but special relativity isn't responsible for these particular time-dilation effects.
Considering just special relativity, a train's proper time is faster than the station's and the station's proper time is faster than the train's. The way out of that is to recognize that the entire concept of simultaneity is lost. If starter pistols are fired on the train at the first and last cars simultaneously (according to train passengers), in the reference frame of someone at the station, the two shots were separated by a finite time, varying linearly with train length. Although they agree on their relative velocity with respect to each other, they don't agree on the length of time the train spent in front of the station or even the length of the train itself. But both are inertial frames.
Until the train turns around. A reference frame which is not accelerating (i.e. an inertial frame) does have a privilege. The earth is in a free-fall inertial frame. A spaceship has to accelerate. If we're only going to consider the common time-dilation and length-contraction effects from special relativity, then relative aging makes no sense just from symmetry. If two spaceships left one point and returned to it after making mirror-image round trips in opposite directions, you wouldn't expect people in one to have specially and relativistically aged faster than people in the other.
But if you left the Earth, and then you returned to show off your youth or bring back rocks, there would have to be an acceleration involved when you turned around. That introduces the time-dilation effects from general relativity: clocks tick faster in free fall than they do on the ground, or any other non-inertial frame that experiences g-force. When the train actually turns around, all the stuff happens that amazes everybody on the return trip. When the train passes the station going the other way, it's pretty clear that everyone at the station has aged more.
In theory you could travel across the universe in your lifetime- but then your life would be ruined by extremely intense acceleration (a first). You'd have to bring a mixed-sex crew to create successive generations or else the mission fails.
Thank you. This is exactly what I was trying to explain, though I was using incorrect terms and generally doing a piss poor job of it. You have clarified it beautifully.
If fate makes you a motorcycle, you become a motorcycle.
I wish I had mod points... parent is relatively correct..
You can be anywhere in ten minutes if you drive fast enough.
I've heard this argument before, and I'm no physicist, but I'm pretty sure it's wrong. If all inertial reference frames were equally valid, there would be nothing to stop you from traveling faster than the speed of light. Also, looking out of your window and seeing the entire universe redshift might indicate that your speed is getting rather excessive. Either that, or you'd be standing there saying "wow, I'm standing completely still and the whole galaxy is moving at the speed of light!".
The argument appears relatively convincing at first glance, but creates all sorts of problems.
"All your base are belong to us".
Then in 40 years, if anyone is there, we could get an answer. "We dare you to come and get all our base".
now we need to go OSS in diesel cars
Probably the best bet is to copy it from visiting aliens, if any ever bother to visit.
I was thinking about this and: we're not ready. To this day, we have people who use what little technology they do have (chemistry etc) to make bomb vests and blow themselves up. We're still an absolutely greedy, violent species who regularly wars all the time.
The mass and energy involved in interstellar travel is sufficient to destroy planets. (I always wondered why they needed the Death Star when they could just accelerate a smallish frigate into a planet at lightspeed and accomplish the same thing. Planetary shields maybe.)
Any aliens moving amongst the stars must have a code of social justice and cooperation sufficient not to destroy themselves with their own technology. That code almost certainly includes rules for not giving technology to belligerent pre-stellar species. Would YOU start handing out laser pistols to a room of tantrumy 2-year olds?
If you wait for all the lights on your journey to turn green before you set out, you'll never leave home.
So what if it's a hundred thousand year journey? Put together a 10,000 crew mission and set them on their way. For certain the fight won't be over who has to go. It will be over who has to stay here.
Help stamp out iliturcy.
True. As a Michigander I can confirm that Yoopers* sound more like Canadians than they sound like Trolls.* "Say yah to da UP, eh!"
*Upper Peninsula dwellers, the region of the state closest to rural Ontario
**People who live "below the [Mackinac] Bridge"
http://alternatives.rzero.com/
First you will have to break several laws of physics just to move fast enough. Your first enemy is gravity. So you plot your course and lets say hit light speed. You're now dead, the gravity well of the Sun has just squashed you like a grape only messier. Now imagine a faster than light system that's capable of detecting objects in the path and avoiding/deflecting/destroying them, it would have to be faster than you are and vastly more complex.
