Adithya A is a space enthusiast and a researcher. His articles are based on Virology, Space Science, Medical Science, etc.
1964 was a spectacular year for alien conspiracy theorists. Lonnie Zamora, a police officer in the city of Socorro, New Mexico, was trailing a car that was speeding out of a car accident when he heard a roar and saw flames bursting out from the ground a few miles away from him. Abandoning the chase, he drove to the site, where he later claimed to have seen something credible to a ‘UFO’, or an extraterrestrial object. The patch of ground on which the ‘UFO’ had laid was smoldering, proving his claim. The UFO sighting is to date ‘unknown’, as per USA’s Project Blue Book, an initiative to classify Unidentified Flying Objects (UFOs), and this incident has been dubbed as The Lonnie Zamora incident.
This wasn’t the first claim of sighting an ‘alien’ and not the last. So, are there beings out there, who could wonder whether there are beings here?
The Kardashev Scale
To answer this question, we must first understand how living organisms could adapt to extraterrestrial planets. They could be extremely rudimentary, like bacteria, or ‘mega lords’ who could calculate terabytes in a second. Their planet would need to be in ‘The Circumstellar Habitable Zone’, also known as ‘The Goldilocks Zone’, where water exists as a liquid. Their planet should also hold an atmosphere of gases, for oxygen to be abundant, along with a variety of other requirements. They would, without a doubt, have different modes of communication, different levels of technology, and different units of measurement than on Earth. Now how could we classify these as ‘advanced’ or ‘basic’?
Regardless of whichever civilization may exist, each of them shares a common factor – they all use energy. This was speculated upon by Nikolai Kardashev, a Soviet astrophysicist, in the year 1964 (the same year as the Lonnie Zamora Incident), who then went on to create the Kardashev Scale.
The Kardashev Scale (also called Kardashev’s scale) divides civilizations based on their energy consumption for 365 days. A primitive civilization would probably not take up much energy and would be unable to tap into the energy of even basic planetary energy sources, such as fossil fuels. A very advanced civilization would be able to harness the energy of not only its planet, but also its star, and perhaps other nearby stars.
Based on Kardashev’s scale, civilizations can be divided as Type 1, Type 2, and Type 3. Additional stages include Type 4 and Type 5.
Here, Type 5 / Type Omega is the most advanced, while Type 1 is the most basic.
The energy requirements for each level are as below:
Type 1: Harnessing the complete energy which the planet harbors (for Earth, it is 1.74×1017 watts)
Type 2: Harnessing the complete energy the planet’s star system has to provide (for Earth, it is 4×1026 watts)
Type 3: Harnessing the energy the planet’s entire galaxy has to lend (for Earth, it is 4×1037 watts)
Another level that could be included is ‘Type 0’ – this level can harness 106 watts.
So, how exactly do we decided the level of a civilization based on its energy consumption?
The level can be decided using this formula:
K=(log10(P) - 6)/10
Here, K represents the level of civilization on Kardashev’s scale, while P represents the energy usage of the civilization. Log10(P) basically means, if log10(P) = x, then 10x = P (10 raised to the power of x is P).
But it is necessary to remember that Physics is not all Math – it is, in fact, quite the opposite. All civilizations can be divided based on this, but the possibilities of these civilizations cannot be realized through this formula. For that, we need imagination and a bit of Physics.
Thinking about Type 2 and Greater Civilizations
Humanity has created marvels of science and technology. So, where do we rank on Kardashev’s scale? By inputting Earth’s annual energy consumption (about 2 x 1013 watts), we find out that humans rank a meager 0.73 on Kardashev’s scale, much to most dismay. If humans, with just a rank of 0.73, have managed to touch the sky daily, with shy attempts of expanding out of our green planet, then where do the possibilities of alien civilizations lie? And how exactly have they reached such levels?
When there’s talk about Kardashev’s scale, there’s talk about Dyson spheres. Dyson spheres, stated briefly, are humongous solar structures that theoretically could circumscribe a star, thereby obtaining the complete light energy the star has to provide. Freeman Dyson was the first person to suggest this, hence the name. The idea came to him while he was reading a sci-fi novel called ‘Star Maker’.
When he first suggested this, the idea was very vague and ambiguous. Questions arose about the physical structure of such a contraption. After the ambiguity was cleared, the final sketch of the Dyson sphere was realized.
The main ambiguity about Dyson spheres (also termed as ‘structure’ or ‘structures’ in succeeding contexts) was whether it would cover the entire star, or whether it would be divided into separate pieces. Let’s see the problem with having an entire machinery ‘gobble’ up an entire star (other than the extensive cost and the number of materials required for it):
The structure ,which encompasses a star, would, by theory, absorb the light energy emanating from the star, convert it into electricity, and use it as desired. Now, any massive object, especially objects like stars with masses in magnitudes of the twenties, tends to attract other objects towards itself due to gravitational force. The star too would try to attract or pull the structure towards itself. The only way the structure would remain in equilibrium with the gravitational force would be by an opposite and equal force; here, radiation pressure, also known as light pressure, would push the structure away from the star. This force comes from the photon particles of light, so minute and small, it is impossible to feel. But, when we are talking about emanators of light as massive as stars, then the force would not be negligible and would be quite enough. This pressure could hold up this structure of the Dyson sphere if it is light enough.
