As of 2020, the Population Reference Bureau (PRB) estimates there are currently 7.8 billion people alive on our planet. In the United States alone, there are about 330 million people. The US National Center for Education Statistics (NCES) estimates 733,445 science, technology, engineering, and mathematics (STEM) degrees were awarded in 2018. This number has risen steadily every year for the past decade.
Science is not only alive and well, it’s ferociously competitive. I only listed the US graduates in the data above. Many other countries have far higher STEM statistics than we do. And virtually all of these graduates worldwide would love to be the next Isaac Newton, Einstein, or Norman Borlaug. Most would settle for advancing science even a little bit.
The above facts are why science is now done increasingly theoretically rather than experimentally – with this many people competing for discovery, the low-hanging fruits have already been picked. Going forward, the remaining discoveries are far more likely to present themselves via predictive theoretical research than the more conventional “go out and test the thing” methods we’re all used to.
In fact, this is already becoming more and more the case:
- The planet Neptune was predicted through mathematical modelling based on Sir Isaac Newton’s Law of gravity
- Radio waves were predicted by James Clerk Maxwell
- Antimatter was predicted by Paul Dirac on the basis of his formulation of relativistic quantum mechanics
- The Higgs boson was predicted by Peter Higgs with a mathematical model
This trend isn’t going to stop. Increasingly, we’re going to guess about things before finding the proof they actually exist.
Extraterrestrial life is no different.
With sound logic and math, we can make reasonable estimates about whether we’re truly alone in the Universe. In fact, this has already been done!
N=R_{*}\cdot f_{\mathrm {p} }\cdot n_{\mathrm {e} }\cdot f_{\mathrm {l} }\cdot f_{\mathrm {i} }\cdot f_{\mathrm {c} }\cdot L
- N = number of civilizations with which humans could communicate
- R_{*} = mean rate of star formation
- f_{\mathrm {p} } = fraction of stars that have planets
- n_{\mathrm {e} } = mean number of planets that could support life per star with planets
- f_{\mathrm {l} } = fraction of life-supporting planets that develop life
- f_{\mathrm {i} } = fraction of planets with life where life develops intelligence
- f_{\mathrm {c} } = fraction of intelligent civilizations that develop communication
- L = mean length of time that civilizations can communicate
The above is the famous “Drake Equation,” which is a tool used to calculate the odds of intelligent alien life capable of communicating with us. The beauty of this equation is all it’s variables can be updated as science progresses. Certainly, the results of the equation have indeed changed considerably over time as science has evolved.
For example, the drake equation was invented in 1961 by Frank Drake, but we didn’t know exoplanets were more the rule of stellar formation than the exception until 2014 when NASA announced hundreds of them had been detected by the Kepler space telescope, which had only analyzed a tiny sliver of the galaxy. This new exoplanet data alone dramatically changed the playing field – more planets means more chances for life to evolve.
However, even now the disparity of expert estimates on the probability of intelligent extraterrestrials is extreme. It tends to range from “we’re alone in our galaxy” to “there are millions of civilizations in our galaxy alone.” The one thing every serious expert does agree on however, is that it’s a statistical certainty that we’re not the only life in the Universe. By simple virtue of humanity existing, exoplanets being extremely common, and the Universe being infinite, we know it’s a statistical impossibility for life not to have evolved independently somewhere else.
Any non-zero number times infinity equals infinity.
Space is really, really big. If we’re lucky, they’ll have evolved within the boundaries of our cosmic endowment. If we’re unlucky, they won’t.
Either way, alien life isn’t going to remain outside of human experience: Just look at how we domesticate the species around us and how we’re already beginning to modify our own bodies. Fast forward a few eons and I find it very probable that human sub-species will be as different from each other as we are to the alien life we dream about today. It only takes one “seed” civilization to populate the galaxy and we could be it.