Touching The Limits Of Knowledge

Cosmology and our View of the World


In Search for Life/Intelligence Beyond Earth
Lead: Christin Chenard, Josh Jones & Liz Poulsen


Summary by Dan Widrew:


In Search for Life/Intelligence Beyond Earth

The presenters began by outlining the major questions they would cover. These were:

  1. Is there intelligent life in the universe?

  2. What would it be? If we found it, would we be able to tell? Could we communicate with it?

  3. What would the impact be if extraterrestrial intelligence (ETI) was discovered? How would this change our understanding of biology, life, philosophy, religion, etc?

To start off the discussion, Liz played a few clips from the movie Contact, which apparently SETI (Search for Extraterrestrial Intelligence) praised for its accuracy. The first clip was a long zoom out, starting on Earth and moving far off into the solar system, then galaxy, then universe. As the camera pulled further back, older radio transmissions were played. The point: we are sending out signals into space that fill a larger and larger sphere around Earth with radio/television signals.
The next clip was the moment in the movie when we first receive signals from the aliens. The last clip was many people's response to this: evangelists and alien worshippers and anti-science people all making a circus of the whole mess. This was shown to give some idea of how people may respond to a real-life contact with ETI.

Christin at this point began talking about the Drake Equation, which computes the number of communicating civilizations in the galaxy. She made the point that there is no way to get exact answers for most of the numbers in the DE, but by looking for them we are pointed in the right directions of what we should be thinking about. The ideas are more important than the numbers. She mentioned though, that on the website, you can try the DE for yourself, and that she got answers from 0.5 to 10,000. Prof. Mobius pointed out how much more we know now about the galaxy than we did when the DE was thought up. For example, we didn't know about planets outside our solar system until 1990.

Josh drew a diagram showing how far we are from other stars and the galactic center. He also pointed out that we haven't even had radio waves yet for 100 years (this compared with the diameter of the Milky Way itself: approximately 100,000 light years). The margin of catching another civilization at near the same point we are at is very small.

Some discussion began at this point about how long it would take for intelligent life to evolve under various conditions, but we don't know enough for a very specific answer. One student stated he considers DE presumptuous. If there is a God, doesn't he decide where and when intelligence can flourish? This would make the probabilities of the DE irrelevant. Prof Mobius' response was that God could have chosen to leave things to chance, and isn't everything more interesting from that perspective? Science, Prof Davis then says, does not need the supernatural, and many scientists don't believe in God. Deism (the idea of a 'watchmaker God' letting the Universe run itself) is mentioned.

Josh tells us there are around 100,000 earth-like planets in the Milky Way, and asked if we believe ETI is possible. One response was that our belief doesn't matter if it isn't based on anything definite: science should not be based on feelings and beliefs, but on evidence and investigation. What one believes about the results does not matter as long as they are faithfully reported. A response to that was the search for ETI itself doesn't matter, and it is a waste of resources. There are myriad problems here on Earth - poverty, disease, etc - that need our attention before all this money is spent on the tiny chance that we find a radio signal from someone who wants to talk. These points are debated but no agreement is reached.

Prof Davis says he thinks there is probably a lot of ETI in the galaxy and that it is likely humanoid. The reasoning behind this is that any ETI we would be able to communicate with would have to have evolved in at least somewhat similar conditions, and is likely to therefore have evolved along similar lines, as life on Earth seems to suggest that the forms that have evolved here are well-suited for their environments.

Some history of SETI is given. It originally was Government funded but is now largely private funding. The Pioneer 10 craft is now twice the distance of Pluto from us (7.4 billion miles) and has been going for 31 years. There are 350 radio telescopes looking at the sky. In response to questions about radio wave degradation, Von Newman (self-replicating) machines are mentioned as an alternative that would not degrade, but they don't seem very effective with speed being their primary limitation.

Liz hands around pictures of the "pyramids" and the "face" on Mars. A lot of speculation has been made about these and the mysterious angle ratios, but they do not show up in more accurate photographs from more recent space missions to Mars. Liz asked us what we thought would happen if proof of ETI was found, and would the Government try to cover it up? Prof Mobius says that they may try but science will not let that happen. If a discovery is made, it will be tested and confirmed, then announced, even if there is danger in doing so. History supports this. A student makes the point that religions would be able to adapt their ideas to fit if the discovery was made.

Christin asks us how would people react if ETI was found? And how would the aliens view us? Would they be so advanced as to make us the equivalent of finding a new species of field mice? Prof Davis says that if they evolved Darwinian style, they would initially see us as threat/competition. It is pointed out that the Earth-like planets the DE looks for would probably encourage human-like evolution to occur, but the counter-argument is that evolution even on Earth is more chaotic than we expect. We don't have enough to judge by.

Liz asks why people have such a need to find ETI and why people want to leave the planet. (Specifically, she mentioned people wanting to live on Mars). The answer given is that the Earth won't support us forever, and to survive we will need to leave. I think also that humanity has a natural urge towards exploration and discovery, but this aspect wasn't discussed. There was debate on our ability to survive off Earth. Would we be able to recreate our Earth environment? Would we want to? The analogy is made to invasive species on Earth-- we might thrive in a new environment.

At this point it was 8pm and I left, but the discussion was still going strong.