Alien Life Forms
Today, Alien life forms. The University of Houston presents this series about the machines that make our civilization run, and the people whose ingenuity created them.
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Back in the 1960s, my wife and I happened upon a copy of a Seventh-Day-Adventist magazine in German. The lead article was, Gibt es Leben im Weltraum? – Is There Life in Outer Space? It argued a conviction that human life was unique.
That was just after the first orbital satellites. Space was suddenly on all our minds. The once-hypothetical idea that other life forms existed was rapidly becoming scientifically plausible. Radio astronomers were now seriously listening for alien radio signals. The Star Trek TV series was just starting to tease us with a parade of imagined alien life forms.
Green Bank Radio Telescope listening for Alien signals (Image courtesy of Wikimeda Commons.)
That was then. So where is this question today? It’s still there, but constantly taking on new forms. Think about the recent renaming of UFO’s – “Unidentified Flying Objects” to “Unidentified Aerial Phenomena”. We’ve become more cautious about suggesting that those flickers in the sky are flying machines. Still, that possibility lingers.
A 1937 imagining of extraterranian life
Meanwhile, astronomers run the numbers. And, depending on which calculation we accept, our own galaxy might have ten thousand planets that could support life as we conceive life. Then there are the other two trillion or so galaxies in the universe. All kinds of life must exist “out there”. And, the controlling mechanism of life – call it a brain – is likely to have evolved into what we would deem intelligence, many times.
But so many twists: We have our own notions of intelligence. Which of those notions might apply? And, how long will any intelligent society survive before it destroys itself. How might it die: By war, climate, disease, or other forms of self-inflicted failure? Where is each of those planets in its perhaps-limited era of intelligent life?
And what about the nature of alien life? Would we even recognize it as life? Here, on earth, we associate life with the element, carbon. Every living creature that we know of is made, in part, of carbon. And our life forms are also generally dependent upon water. Science now offers many possible chemical scenarios – far different ones – that might result in something which might qualify as life.
So let us go back to the nineteen sixties. We generally supposed that alien life would have to’ve arisen in circumstances like those here on earth. And the creatures who would have arisen – they would’ve had much in common with us. Shows like Star Trek simply reinforced that thinking, even while we did not take it seriously. But now ...
Now, we realize that we can no longer view this vast universe through the lens of our earth-bound experience. With increased knowledge we’ve achieved far greater ignorance than we once realized we had. And that is good – since without recognizable ignorance, we cannot learn.
A galaxy 55,000 light-years away. Who do you suppose lives there? (Image courtesy of Wikimedia Commons)
I’m John Lienhard, at the University of Houston, where we’re interested in the way inventive minds work.
(Theme music)
Some sources
Search for extraterrestrial intelligence - Wikipedia
Extraterrestrial life - Wikipedia
Unidentified flying object - Wikipedia
Hypothetical types of biochemistry - Wikipedia
Some previous Engines episodes about extraterrestrial life over the years reflect our changing and varying perspectives.
The Search for Extra-Terrestrial Intelligence | The Engines of Our Ingenuity
Encounter of the Third Kind | The Engines of Our Ingenuity
Are We Alone? | The Engines of Our Ingenuity
I suggest that our galaxy might have 10,000 life-bearing planets. That is what the Drake equation suggests. It is really a small number when one considers that our galaxy is home to between 100 and 400 million stars.
This Episode first aired June 22, 2026.