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!
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