On today's episode, we are getting into the latest space news, including after
fifteen years, scientists make a massive new discovery regarding our universe and Europe test
fires their new reusable rocket for the first time. This is the space Race.
A scientific discovery on the universal scale has been published, seeking to prove
one of the last big predictions from Einstein's theory of general relativity and the method
for detecting this discovery took researchers fifteen years, three of the biggest radio telescopes
ever made, and a detection erow that spanned light years. On June twenty
eighth, the North American Nanohurts Observatory for Gravitational Waves or NANOGrav, posted a
report to the Astrophysical Journal of Letters. In it, the organization, which
is made up of over one hundred and ninety scientists across seventy institutions, detailed
their fifteen year study, which seemingly proves the existence of gravitational waves at the
cosmic level, a background hum of the universe. Now, gravitational waves are
not exactly new. They were theorized a while ago, and scientists have been
spending a lot of time trying to measure them. The basics are that anything
with mass emits gravitational waves when interacting with other things that have mass. These
waves are just like ripples in a pond, except instead of water, gravitational
waves move and bend the fabric of space itself. If you bump into a
coffee table or swat a fly, that causes a wave in the gravitational fields
that we all emit. Obviously, things like flies, coffee tables, and
people are too small to cause ripples that are noticeable. In fact, even
something the size of Earth or Jupiter, or even our own Sun doesn't have
enough mass or acceleration to produce gravitational waves that we can detect. For that,
we need black holes, and more importantly, they need to be eating
each other. Black Holes are usually formed by stars much bigger than our sun,
so even small ones tend to be large enough to notice when they act
oddly, and as it turns out, black holes do manage to do some
weird stuff. The most useful scenario for catching gravitational waves, though, is
when one black hole swallows another. Sometimes these swirling masses orbit each other,
just like binary stars, and this often ends in the pair slamming into each
other at extremely high speeds. This is what LIGO discovered. The Laser Interferometer
Gravitational Wave Observatory was fully constructed in twenty fourteen. It's a multikilometer long detection
array which uses finally tuned lasers to sense gravitational waves on the sort of scales
that we've been talking about, and in twenty sixteen they recorded their first real
proof of gravitational waves. One point three billion years ago, two black holes,
each about thirty times the mass of our Sun, collided out in the
universe. They produced such an incredible amount of energy that LIGO was finally able
to make a definitive inection of the waves in space that were produced and confirmed
Einstein's theories. Now we had to go over that because you needed to have
some understanding of how hard it is to find these waves and the scale of
energy needed to make them, because Einstein predicted something way bigger. The idea
was that if large enough masses could produce gravitational waves that we could detect,
then there should be objects so massive floating out in space that the ripples they
make would form a sort of background hum a frequency whose wavelength is so colossal
that they span light years the gravitational wave background. Think of it as sort
of the ambient swell of the ocean. Everything would be affected by it,
but being inside those enormously long waves means that you wouldn't really notice unless you
had a detector sensitive enough. And now we're getting to the really wild stuff.
Waves at that scale means two things. First, they would have to
be created by binary supermassive black holes slamming into each other. Every large galaxy
has one of these supermassive black holes at the center millions of times the mass
of our sun, or even regular sized black holes. We've observed, even
the one that sits at the heart of our own galaxy, so we do
know they exist. What we're not sure about is if any exists that orbit
each other in a binary supermassive system. Einstein theorized that some of them would
have to exist, and that they would be moving so fast that they would
have to be emitting this background wave, especially once they collided, And that
brings us to the second thing. We were going to need an astronomically sized
detector array if we hoped to find this wave. Remember lego kilometers of a
ray spased using a delicately tuned laser beam to detect just a normal black hole
eating another one. There's no hope of using something that small to detect a
gravitational wave at the scales we are discussing here. So the scientists at Nanogra
built themselves in an array that spanned across the galaxy, and to accomplish that,
they used pulsars. Pulsars are stars that were not quite big enough to
become black holes. Instead, they collapse into super dense cores, spinning incredibly
quickly regularly, sending beams of high intensity radiation out into space. Every once
in a while we detect these beams like cosmic lighthouses. Pulsars spin incredibly regularly,
and sometimes they also eat a binary sibling, which leads them to spinning
even faster. Astronomers call these millisecond pulsars because they complete a full rotation in
under a single second, and it's these types of pulsars the researchers used.
