Reality Straight Up!

Thoughts & Observations of a Free Range Astrophysicist

Looking for E.T.

Where Are They?

Why E.T. might stay home

It would be fun to think there is a flourishing interstellar civilization of humanoid aliens out there. But then it would also be nice to believe in unicorns and midichlorians. It would be nice, but they probably aren’t there.

This article originally appeared in my Astronomy Magazine column, For Your Consideration.


Along with a lot of you out there, I grew up on stories of sprawling interstellar societies full of creatures very like us. Spacecraft powered by unexplained technologies sidestep the laws of physics as we know them, allowing various species of bipedal humanoids to get together and do what we bipedal humanoids are wont to do. I still love a good space opera. But, alas, such things are not to be.

Enrico Fermi wondered, “If E.T. is out there, why aren’t they here?”

During an informal lunchtime conversation at Los Alamos in 1950, a group of physicists were joking about a cartoon in The New Yorker depicting aliens and a flying saucer. The cartoon inspired Enrico Fermi to ask a simple question: “Where are they?”

Enrico Fermi

Enrico Fermi was a brilliant, Nobel-Prize-winning nuclear physicist, but his name is perhaps just as widely recognized for his question, “Where is E.T.?”

If the universe contains numerous intelligent civilizations whose inhabitants routinely travel among the stars, then, Fermi reasoned, those civilizations should quickly spread throughout the galaxy. Yet, fantastical claims about UFOs aside, there is no evidence that we have been visited. Fermi never thought of this as a paradox. (That term didn’t appear for another 25 years.) He just took it as evidence that interstellar travel must be really hard, and that coming to Earth isn’t worth the effort.

For biological creatures, interstellar travel is hard

Concerns about the difficulty of interstellar travel are well founded. In the real world, you don’t get to sidestep physics, and physics says that sending humans across interstellar distances would require vast resources and journeys lasting many lifetimes.

From suspended animation to zygote-laden incubator ships to multigenerational vessels, people have played with lots of ideas for how we might mount such a campaign. But any way you slice it, space is a hostile environment for biological organisms. Protecting passengers and keeping them alive and healthy for centuries or more is a formidable task.

Then there are the extraordinary psychological stresses involved. Drawing on experience with Antarctic exploration, long-duration space flight, and numerous experiments aimed at understanding the human factors encountered during a quick trip to Mars, one thing seems clear. Managing the isolation, confinement, culture, and other psychosocial aspects of interstellar travel could be as daunting as the challenges facing spacecraft engineers. It seems likely that any intelligent social species would face their own versions of such hurdles.

E.T. and humans doubtless have very different biochemistry

Evolution has no destination. Each time you push the “go” button, you end up someplace different. Start things over on Earth (or on another Earth-like planet) and not only would there be different species with perceptions and intelligences that vary wildly from our own, the very chemistry of life would be altered as well!

That’s conjecture — but it’s pretty safe conjecture. To see why, let’s do a quick back-ofthe-envelope calculation.

Among other things, our DNA contains instructions for building proteins out of sequences of amino acids. For simplicity, let’s assume that life always evolves that same basic molecular machinery. There are 500 or so known amino acids, of which life on Earth uses only 23. Sticking with our KISS (keep it simple, stupid) approach, let’s assume all life uses those same 23.

Protein Molecule

There are 10613 different possible proteins with a length of 450 amino acids. Only about 10 million of those are used by life on Earth. The likelihood that life elsewhere uses any of those same proteins is effectively zero.

The average protein in a eukaryotic (nucleus-containing) cell on Earth is about 450 amino acids long. There are therefore 23450 (=10613) different proteins of that length that the machinery of our DNA might construct. That’s a huge number! Not surprisingly, terrestrial life has stumbled upon uses for only a small fraction of those possible proteins — about 10 million.