Better to point antennas at it, and worse if there is any advanced civilization there, they're currently still watching the cold war on TV. I'm sure they can not wait to visit, or worse they're a few years from arriving and wiping us out.
*Damn it! Where my tin foil hat!*
You don't have to take the two extremes described in the article, though -- there is a middle ground between .92c / 22.4 Earth years / 6.1 traveller years -- and 0.00012c / 180,000 years.
Producing 530(/2) times the mass of a colony ship's worth of antimatter is pretty much a preposterous concept with current known tech. We just can't even come close. But there are a lot of techs that have been proposed that, while not as impressive as a pure matter/antimatter drive, are achievable with current tech. For example, antimatter-initiated microfusion looks like we could feasibly build a colony ship that could reach about 0.1c. That's 200 earth years / 199 traveller years. So it would need to be a generation ship, but then again, if you're planning to colonize, you better be able to handle reproduction and long-term habitation to begin with. Such a ship could conceivably be launched in ~50 years or so if there was sufficient dedication to the cause. That's far less than the time it'll take us to learn how to colonize a planet well enough for the mission (at 20 light years away, it has to be essentially 100% independent, all the way down to producing microprocessors and the like). This isn't Star Trek; even a planet in the "Goldilocks Zone" isn't going to be something you can just land on in your shirtsleeves and settle with nothing more than the phaser on your belt, like some space version of Jamestown. You need a large chunk of our planet's entire tech tree to maintain life support, mining, refining, and production infrastructure.
While tech does indeed change over time, I guarantee you, we're not going to learn how to produce those absurd amounts of antimatter for a matter-antimatter drive in a couple centuries.
Sigur RÃs: I didn't know that Heaven had a rock band.
That's not the way I remember it. The planet was colonized by a robotic "seed ship", with no humans aboard. The first generation was raised by the ship, and they bred the subsequent generations. The planet's population was quite small, but the planet had little habitable area anyway (it was almost all water). The newly-arrived ship was the last of the humans, and was packed with everyone left from Earth at the very end, in suspended animation. They stopped at the planet to see if they could live there, only to find there was no room, so they had to go on to another seeded colony planet. The new ship wasn't that much faster than the previous ships though; it still didn't have FTL, though it was powered by quantum fluctuations. Arthur C. Clarke never uses FTL in his stories, from what I can tell.
The main problem in the story is that this new ship needs to take some water from the planet to turn into ablative ice shielding for the rest of their voyage, as their shields have run out.
The entire Baldwin family and many other Hollyweirds who've promised to leave to political utopias if Hillary wasn't appointed Goddess of the world, now have a place to go.
Hey, Adam Baldwin is a cool guy!
...than the fact that currently we don't have a way to get there is the fact that now we have the reason to find the way.
It's been a few decades - I read it when it first came out, so I can go with your version. I'll have to check if I still have the book.
The one time Clarke had any sort of FTL was in 2001: ASO, and he repudiated that (to bad effect, IMHO) in 3001: TFO.
The living have better things to do than to continue hating the dead.
