The Fermi Paradox: Too Rare?

In this post, I will discuss the solution that interstellar-capable extraterrestrial civilizations are rare or nonexistent. For most of that solution, we must extrapolate from our civilization, with all the risks of extrapolating from a single example. So I must work with an emergence scenario that has several steps, and at least one of them can be a bottleneck. Here are the steps that I will discuss:

  1. Stars
  2. Planets
  3. Origin of Life
  4. Origin of Photosynthesis
  5. Multicellularity
  6. Colonization of Land
  7. Intelligence
  8. Technology
  9. Abstract Science

Since this post has grown to be rather long, I will leave off at the origin of life.

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Where are they? The Fermi Paradox

Around 1950, Italian physicist Enrico Fermi asked “Where are they?” about extraterrestrial civilizations with interstellar communications or transportation capabilities. As a result, the name “Fermi paradox” has become applied to the conundrum that there ought to be lots of such civilizations, despite our not observing any broadly-convincing evidence of them.

This conundrum has been abundantly discussed with a large number of proposed solutions. Like here:

The solutions fall into three main categories:

  1. The ET’s are rare, if not absent.
  2. The ET’s are common, but it is difficult or impossible to make contact.
  3. The ET’s are common, and they choose to hide from us and/or to not make contact with us.

In my next posts, I will explore these possibilities.

Was Pi Designed?

I don’t mean the food item, I mean the number, also known as Archimedes’s constant and the circle constant: 3.141592653589793…

In “The Artist’s Signature”, the last chapter of Carl Sagan’s novel Contact, we find that the digits of this number have a message contained in them, a message from the designer of our Universe. But such a message would only be possible if pi could have some other value. But pi has the value it does out of logical necessity, and thus could not have been designed. There are many ways to compute this number, so for illustration, I will show only one of them, 4*arctan(1):

4*(1 – 1/3 + 1/5 – 1/7 + 1/9 – 1/11 + …)

This is an infinite sum, but it has only one possible value. That can be shown because the partial sums of this sum form a “Cauchy sequence”, a sequence whose convergence can be deduced from the sequence members without using the series limit.

Gods from Outer Space

Transcendent Outsiders, Alien Gods, and Aspiring Humans: Literary Fantasy and Science Fiction as Contemporary Theological Speculation by Ryan Calvey, discusses a range of such entities, and I wish to fill out his discussion further. His hierarchy is:

  • Transcendent outsiders: entities much more powerful than us.
  • Human beings.
  • Aspiring human beings: a huge collection of robots, software constructs, magically-animated toys, assembled organisms, and the like. They want to either become human or else to have the sort of respect that we give each other.

About the first one, RC distinguished between authoritarian and friendly ones, and I have expanded on his classification.

  • Authoritarian and Punitive: the movie The Day The Earth Stood Still
  • Friendly and Helpful: Carl Sagan’s book and movie Contact
  • Aloof: the movie 2001: A Space Odyssey
  • Absent or Nonexistent: Isaac Asimov’s Foundation series
  • Emergent: Isaac Asimov’s short story “The Last Question”

I’ll explain more about each of them after the fold.

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Names for Exoplanets

As I’d mentioned earlier, many exoplanets currently have names like Kepler-7b, HD 189733b, GJ 1214b, Gliese 581g, Kapteyn b, Gliese 667 Cc, … Why not names like Wu Tang Clan or Ghostface or Alderaan or Gallifrey? In 2014, the International Astronomical Union decided to change that by having a contest to name some exoplanets.

The IAU first came up with a list of 305 well-studied exoplanets that had been discovered before the end of 2008, exoplanets that are members of 250 exoplanetary systems. Several astronomy clubs and other such organizations then applied to the IAU to become registered voters in this contest. The accepted ones then selected 20 exoplanetary systems to vote on, and they then submitted sets of names for them. In 2015, the IAU had a public vote on which name set, and then announced the winners. The Approved Names, The Process, The ExoWorlds, The Proposals, and The Statistics.

I don’t know how well this contest turned out, or whether the IAU is willing to have another one. But if the IAU ever does, then there are now a lot more planets to choose from, like the Kepler ones and TRAPPIST-1.

Some names and details below the fold.

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Stars and exoplanets: where do their names come from?

JPL | Videos | Q and Alien: What’s in an Exoplanet Name?, also at ▶ Q&Alien: What’s in an Exoplanet Name? – YouTube

Why do exoplanets have weird-looking names like these? Names like:

Kepler-7b, HD 189733b, GJ 1214b, Gliese 581g, Kapteyn b, Gliese 667 Cc, …

Why not names like Wu Tang Clan or Ghostface or Alderaan or Gallifrey? For starters, astronomers have discovered a *lot* of exoplanets, and giving them individual names would be a lot of trouble. Also, their names have a certain descriptive value:
(star) + (planet letter)

The star is typically (catalog) + (number):
Kepler-7 is the 7th star that the Kepler team discovered to have planets.
HD 189733 is the 189733’th star in the Henry Draper star catalog

The first planet named is small-letter b, because “a” is reserved for its star. They are named in order of discovery, and if several are discovered at the same time, they are then named in order of distance. Stars, however, have capital letters: A, B, C, … in order of brightness or discovery.
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Planets of Other Suns

Exoplanets, planets of other stars. How did we discover them?

It took a long time to do so, with plenty of false alarms along the way. I am old enough to remember when Peter van de Kamp’s 1960’s and 1970’s claimed discovery of planets around Barnard’s Star was taken very seriously. But it was later discovered that maintaining his telescope caused the largest observed effects, and that discovery is now discredited. In 1991, Andrew Lyne, M. Bailes, and S.L. Shemar claimed that they had discovered a planet orbiting pulsar PSR 1829-10, a planet with orbit period half a year. But they then discovered that they had made a small error in their accounting for the Earth’s position, and they retracted their discovery.

The first confirmed discovery of an exoplanet was in 1992, when Alexander Wolszczan and Dale Frail discovered two planets orbiting pulsar PSR 1257+12. This was followed by a third one in 1994. The first one for a “normal” sort of star was in 1995, when Michel Mayor and Didier Queloz discovered a planet around the Sunlike star 51 Pegasi.

These discoveries were followed by numerous other ones, and some 3500 planets are now considered confirmed to exist. In particular, the Kepler space telescope’s observations have yielded a large number of discoveries, about 2/3 of all known exoplanets.

More below the fold.

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