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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...
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.
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.
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
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,
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.
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.
Disregarding science-fiction babble like in this article, the fastest we can get to Proxima Centauri is 80k years assuming no fundamental breakthrough, or 100 years with ultimately advanced technology that's not known to be impossible with our current knowledge of physics.
Writers of such articles tend to forget that every gram of fuel needs to be accelerated by previous stages, and even worse, all the fuel needed for deceleration must be first accelerated all the way then decelerated partway. This puts a hard cap even if you magically got 100% efficiency.
But fortunately, such writers are also forgetting that physics isn't the only technology field that advances. I'd expect that both stopping aging and sentient AI are no more than 100-200 years away. Just don't forget to take playing cards with you to spend time during than 80k years long trip.
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
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.
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)
I dearly hope so. For those who can barely tolerate the rest in steerage, imagine decades with your fellow man!