# Is there ANY realistic mode of interstellar travel? **URL:** \ **Category:** Factual Questions\ **Created:** [July 1, 2006, 12:38am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818 "2006-07-01T00:38:39Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Dunderman](https://avatars.discourse-cdn.com/v4/letter/d/ecb155/32.png) [@Dunderman](https://boards.straightdope.com/u/Dunderman)\ **Post date:** [July 1, 2006, 12:38am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/1 "2006-07-01T00:38:39Z")
Right now we can’t travel between stars without it taking years and years and years and a few more years, and we won’t be able to for quite some time, it seems. But surely there must be some way suggested by current physics that we could at least theoretically use to travel between star systems in a way that (a) didn’t take years and (b) didn’t mean hundreds of years passed on Earth while we were away. Warp drives, portable worm holes, some form of teleportation, something with “quantum” in its name, whatever. Is there such a theoretical but realistic mode of travel, something we might one day actually use to go from one star to another and back within a reasonable time and without the Earth turning unrecognisable in the meantime? ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [July 1, 2006, 1:33am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/2 "2006-07-01T01:33:24Z")
Currently, about the only realistic hope is that “wormholes”- shortcuts through space- can actually exist and that we could hope to be able to build them someday. Right now the debate is between whether they’re impossilbe or merely inconceivably difficult to create. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [July 1, 2006, 1:45am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/3 "2006-07-01T01:45:35Z")
Wiki’s got a pretty decent article on [Interstellar Travel](http://en.wikipedia.org/wiki/Interstellar_travel). They’re hot on Orion type [nuclear pulse propulsion](http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion). However, there’s not much going on in that field these days, and even the less flashy [Prometheus Nuclear Systems and Technology Program](http://exploration.nasa.gov/programs/prometheus/) appears to be dying on the vine. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 1, 2006, 2:45am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/4 "2006-07-01T02:45:56Z")
Short answer, no. People can talk about wormholes and other exotic artifacts of the equations but there is nothing even imaginable, let along realistic, we can do with them with any system we can envision in any foreseeable future. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [July 1, 2006, 2:58am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/5 "2006-07-01T02:58:44Z")
Before he died, former Hughes researcher (later founder of Forward Enterprises) Robert L. Forward wrote and lectured about constructing laser-driven “webships”, ultralight lightsail craft capable of interstellar travel on believable timetables. They’d have to be ultralight (no human passengers), and driven by huge lasers back home over long periods of time, but it was a serious considered proposal for getting human probes to the stars. I attended a lecture he gave on it at a local section meeting of the American Aeronautics and Astronautics Association at the Boston Museum of Science several years ago. Now that he’s gone, I don’t know if anyone has picked up the torch. You can read about this and other of his oddball speculations and suggestions (like how to build a Space Elevator-type device without requiring ludicrously huge tensile sttrength materials) in his book **Indistinguishable from Magic**. ---
**Author:** ![Glaze](https://avatars.discourse-cdn.com/v4/letter/g/7c8e57/32.png) [@Glaze](https://boards.straightdope.com/u/Glaze)\ **Post date:** [July 1, 2006, 3:07am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/6 "2006-07-01T03:07:14Z")
Only thing that will work is colony ships,one way never to return. If you leave on the ship Earth on longer matters,except for radio for a few years. Stay behind and the people who leave are gone for good. Sorry but no contact between the two, but we should do it anyway.MHO. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 1, 2006, 4:18am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/7 "2006-07-01T04:18:58Z")
> [@CalMeacham](#): > > Before he died, former Hughes researcher (later founder of Forward Enterprises) Robert L. Forward wrote and lectured about constructing laser-driven “webships”, ultralight lightsail craft capable of interstellar travel on believable timetables. They’d have to be ultralight (no human passengers), and driven by huge lasers back home over long periods of time Sure, but this violates the “didn’t take years” stipulation of the OP. Lots of people have suggested long-term ways to get to the stars, but that’s specifically what the OP didn’t want. I realize that people are going to list these anyway because otherwise the thread would come to a thudding end. 🙂 ---
**Author:** ![Diogenes\_the\_Cynic](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@Diogenes\_the\_Cynic](https://boards.straightdope.com/u/Diogenes_the_Cynic)\ **Post date:** [July 1, 2006, 4:36am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/8 "2006-07-01T04:36:17Z")
This very problem is the reason that so little credence is given to the possibility of extraterrestrial visitation. The problem is not that ETs can’t theoretically exist (they can) but that the distance between stars is so great that the likelihood any of them finding their way to us is infinitesimal, the chance that they would be able to shuttle back and forth between their world and ours even more so. Alas, hypothetical modes of hyperspeed or even light speed travel (for people anyway) are barely any more realistic than time travel at this point. I don’t know if technology will ever be able to help us on that one. ---
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [July 1, 2006, 6:00am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/9 "2006-07-01T06:00:10Z")
> [@Exapno Mapcase](#): > > Sure, but this violates the “didn’t take years” stipulation of the OP. Lots of people have suggested long-term ways to get to the stars, but that’s specifically what the OP didn’t want. I’m not so sure. [This proposal](http://www.guardian.co.uk/medicine/story/0,11381,651199,00.html) calls for ultralights attached to 10 mile wide sails and powered by orbital lasers. It might reach 10% of the speed of light or more - fast enough to reach alpha Centuri in 40 years. Of course there’s the small matter of slowing down. Back to the drawing board. In other news, here’s a [space.com](http://space.com) article on interstellar flight: [How to Get to Alpha Centauri | Space](http://www.space.com/businesstechnology/technology/interstellar_travel_031217-1.html) ---