Think of it like the laser beam at the Ligo array. Gravitational waves bend
the fabric of space, literally bringing two points closer and then further away from
where they started. At Ligo, scientists measured the laser beam for the amount
of time it took to reach their instruments at the other end kilometers away.
They know the speed of light, so if there was any deviation, no
matter how small, that was confirmation. So when the nanograph researchers audited the
millisecond pulsars they found, they studied the spin rate of each individual one.
Then they waited and took careful notes across sixty eight known pulsars over fifteen years.
This pulsar timing array is an ingenious way to use the universe as a
tool, and it worked over the course of the first twelve years of the
study. The team used the now decommissioned Arecibo telescope, the Very Large Array,
and the Green Bank telescope to measure the changes in these pulsars, and
over the next three years they gathered and analyzed the data, finding that these
pulsars were being pushed and pulled on waves that spanned light years. The biggest
takeaway from a study like this is that now we know that supermassive black hole
binary events likely exist, or an equally large event. Either way, it
helps lidify Einstein's theory of general relativity. A fundamental part of our understanding of
the cosmos. More practically, though, this study shows a new method for
detecting phenomena at an amazingly humongous scale. Gathering easily verifiable data from stellar objects
light years away is an application we could use to figure out other big questions
we have about our universe. On June twenty second, the Aryan Groups successfully
test fired Prometheus, the engine that will be powering the European Space Agency's new
fleet of reusable rockets. The prototype three D printed engines were brought to the
Aryan Group's test site in Vernon, France, and mounted on a Themis first
stage booster and lit for twelve seconds. Prometheus can put out one hundred tons
of force and normally runs off oxygen and methane, just like a lot of
other engines in the industry, but for this burn, Aryan Group decided to
test the use of both normal and biomethane fuels, showing that the ess Prometheus
equipped rocks will be versatile and environmentally friendly. These two pieces of hardware were
commissioned in late twenty twenty and are part of the Aryan Next Joint, a
joint venture between the European Space Agency and the French CNS, with Aryan Group
as the primary contractor. The ESA has been using Aaryan Group for some time
now. This company has designed and run most launch hardware for the ESA since
it was formed in twenty fifteen. Vega, the European version of the Soyuz
capsule, and of course are in five and six, the last of which
is still in development. So it's not surprising that Aaryan Group is running the
show again for this next chapter of European spaceflight. What is surprising is how
they're going about it. You all might notice that both the Themis module and
the Prometheus engine looked a little rough in this test. Prometheus didn't have its
nozzle extensions, some combustion tech wasn't quite ready to be tested yet, and
Themis itself wasn't exactly a complete booster yet. This is because the Aryan next
project is designed to run on a tight budget, with tests happening as early
as possible in the development cycle in order to help the engineers learn and iterate
as quickly as possible. And if this is all sounding a lot like how
SpaceX does things, then you are extremely correct. Up until now, Aryan
Group had been known for playing things safe. They have been criticized for requesting
more budget than would be necessary, but with the ESA falling behind and launch
utility, it seems Aryan Group has decided to see if they can use a
SpaceX style approach in order to develop a competitive vehicle system that will have versatility
and more importantly, be extremely cheap to operate. And the real key to
that is the fuel type. Up until now, Aryan Group's designs have made
use of hydrogen as the main fuel, similar to NASA's SLS rocket. Hydrogen
is very safe for the environment, not to mention extremely efficient, but it
needs to be stored at very low temperatures compared to something like methane. So
not only can the new engines use a fuel type that doesn't need to be
so cold that it changes the shape of all their plumbing, the methane fuel
can be stored in a denser package, allowing them as to use smaller tanks
and take up less space. Testing for the new Prometheus engine will reportedly be
ongoing for the rest of this year, with the goal to reach a SpaceX
style hop test. Once the landing legs for themis are figured out, it
will be very interesting to see if the ESA can copy the success of companies
like SpaceX. Area Next is in very early days still, but a live
fireburn conducted this soon into its development would seem to be pointing to them being
on the right track.