The movie 'Contact', starring Jodie Foster, was based on the premise of radio contact with extraterrestrials (ETs). Foster played the role of an 'alienated' radio astronomer, who was determined to search for extraterrestrial signals, and actually managed to acquire some extremely sophisticated ones.
But, is the central premise of 'Contact' valid? Is it plausible that astronomers should spend innumerable hours listening for radio messages from ET? Are there advanced extraterrestrials pummelling our atmosphere with their coded messages even as these words are written?
The assumption of the plausibility of radio contact with ETs led to SETI ('Search for Extra-Terrestrial Intelligence'). In its early stages, millions of radio channels were scanned nightly for any sign of intelligence. Now known as Project Phoenix, its scope has expanded to the radio coverage of some billions of channels to search for some sort of alien calling card. In particular, an incontrovertible intelligent calling card - left by an advanced race of beings.
Is the Phoenix group wasting its time and money? My contention is that they are, but the reasons are somewhat different from others that have gained wide currency. For example, some, like physicist Frank Tipler, assert that no intelligent aliens exist, because if they did they'd have already visited us by now. They haven't, ergo they do not exist![1]
However, I don't necessarily preclude alien existence, merely their communicating with us. I believe the two premises must be treated separately. Unfortunately, the standard assumption made by most humans conflates them: if intelligent extra-terrestrials exist, they must want to contact us.
But why? What if we are little more than a galactic 'ants' nest'? Why should they even care about our existence? The fact is, it is we who inflate our own self-importance by believing we deserve this much attention. But I am getting a bit ahead of myself.
Let me refer to a basic physical law, to show how and why I believe ET messages are improbable. I am referring to the so-called 'entropy law', also known as the 2nd law of thermodynamics. What is entropy? Basically, a measure of the disorder in a physical system. For example, gasoline that has undergone combustion has more entropy than gasoline which has not. Firewood which has been burnt has more entropy (states of disorganization) than firewood that is stacked next to the fireplace.
Entropy is not restricted to our planet. It applies throughout the universe. This is part of the fundamental principle known as 'the cosmological principle'. It says that the same exact physical laws apply throughout the cosmos. There is no region that behaves differently, in a physical sense, from the region we inhabit.
For example, in the case of the whole universe, maximum entropy (disorder) will be reached if it continues to expand forever reaching a final 'heat death'. (Where all parts of the universe eventually have the same temperature - so there is no flow of energy to any other part, say from a star to a planet). If the universe turns out not to expand forever, it will still reach a maximum entropy - this time in the 'Big Crunch', in which all the galaxies collide with each other, after reaching maximum expansion.
The entropy law simply says that - for a closed system - the total entropy is always increasing, never decreasing. People cannot help but use food, process chemicals, and burn fuels. The effect is that the total amount of disorder in the world is increasing. To slow this down (or try to stop it) more energy must be expended from the outside, than the closed system uses in generating entropy. (A simple way to put this is that if you leave your house, and never apply energy to clean it up, the resulting disorder will soon occupy all existing space.)
The tendency for entropy to increase is invariably accompanied by a loss of useful energy. When an amount of disorder is produced, say in burning gasoline, it is at the expense of the useful energy that was originally in the tank. One might write a simple expression to represent this:
Ten gallons gasoline -> 1 gallon useful energy + 9 gallons waste energy
This means that 90% of the initial energy is converted either to heat, or to effluent (carbon monoxide, carbon dioxide, sulphur dioxide etc.). Is there a way to get ten gallons worth of energy, from ten gallons of gasoline, without waste? No. It is impossible. It goes against the entropy law and the nature of the physical world we inhabit. The first commandment of the entropy law is 'The universe provides no free energy lunch.'
So what does all the above have to do with the ability of ETs to communicate with us? (Assuming they would wish to) As it turns out, everything. In order to communicate, say over thousands (or even hundreds) of light years' distance, information is transmitted. It requires energy to do this. Interestingly, a relation between energy and information is available. It can be written as:[2]
E = 0.693 kT
Here, E is the energy associated with transmission of 1-bit of information. T is the temperature of the environment in which it is sent (say the radio transmitting antenna) and k is a physical constant known as the Boltzmann constant.[3]
Imagine an alien civilization sending the equivalent of a small novel to humans. This would be approximately 10^20 bits of information. The associated energy would be about 0.3 (three tenths) of a Joule.[4] The energy required, from a practical standpoint, would be much, much larger - maybe 100 million times larger. Why? Because in the process of pure transmission (over light years distance) a significant fraction of signal dilutes. So, at least 30 million Joules would be needed, to have it get to Earth in a useful form.
