SETI: Other Creepy technosignatures we might detect
Welcome, everybody! Are you a fan of sci-fi films and novels?
Have you ever had creepy thoughts? If your answers are YES,
well, this video is for you! We will talk again about SETI,
which stands for the “Search for Extra-Terrestrial Intelligence” program,
and technosignatures of alien civilizations that we hope we'll never detect!
We said “we will talk again” because we already touched the argument in a previous
video on the channel! In fact, this is the second part of the video on the topic ( that
we strongly recommend watching!). You can find the first part of the link below: (
https://www.youtube.com/watch?v=nQgJEGtQbRs&t=12s&ab_channel=InsaneCuriosity )!
Today we will focus on some of the creepiest and craziest technosignatures we might
detect in the future – with the help of better technologies (and some bad luck).
Most of them are actually signals coming from sci-fi scenarios, but...who knows!
1) Nicoll- Dyson Beam
Luckily, for what we know at the moment, the Milky Way is a peaceful galaxy.
There are no ongoing wars. No emperors want to expand themselves. Our detecting systems seem
to hint that we are alone. Alone in this small (yet huge) part of the universe, in the so-called
“local group”. But are we?
What if we are not alone? It might be an alien civilization whose only intentioned
in conquering all the galaxy. They might have learnt to produce new weapons,
new extraordinary firearms, or nuclear ones. Maybe they are out there, but we can't
communicate with them, nor see them because they are simply...hiding from us!
What kind of gun could they have? In order to conquer the galaxy, they must
have developed powerful tools and invested very much in weapons. One of the most feared weapons
ever designed is a Nicoll-Dyson-beam. Have you ever heard of it?
The Nicoll-Dyson beam was a beam that would harness a stars entire energy output and
destroy other celestial bodies. It makes uses of a megastructure built around a star that collimates
the energy of the star in one single point, using it as a powerful gun, the Dyson Sphere.
So, a Dyson sphere is a hypothetical megastructure that completely encompasses a star and captures
a large percentage of its power output. The power of a collimated beam is limited
by the focus of the beam when it reaches a distant target. One way to improve this focus
is to increase the effective aperture of the emitter. Dyson Sphere collects considerable
amounts of energy from the stars they contain. If some of that energy can be stored, then directed
towards a target in a different planetary system, considerable damage can result. In practice,
the outermost elements of the swarm, or the outer surface of a dynamically supported Dyson Shell,
become a phased array emitter. This allows a powerful beam to be focused
on a distant target in another planetary system. This concept was first suggested by James Nicoll
in the Information Age and is known as a Nicoll-Dyson Beam for this reason.
Nicoll-Dyson beams are routinely used to propel laser-sail craft at interstellar distances in
sci-fi movies and books and have been used to send messages to distant locations.
Nicoll-Dyson arrays can also be used as weapons. Severe damage
can be inflicted on a planet's surface, or on a megastructure, at great distances.
However, if you think about it, it is not a great weapon. In fact, if a beam is fired,
this results in significant destruction in a distant system many years later (due to
the finite velocity of waves). Suppose civilizations were on
a war period between emperors. During the intervening period,
wars may have ended, treaties may have been signed, and the political landscape
may have changed. Nonetheless, the beam is still on its way, and cannot be recalled.
We hope we never detect such beams because if we were, we would be done!
2) DNA Seti
While a long shot, it is plausible that earth has been visited by an alien civilization
sometime in the distant past. Perhaps even millions or even a billion years or more!
If it happened long enough ago, there are a few ways where evidence of a visit might be preserved.
But we know Earth loves to erode and renew its surface leaving little room for any artefacts
to be preserved. Where shall we find them? Well, we know it’s a different story with
some of the areas of the solar system. In fact, we might find some oddly depleted asteroid that
might have been subjected to mining at some stage or we might even find some artefact in space,
or even on the moon, where things tend to preserve longer (though not indefinitely!)
But there is one medium, maybe the most important one and the creepiest we could detect, where
evidence may be preserved almost indefinitely, and that is the information encoded in DNA.
It has been suggested that if an alien civilization had visited earth,
say when life was simple and exclusively microbial, they might have altered the
DNA of early life or even later complex life to reflect a kind of SETI message.
This could be a very simple message or a more complex message.
It could be just a note that someone had visited here in the past and left telltale patterns or
markers encoded in life itself. It would be a kind of postcard!
Or maybe the message could be very complex, giving us a kind of encyclopedia Galactica
regarding alien civilizations of long ago, like the one described in the famous book,
“the hitchhiker's guide to the galaxy!” Another possibility is encoded messages
in microbial life that might have travelled here via panspermia or even life on other
solar system bodies if that proves to exist at places like Mars or Europa.