So now let’s take those 10613 possible proteins and split them into planet-proportioned groups of 10 million each. With no overlap at all, there would be 10606 of those piles! There are no more than about 1023 habitable planets in the entire observable universe. You could spread those stacks of proteins over the planets in 10583 similar universes without having to duplicate a single protein on any two planets!

The takeaway is this: The likelihood that any two lifebearing planets in the universe share even remotely compatible biochemistry is effectively zero.

That interstellar civilization might still exist. Watch this space.

Put all of that together, and a civilization looking at Earth as an interstellar destination might reasonably assume three things: 1) The existence of life means that Earth is at best useless and at worst highly poisonous, 2) communication might be as problematic as communication between humans and octopuses, and 3) a decision to send emissaries in our direction would be costly indeed.

So perhaps the answer to Fermi’s question is that everybody out there with technology that might allow them to travel the stars in search of life understands that there is no reason to do so.

Or perhaps not.

Personally, I think there probably is a thriving civilization out among the stars. Watch this space.

Where Are They? ^ Why E.T. might stay home  © Dr. Jeff Hester
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  • Shaking the hand of someone you disagree with isn’t as much fun as shouting them down, but it is far more effective.


    When you live in small groups on the savanna, as our ancestors did for most of our evolutionary history, it pays to be suspicious of strangers. Other groups were competition. Strangers didn’t drop by for a cup of tea and a friendly chat about our emotional well being. We couldn’t afford to see a stranger as a real person at all.  It was an “us versus them” world. Fear and aggression were the only rational responses. People who did well in that world (AKA our ancestors, the people from whom we get our DNA), knew that the only safe thing was to beat strangers with a club first and ask questions later.

    Fear of “The Other” is hardwired, and talking about it doesn’t help.

    We may not live in small groups on the savanna any more, but our brains don’t know that. For better or worse we are stuck with our evolutionary baggage. Nothing is going to change that. When you encounter someone who your brain perceives as “other”– and by this I mean you personally, dear reader, as well as myself and every other human on the planet — all of that machinery jumps to life in milliseconds. Long before we are consciously aware of anything, our brains are screaming “Danger Will Robinson! Danger!”

    Call this tribalism. Call it racism. Call it in-group/out-group dynamics. Call it identity politics. Call it polarization. Call it whatever you like. It all comes down to the same thing. When we perceive someone as other our reactions are hard wired, preconscious, and impossible to turn off.

    Good intentions don’t matter. Get high and sing Kumbaya all night. Talk about it until the cows come home. Hold workshops. Post platitudes or scream about it on the internet. If you want to judge the effectiveness of those strategies all you have to do is pick up the paper. The louder the mob screams, the more ground they lose. We’ve tried those approaches. They make things worse, not better.

    Quoting Einstein’s famous parable, “Insanity is doing the same thing over and over and expecting different results.”

    There is only one solution: Humanize yourself by embracing the humanity of others.

    If you perceive someone as other you will respond to them as a threat. There’s nothing we can do about that. Or is there? Take a step back and the answer is obvious. We can’t change how we react to other, but we can change who we perceive as other.

    There is going on 70 years of really fascinating sociological, psychological, political and even neurological research that all supports the same conclusion: If you know and respect someone, it’s hard not to care about them. Break bread together, laugh together, talk deeply, listen, show respect (even when it’s difficult), build bridges, find common purpose and work arm in arm.

    I could dig into that research, but mercifully for you I won’t. Instead I am going to share an uplifting and illustrative story of what effective anti-racism really looks like.

    How did a Black musician change the hearts of hundreds of Klansmen?

    Daryl Davis is a Black blues and jazz musician with a very strange hobby. He goes to events like KKK rallies not to shout or protest, but to listen, shake hands, talk, and befriend. Literally hundreds of the Klan members who Daryl Davis has become friends with have renounced the Klan. He has a large collection of their robes, including the robe of a man who, when they met, was the Grand Wizard himself.

    Read that last sentence again. Then if you honestly care about fighting racism you owe it to yourself to invest 18 minutes and listen to Daryl Davis’s story in his own words.

