What do you get from 100 billion galaxies, each made up of about 100 billion stars, when half to three-quarters of each star is home to at least one planet?
You get life, and a lot of it, according to Seth Shostak of the SETI institute. Shostak gave a lecture titled "When Will We Find the Extraterrestrials? (And What Will We Do When We Find Them?)" last night as part of the Interdisciplinary Seminar for Humanities and Arts lecture series.
As a senior astronomer at SETI, Shostak has authored a number of articles and books, worked on documentaries, podcasts and has been a consultant on science-fiction movies.
The acronym SETI stands for the Search for Extraterrestrial Intelligence. Given the staggering number of stars in the universe, life, never mind intelligence, is extremely difficult to find Shostak said.
"This has been likened to looking for a needle in a haystack," he said. "You know how big the haystack is, we know how fast we're looking…what we don't know is how many needles there are, if any."
The near infinite amount of stars make the search for life seem daunting, gives confidence to the members of SETI. Given that there about one hundred sextillion stars that are visible to us on Earth, it seems impossible that Earth occupies the singular unique place in the universe that allows life to exist, according to Shostak
"You have to admire that point of view. It's audacious. It makes you special" he said.
That's not to say all life in the universe will have reached the level of intelligence achieved by humans. It is possible that even planets or moons in our own solar system are supporting or supported microbial life.
Shostak and the other scientists working at SETI aren't interested in microbial life. They are focused on beings that have reached at least the brain power of humans, life forms capable of interstellar communication.
Shostak discussed the different methods of detecting extraterrestrial intelligence. The first method is to look for artifacts. He addressed crop circles, saying it is highly unlikely they were caused by aliens.
"These things tend to pop up overnight…and over the weekends," he said. "Maybe [the aliens] have strange labor laws." He outlined an extraterrestrial senate's elaborate plan to come to Earth and "carve graffiti in their wheat," highlighting the ridiculousness of the charge. He chalked it up to students who get too bored on the weekends.
It is possible to detect life by looking for signs of astro-engineering, or means of travel through space. Because the age of the universe, (about 13.7 billion years) is so much older than the age of our solar system (about 4.6 billion years), it's feasible that other planets had billions of years longer than us to create life said Shostak.
"Plenty of time for societies to be literally billions of years ahead of us," he said.
The most plausible way of detecting life, however, seems to be looking for a radio broadcast from other worlds. No matter what alien beings might be doing in their day to day life, they could be broadcasting, much like we have been for decades.
He showed a photo of a large detector set up in Puerto Rico that can see one third of the sky and can detect a few thousand watts. This detector looks for a narrow band signal, or small disturbances in radio waves that are not accounted for in earthly routines. According to Shostak, we need to "find the 'on the air' sign."
If we are going to find these broadcasts, Shostak believes that they will be detected within 24 years. He cited numbers provided by three prominent astronomers, Carl Sagan, Isaac Asimov and Frank Drake. The three predicted extraterrestrial intelligence will be detected between 2015 and 2026.
"I feel moderately strong this is correct," Shostak said. "I bet you a Starbucks coffee." He continued to say that unless there is something fundamentally wrong with our calculations we will have made contact by the year 2026.
But who's to say the aliens haven't already arrived? According to statistics offered by Shostak, pulled from a poll conducted by CNN, 65 percent of Americans indicated they believe there was a UFO crash in Roswell, N.M., while 80 percent say the government is hiding information about aliens.
Shostak is very skeptical about this saying that aliens crashing in Roswell would mean they successfully navigated billions of light years, then "make a navigational error over the deserts of New Mexico."
And aliens would have to travel billions of light years. Unless aliens were out, perusing the galaxy for planets rife with life, they would be unable to detect planet Earth until relatively recently.
The light year, which is a unit of distance, is measured by the amount of distance traveled by light in one year. Light does not travel from one point to another instantaneously. Instead, it has a speed limit.
All light travels at exactly 300,000 kilometers per second. A light year is the how far light travels in 31,556,926 seconds, which turns out to be a little more than 9 trillion kilometers.
Earth started broadcasting its location about 60 years ago with television and radio. These signals have only been able to travel 60 light years in that time.
"If they're here now, they can't be [living] more than 30 light years away," Shostak said.
Since nothing can move faster than the speed of light, it would take 30 light years for the information to reach the aliens, then 30 light years for them to reach Earth. Because there are only a couple thousand stars in that radius from Earth, it seems unlikely that this is the case said Shostak.
Aliens probably aren't here on Earth, and we are another couple of decades away from detecting their signals. This gives Shostak and other SETI scientists time to reflect on what they will do when they finally make contact.
"The first thing that would happen," Shostak said, "We would open the bottle of the champagne that is sitting in the refrigerator."
The astronomers can also imagine what the extraterrestrials would look like, or what they would do to the planet. Right now, they don't have too many ideas.
"Fortunately, Hollywood does," he joked. "They're either here to trash the planet or abduct you."
As for the bulbous head and black, almond shaped eyes? "This is just a representation of what we think we're going to become," he said. Shostak believes, with the exponential rate at which technology evolves, any contact with aliens will be contact with artificial intelligence, the remnants of a highly evolved civilization.
One major question Shostak asked is "If we ever do make contact, will we even understand what we are hearing?"
"If we pick up a signal not meant for us, we may never figure it out," he said.
This leads to a question that was inevitably asked during the Q&A session at the end of the lecture - "why even bother?".
"I think [we] do this because of curiosity," he said. It comes from a need to know whether life here on Earth is special, or, as he said, "is this something as common as cheap motels?"
Stephanie McPherson can be reached at smcphers@student.umass.edu.
Be the first to comment on this article!