Search for Exoplanets and Physics of Advanced Civilizations

What do aliens look like?

Jun 12, 2022

Civilization begins with order, grows with liberty, and dies with chaos. - Will Durant

Greetings, fellow Bohron

The existence of aliens and our search for them is one of the most fundamental questions humans face right now. It seems absurd to think that we are alone in the universe. That way, we will have a really special place in the eyes of the Creator.

Artist’s concept compares sunsets as viewed from Earth and from each of the 2 newly discovered planets orbiting Teegarden’s Star. *Source*

Perhaps, alien life might harbour on Earth-like planets. So we need to first search for such celestial bodies, then question what would alien life look like on that planet. Let’s explore this question.

The Search for Earth-like Planets

Research into extrasolar planets is slow because they are invisible to any telescope since they don’t emit light on their own. In a solar system consisting of a Jupiter-sized planet, the mother star and the planet revolve about a common centre of mass. A telescope cannot see the planet, but the mother star is clearly visible and appears to wobble back and forth.

Aleksander Wolszczan discovered the pulsar PSR B1257+12 in 1990 and in 1992 found that the pulsar was orbited by two planets. This was the first confirmed discovery of planets outside the Solar System. As of 2 June 2021, 4,401 exoplanets have been confirmed.

Some of the earth-like exoplanets discovered by NASA’s Kepler space telescope. *Source*

What do Aliens look like?

By examining how life evolved on an exoplanet, we might be able to speculate about how intelligent life might have evolved on Earth. Scientists have concluded that intelligent life probably requires:

Eyes or a light-sensing mechanism to examine its surrounding.
A tentacle, claw or a thumb to grab things.
A communication system, such as speech.

An octopus seems like a more realistic version of aliens than those depicted in Hollywood. *Source*

Note that these three features are mere guesses; real aliens may look like creatures we didn’t even imagine in our wildest dreams.

In Hollywood, aliens are depicted as having a humanoid shape with bilateral symmetry and child-like, bug eyes. In reality, they might look different altogether. Hollywood also depicts aliens as flesh-eaters which might be correct. We can also estimate what their body size might be by application of what is known as Scale Law.

Predator is perhaps the most famous of all aliens depicted in Hollywood. *Source*

Monsters and Scale Law

If aliens do exist on Earth-sized planets and have the same rough density as water, then huge creatures like King Kong and Godzilla are probably not possible.

Scale law states that the laws of physics change drastically as we alter the scale of any object.

An ape 10 times its normal size would have 1000 times increased volume and hence 1,000 times heavier. However, the cross-sectional area of its bones and muscles would only be 100 times larger. 10 times bigger King Kong would be only 100 times stronger, but 1,000 times heavier. So it would be relatively 10 times weaker than a normal ape. Consequentially, its legs would break.

King Kong looks interesting only on screen. *Source*

Scale Law can help us estimate the rough shape of terrestrial animals and aliens. The heat emitted by an animal depends upon its surface area whereas the heat content within its body depends on volume. 10 times bigger creature would lose heat 100 times faster but would harbour 1000 times more heat. Hence, large animals lose heat more slowly than small animals.

The Physics of Advanced Civilizations

If we look at the advancement of human civilization ever since it began 100,000 years ago, we can classify it in various stages of development on the basis of energy consumption. Russian astrophysicist Nikolai Kardashev grouped the possible civilizations into three types:

Russian astrophysicist and SETI pioneer Nikolai Kardashev. *Source*

Type I civilizations

Such a civilization harvests planetary power using sunlight. They possibly can manipulate the weather, control earthquakes and volcanoes, and build cities on the ocean. All planetary power is within their control.

Type II civilizations

These can utilize the entire power of their sun, making them 10 billion times more powerful than a Type I civilization. They have the potential to become immortal; since ice ages, meteor impacts, or even supernovae would prove to be futile in destroying them.

Type III civilizations

They are 10 billion times more powerful than a Type II civilization and can even exploit the power of the black hole at the centre of their galaxy. They have colonized billions of star systems.

Over the years, the Kardashev Scale has been re-evaluated by Carl Sagan, Michio Kaku and others. *Source*

Our civilization fits none of the three classes described above as we still depend upon dead plants, oil and coal and utilize only a tiny fraction of the sun's energy as fuel.

Given the rapid advances in SETI and discovering exoplanets and assuming that an extraterrestrial civilization exists in our vicinity, Michio Kaku believes that contact with them may occur within this century, a Class I impossibility. Will we ever be able to reach them? We will talk more about this in the near future.

Bohring

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