Photonics advances allow us to be seen across the universe, with major implications for the search for extraterrestrial intelligence, says UC Santa Barbara physicist Philip Lubin
Looking up at the night sky — expansive and seemingly endless, stars and constellations blinking and glimmering like jewels just out of reach — it’s impossible not to wonder: Are we alone?
For many of us, the notion of intelligent life on other planets is as captivating as ideas come. Maybe in some other star system, maybe a billion light years away, there’s a civilization like ours asking the exact same question.
Imagine if we sent up a visible signal that could eventually be seen across the entire universe. Imagine if another civilization did the same.
The technology now exists to enable exactly that scenario, according to UC Santa Barbara physics professor Philip Lubin, whose new work applies his research and advances in directed-energy systems to the search for extraterrestrial intelligence (SETI). His recent paper “The Search for Directed Intelligence” appears in the journal REACH – Reviews in Human Space Exploration.
“If even one other civilization existed in our galaxy and had a similar or more advanced level of directed-energy technology, we could detect ‘them’ anywhere in our galaxy with a very modest detection approach,” said Lubin, who leads the UCSB Experimental Cosmology Group. “If we scale it up as we’re doing with direct energy systems, how far could we detect a civilization equivalent to ours? The answer becomes that the entire universe is now open to us.
“Similar to the use of directed energy for relativistic interstellar probes and planetary defense that we have been developing, take that same technology and ask yourself, ‘What are consequences of that technology in terms of us being detectable by another ‘us’ in some other part of the universe?’” Lubin added. “Could we see each other? Can we behave as a lighthouse, or a beacon, and project our presence to some other civilization somewhere else in the universe? The profound consequences are, of course, ‘Where are they?’ Perhaps they are shy like us and do not want to be seen, or they don’t transmit in a way we can detect, or perhaps ‘they’ do not exist.”
At about four light-years from the sun, Alpha Centauri is the closest star system to the solar system. While that may seem relatively close, it would still take humanity thousands of years to reach, based on current propulsion technology.
In fact, it took Voyager 1, which was launched in 1977, 37 years to reach the outskirts of the solar system. That spacecraft flew at 17 km/sec, less than 0.006% the speed of light.
“We have to radically rethink our strategy or give up our dreams of reaching the stars in a way romanticized in books and movies,” wrote Philip Lubin, of Univ. of California, Santa Barbara’s Physics Dept.
In his paper, “A Roadmap to Interstellar Flight,” and in a video from NASA 360, Lubin states that photonic propulsion, or the propulsion of objects through light particles, could help humanity achieve quick interstellar travel, turning science fiction into science fact.
Currently, NASA estimates that it would take humans roughly six months to travel to Mars. According to Lubin, his theoretical technology could propel a 100 kg robotic craft to Mars in a few days, and a shuttle-sized craft in about one month. The former robotic craft would travel around 1,200 km/sec.