I still have the book (very yellowed with age), and Grishnakh is right in his correction. The later ship arrives much more quickly than the seed ship did, due to scientists discovering the necessary mathematics and techniques for harnessing zero-point energy, allowing a much more massive ship to be built that does not need to carry so much fuel. This ship is able to take along living human colonists, unlike the seed ships which contained only enough genetic material for the machinery on board to produce and educate the first generation. The particular seed ship that colonizes Thalassa is also one where the decision was made to exclude historical topics of religious and racial conflict from the education of the seeded colonists. The 'ark' containing the later colonists, obviously, provided no such opportunity for sanitizing history. One of the sources of conflict in the novel is this meeting of two societies -- an older, cynical, more worldly new arrival interacting with the newer, Utopian, and idealistic one. Other points of interest are that the technology brought along by the seed ship on this mostly-oceanic planet has already been noticed, has been stolen, and is accelerating the development of a native aquatic species. This topic is left as a cliffhanger at the end of the novel. Another is that the finale of the book is a mutual celebration held by the two groups in the novel, with videos of earth-based life played for the enjoyment of the Thalassians, and a concert to entertain all. Musician Mike Oldfield wrote to Arthur C. Clarke, asking permission to compose a suite based on the concept of this concert finale. The resulting album is also called, "Songs of a Distant Earth", and features a liner note by Arthur C. Clarke. The CD release was one of the very first "Enhanced CDs", containing a short virtual-reality sequence and a simple musical puzzle one must solve in order to unlock the video to the composition, "Let There be Light". The VR sequence and parts of the video, I have read, was rendered using early versions of Mike's software project, MusicVR ( http://www.mikeoldfield.org/info/discography/mvr.htm ). I also recognize some of the video sequences I had seen demonstrated from that in the old "Beyond the Mind's Eye" videos. Mike has since spent 25M pounds developing the software and games around it. The games can be downloaded from the sidebar of his fan site ( http://tubular.net/ ). I've never looked at them; I don't run Windows and I don't play games, but I think it is interesting just the same. A final point of interest is that Clarke supposes several technologies in this novel that he has since become known for, including the space elevator, and ablative ice shields to protect the ships from erosion by space debris. Indeed, replacing this ice shield is the reason the later ship stops at Thalassia.
Yes, I think tiny self-aware probes will be the way we'll do it. A one-gram probe would still require a Hiroshima to get it to .85c.
You'd be able to launch billions of them, both to target many stars at once, and also to allow the probes to communicate down chains.
You'd be aiming to impact a planet (make it survivable by building the probe mainly out of diamond), after which the nanotech would sprout and build something better. Rather than a simple scatter-gun approach, the probe could steer as it travels by releasing radioactive decay particles left and right.
Using this you could expand the front of exploration at .8c, and pwn the galaxy in 100k years.
Major questions: how to accelerate the probes, and can a .85c impact be survived.
I've always been amused by these theoretical journeys. How annoyed would you be if you got all the latest kit together set of for a star knowing that your great-great-great-(whatever, you get the gist)-grand children will be the first people to shake hands with an alien (or get zapped by their photon gun) when all of a sudden you get over-taken by some upstart joyrider in the latest spolundigated retrocharged thunder rocket (tm) which hadn't been invented yet. Oh well, you think. They will probably get over taken too. Its the only journey that you will complete faster by sitting on you **** doing nothing.
The acceleration of the ship as it nears c is the "time-dilation" cause for the ship.
A Haiku: my language choices/assembler pascal lisp c/old school programmer
Antimatter production is almost impossible with current technologies. Aneutronic nuclear fusion is more affordable. Furthermore, we need spacedrive more efficient in terms of energy usage than expelling-mass rockets. spacedrive video
If all inertial reference frames were equally valid, there would be nothing to stop you from traveling faster than the speed of light.
Wrong.
You cannot travel "faster than the speed of light" because no matter where or how you measure it, light always travels at speed c.
The wikipedia page on Special Relativity explains this clearly from first principles. Don't expect to understand this in half an hour. It will take a few hours of reading and doing worked examples. Since it is out of our sphere of everyday experience, it is not intuitive.
Stick Men
"One scientist puts the travel time at 180,000 years based on current space flight technology, while another explains that it could be quite quick if we build a matter-antimatter drive, and can figure out how to bring along 530 times as much mass in fuel as is contained in the ship and cargo itself."
As this article explains, there's new science afoot, and propulsion need not require expulsion of mass any more. Note that energy would still be needed, and the technique needs to be engineered up from the current proof of concept stage to an actual ship, but the need for big mass may be gone.
Since the acceleration is based on mv=mv, accelerating low mass particles to very high velocity might offer a very high thrust to mass ratio. In other words that "530 times" is open to improvement if higher exhaust velocities are used.