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [July 1, 2006, 6:07am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/10 "2006-07-01T06:07:08Z")
> [@Diogenes the Cynic](#): > > The problem is not that ETs can’t theoretically exist (they can) but that the distance between stars is so great that the likelihood any of them finding their way to us is infinitesimal, the chance that they would be able to shuttle back and forth between their world and ours even more so. But recall the [Fermi Paradox](http://en.wikipedia.org/wiki/Fermi_paradox). Shuttling back and forth may be impossible, but a long term colonization program is more plausible: an entire galaxy might be explored in only 5-50 million years. (Source: See footnote 3 in the Wiki article). ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [July 1, 2006, 8:34am UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/11 "2006-07-01T08:34:54Z")
[Someone might have figured something out.](http://boards.straightdope.com/sdmb/showthread.php?t=352753) > [@](#): > > EVERY year, the American Institute of Aeronautics and Astronautics awards prizes for the best papers presented at its annual conference. Last year’s winner in the nuclear and future flight category went to a paper calling for experimental tests of an astonishing new type of engine. According to the paper, this hyperdrive motor would propel a craft through another dimension at enormous speeds. It could leave Earth at lunchtime and get to the moon in time for dinner. There’s just one catch: the idea relies on an obscure and largely unrecognised kind of physics. Can they possibly be serious? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 1, 2006, 3:11pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/12 "2006-07-01T15:11:33Z")
> [@](#): > > Can they possibly be serious? Short answer: No. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [July 1, 2006, 3:26pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/13 "2006-07-01T15:26:30Z")
A lot of these wormhole and gravity manipulation ideas aren’t exactly forbidden by physics…they just require exotic materials that we have no reason to suspect actually exist. So when you come up with material with negative mass let me know, I’ll start building your wormhole then. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [July 1, 2006, 3:56pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/14 "2006-07-01T15:56:46Z")
The Bussard ramjet is promising – but is there enough free hydrogen between stars to fuel one? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 1, 2006, 4:03pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/15 "2006-07-01T16:03:02Z")
> [@BrainGlutton](#): > > The Bussard ramjet is promising – but is there enough free hydrogen between stars to fuel one? [No](http://en.wikipedia.org/wiki/Bussard_ramjet). Even if the drag force was conquered, the scoop wouldn’t be large enough to achieve high relativistic speeds. Of coure, I’ve used it in stories myself, conveniently ignoring the problems. You have to get to the stars somehow. 🙂 ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [July 1, 2006, 4:33pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/16 "2006-07-01T16:33:55Z")
> [@Measure for Measure](#): > > I’m not so sure. > > [This proposal](http://www.guardian.co.uk/medicine/story/0,11381,651199,00.html) calls for ultralights attached to 10 mile wide sails and powered by orbital lasers. It might reach 10% of the speed of light or more - fast enough to reach alpha Centuri in 40 years. > > Of course there’s the small matter of slowing down. Back to the drawing board. Actually, that’s been solved. You make the center of the sail detachable, and release it when you need to stop. If it’s configured right, the laser will bounce off it, hit the main sail _from the front_ and slow you down. > [@BrainGlutton](#): > > The Bussard ramjet is promising – but is there enough free hydrogen between stars to fuel one? Besides what the article linked by \*\*Exapno Mapcase \*\* said, we happen to be in a low density bubble, due to an ancient supernova. Even if it worked, there’s not enough fuel. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [July 1, 2006, 4:40pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/17 "2006-07-01T16:40:26Z")
> [@Glaze](#): > > Only thing that will work is colony ships,one way never to return. Oh, I don’t know about that. I wouldn’t rule out some form of suspended animation, like cryogenic storage. Granted, such a system would require an extremely high degree of reliability and would therefore be horrendously expensive, but it’s at least a possibility in theory. If such a system were workable, our astronaut(s) could return, although Earth would be practically unrecognizeable to them. ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [July 1, 2006, 5:31pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/18 "2006-07-01T17:31:49Z")
A lot of the pessimism/skepticism in this thread reminds of the comments many people made when new types of transportation were about to become reality (such as flight). It is highly likely that a future society may devise some new currently unimaginable technology which would make interstellar travel a piece of cake. Or not. Perhaps the economics would be prohibitive even if physically possible. Either way I’m not about to sit here in CE 2006 and tell someone in 3132 that what they are doing is impossible. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 1, 2006, 6:04pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/19 "2006-07-01T18:04:56Z")
> [@John DiFool](#): > > A lot of the pessimism/skepticism in this thread reminds of the comments many people made > when new types of transportation were about to become reality (such as flight). It is highly > likely that a future society may devise some new currently unimaginable technology which > would make interstellar travel a piece of cake. > > Or not. Perhaps the economics would be prohibitive even if physically possible. Either way > I’m not about to sit here in CE 2006 and tell someone in 3132 that what they are doing is > impossible. And what part of “current physics” in the OP did you miss? ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [July 1, 2006, 6:42pm UTC](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818/20 "2006-07-01T18:42:20Z")
This is like 18th Century people speculating on whether it’s possible to break the sound barrier when the fastest things available are racehorses and clipper ships. Before we can even think of going to the stars, we need to find a way to [propel a spaceship without expelling any reaction mass.](http://boards.straightdope.com/sdmb/showthread.php?t=168034) I see no other way to get a constant-boost drive. [Next page](https://boards.straightdope.com/t/is-there-any-realistic-mode-of-interstellar-travel/362818.md?page=2)