World Library  
Flag as Inappropriate
Email this Article

Superluminal communication

Article Id: WHEBN0000028751
Reproduction Date:

Title: Superluminal communication  
Author: World Heritage Encyclopedia
Language: English
Subject: Faster-than-light, BattleTech, Star League, Ansible, Faster-than-light communication
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Superluminal communication

Superluminal communication is the hypothetical process by which one might send information at faster-than-light (FTL) speeds. The scientific consensus is that faster-than-light communication is not possible and to date superluminal communication has not been achieved in any experiment.

Some theories and experiments include:

According to the currently accepted theory, three of those four phenomena do not produce superluminal communication, even though they may give that appearance under some conditions. The third, tachyons, arguably do not exist as their existence is hypothetical; even if their existence were to be proven, attempts to quantize them appear to indicate that they may not be used for superluminal communication, because experiments to produce or absorb tachyons cannot be fully controlled.[1]

If wormholes are possible, then ordinary subluminal methods of communication could be sent through them to achieve superluminal transmission speeds. Considering the immense energy that current theories suggest would be required to open a wormhole large enough to pass spacecraft through it may be that only atomic-scale wormholes would be practical to build, limiting their use solely to information transmission. Some theories of wormhole formation would prevent them from ever becoming "timeholes", allowing superluminal communication without the additional complication of allowing communication with the past.

The microscopic causality postulate of axiomatic quantum field theory implies the impossibility of superluminal communication using phenomena whose behavior can be described by orthodox quantum field theory.[2] A special case of this is the no-communication theorem, which prevents communication using the quantum entanglement of a composite system shared between two spacelike-separated observers. Some authors have argued out that using the no-communication theorem to deduce the impossibility of superluminal communication is circular, since the no-communication theorem assumes to start with that the system is a composite system.[3]

However, some argue that superluminal communication could be achieved via quantum entanglement using other methods that don't rely on cloning a quantum system. One suggested method would use an ensemble of entangled particles to transmit information,[4] similar to a type of quantum eraser experiments where the observation of an interference pattern on half of an ensemble of entangled pairs is determined by the type of measurement performed on the other half.[5][6][7] In these cases, though, the interference pattern only emerges with coincident measurements which requires a classical, subluminal communication channel between the two detectors. Physicist John G. Cramer at the University of Washington is attempting to perform one type of these experiment and demonstrate whether or not it can produce superluminal communication.[8][9][10]

See also

References

  1. ^  
  2. ^ Eberhard, Phillippe H.; Ross, Ronald R. (1989), "Quantum field theory cannot provide faster than light communication", Foundations of Physics Letters 2 (2) 
  3. ^ Peacock, K.A.; Hepburn, B. (1999). "Proceedings of the Meeting of the Society of Exact Philosophy". 
  4. ^ Millis, M.G.; Davis, E.W., eds. (2009). Frontiers of Propulsion Science. Progress in astronautics and aeronautics. American Institute of Aeronautics and Astronautics. pp. 509–530. 
  5. ^ Strekalov, D.; Sergienko, A.; Klyshko, D.; Shih, Y. (1 May 1995). "Observation of Two-Photon "Ghost" Interference and Diffraction". Physical Review Letters 74 (18): 3600–3603.  
  6. ^ Dopfer, Birgit (1998). Zwei Experimente zur Interferenz von Zwei-Photonen Zusẗanden (PhD Thesis). Univ. Innsbruck. 
  7. ^  
  8. ^  
  9. ^ Paulson, Tom (14 November 2006). "Going for a blast into the real past". Seattle Post-Intelligencer. Retrieved 11 July 2011. 
  10. ^ Barry, Patrick (30 September 2006). "What's done is done… or is it?".   (subscription required)
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.