Or the message might be more sinister, raising the question of past manipulation of life on Earth.
Lastly, but not least, DNA SETI could even contain a warning message of some kind
of a threat that each and every one of us would carry in our own bodies
placed there long ago by an alien civilization!
I know, it's very weird. It's best not to think about it!
3) Self Replicating Spacecrafts Say an alien civilization (or us)
wanted to mine an entire asteroid or moon. It would be a large-scale mining operation.
This is not sci-fi, because we all know that, at some point, we'll have to go and search
for new materials on other celestial objects, rather than the Earth: resources are finite!
Scientist and Mathematician Von Neumann proved that the most effective way of performing
large-scale mining operations such as mining an entire moon or asteroid belt would be by
self-replicating spacecraft, taking advantage of their exponential growth.
What does it mean, in practice? Well, a self-replicating spacecraft could be sent
to a neighbouring planetary system, where it would seek out raw materials (extracted from asteroids,
moons, gas giants, etc.) to create replicas of itself. These replicas would then be sent
out to other planetary systems. The original "parent" probe could then pursue its primary
purpose within the star system. This mission varies widely depending on the variant of
self-replicating starship proposed. We know it is a very difficult project
to accomplish, and so far we never detect signals of a self-replicating spacecraft
in the solar system (luckily, I guess!). But there is one ethical problem with that.
Given this pattern and its similarity to the reproduction patterns of bacteria,
it has been pointed out that von Neumann machines might be considered a form of
life. In his short story "Lungfish" (see Self-replicating machines in fiction),
David Brin touches on this idea, pointing out that self-replicating machines launched by different
species might actually compete with one another (in a Darwinistic fashion) for raw material,
or even have conflicting missions. Given enough variety of "species" they might even form a type
of ecology, or – should they also have a form of artificial intelligence – a society. They may even
mutate with untold thousands of "generations". It has been also theorized that a self-replicating
starship utilizing relatively conventional theoretical methods of interstellar travel (i.e.,
no exotic faster-than-light propulsion, and speeds limited to an "average cruising speed" of 0.1c.)
could spread throughout a galaxy the size of the Milky Way in as little as half a million years.
Do you think it will be possible for us to build such Self-replicating spacecraft?
At the moment, there are a lot of speculations on that,
and also many papers were published in order to give a boost to this field of research!
We just have to wait, and see what the future will be like! And we hope that, if we ever detect
signals of such Self-replicating spacecraft, it will be from a peaceful alien civilization!
4) The closing in signal We are used to imagining that,
if we ever detect an alien signal, it would be from a thousand light-years away.
In fact, there are very small chances to detect signals from very near celestial objects.
Or is it so? What if one day we woke up with this news:
ALIEN SIGNAL DETECTED FROM RADIO TELESCOPE!
And we found the signal was sent from a very close star, or from a very close celestial object?
Plus, what if we found that the signal was blueshifted?
It would mean that the signal emitter, i.e. the alien probe, is coming toward us.
It would be very creepy, can you think about it? What would your first reaction be?
I'd probably go crazy, running the stairs of my condominium up and down all day!
There would be very little we could do about that.
At least in the short term, we would simply just have to wait
until it arrived to find out what its real intentions were, whether friendly or otherwise.
We would pass our days trying to imagine what the alien would be.
Of course, no such signal has been found today, but there is a candidate.
Have you ever heard about the WOW signal? One little known aspect of the famous 1977 WOW!
signal that may have been a veil in origin is that it’s not actually known how distant it really was.
Actually, it could be a signal coming from a very distant object,
but studies actually suggest that it could have been emitted from a nearer source.
All that is known is that it had to be at least half the distance to the moon!
Beyond that, it could have been light-years away, but one hallmark of the WoW signal was that it
was very strong - indeed the strongest signal of its type picked up by the Big Ear telescope and
its entire decade-long run with SETI. That could suggest that either the
signal was being transmitted with enormous power from a distance,
or that it was closed, and this brings up another little known aspect of the signal: it was actually
just above the 1420 megahertz hydrogen line. Now, this is a commonly used frequency in
satellite and probes communication, suggesting either that it was intentionally broadcast
that way or that it had a very slight blue shift, suggesting that whatever it was it was
coming towards us very slowly (about 10 km/s according to scientist estimate).
That’s slower than many of our own space probes are moving! It means that probably,
it could be not one of our launched probes! But until that signal repeats, which it may
never do, we’ll never know what it was or how far away it originated...or will we?
"This video ends here! Thanks for watching everyone! Do you think we are alone in the
universe? Did you hear of some other types of technosignatures that SETI could detect?
Let us know in the comments below!
See you on the channel, and remember to stay curious!