Arguably, aliens genuinely interested in contact would not waste time or effort with anything so puny as a small novel. It is more probable, if they went to the trouble of first contact (as in the film 'Contact') they'd send a lot of information. Say, equal to an alien encyclopedia of mathematics, or their most prevalent language. In this case, the information content soars to millions of megabytes, and the energy accordingly. For one million megabytes (10^12 bits) the aliens are looking at an energy for transmission on the order of 3 x 10^19 Joules.
It is well to realize that time factors into this as well. If the aliens kept the transmission going for at least one hour (Earth time), 3 x 10^19 kilowatts of power are needed (assuming the aliens are ale to sustain a rate of energy conversion of 1 Joule per second). In the civilization classification scheme of the late Russian astrophysicist I.S. Kardashev, this would put them at a bit beyond Type I, but not quite Type II. Kardashev's three-class scheme is:[5]
I: Able to harness the equivalent power of the planet Earth
II: Able to harness the power equal to a typical star (10^23 kw)
III: Able to harness the power equal to a typical galaxy (10^33 kw)
The question is: To what extent have the ETs circumvented the Entropy law? This is important, in terms of how much their energy use (say to transmit powerful radio messages) compromises their own world's environment.
For reference, consider a terrestrial example: the United States. It is currently reckoned to have as many cars as people: about 250 million. Say one half of those are being driven at any one time: 125 million vehicles. Each one consumes on average 1000 Joules of energy and 1 kilowatt of power. That is 125 million kilowatts of power. If each vehicle runs 1000 hours per year, that is 125 billion kilowatt-hours of energy. Nine tenths ends up as waste heat, and effluent. The effluent contributes dramatically to The Greenhouse Effect. (Last year EPA statistics showed that the carbon levels in the country rose 3%).
What about the alien civilization which I hypothesized above? Well, their energy/power use would be absolutely enormous. Just for the purpose of interstellar communication, I would estimate 3 x 10^19 kw. This is nearly a quarter of a trillion times more than what the vehicles in the U.S. generated last year. Imagine the pollution, atmospheric damage and other ills triggered on the alien home world! (And we are not even looking at all their other possible energy expenditures - whether for agriculture, domestic energy use, transportation, or whatever.)
Could aliens be sufficiently advanced to beat the entropy law? Hardly. For example, even if the alien civilization had perfected its technology to the point that it obtains 50% energy efficiency (totally unheard of in any practical terms) they still have 1.5 x 10^19 joules of energy ending up as waste every hour they attempted radio transmission! (Given the same set of assumptions made earlier). And remember, this is not reckoning all the other energy conversions, for their own needs!
Since the cosmological principle shows the law of entropy is applicable everywhere, it must apply no less to alien species and alien worlds. These other civilizations, in some form or fashion, passed through the same reckless, energy consumption phase humans are confronted with on Earth. In other words, they were threatened by a similar global warming effect, or some other manifestation of entropy (like ozone erosion). At some critical junction, they made similar calculations, and were forced to make a profound decision. To expand energy use for a temporary higher life quality, or curtail it for the greater planetary welfare.
My contention is that they chose the latter path: they rejected the imperative for ever increasing energy consumption. This includes all mammoth energy-consuming projects, such as transmissions to other worlds, re-shaping whole planets and solar systems into imitations of their own planet, constructing black hole-based energy devices, and space faring to other worlds.
Like us, they may have long conjectured about 'ETs', and perhaps listened for a time. But eventually, they realized someone needed to 'break the ice' in respect of transmitting. However, seeing the exorbitant energy cost, they decided they would not be the first. Thus, in my conjecture, they backed away from any grandiose schemes of interstellar contact. This is exactly why no signals are being picked up from ET - because frankly ET isn't talking. 'He' is not willing to pay the cost, in terms of disastrous energy change on his own planet. He is not prepared to purchase a dream at the expense of suffocating in pollution, or roasting slowly in a Greenhouse type inferno.