    This is not your Woke friend’s Anti-Racism.

    It feels good to gang up and shout at people. The difference between the shouters and the shoutees makes it really easy to tell who is “us” and who is “them.” Our brains love that. The dopamine flows like a river.

    But that is not what Daryl Davis did. There was no shouting about racism. Terms like “White privilege” and “White fragility” were never used. Daryl Davis never complained about microaggressions or political correctness. DEI workshops were not part of the program. Mr. Davis did not wear his feelings on his sleeve. Quite the contrary, Daryl Davis listened even to open hatred and tried to understand where it was coming from. There was no talk of victims and oppressors. There were no social media attacks or calls for deplatforming. There was no virtue signaling about Wokeness.

    Instead, Daryl Davis treated those who were predisposed to hate him with dignity and respect. He listened. He questioned. He befriended. He humanized himself by seeing and acknowledging the humanity of others, including those with whom he deeply disagreed. In the process he did what few have ever accomplished. Daryl Davis changed the hearts of hundreds of the most committed racists in the nation.

    This is what real, effective anti-racism looks like. And as Davis mentions at the end of his talk, if he can do it, so can we.

  • What do record fire seasons in the West, record hurricane seasons in the Atlantic, record winter storms in the South and the hottest years in history have to do with each other? Everything.

    This article originally appeared in the December 2019 issue of my Astronomy Magazine column, For Your Consideration.

  • You don’t tug on Superman’s cape. You don’t spit into the wind. Yes, schools are desperately important to kids. No, COVID-19 doesn’t care, and COVID is making the rules right now. Attempts to open schools this fall will fail of their own accord. The relevant question is how to meet the needs of children, families and the community in the face of that reality.

  • Currently new cases of COVID-19 in Arizona are doubling every 7 days. ICU beds in the state are already full. The rest of the country isn’t that far behind us. You do the math.

  • Now is not the time for scientists to be circumspect and silent. We are on the short end of a battle over whether truth even matters. If scientists do not stand up for what is real, who will?

  • The morning cyclist in my neighborhood may not be standing in the Michigan Statehouse carrying a gun and demanding her right to spread contagion far and wide, but she may as well be.

  • You know those nice charts and graphs that make it look like we are over the hump of COVID-19 and that things are about to get better? Those predictions are dead wrong, with an unfortunate emphasis on “dead.”

  • Imagine three gregarious scientists, each with the gift of the gab, all coping with stay-at-home orders. Of course we started a livestream/podcast talk show! What else would we do? Welcome to the kickoff episode of Scientists Stuck Inside.

  • Even after COVID-19 kills hundreds of thousands in the U.S. over the coming weeks, we will still be almost as vulnerable to the pandemic as we are today. We’d all love to “get back to normal” after that, but the price could be a second wave, worse than the first. Some see us facing either economic Depression or allowing vast numbers of preventable deaths, but that is a fool’s choice. There are better options if we have the will to find them.

  • There is a lot of information about COVID-19 out there, much of it misleading. When looking at the future, start with what the science really says.

  • If someone can’t tell you how they would know that they are wrong, they don’t have a clue whether they are right.

    This article originally appeared in my Astronomy Magazine column, For Your Consideration.

  • Once seemingly incomprehensible, the origin of life no longer seems such a mystery. Most of what once appeared as roadblocks are turning out to be superhighways.

    This article originally appeared in my Astronomy Magazine column, For Your Consideration.

Over his 30 year career as an internationally known astrophysicist, Dr. Jeff Hester was a key member of the team that repaired the Hubble Space Telescope. With one foot always on the frontiers of knowledge, he has been mentor, coach, team leader, award-winning teacher, administrator and speaker, to name a few of the hats he has worn. His Hubble image, the Pillars of Creation, was chosen by Time Magazine as among the 100 most influential photographs in history.
©Dr. Jeff Hester LLC, 5301 S. Superstition Mountain Dr., Suite 104 #171, Gold Canyon, AZ 85118