If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?: Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life

by Stephen Webb

When Fermi asked “where is everybody?”, the “everybody” referred to intelligent extraterrestrial creatures. While the discovery of any life elsewhere would be profoundly important, it’s intelligent life we search for with passion. It is (presumably) only intelligent life that can travel between stars and with whom we can communicate, interact and learn from. But perhaps intelligence—the sort that can investigate and understand the laws of physics—is rare in the universe? As many as 50 billion species have lived on Earth, but only one has evolved the sort of intelligence that can determine the existence of the Higgs boson. Could it be that the development of intelligence is a fluke, so that the term in the Drake equation is small?

Carl Sagan once remarked, “all things being equal it’s better to be smart than to be stupid”.

What’s the difference between being dead, and just not knowing you’re alive? Peter Watts, Blindsight

Nevertheless, one quite widely accepted explanation of the phenomenon is that the human eye sends information to two quite distinct visual systems in the brain: an advanced mammalian system, which is located in the occipital lobe, and an older, more primitive reptilian system located in the midbrain. Damage to the occipital lobe can stop signals from reaching the mammalian visual system, but it wouldn’t stop those signals from reaching the reptilian visual system in the midbrain.

The “Gaia” explanation is based on the hypothesis, originated by James Lovelock, that various feedback mechanisms allow life itself to create, maintain and develop the conditions needed for life to survive and thrive: Earth can be seen as a single, living, self-regulating organism. Life has undeniably had a significant impact on Earth—the atmosphere would look quite different if our planet were lifeless, for example—but the Gaia hypothesis is not without its critics. Although Lovelock’s idea has been the spur for a great deal of biological research, it still lacks clear observational support. Gaia might exist; it might not.

As planetary scientists learn more about exoplanets, and the different ways of building a planetary system, they’ll be better able to understand whether Earth truly is an oddball. At present it’s too early to say. But it’s certainly possible that we live on the Lucky Planet.

When facts are few, speculations are most likely to represent individual psychology. Carl Gustav Jung

There are about 500 billion galaxies in the universe, and so there might be as many as 50 sextillion potential homes for life. That’s a 5 followed by 22 zeros. Surely we can’t be the only intelligent species when there are so many sites on which intelligent species could evolve? A sextillion is a big number, right?

We’re searching for ourselves…

The various “Solutions” discussed in chapter 4 don’t, I believe, solve the Fermi paradox; but they do describe a range of possible futures for our descendants. We can choose which future we want. If we survive, we have a Galaxy to explore and make our own. If we destroy ourselves, if we ruin Earth before we’re ready to leave our home planet…well, it could be a long, long time before a creature from another species looks up at its planet’s night sky and asks: “Where is everybody?”