Söker seti i universum
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However, SETI has new experiments that capture a vast amount of more detailed data than previously, allowing us to confidently rule out terrestrial signals much faster.
The lack of a signal does not rule out the existence of intelligent life forms in our Galaxy.
Kepler is a telescope that searches for planets around other stars. Platforms like SETI@home (active until 2020) allowed people to donate their computer’s idle processing power to help analyze SETI data—a crowdsourced approach to the biggest question ever asked.
Criticisms and Controversies
SETI is not without its critics.
Some argue that the search is a waste of resources—money, time, and talent that could be spent on more “practical” science.
The waves from our broadcasts leak outwards in a spherical shell. With terabytes of data streaming in from modern telescopes, AI helps sort signal from noise, identifying promising patterns that might be overlooked by human analysts.
Future SETI searches may even rely on AI systems trained to recognize not just narrow-band radio signals, but more complex, structured data—patterns that might indicate artificial origins.
There’s also speculation that alien civilizations might use AI probes rather than broadcasting signals.
Using the Green Bank Radio Telescope in West Virginia, Drake pointed the dish toward two nearby Sun-like stars—Tau Ceti and Epsilon Eridani—and listened for any signs of artificial radio signals. Breakthrough Listen scans millions of stars, covering ten times more sky than previous efforts and listening across a wider spectrum.
SETI efforts also involve citizen scientists.
Curiosity is a natural human driving force. UC Berkeley is notable for its work with SETI@home and radio searches, among other efforts.
N = R* × fₚ × nₑ × fₗ × fᵢ × f𝚌 × L
Where:
- N is the number of civilizations we might communicate with
- R* is the rate of star formation
- fₚ is the fraction of those stars with planetary systems
- nₑ is the number of planets, per system, with an environment suitable for life
- fₗ is the fraction of suitable planets where life actually appears
- fᵢ is the fraction of life-bearing planets where intelligent life evolves
- f𝚌 is the fraction of civilizations that develop detectable technologies
- L is the average length of time such civilizations release detectable signals
Each term reflects a different layer of complexity and mystery.
The search is really just beginning; we have probed such a small region of the Galaxy that we can't yet make any strong statement about the prevalence of ETI. But a signal could come at any time, so it's important to keep surveying the sky!
Berkeley and SETI
We have several SETI programs operating at multiple wavelengths, from radio, through infrared, to visible light.
SETI is primarily a privately funded project. Older publications and non-peer-reviewed publications can be accessed on NASA Astrophysics Data System.
Other Research and Agencies
Researchers from universities all around the globe contribute and participate in SETI efforts.
The genie is already out of the bottle.
SETI and the Future of AI
Artificial intelligence is becoming increasingly vital in SETI. A Harvard team works on optical SETI and operates the Planetary Society funded All-Sky OSETI Telescope. A rare natural phenomenon?
We may never know. Limitations include the frequency coverage and sensitivity of our detectors, and the sheer vastness of the Galaxy.
In particular, planets within the “Habitable Zone” where liquid water could exist on a planet's surface are good candidates for SETI searches.