The date is 2001, and in the Australian outback
a 64 meter radio telescope scans the sky for electromagnetic signals from deep space. With most of the electromagnetic energy in
the universe being generated by stars and black holes, and outside of the visible light
spectrum, the radio dish and the data it collects as it steadfastly surveys the sky is instrumental
in making new discoveries about phenomenon millions of light years away. Unbeknownst to its operators and buried deep
in the incoming data, the dish picks up a powerful 5 millisecond burst of radio energy-
something unlike any observed cosmic phenomenon to date! The burst of incredibly powerful radio energy
will remain buried in the data for another six years though, until in 2007 astronomer
Duncan Lorimer assigns a student to look through the archival data from over half a decade
ago. Stumbling across the mysterious transmission,
it's first believed to be a technical glitch, but slowly Lorimer and his student realize
that this is in fact exactly what it appears to be: a massively powerful radio signal coming
from somewhere in space outside our galaxy. The rest of the astrophysics community largely
discounts what comes to be known as the Lorimer pulse though, assuming it to be faulty equipment
or an inappropriately observed commonplace phenomenon. Then in 2010, a survey involving many different
radio dishes around the world picks up sixteen pulses- now known as Fast Radio Bursts. Immediately heated debate begins amongst scientists,
even as more FRBs are discovered year by year. Theories range from the incredibly unlikely-
neutron stars caught in a specific set of circumstances near a black hole- to the flat-out
incredible: alien communications. Yet FRBs proved elusive, and would never repeat
themselves, leaving scientists completely in the dark as to their true origin. Then in 2016 scientists working at the Green
Bank Telescope in West Virginia and working with the Breakthrough Listen initiative make
a startling discovery. The Breakthrough Listen project is aimed at
detecting signs of intelligent life via eavesdropping on the universe at large within a variety
of different radio frequencies. With the correct frequency that an alien civilization
may be broadcasting in impossible to guess, Breakthrough hopes to use computers to scan
through enough frequencies fast enough to catch rare one-off transmissions that might
just be coming from a technological civilization. Then suddenly, late one night on August 26th,
astronomers pick up an incredibly powerful radio signal coming from deep space. The energy of the signal is so great, that
a natural origin is all but impossible, and so the astronomers turn all their electronic
ears on the source of the transmission. For the next five hours radio telescopes pick
up a further fifteen bursts of intense radio energy, all coming from the same spot in the
sky. The scientists end up collecting a whopping
400 terabytes of data. Never before had scientists detected repeating
FRBs, and the discovery of a repeating FRB throws out a great deal of theories for a
natural origin. Stopping well short of announcing the discovery
of alien intelligence, scientists are still forced to seriously consider that the repeating
transmissions cannot be of natural origin. One natural theory is put forward though,
claiming that the FRBs could be coming from a newly formed magnetar- a very quickly spinning
neutron star with an extremely powerful magnetic field. While plausible the theory fails to explain
why the transmissions only lasted for five hours though. Other theories are presented as well, and
most involve incredibly specific circumstances affecting very rare cosmic phenomenon. Given the size and age of the universe, these
extremely low-probability theories are not truly impossible, but are implausible. Slowly though more and more scientists come
around to the possibility that FRBs are not natural in origin, and are in fact signs of
advanced intelligent life. To discover the plausibility of an alien origin
astrophysicists first calculated just how much energy would be needed to send a signal
as powerful as an FRB all the way across galaxies. What they found is that by building an extensive
network of solar arrays twice the surface area of the earth around a star similar in
size to our sun, they could provide enough power to send such powerful transmissions
across the universe. Such a construction is far beyond the bounds
of what would be feasible for us humans, but what about advanced aliens? Well, if aliens really wanted to build such
a mega structure it would actually turn out to be relatively easy, and really only require
a very large investment in time. First, the aliens would build a set of pre-programmed
Von Neuman drones and launch them at the moons of neighboring planets or an asteroid belt
if they had one. Von Neuman drones are hypothetical but completely
plausible autonomous robots which would be programmed to turn raw materials into copies
of themselves- the replication process of a small fleet of Von Neuman robots would be
so efficient that in fact it's estimated that a single species could scout the entire galaxy