Our disbelief or non-acceptance of this is a reflection of exaggerated human self-importance, and an inability to accept the harsh limitations imposed by the entropy law. Most humans prefer, in their boundless energy naivete, to believe in an ever more bountiful future, chock full of new energy devices: self-powered robots, anti-grav jet cars, rocket trains, and ion-propelled spaceships. In the end, all childish fancies in which entropy never rears its ugly, limiting, pessimistic head.
In such a fantasy world, engendered by overblown expectations, humans can afford to entertain such grand concepts as 'Dyson spheres' and harnessing whole stars for communication purposes. Such visions will recede into oblivion as the effects of entropy buildup are more perceptibly felt on Earth. Only then will humans appreciate why such reckless and profligate energy scenarios have been studiously avoided on others.
These considerations inevitably lead to my own classification scheme for alien civilizations: alphas and omegas. The alphas are the energy spendthrifts like us, who have not yet been taught the error of their non-conserving ways. They have yet to feel the heat as their global temperatures warm ten or more degrees Fahrenheit, or see diseases spread out of control with Greenhouse warming, or watch helplessly as their coastal lands are reclaimed by rising seas (from their melting polar ice caps). Their visions of energy appropriation have not yet been tempered by harsh realities.
Then there are the omegas. At some point in their development they were confronted by an imminent energy-entropy crisis (such as we are now approaching with the combination of Peak Oil and accelerated global warming). This forced them to make hard choices. Consume energy, and extract a higher 'quality' life - but at the cost of exponentiating entropy, or conserve, and tolerate a life with fewer amenities?
The prospect of compromising their dreams was surely painful, but they recognized that their survival depended on it. As their unrealistic energy aspirations vanished, so did their visions of interstellar communication, and of course, interstellar travel.
As total accommodation to the priority of entropy control took hold, new directions were set. New imperatives defined. Fierce competition for, and reckless use of limited resources was curtailed. Population growth was curbed, by means of forced birth control, or optional inducements. Travel or consumption, without purpose, was inhibited. Agriculture was converted to the least energy-demanding forms. External, consumptive preoccupations gave way to internal ones: art, music, meditation, self-education - the cultivation and maximization of the interior universe.
If my conjecture is valid, as I believe it is, then other alphas are our only hope for extraterrestrial contact. However, I place the probability for this at near zero. For contact to succeed, they need to be at our same stage of technological development, give or take 25 years. This is because all energy spendthrift phases are extremely transitory. At the same time, consider that Earth is at least 50 light years from the nearest plausible alpha planets. At this distance, a minimum of 100 (Earth) years would elapse between sending a first signal and receiving a response. Because of the spendthrift phase limits, either one or both communicating civilizations would never get a chance to make contact. Either one (or other) would have emerged from the alpha stage (becoming embryonic omegas) or gone on to exterminate themselves in a planet-wide ecological catastrophe.
Without waiting further, terrestrial radio telescopes ought to be directed toward more productive pursuits. We’ve had our fling with fantasy, and we’ve dreamed of conversing with ET. It’s been a pleasant diversion, but now it is time to return to reality. For while we indulge in fantasy a whole universe begs further discovery: colliding galaxies, massive core black holes, and sundry distant space phenomena such as cosmic masers.
In every interstellar atom, dust grain and cloud are embedded clues to our history, and ultimately our own identity. Human destiny is to ferret out these clues, and disclose ourselves and our planet in the process. We cannot truly do this as long as we are obsessed, and distracted, with a dream that can never be. So, if ET isn't talking - why should we? The answer may well hold the key to our future, and whether we survive as a species.
[1] Tipler, F.: 'Extraterrestrial Beings Do Not Exist', in Frontiers of Modern Physics, Dover Publications, Inc., p. 155.
[2] Pierce, John, R: 1980, An Introduction to Information Theory: Symbols, Signals and Noise, Dover Publications, Inc., p. 204.
[3] Boltzmann constant: A well-known constant from physics: k = 1.38 x 10^-23 Joule/Kelvin.
[4] You use 1 Joule of energy lifting a 100 gram golf ball 1 meter (or 3.3 feet).
[5] Shklovskii, I. and Sagan, C.:1966, Intelligent Life in the Universe, Dell Publishing Co., p. 394.
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