The force arises from the exchange of momentum between the photons and the surface of the structure. It can be expressed as:
P = hc/λ
Where P is the momentum of a single photon; λ is the debroglie-wavelength for that photon; and h is the Planck’s constant, which is around 6.626 x 10-34 SI units.
This momentum is what creates the force, as force is nothing but the change in momentum divided by the time taken for that change. When there are billions of trillions of photons, this momentum - which is almost negligible - multiplies to a considerable amount of momentum, giving enough force to hold up the structure against the gravitational pull of the sun.
The problem arises when the structure completely encompasses the star, thereby leaving no gap between it and the star. This, by far, would be very dangerous. The light would get reflected from the surface of the structure to another part where it would get reflected again, and so on. Without any place for the light to exit, this would cause the entire structure to ‘explode’ by the force of the photons.
Hence, a Dyson sphere cannot fully encompass the star. This would mean that a Dyson sphere would have to consist of separate components, each of which would encompass a certain region of the star.
For the best result, the Dyson sphere would consist of a plethora of thin, extremely light solar panels. This is known as a Dyson Swarm. These would be ejected towards the star with the help of a mass driver, an ejecting contraption that could send the panels flying towards a star at unimaginable speeds. Precise calculations would allow radiation pressure to balance out with the gravitational pull of the star, and wouldn’t cause the structure to break as there would be space for the photons to exit. You can imagine a Dyson swarm as multiple solar panels surround a star with gaps between each of the panels
For civilizations to stand on Type 2 or Type 3, it would have to have some kind of ‘Dyson swarm’ to take in all that energy. And once a Dyson swarm is completed, there would be no stopping for them. So, if aliens are real, where are all the Dyson swarms?
Fermi’s Paradox and The Great Filter
“But where is everybody?” – this was Fermi’s exclamation, according to his friend Konopinski.
This was during a casual lunch between Fermi and Fermi’s friends, whose numbers vary based on the source. And, this is probably your doubt too – where are all the aliens? Why don’t we see flying saucers everywhere in the sky?
This brings us to the next question – are we the only ones out here? Are humans the only living beings in this vast space known as a universe? Well, probably not. There are so many stars, galaxies, and planets to inhabit, the chances of not having life out there are extremely low.
So, if there are aliens out there or if alien life is possible, then why didn’t they reach out to us yet?
This is Fermi’s paradox. It’s a paradox – it has no viable answer to it, yet. There are reasons which support alien life out there, but the lack of evidence just seems to contradict that. Imagine, if alien life did exist, it would have probably evolved just as beings on Earth. It would have taken millions of years for it to become ‘intelligent species’, and much more for it to become like us and beyond. This period is very short, relatively with the age of the universe. If alien civilizations began any few billion years before us, we would be expecting at least primitive shreds of evidence. If the civilization is given more time it would have, by no doubt, expanded throughout space, planet to planet, star to star. Yet, to our dismay, there exists absolutely no evidence out there of alien remains or presence. Scientists have pondered upon this with various solutions, but only one truly pops out – The Great Filter.
The Great Filter is just as how it sounds – a ‘barrier’ that prevents civilizations from advancing more. This could mean the destruction of civilization as soon as it reached a certain technological stage or through misuse of a certain technology. For example, a nuclear showdown, bio-engineered viruses, or sheer global warming are all depictions of advancement in technology, yet could be the cause of destruction for any planet.
However, there is no complete evidence for this theory, so you can never be sure of it. Only the remains of ancient alien civilizations could strengthen this theory.
Another interesting aspect, which many are curious about, is just the probability of ancient civilizations out there. This was proposed by Frank Drake, in 1961, with the following formula:
N = R × fp× ne× fl × fi × fc× L
N is the number of advanced civilizations in the Milky Way (our galaxy); R is the rate of formation of stars; fp is the fraction of those stars with planetary systems; ne is the number of planets with an environment suitable for organic life; fl is the fraction where organic life may appear; fi is the fraction where intelligent life appears; fc is the fraction of the planets in which technology becomes sophisticated enough to dispatch signals; L is the length of time the civilizations dispatch their signals.
This formula is however useless, as the last 4 variables are unknown to us. Until we discover an alien civilization, such estimates will be not be yielding the correct probability.
Coming back to our original question – are aliens real? The answer needed this explanation, for the answer is... uncertain. The probability arrow tips towards ‘yes’, because, as modern astrophysicists are concerned, there is a huge probability that there are other lifeforms out there. But don’t keep your hopes too high – the chances are greater these ‘aliens’ won’t be intelligent, talkative aliens, but microscopic viruses and bacteria, who will need ages and ages more to become like us. You probably won’t see a flying saucer anytime soon.
- ‘The Future of Humanity’, by Michio Kaku
- ‘Physics of the Future’, by Michio Kaku