in only a few tens of thousands of years by sending out probes that arrive at a star system,
replicate, and launch off to new star systems. In our scenario though our drones will first
spend a decade breaking down the raw materials of asteroids or a moon and processing them
into new drones, creating a fully autonomous workforce of millions of drones in just a
few years. Once the work force is created, the drones
would then turn to the process of assembling the giant solar dishes required to power the
huge transmitter. For decades the robots would mine raw materials,
refine them, and transport them for assembly in space, all without interference from the
aliens who built them. The aliens could literally kick their feet
up and relax as their vast swarm of drones slowly but surely construct a massive radio
dish and solar power collectors in space outside their planet. Within a few decades to a century, the project
would be complete, with the drones then breaking themselves down to use their own bodies as
the final raw materials needed. Now that would be recycling on a galactic
scale. With the huge radio dish and the solar collectors
needed to power it completed though, the question is what exactly would aliens want to do with
it? Well, here on earth we have for a long time
known of a way to propel spacecraft incredible distances at speeds approaching a significant
fraction of the speed of light. Typically these propulsion systems involve
a large array of powerful radio antennas or laser emitters built on the surface of the
earth or in space, which would then fire microwaves or pulses of laser light at the rear end of
a spaceship. With no friction in space to slow down a spacecraft,
the tiny push of radio energy or photons on the hull of the ship would quickly add up,
and could propel a ship twenty times the size of a modern cruise liner to speeds that would
make reaching nearby star systems a matter of years! An advanced alien civilization could thus
use an array of huge radio transmitters to push spacecraft along electromagnetic interstellar
highways, and with a powerful enough transmitter they could even propel spacecraft across intergalactic
distances! With a star powering the transmitter, the
spacecraft could be powered for years, decades, or even longer if necessary, and the extremely
high energy state of FRBs could make such a propulsion system effective even across
intergalactic distances. The only limitation would be the biological
needs of the ship's crew, but if an alien civilization is advanced enough even that
would be of little concern as they might simply put their crew into stasis that lasts for
hundreds or thousands of years. The alien propulsion hypothesis would even
fit in with the fact that FRBs are almost never observed repeating. This is because a giant transmitter near an
alien world would itself be orbiting its host star, while that star orbited around the galactic
core of its home galaxy, and that galaxy itself moved relative to other galaxies around it. This means that we would only be able to detect
an FRB during the very rare and very short-lived moments that the beam of the transmitter crosses
paths with the earth. Of course, FRBs could also be used for signaling
to other alien life, and not just to push ships around space. Given their extremely high energy state and
lack of similarity to any observed or easily explainable natural phenomenon, FRBs could
be nothing more than something similar to shining a very bright flashlight in the middle
of a forest, hoping that someone outside the forest is looking in your direction and noticing
the bright flash of light. The key would be to make sure that the pulses
are repeatable over a shorter duration, that way an alien civilization who detects them
would have a very hard time explaining them as having a natural origin- which is exactly
the case with our current observations of FRBs. With such a vast universe though, it would
be extremely unlikely that earth would be in the direct path of a series of FRB pulses,
and much like in the scenario earlier where they are being used to push alien space ships
along, we would only detect them by accident when the beam crosses our path. However, if an alien civilization was actively
transmitting throughout space, then eventually the earth would be in the direct path of a
set of pulses, exactly as happened in 2016. Given the size of the universe, it's very
likely that many civilizations would all have the same idea for intergalactic communication
with other species, and thus our detection of so many FRBs could be a tiny percentage
of what is essentially a huge intergalactic conversation of which we've yet to take part. Of course, FRBs could also end up being nothing
more than another weird astronomical phenomenon that we don’t quite understand yet. Our top scientists here at The Infographics
Show though can confirm that FRBs are definitely not transmissions from Zeti Reticuli aliens
who are definitely not coming, and are definitely not already here, to eat your delicious brains. What do you think FRBs are? Do you think we'll ever find intelligent life? Let us know in the comments! And as always if you enjoyed this video don't
forget to Like, Share, and Subscribe for more great content!
