something that is truly incomprehensible
are the voids that occupies the space
between the visible matter in the
universe some voids appropriately called
super voids can be millions of
light-years across
take the bow out this void for example
it's 250 million light years of almost
nothingness from this image it might not
look that bad until you realize that
almost all of the galaxies shown in the
circle lie in front or behind it to date
only 60 galaxies has been found within
this void a space that large could
easily contain 10,000 galaxies when
compared to other regions
just imagine if an alien civilization
like our own exists on a planet within
one of these galaxies the nearest
neighbor would be tens of millions of
light years away even worse if your
planet is orbiting an intergalactic star
it's a star or star system that has been
ejected from its home galaxy and is now
floating freely through the cosmos
magnetars is a form of extremely
magnetic neutron stars from around 400
kilometers the magnetic field would
strip you of all metallic objects such
as your phone watch belt glasses and so
on and if you got really close it would
eventually start ripping out the iron in
your red blood cells out of your body
there's a weird correlation between the
distance and size of the Sun and our
Moon because during a solar eclipse the
moon almost perfectly covers the Sun but
there's really no physical reason why
this has to be the case the moon just
happens to be 400 times smaller than the
Sun but the Sun just happens to be 400
times further from the earth than the
moon is another object we can see with
the naked eye is the end dromeda galaxy
and it looks a little something like
this
but because Andromeda is so far away we
only see the very bright center of it if
we could see all of Andromeda our skies
could look like this every night it
would be several times larger than the
moon even though it's 2.5 million light
years away right now no matter if you're
moving or sitting still in a universe
where everything is orbiting spinning or
pulling you're moving at incredible
speeds electron spins around the nucleus
of atoms and we humans being made of
atoms rotate along with the earth the
moon orbits the earth the Terran system
rotates around the Sun and the Sol
system rotates around a black hole in
the center of the Milky Way galaxy
several smaller galaxies part of the
Milky Way subgroup orbits the Milky Way
the Milky Way subgroup rotates around
the gravitational center located
somewhere between the Milky Way and
Andromeda
which is all part of collection of
larger galaxies called the low
group and our local Group of galaxies
orbits along other groups of galaxies
within the Virgo supercluster and this
super cluster is along with countless
other super clusters being pulled
towards a much larger super cluster
called the Great Attractor and in turn
the Great Attractor is pulled towards
the largest known super cluster in the
local universe named the Shapley
supercluster the days on Venus is longer
than a Venusian year Venusian that
sounds so sci-fi for some reason
Venusian basically Venus completes an
entire orbit around the Sun in a little
more than two hundred twenty four Earth
days but take 243 days to rotate around
its own axis only once thus its days are
longer than its years we all know that
sound cannot travel in a vacuum and that
space is a vacuum sound waves cannot
travel through it pretty basic stuff I
even talked about this in previous
episodes however something that
surprised me when researching for this
episode is that this isn't exactly true
because space is not a total vacuum it's
often made out to be space contains lots
of particles and atoms and gases which
sound can use as a medium to actually
travel through but of course these
particles are very very sparsely spread
out so you need an extremely sensitive
microphone to be able to hear anything
at all and NASA did just that they used
a very sensitive microphone of sorts and
aimed it at a galaxy with a black hole
at its centre and the sound it produced
is the lowest note in the universe 57
octaves below middle C the frequency is
more than a million billion times deeper
than limits of the human ear
back in 1962 during the Cold War the
u.s. decided to blow up a hydrogen bomb
in space not only that it was 1,000
times more powerful than the bomb that
hit her Oshima during World War two
what's so crazy about it is that they
did it because they simply wanted to see
what happened and equal in the same plan
was something called Project a119
the project had a goal of detonating a
nuclear bomb on the moon fortunately
this never actually took place ever
watched a sci-fi show such as Star Trek
and wondered how they navigate I mean
how do they know where to go when space
is mostly nothing because you can't use
our GPS in space right well the
scientists have been working on
something called X nav the way it works
is by detecting signals from pulsars in
a similar way to how our GPS sends and
receive signals from satellites pulsars
are dense rapidly rotating stars
sweeping their emissions across the
cosmos at rates that are so stable they
rival the performance of atomic clocks
this timing property is perfect for
stellar navigation and would have an
accuracy of between 5 to 10 kilometers
that's the equivalent of having a GPS
here on earth having an accuracy of a
few nanometers however the technology to
create such a device is not quite here
yet but we will almost certainly see it
in the near future
turn right in five million light years
you may or may not have heard about
something called dark matter
basically when scientists use the word
dark to explain something it's some
really complicated stuff but I'm gonna
try and explain it anyway think of our
solar system our Sun all the planets and
everything else that we can see has
as the more mass an object has the
stronger gravitational force it has okay
we know this stuff we can accurately
calculate the correlation between mass
and gravity
now take the mass of the entire Milky
Way galaxy take everything we can see
and put all that mass together but
here's the problem the amount of
gravitational force that the galaxy has
is not consistent for the amount of mass
it has we have done these calculations
over and over again accounting for all
the stars dust and gas everything but it
never seems to add up what does this
mean this means that there is something
we cannot see affecting the gravity
around us and here is where dark matter
comes into play a good analogy could be
wind for example if you're inside a
house looking out the window you can't
see feel or hear the wind outside but if
you look at that flag you can see that
it's somehow moving thus you can prove
that something you cannot see must be
affecting it and that's a very
simplified version of what dark matter
is the most recent calculations shows
that as much as eighty four point five
percent of the total matter in the
universe could be dark matter a common
argument you hear people use against
space exploration is that we still have
huge problems down here on earth and
that we should focus on solving these
issues first before we even start
thinking about venturing out into space
and while it is true that we as a
species have yet to solve numerous major
global problems with our society and the
planet itself space exploration does
actually help you down here on earth
more than you might think for example
when NASA tried to find ways to minimize
the size of the cameras on their
spacecrafts it led to the invention of
the first active pixel sensor it's the
reason we can all do this with our
phones today in the 1980s NASA developed
a unique polymide material which
be used to make flexible circuits how
would that benefit me you'll say well
today almost every electronic consumer
product like mobile phones digital
cameras TVs computers etc is made
possible because of this NASA's robotic
research has greatly contributed to both
the appearance and functionality of
artificial limbs scratch resistant glass
was invented for devisor on astronauts
helmets many of the athletic shoes you
can buy today were inspired by the
spacesuits from the Apollo missions
today you can find space blankets in
almost every first-aid kit infrared ear
thermometers measures your body
temperature the same way NASA measures
the temperature of stars they have
developed water purification systems
which can yield safe drinkable water
from some of the most challenging
sources such as urine sweat and even mud
these systems are helping people without
freshwater around the world right now
the point is not that we must go to
space to find these technologies the
point is that because we went to space
we did
you