Jump to content

Intergalactic travel

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Nicholas Weiner (talk | contribs) at 03:27, 21 June 2011. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Intergalactic travel is space travel between galaxies. Due to the relatively enormous distances between our own galaxy and even its closest neighbors, any such venture would be far more technologically demanding than even interstellar travel. In comparison, intergalactic distances are roughly one-million fold (six orders of magnitude) greater than their interstellar counterparts.

The difficulties of intergalactic travel

Intergalactic travel, as it pertains to humans, is impractical by modern engineering ability and is considered pure science fiction. It would require the available means of propulsion to become advanced far beyond what is currently thought possible to engineer in order to bring a large craft close to the speed of light. While it takes light approximately 2.54 million years to traverse the gulf of space between Earth and the Andromeda Galaxy, it would take an arbitrarily short amount of time for a traveler at relativistic speed due to the effects of time dilation; the time experienced by the traveler depends both on velocity, being anything less than the speed of light, and distance traveled (length contraction).

Unless the craft were capable of reaching extreme relativistic speeds, another obstacle would be to navigate the spacecraft between galaxies and succeed in reaching any chosen galaxy, star, planet or other body, as this would need an understanding of galactic movements and their coordination that is as of yet not understood.

In addition, the craft would have to be of considerable size and, without reaching speeds with noteworthy relativistic effect as mentioned above, it would also need a life support system and structural design able to support human life through thousands of generations and last the millions of years required, including the propulsion system—which would have to work perfectly the millions of years after it was built to slow down the machine for its final approach.

Even for unmanned probes which would be much lighter in mass, the problem exists that the information they send can only travel at light speed, which would mean millions of years just to receive the data they send.

Current physics states that an object within space-time cannot exceed the speed of light,[1] which seemingly limits any object to the millions of years it would at best take for a craft traveling near the speed of light to reach any remote galaxy. Science fiction frequently employs speculative concepts such as wormholes and hyperspace as more practical means of intergalactic travel to work around this issue.

Natural intergalactic travel

Theorized in 1988,[2][3] and observed in 2005,[3][4] there are stars moving faster than the escape velocity of the Milky Way, and are traveling out into intergalactic space.[3] A theory for their existence is that the supermassive black hole at the center of Milky Way ejects stars from the galaxy at a rate of about one every hundred thousand years.[3] By 2010, sixteen hypervelocity stars have been observed.[3][5] Intergalactic dust is also thought to be ejected from galaxies, and has been observed in intergalactic space.[6]

See also

References

  1. ^ Star Trek's Warp Drive: Not Impossible from space.com
  2. ^ Hills, J. G. (1988). "Hyper-velocity and tidal stars from binaries disrupted by a massive Galactic black hole". Nature. 331 (6158): 687–689. Bibcode:1988Natur.331..687H. doi:10.1038/331687a0.
  3. ^ a b c d e Ray Villard - The Great Escape: Intergalactic Travel is Possible(May 24, 2010) - Discovery News (accessed October 2010)
  4. ^ Brown, Warren R. (2005). "Discovery of an Unbound Hypervelocity Star in the Milky Way Halo". Astrophysical Journal. 622 (1): L33–L36. Bibcode:2005ApJ...622L..33B. doi:10.1086/429378. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  5. ^ Edelmann, H. (2005). "HE 0437-5439: An Unbound Hypervelocity Main-Sequence B-Type Star". Astrophysical Journal. 634 (2): L181–L184. Bibcode:2005ApJ...634L.181E. doi:10.1086/498940. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  6. ^ M. E. Bailey, David Arnold Williams - Dust in the universe: the proceedings of a conference at the Department of Astronomy, University of Manchester, 14-18 December 1987 - Page 509 (Google Books accessed 2010)
Retrieved from "https://en.wikipedia.org/w/index.php?title=Intergalactic_travel&oldid=435393463"