Cosmology and our View of the World
Life in the Universe
Lead: Gregory Kiker & Katy Randall
Summary by Vanessa Ruiz
Search for Life beyond Humans
As we persist in our quest for an understanding of the wilderness of space, Greg and Katy aid us as we digest the question “are we alone in this vast universe?” Dissecting the process of searching the universe for signs of life and intentional signals from aliens, we see the delicate complexities of our habitable zone. Wrestling with the challenges and adventures of the search, we settled on the main thing being we must not give up and always continue searching.
Setting in motion our discussion, we identified two strategies for the pursuit of intelligent life in space. On one hand, we must develop an accurate way to look for aliens directly by searching the universe for signs of life and intentional signals from aliens. On the other hand, we must pursue a deeper understanding of our planet and other planets and of how life evolved here.
SETI, (searching for extraterrestrial intelligence), for the last 50 years, has had volunteers from around the world who have assisted in the search for life. SETI scientists also examine laser messages being shot into space in hopes for a return signal. The question that came up in our discussion, what if we did find intelligent life, how similar to humans would that intelligent life actually be? What kind of genetic language would they adhere to?
Keeping faith in the search, we pointed out that, although we’ve had no discovery yet of extraterrestrial intelligence, absence of evidence is not evidence for absence of intelligent life in the universe.
We moved on to talk about the Drake Equation created by Frank Drake, as a way “to organize our guesses about the potential number of extraterrestrial civilizations in our galaxy, the Milky Way.” We used the Internet to try to use the Drake Equation calculator.
The process is broken down as follows:
N = the number of communicative civilizations in the Milky
R* = is the average rate at which suitable stars- those that could potentially harbor life- are born each year in our galaxy
fp = the fraction of those stars that have planets
ne = the number of planets per star that are in principle suited for life
fl = the fraction of habitable planets on which life actually originates
fi = the fraction of life bearing planets where intelligent life emerges
fc = the fraction of those planets on which technology capable of producing detectable signals develops
L = the average lifetime of a communicating civilizations
The presenters then asked the question, what made life possible on Earth and what role did special conditions play? They provided the key properties that make earth suitable for life as basis for this question.
1. Jupiter and Earth's nearly circular orbits have been favorable for life's
2. Earth's distance from the sun is in the “habitable zone” of the solar system
3. Earth's relatively thin crust and abundant surface water allow continued geological activity
4. The moon which stabilizes earth's rotation and climate
5. Our solar system lies in the “galactic habitable zone”
The habitable zone in our solar system is the region around Mars, Earth, and Venus where temperatures are moderate. As a result of the complexities of the habitable zone and solar system, I feel really lucky to be alive. This concept brought the conversation in an interesting direction. As for the galactic habitable zone, stars with life-bearing planets need to be far enough away from the galaxy center so that there is not too much deadly radiation from supernovae. From the other side, the stars must be still close enough so that a significant amount of heavy elements formed through supernovae.”
The question arose in reflection on our habitable zone, how do we get life from non-life? Professor deVries used the example of making salad dressing to conceptualize non-living elements mixed with other non-living elements creating something. The question then was posed, why is there only one genetic code and where did it come from? Did it travel to earth? The concept of DMT, was then discussed. According to Wikipedia, DMT is Dimethyltryptamine, a naturally occurring psychedelic drug. It is produced in the Pineal Gland and is released naturally three times during life, birth, death, and in dreams. We pondered how people said to be on DMT have heightened perceptions and are potentially able to communicate with intelligent life in the universe.
There was talk about Darwin’s “sexual selection” that the human mind evolved because it was selected in mating; humans are attracted to intelligence when choosing mates. Continuing on in discussion, we questioned, if evolution started over on earth, what would be different or would everything be the same? I find it hard to believe that everything would be the same, judging by the complexities within living organisms.
The concept of Panspermia was mentioned. It is defined according to Wikipedia as, “The hypothesis that "seeds" of life exist already all over the Universe, that life on Earth may have originated through these "seeds", and that they may deliver or have delivered life to other habitable bodies”. I think maybe based on the infinite size of the universe these seeds could exist in places we have not discovered yet and are waiting to be united in some way with a place to grow. Our pondering concluded with questions without answers that lead us to another week of exploring the universe and never giving up on our quest. In conclusion, it seems so unrealistic to say that out of the vastness of the universe there isn’t any intelligent life. I think there has to be life based on the size of the universe, and one day, one way or another, we will communicate with it.