The real limiting factor is how much acceleration the payload can take, and what your target top velocity (cruising speed) will be before braking starts, and of course available energy regardless of mass requirements. Assuming Vmax of .5c gets to the destination in a lifetime, but doesn't get data back. If entangled particles could be used to pass data, the requirements would no longer include return hardware, and results would be in quickly. Interesting speculation. Of course there are nearer systems, and while ideal planets haven't been seen, they could exist and would be currently undetectable.
lol. Well, thanks. I don't know what I would have done if you hadn't stepped in with your extensive wikipedia-based education. Now perhaps you'd care to comment on what was actually being discussed?
A spacecraft is at rest with respect to Earth (for argument's sake). It might be in low earth orbit, ready to leave. To all intents and purposes their clocks tick at the same rate. Communication is to all intents and purposes instantaneous between them.
The rocket starts accelerating away from the Earth. The people on the Earth see the rocket moving away faster and faster. The people on the rocket see the Earth moving away faster and faster.
As the rocket approaches a substantial fraction of the speed of light, as observed from the Earth, clocks on the rocket appear to slow down. Light from the rocket appears red-shifted. The rocket's length contracts in the direction of travel. On Earth, the clocks there are still going at the same rate.
As observed from the rocket, clocks on Earth appear to have slowed down (by the same amount that the clocks on the rocket appear to have when viewed from the Earth). Light from the Earth appears red-shifted. The Earth has contracted in length along the direction of travel of the rocket.
The faster the rocket gets (as observed from Earth), the slower its clocks appear to run, the more red-shifted it looks and the shorter it gets. The people on the rocket appear to age more slowly.
Meanwhile, on the rocket, the people on Earth appear to be aging more slowly and clocks appear to run slower etc.
Another consequence of this is that wherever the rocket is going, the distance to its destination shrinks as seen from the rocket. For very high velocities, the more energy added (the more the rocket accelerates) this distance shrinks.
Put another way, if you are on this rocket you could effectively reduce the distance to anywhere arbitrarily if you could add enough energy with a sufficiently powerful engine and enough fuel.
The trouble is, it's an awful lot of energy.
By the way, the mass of the rocket also increases the faster it goes (and so does the Earth's). The Lorentz transform is the key to it all and comes from the principle of simultaneity.
Stick Men
As observed from the rocket, clocks on Earth appear to have slowed down (by the same amount that the clocks on the rocket appear to have when viewed from the Earth).
This is the bit that's being contested. You can continue repeating it as many times as you want, but that doesn't really get us anywhere. Your assertion is - essentially - that time continues to pass at the same rate in both locations. Every other source says that an object traveling near the speed of light will experience time at a slower rate, so that - when it returns to it's starting point within the lifespan of those onboard - hundreds of years may have passed for those left behind. I'm open to having my mind changed, but you're going to have to do better than just flat assertions.
Light from the Earth appears red-shifted.
The universe appears red-shifted. When I'm driving down the road in my car, I could say that my house is actually driving away from me. But when the whole fucking planet is passing in the same direction, it seems a little egotistical to insist that my observation is the only one that matters, or even that they're both valid.
Actually, egotistical is the wrong word - fucking insane fits a lot better.
IIRC, your argument hinges on the idea that light observed to be coming from the earth will show the planet to be moving at a slower rate, which is true, just like it's true that my house appears to be moving away from me when I drive away. However, the twin paradox exists for a reason - we know that the person who actually IS traveling at velocities approaching C really will experience time at a slower rate, regardless of what he sees when he looks back at the earth. If it were true that both reference frames were equally valid, you'd see something different - both twins would see each other age more slowly while traveling away, and then see each other aging more quickly while traveling towards each other, with the end result that both would have aged exactly the same amount after being reunited. As long as we accept that this is not the case, we can safely say that time really does slow down as your velocity approaches the speed of light.
