Impact: Earth! Astronomy Picture of the Day Archive. Stephen Hawking - Scientists weigh in on Hawking's alien warning. Famed physicist Stephen Hawking set off chatter in the scientific community in late April when he posited the existence of intelligent aliens on his new TV series, "Into the Universe with Stephen Hawking" —adding that it would be best for human beings to avoid contact with them. Hawking speculated that such aliens would likely be nomads, living in ships after sucking their own planet dry of resources, and hopping from one interstellar refueling station to the next.
Earth, he said, shouldn't do anything to encourage their visit. "If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn't turn out very well for the Native Americans," he said. Hawking has made such statements for years — in a 1996 essay, for example, he said humans should be "wary of answering [aliens]" until our species has become more sophisticated. The Journal of Cosmology compiled responses from a dozen scientists and has published them online. Randy D. The Physics of Extraterrestrial Civilizations : Welcome to Explorations in Science with Dr. Michio Kaku.
How advanced could they possibly be? The late Carl Sagan once asked this question, “What does it mean for a civilization to be a million years old? We have had radio telescopes and spaceships for a few decades; our technical civilization is a few hundred years old… an advanced civilization millions of years old is as much beyond us as we are beyond a bush baby or a macaque.” Although any conjecture about such advanced civilizations is a matter of sheer speculation, one can still use the laws of physics to place upper and lower limits on these civilizations.
In particular, now that the laws of quantum field theory, general relativity, thermodynamics, etc. are fairly well-established, physics can impose broad physical bounds which constrain the parameters of these civilizations. This question is no longer a matter of idle speculation. But the best is yet to come. Physics of Type I, II, and III Civilizations 1) The laws of thermodynamics. 2) The laws of stable matter. New Developments. Every black hole may hold a hidden universe - space - 23 July 2010. Sixty Symbols - Physics and Astronomy videos. 40 Mind-Blowing Hubble Astrophotographs. The natural beauty of our universe is absolutely astounding. Whether they’re once-in-a-lifetime sights like supernovae, or just the everyday brilliance of the starry skies, humanity has been captivated by the heavens for thousands of years. Even in the past decade, our understanding of our universe, and even our own galaxy has increased measurably, but we are still only scratching the surface of the mysteries of our universe.
In this post, we’ve rounded up 40 absolutely mind-blowing, breathtaking and stunning astrophotographs from the Hubble Space Telescope’s website, From brilliant whirlpool galaxies to star clusters containing thousands, millions, possibly even billions of stars, and gaseous nebulae that will leave you breathless, you’ll be left in wonder by the beauty of the cosmos. Hopefully you enjoy the post, if you do, check out HubbleSite’s full galleries, they have a ton more brilliant images.