PROBABILITY OF A LIVING PLANET

Anonymous

(Investigator 194, 2020 September)


As of 23 July 2020, there are 4,197 confirmed exoplanets, the majority of which were discovered by the Kepler space telescope. There are an additional 2,418 potential exoplanets from Kepler's first mission yet to be confirmed, as well as 889 from its "Second Light" mission and 1,288 from the Transiting Exoplanet Survey Satellite (TESS) mission.
https://en.wikipedia.org/wiki/Lists_of_exoplanets







NUMBER OF PLANETS

Our Solar System has eight planets. Pluto, discovered in 1930, was considered the ninth but is no longer regarded as a planet. In the 1990s exoplanets — planets of other suns or stars outside of our Solar System — began to be discovered, and currently number about 4200.

Of the 4200 exoplanets so far discovered Wikipedia lists 48 in the "habitable zone". This does not mean they're inhabited, merely that they have some of the necessary preconditions:

Surface planetary habitability is thought to require orbiting at the right distance from the host star for liquid surface water to be present, in addition to various geophysical and geodynamical aspects, atmospheric density, radiation type and intensity, and the host star's plasma environment...

In November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way, 11 billion of which may be orbiting Sun-like stars. (Wikipedia)



THE BIBLE

According to the Bible, it was God's special activity that shaped planet Earth for human habitation.

The Bible gives no indication that "God" intervened on any other planet to organize it for intelligent life and civilization. It says that humans are "a little lower than the angels" (Psalms 8:3-5) which may imply that there is no physical life more advanced than humans.

The question I will investigate is: How small must the probability that a planet can self-organize itself for intelligent life and civilization have to be, before we should agree with the Bible that God did it or at least assisted?


MARTIAN CANALS

In the 19th century many people believed there is human-like life on Mars.

The idea became popular after Italian astronomer Giovanni Schiaparelli described straight lines on Mars' surface and in 1877 referred to them as "canali". This means "channels" or "grooves" but got translated into English as "canals". 

American astronomer Percival Lowell (1855-1916) saw the lines too and concluded they are constructed canals, which implied that an intelligent, technological civilization built them. (But some scientists disagreed and interpreted the "canali" as optical illusions or areas of vegetation.)

Lee (2018) cites the Los Angeles Times of 1907:

Scientists now declare that the many lines and spots on Mars represent verdure along a most wonderful canal system, which the inhabitants of the planet have constructed for purposes of irrigation.

The canals featured in science fiction literature from the 1890s onwards. Wikipedia under "Martian Canal" lists many novels in which the "canals" are presented as intelligent constructions by Martians.

The UFO phenomenon after 1948 attributed the origin of flying saucers and aliens to all over the Universe — Mars became only one origin among many. Shelves of bookshops filled with books about UFOs, and the Universe began to seem like it's crowded with alien, technological civilizations. Most famous was Erick von Daniken's Chariots of the Gods

Some writers even argued for an outer space origin of the human race. Flindt & Binder (1974) claimed "Earth has been visited more than 5000 times by creatures from other planets" and "The human race may be an interstellar colony..." Crowley & Pollock (1989) argue that the Garden of Eden was on Mars and humans emigrated to Earth to survive a cataclysm that occurred on Mars 40,000 years ago!



THE ODDS

With two out of eight known planets, Earth and Mars, believed to be inhabited by technological civilizations, atheists and evolutionists could have concluded that the odds of a planet self-organizing itself for intelligent life from the laws of physics and chemistry without supernatural assistance, is 2/8 or 25%. Whether anyone made such a claim I don't know, but it would have been evidence-based.

In 1965 began the era of high-resolution mapping of other planets when the Mariner 4 space probe sent back pictures of Mars' surface. These decisively showed there are no canals. 

That still left one planet, Earth, with intelligent life and civilization. The odds of planet Earth having originated solely by the working of the laws of physics and chemistry without any God could therefore be construed as 1/8 or 12.5%. If this argument is valid it implied that 1/8 of all planets should have technological civilizations. A good many science fiction novelists wrote as if this is the case — that thousands of planets within reach of Earth support advanced civilizations.

However, if intelligent workmanship, i.e. God's supernatural intervention, is necessary to make planets fit for civilization, then the odds of planets producing civilizations without divine help would not be 1/8, but zero.



THE PROBABILITY GOES DOWN

In 1961 astronomer Frank Drake proposed the "Drake equation" of seven factors needed to estimate the number of technological alien civilizations. The problem is that although several factors can be estimated such as the number of stars, the others are subjective guesses — resulting in estimates for the number of alien civilizations in the Universe other than on Earth as somewhere between billions and zero.

In 1992 astronomers began discovering "exoplanets" i.e. planets outside our Solar System. Thirty were discovered by 2000 CE. None of them have been confirmed suitable for human life or even for any biological life.

This reduced the probability of planets being able to self-organize to support intelligent life to 1 in 38 — or lower since the odds showed a downward trend.

In January 2012 the number of confirmed alien worlds reached 720 — but none have been confirmed fit for human life or any life. Some are too cold, others too hot, too dry, too big with crushing gravity, or lack a solid surface or stable orbit, or are bathed in lethal radiation with no ozone layer or magnetic field for protection.

This made the probability, as based on observation 1/720 — or lower since the observed odds are still decreasing.

The current count of discovered planets is about 4200 but with no indication yet of life on any of them. This makes the probability 1/4200 or lower.

No exoplanets are yet confirmed as fit for human life. Some exoplanets are called "Earth-like". This does not imply that living things live there, but merely that the planets are approximately the right size and a suitable distance from their Sun. This much is also true of Mars, Venus and the Moon — but all three seem lifeless.

