SC_NATS1880 A - Life Beyond Earth .odt - Lecture 2 Does life beyond earth exist ● ● Science fiction believes so Scientists are interested about the

SC_NATS1880 A - Life Beyond Earth .odt - Lecture 2 Does...

This preview shows page 1 - 3 out of 19 pages.

Lecture 2: Does life beyond earth exist? Science fiction believes so! Scientists are interested about the possibility but there is no clear evidence. There is some evidence, but it doesn’t pass the strict tests that are required This question is very long-standing: Metrodorus of Chios (4th century B.C) (2 and a half millennia ago) “A single ear of wheat in a large field is as strange as a single world in infinite space.” - School of study he’s coming from envisions the universe as being infinite - It MAY be infinite - Math is not necessary, if you can’t express it in normal speaking, you either don’t understand it or are arrogant - It MAY be the case that we live in a universe that’s 14 billion years old - No doubt that the universe is flying apart, and 14 billion years ago everything was touching, literally - Because it’s only 14 billion years old, we can only see 14 billion light years in each direction - Universe could be infinite but we can only see a small part of it, or this universe may be it Sir Arthur C. Clarke (1917-2008) “Sometimes I think we’re alone in the universe, and sometimes I think we’re not. In either case, the idea is quite staggering.” - Some people think we might be alone in the universe as the most intelligent species, but there’s pretty compelling evidence that there’s not a lot ofd extra terrestial life out there - Imagine what they could teach us - What would happen if we were alone What exactly are we looking for? We are searching for any sign of life, macroscopic (something we can see with eyes) or microscopic (stuff you can’t see with eyes), not just intelligent life. Defining life is not easy (even on Earth!). To begin this search, we tend to look for life we would recognize, such as what we find on Earth. (something familiar) This does not mean that carbon-based life is the
Image of page 1

Subscribe to view the full document.

only form of life that can exist. However, we must start the search somewhere. The notion of life beyond Earth is an old theme but had little factual basis until quite recently. (we have to do everything systematically) “Observations” of canal’s on Mars and jungles on Venus – both erroneous – advanced the notion of life in the Solar System. What we do know now? Macroscopic (multi-cellular) life does not exist anywhere in the Solar System except Earth. Microbial (bacterial) life, perhaps does exist in other locations in the Solar System. Many stars in our Galaxy have planetary systems suggesting many more potential sites for life. (a galaxy is the largest most distinct assembly of stars but they like to get together in groups called a galaxy of around 100 billion. Our galaxy is milky way. Incredible numbers of signs of life in other galaxies) Technology is now available for a more thorough search for signs of life beyond Earth.
Image of page 2
Image of page 3

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Ask Expert Tutors You can ask 0 bonus questions You can ask 0 questions (0 expire soon) You can ask 0 questions (will expire )
Answers in as fast as 15 minutes