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Text File  |  1992-11-18  |  1.8 KB  |  31 lines
  1. Newsgroups: rec.puzzles
  2. Path: sparky!uunet!charon.amdahl.com!pacbell.com!ames!saimiri.primate.wisc.edu!zaphod.mps.ohio-state.edu!news.acns.nwu.edu!ftpbox!mothost!lmpsbbs!sleipnir.mnesouth.corp.mot.com!johnson
  3. From: johnson@sleipnir.mnesouth.corp.mot.com (Mark Johnson)
  4. Subject: Re: Billion-year survivability
  5. Reply-To: johnson@sleipnir.mnesouth.corp.mot.com
  6. Organization: Motorola Wireless Enterprises, Schaumburg, IL
  7. Date: Wed, 18 Nov 1992 15:55:17 GMT
  8. Message-ID: <1992Nov18.155517.19541@lmpsbbs.comm.mot.com>
  9. References: <1992Nov10.114703.26890@ugle.unit.no> <1992Nov12.195311.22523@wisipc.weizmann.ac.il> <1992Nov17.163245.14885@oucsace.cs.ohiou.edu> <1992Nov18.025956.9361@cs.cornell.edu>
  10. Sender: news@lmpsbbs.comm.mot.com (Net News)
  11. Nntp-Posting-Host: 129.188.176.18
  12. Lines: 17
  13.  
  14. In article <1992Nov18.025956.9361@cs.cornell.edu>, karr@cs.cornell.edu (David Karr) writes:
  15. =)Now, what is the power of the signal you receive back after a billion
  16. =)years, after taking into account the dissipation of the signal over
  17. =)these large spheres of propagation?  (Just to add insult to injury,
  18. =)don't forget to include the Doppler red-shift due to the motion of
  19. =)your reflector due to the expansion of the universe.)  What is an
  20. =)appropriate unit in which to measure the power?  electron-volts
  21. =)per second?  Or micro-, pico-, or atto-ev per second?  Per year?
  22.  
  23. Pick a frequency and try photons/minute.
  24. -- 
  25. +-----------------------------------------------------------------------------+
  26. | "Johnson"                              |Just because you're paranoid doesn't|
  27. | johnson@sleipnir.mnesouth.corp.mot.com |   mean they're not out to get you. |
  28. +-----------------------------------------------------------------------------+
  29. | Let's face it; if our lawyers knew what went on here, they'd shut us down.  |
  30. +-----------------------------------------------------------------------------+
  31.