We began with observable odds of 2/8 and are now down to 1/4200.


WILL THE PROBABILITY GO DOWN TO ZERO?

Wikipedia under "List of potentially habitable planets" says:

In November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way, 11 billion of which may be orbiting Sun-like stars.

Science News, quoting Professor Conselice, reports:

"There should be at least a few dozen active CETI civilizations in our Galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, as on Earth," said Professor Christopher Conselice...

Nicola Davis (2020) reports in Astrophysical Journal:

But according to new calculations there could be more than 30 intelligent civilisations in our galaxy today capable of communicating with others.
 
“I think it is extremely important and exciting because for the first time we really have an estimate for this number of active intelligent, communicating civilisations that we potentially could contact and find out there is other life in the universe...” said Christopher Conselice, a professor of astrophysics at the University of Nottingham and a co-author of the research.

Paul Davies noted:

In recent years it has become fashionable to assume that life emerges rather readily under Earth-like conditions and is therefore likely to be widespread in the universe. This belief underpins the ambitious astrobiology programmes of NASA and the European Space Agency, the goal of which is to discover a second sample of life. (2006)

 Davies subsequently authored The Eerie Silence (2011), discussing the total absence of radio signals of intelligent origin, or other signs of aliens, and seeking explanations for this absence. 

Davies also wrote The Goldilocks Enigma Why Is the Universe Just Right for Life? (2008) and shows that: "Calculations suggest that even small changes in some key parameters would wreck familiar structures in the universe and prevent life from arising."

The anomalous situation therefore is that we have a "Universe Just Right for Life" but also an "Eerie Silence" as if there is no technologically advanced life except on Earth.

With the odds of intelligent life as calculated from the number of lifeless discovered planets going down, down, down, how low must the odds get before it's reasonable to conclude: "God intervened supernaturally to prepare Earth for human life?"

NASA's latest planet hunting telescope, the Transiting Exoplanet Survey Satellite, "should be able to find 20,000 planets of all sizes ranging from Jupiter-sized planets to planets the size of Earth or even the size of Mars." (Weule 2018)

If all 20,000 planets turn out lifeless, the calculated odds of intelligent life arising by natural means would decrease to about 1 in 24,000 or lower.

Wikipedia says:

In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure. Note that this does not ensure habitability...
(List_of_potentially_habitable_exoplanets)

The article mentions planets initially considered habitable but mistakenly so:

•    HD 85512b was initially estimated to be potentially habitable, but ... is now considered non-habitable.
•    Kepler-69c has gone through a similar process; though initially estimated to be potentially habitable, it was quickly realized that the planet is more likely to be similar to Venus, and is thus no longer considered habitable.
•    Similarly, Tau Ceti f was initially considered potentially habitable, but the improved model of the circumstellar habitable zone places the planet exterior to the outer limits of habitability...
•    Kepler-438b was also initially considered potentially habitable ...  however, it was later found to be a subject of powerful flares that can strip a planet of its atmosphere, so it is now considered non-habitable.
•    KOI-1686.01 was also considered a potentially habitable exoplanet after its detection in 2011, until proven a false positive by NASA in 2015.


HOW MANY PLANETS?

A rough estimate is that the Universe has 100 billion galaxies and an average of 100 billion stars per galaxy. With one planet on average around each star that's a lot of planets — in fact 10,000,000,000,000,000,000,000 (=1022).

Regarding the Milky Way galaxy Wikipedia says:

About 1 in 5 Sun-like stars have an "Earth-sized" planet in the habitable zone. Assuming there are 200 billion stars in the Milky Way, it can be hypothesized that there are 11 billion potentially habitable Earth-sized planets in the Milky Way, rising to 40 billion if planets orbiting the numerous red dwarfs are included.

These numbers are so big that scientists won't soon confirm the zero probability — unless they discover general principles, distinct from discovering and analyzing planets, by which to rule out intelligent physical life outside our Solar System.


THE QUESTION

How small must the odds of intelligent, technology-using life originating entirely naturally on a planet become before it's reasonable to conclude that Earth became a "living planet" by supernatural intervention?



REFERENCES

Davis, N. (2020)
https://www.theguardian.com/science/2020/jun/15/scientists-say-most-likely-number-of-contactable-alien-civilisations-is-36

Davies, P. In Search of a Second Genesis, New Scientist, 11 February, 2006, 48-49

Davies, P. 2008 The Goldilocks Enigma, Mariner Books

Davies, P. 2011 The Eerie Silence, Mariner Books

Haynes, K. February 12, 2020
https://www.discovermagazine.com/the-sciences/how-many-exoplanets-have-been-discovered-and-how-many-are-waiting-to-be

Lee, K. (2018) https://blog.newspapers.com/mars-canals/

Smith, H.A. Alone in the Universe, American Scientist, July-August 2011, 320-327

Weule, G. (2018)
https://www.abc.net.au/news/science/2018-04-15/nasa-tess-telescope-and-the-search-for-alien-planets/9627914

https://en.wikipedia.org/wiki/Kepler_space_telescope

https://en.wikipedia.org/wiki/List_of_potentially_habitable_exoplanets

https://en.wikipedia.org/wiki/Martian_canal

https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets

https://www.nationalgeographic.com/science/space/universe/exoplanets/

https://www.sci-news.com/astronomy/communicating-extraterrestrial-civilizations-milky-way-08536.html


http://users.adam.com.au/bstett/

http://ed5015.tripod.com/