Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Far or Near

  1. May 25, 2004 #1
    Would you please tell me how far people have gone to explore the Universe ?
    Why do people keep wondering if there exists to be any lifeforms in outer space ? Do we already have any evidence about them ?

    Thank you,
  2. jcsd
  3. May 25, 2004 #2
    Many radio antennas and such are comitted to listening for alien signals, SETI being one of the larger organizations. As to why we wonder whether or not there are other lifeforms out there, who hasn't ever looked up at the sky and asked that question? It is human curiosity. As of yet there are plenty of UFO sightings and such, but no solid proof of alien lifeforms. (At least not officialy :rolleyes: )
  4. May 25, 2004 #3
    That mean you ask that question whenever lookin up the sky ?????
    I never do that ! I used to hear that on TV about aliens. Perhaps I have met some around here... I will go check again :tongue:
  5. May 25, 2004 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Manned missions have reached the Moon (a quarter million miles away).

    Robotic spacecraft have gone past the outermost planet (Pluto) in our solar system, but have not left our solar system (billions of miles away).

    Telescopes are used to explore the universe almost all the way back to the beginning (billions of trillions of miles).

    In each case, we've only explored a tiny fraction of what there is out there.

    Human curiosity & a desire to know our place in the universe.

    Many people here will say no. But the level of "no" varies. Some people say there is absolutely no evidence (but many of them will agree that it's possible that there is other life out there). Others say that there is no definitive evidence, but there are some good suggestions (go check out our Skepticism forum & talk with Ivan).

    As Grizzlycomet said, the SETI program is the biggest scientific search for intelligent alien life. NASA (and others) are searching for any life too (for example, the Mars rovers looking for water, telescopes looking for planets around other stars, etc.).
  6. May 25, 2004 #5
    It might have some relevance to questions involving entropy principles to know if technologically advanced life exists elsewhere in the universe. Could it be that there exists some sort of entropy balance requirement that would require the existence of complex life forms?
  7. May 25, 2004 #6
    Firstly, Thank you Phobos a lot for your useful information.

    Mike2, can you please tell me what book i should read about entropy principles? Is that the entropy usually mentioned in thermodynamics-physics books ?
    Thank Mike a lot, also.
  8. May 26, 2004 #7
    Try reading Cosmic Evolution, by Eric J. Chaisson. This book describes how complexity can arise in nature. This is not a physics text book, though. It does not cover entropy in detail. I suppose any undergraduate general physic text will have a more in depth introduction to entropy in it.
  9. May 26, 2004 #8
    Thank you very much,
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook