NS> Vol.4 No.10, October 2012
Views: 33,134    Downloads: 12,262

Speed kills: Highly relativistic spaceflight would be fatal for passengers and instruments

DownloadDownload as PDF (Size:216KB) Full-Text HTML PP. 749-754   DOI: 10.4236/ns.2012.410099

ABSTRACT

Highly relativistic speeds are desirable for interstellar travel. Relativistic time dilation would reduce the subjective duration of the trip for the travelers, so that they can cover galaxy-scale distances in a reasonable amount of personal time. Unfortunately, as spaceship velocities approach the speed of light, interstellar hydrogen H, although only present at a density of approximately 1.8 atoms/cm3, turns into intense radiation that would quickly kill passengers and destroy electronic instrumentation. In addition, the energy loss of ionizing radiation passing through the ship’s hull represents an increasing heat load that necessitates large expenditures of energy to cool the ship. Stopping or diverting this flux, either with material or electromagnetic shields, is a daunting problem. Going slow to avoid severe H irradiation sets an upper speed limit of v ~ 0.5 c. This velocity only gives a time dilation factor of about 15%, which would not substantially assist galaxy-scale voyages. Diffuse interstellar H atoms are the ultimate cosmic space mines and represent a formidable obstacle to interstellar travel.

KEYWORDS


Cite this paper

Edelstein, W. and Edelstein, A. (2012) Speed kills: Highly relativistic spaceflight would be fatal for passengers and instruments. Natural Science, 4, 749-754. doi: 10.4236/ns.2012.410099.

References

[1] Forward, R.L. (1984) Roundtrip interstellar travel using laser-pushed lightsails. Journal of Spacecraft, 21, 187- 195. doi:10.2514/3.8632
[2] Krauss, L.M. (1995) The physics of star trek. Harper Perennial, New York.
[3] Forward, R.L. (1984) Flight of the dragonfly. Simon and Schuster, New York.
[4] French, A.P. (1968) Special Relativity. CRC Press, Boca Raton.
[5] Gibbs, P. and Koks, D. (2006) The relativistic rocket. http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html
[6] Purcell, E.M. (1963) Radioastronomy and communication through space. In: Cameron, A.G.W., Ed., Interstellar Communication, W. A. Benjamin, Inc., New York.
[7] Ewen, H.I. and Purcell, E.M. (1951) Observation of a line in the galactic radio spectrum. Nature, 168, 356. doi:10.1038/168356a0
[8] Muller, C.A. and Oort, J.H. (1951) The interstellar hydrogen line at 1420 Mc./sec., and an estimate of galactic rotation. Nature, 168, 357-358. doi:10.1038/168357a0
[9] Frederick, L.W. (1989) Astronomy and astrophysics. In Anderson, H.L., Ed., A Physicists Desk Reference, American Institute of Physics, New York, 66-78.
[10] Resnick, R. and Halliday, D. (1992) Basic Concepts in Relativity. Maxwell Macmillan International, New York.
[11] Mermin, N.D. (2005) It’s about time. Princeton University Press, Princeton.
[12] Hellweg, C.E. and Baumstark-Khan, C. (2007) Getting ready for the manned mission to Mars: The astronauts’ risk from space radiation. Naturwissenschaften, 94, 517- 526. doi:10.1007/s00114-006-0204-0
[13] “Alpha Centauri,” Wikipedia. http://en.wikipedia.org/wiki/Alpha_Centauri#cite_note-S-9
[14] Gilster, P. (2011) What are the fastest spacecraft we’ve ever built? http://io9.com/5786083/what-are-the-fastest-spacecrafts-ever-built
[15] “Milky Way,” Wikipedia. http://en.wikipedia.org/wiki/Milky_Way#cite_note-ask-astro-0
[16] Bichsel, H., Groom, D.E. and Klein, S.R. (2010) Passage of particles through matter. http://pdg.ge.infn.it/reviews/rppref/sports/2010/passage-rpp.pdf
[17] Wrixon, A.D. (2008) New ICRP recommendations. Journal of Radiological Protection, 28, 161-168. doi:10.1088/0952-4746/28/2/R02
[18] Turner, J.E. (2007) Atoms, radiation and radiation protection. 3rd Edition, Wiley-VCH, Berlin.
[19] Lefevre, C. (2009) CERN Faq: LHC, the guide. http://tinyurl.com/yfcowz5
[20] Dodd, P.E., et al. (2010) Current and future challenges in radiation effects on CMOS electronics. IEEE Transactions on Nuclear Science, 57, 1747-1763. doi:10.1109/TNS.2010.2042613
[21] Townsend, L.W. (2005) Critical analysis of active shielding methods for space radiation protection. 2005 IEEE Aerospace Conference, Montana, 5-12 March 2005, 724- 730.
[22] Schenck, J.F. (2005) Physical interactions of static magnetic fields with living tissues. Progress in Biophysics & Molecular Biology, 87, 185-204. doi:10.1016/j.pbiomolbio.2004.08.009
[23] Burger, M.J., et al. (1993) Stopping powers and ranges for protons and alpha particles. ICRU Report, Report NO. 49.
[24] “pstar: Stopping-Power and Range Tables for Protons,” http://physics.nist.gov/PhysRefData/Star/Text/PSTAR.html

comments powered by Disqus

Copyright © 2014 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.