I've never read any sci-fi about these earlier ships getting sent out, and then being overtaken and boarded by later ships, and then those ships being overtaken, etc., etc. Presumably they'd know what route was taken, and could add a few centuries/years/months/weeks/second to their trip to slow down and scoop them up. That'd also be a great way to encourage the whole human population to maintain reproductive compatibility on these millenia-long flights - just stock the earlier ships with women and some sperm banks, and tell the engineers back on earth that the girls got a head start, get to work. Even though it would take centuries to get anywhere, we'd keep catching up to earlier populations and mixing our gene pools with them.
Can I just skip the hard part and accept my Hugo now?
Actually, egotistical is the wrong word - fucking insane fits a lot better.
The whole point of Relativity is that there's no "preferred reference frame" i.e. you can't just assume that you can measure things anywhere presumably against the universe as some kind of fixed backdrop (the Newtonian view) and expect to get the right answers. Speed, distance, mass, time and gravity all depend of the frame of reference in which they are measured. Two objects moving with respect to each other are, by definition, in different frames of reference.
It might be better if you read the Wikipedia articles on the Lorentz Transform and Special Relativity. The Lorentz Transform article explains simultaneity and measuring the speed of light leading to the Lorentz Transforms which lead straight to Special Relativity.
As I said before, Special Relativity is counter-intuitive because it is outside of our sphere of everyday experience. The only way to really understand it is by reading good articles on the subject that explain it from first principles and that use maths. It will take you a few hours of reading, thinking and trying the maths before you will really begin to appreciate it.
Arguing on a discussion forum isn't really sufficient.
Time travels at the same rate in the different locations for people at those locations. However, when they look at the other location from where they are, they will see time there traveling slower. Since there is no preferred reference frame, they both see the same effect. That's not insane, it's physical reality, the maths predict it and it is observable in Nature by experiment.
You're missing something very important about the Twin Paradox: that is how long it takes for information about one of the observers in one frame to reach the observer in the other.
It's 18 years since I went to university to study Astrophysics. In our first year, the Special Relativity text book we had was Special Relativity by A P French from the M I T Introductory Physics Series. It's clear and concise and you can buy it from the likes of amazon.com.
Stick Men
The whole point of Relativity is that there's no "preferred reference
Yes, I get that. I've already acknowledged that. From a purely impartial perspective, it's completely valid. From a human perspective, it's retarded. As a child grows, we COULD say that the rest of the world is actually shrinking, but that would, likewise, be retarded. We could also say that both views are equally valid; this would also be retarded. It might prove useful in some circumstances, when playing around with abstract math, but when it comes to everyday discussion there's only one valid reference point.
It might be better if you read the Wikipedia articles on the Lorentz Transform and Special Relativity.
I've read them. I read them a long time ago. I re-read the article on special relativity when you first mentioned it, and I re-read the article on the Lorentz transform just now. I'm as familiar with the concepts as a person can be without fully grasping the mathematics involved. Neither article does anything to support your claim. Time dilation is still a real, observed phenomenon.
Time travels at the same rate in the different locations for people at those locations. However, when they look at the other location from where they are, they will see time there traveling slower.
Once again - already acknowledged. Again, you're just repeating the same assertion over and over.
You're missing something very important about the Twin Paradox: that is how long it takes for information about one of the observers in one frame to reach the observer in the other.
No, I'm not missing it - I explicitly stated that your entire argument hinges on the time needed for "information" (ie. light) to reach the traveling observer. I think YOU are missing something very important about the Twin Paradox: that the traveling twin WILL ACTUALLY BE YOUNGER than the stationary twin, upon his return to earth. No amount of wikibation can change that.
...and the "traveling twin" will see the stationary one as younger...
So what would happen if the "traveling twin" turns round once he gets to his destination, and comes back at the same speed?
Stick Men
It wasn't about the ships getting overtaken, boarded, etc. In Clarke's book I had thought it was about a later, faster ship colonizing a planet, and then an earlier ship visiting that same planet on its way past. Apparently slightly defective memory.
In the Hitchhiker's and Gentle Voices cases, the whole purpose was to get rid of your "surplus popluation", perhaps a little less cynically than in "The Marching Morons."
The living have better things to do than to continue hating the dead.
Just check wikipedia, ok? :)