Where is the solar system in the milky way
You Are Here (Part 1: Space)
where exactly is the earth what the
Milky Way cool now where's that exactly
let's get to it
okay so we know our planet Earth 70%
water comfortable temperature great
music and culture 10 out of 10 would
visit again but where exactly is the
earth the earth is here in the inner
solar system orbiting a star called very
imaginatively by humans the Sun or soul
to give it its Latin better name the Sun
is a rather mediocre but stable
main-sequence star that is about halfway
through its lifecycle in about four
billion years it was swell and
completely obliterate all traces of a
long dead civilization but we haven't
gotten to that bit yet it is currently
powered by fusion of hydrogen into
helium and energy and where's 9.8 nah
million kilograms which is such a
massive number that our primitive simian
brains can't even visualize that massive
amount especially the ones that still
use Imperial the Earth orbits 149
million kilometres or one astronomical
unit away in the inner solar system
while Jupiter is five times further out
Neptune is at 30 au and the edge of the
solar system and Voyager are between 80
and 100 thousand au away which is very
specific but where's the solar system
right his work gets interesting and I
can start filling this video with more
facts and less spite our nearest star
Proxima gets what that's called in Latin
and Alpha Centauri which are 4.4
light-years away as well as Barnard Star
Wolf 359 and quite a lot of others is
quite hard to visualize our position in
3d space but I'm going to try my best or
will try my best as I haven't edited
this video yet this is made especially
hard as all of these surrounding stars
are travelling in random different
directions compared to us our local
neighborhood of Stars is inside an
interstellar gas cloud called the local
cloud in fact the Sun will enter a
separate cloud called the G cloud in the
next 20 millennia or so both of these
clouds are flowing out from a dense area
and star forming gas called the Scorpius
centrist Association which sounds like
an accounting business but for our human
purposes we can just ignore most
movement as it really where matter on
the timescales we're talking in the
cloud there aren't as many stars as
elsewhere in the galaxy but the whole
thing is 1.5 million astronomical units
or
30 light-years across which is pretty
small compared to what's to come
zoom out further when we see our local
interstellar cloud is pretty much
exactly halfway down the Orion Arm of
the Milky Way which is about ten
thousand light-years long but despite
this figure it is only a very minor arm
as the offshoots from the massively
large Perseus arm which is about three
and a half times larger yeah and this
leads us to the Milky Way you may have
heard of it it's our galaxy and for once
it's kind of big compared to its
neighbors but not the biggest we'll get
to that later
it's a barred spiral galaxy called that
because of the bar shape in the center
it is over 150,000 light-years across
around 2,000 light-years thick with a
bulge in the middle way is an amazing
0.5 Treader Cillian kilograms which is
over 400 billion times what the Sun
weighs and looks also something like
this yeah this or a version of this is
literally the only photograph we have
because this solar system is the only
perspective we have and we are inside
the thing we are trying to photograph
which makes it a bit difficult yeah it's
not like we can step back and look at it
from the side because not only will it
take a million years for even light to
get that far but there is no side in
space it's all relative so how do we
know what it would look like well we can
calculate how far away they are due to
how far they appear to have moved in a
six-month span in reality we're the ones
that have moved but judging from how far
that star has moved relative to distant
galaxies called its parallax we can
determine through simple geometry how
far away they are also we see other
galaxies from the side or top or
whatever and work out generally how
galaxies are structured we can't see
most of the stars on the other side of
the core due to the intense light and
mass there but applying our general
rules of galaxies to the distance stars
we can see we get a map something like
this hooray usually in films also you
hear about the Alpha Quadrant of a
galaxy the quadrants are a thing for
real galaxies as well except they're
numbered and
technically we're in - yeah because the
zero degree line the equivalent of the
Greenwich Meridian for the galaxy is
always drawn so the intersects with the
Sun which is a very self-centered thing
to do but we don't exactly have much
else to base it off of but like a Sun
the Milky Way has its own local cluster
of galaxies and that's what it's called
the local cluster most are tiny compared
to ours and some even orbit the Milky
Way like planets to a star the Milky Way
is one of the biggest in the local
cluster and second only to the Andromeda
galaxy it is - a widely known fact that
these two galaxies are destined to
collide and the black holes at the
center of each will merge and form the
initially chaotic milk dromeda galaxies
hopefully in the 3.5 billion years until
then we can come up with a better name
than milk dromeda I mean come on that's
worse than calling a Galaxy Eric who's
cooler Eric instead of milk dromeda is
probably better but for now that's our
local cluster zoom out further when we
see the Virgo supercluster
a cluster of clusters including the
local cluster and the Virgo cluster
which gives the cluster its name
have I said cluster enough for cluster
to lose its meaning of cluster cluster
cluster cluster cluster cluster cluster
cluster cluster cluster cluster anyway
is approximately a hundred million
light-years across
and in it there are a hundred clusters
with their own stars and their own
worlds yeah these stars are too far away
to use the Stars parallax to measure
their distance so we're going to have to
use the very light itself using the
Doppler effect okay quick subtle ninja
edit here I completely messed up the
definition of the Doppler effects I'm
going to try to explain it to you
without a script array this isn't going
to go wrong whatsoever the Doppler
effect occurs when the thing that's
emitting this slight or sound is
traveling at a different speed to you
that has the effect of squashing or
stretching the sound or light waves now
with light this can manifest itself as a
higher or lower colour on the spectrum
with sound it's a higher or lower pitch
that's why when sirens go past it seems
higher and then as it goes past and is
moving away from you it seems lower this
has the effect in space of because
of the expansion of the universe the
further things are moving faster away
and therefore the more stretched out the
light is as a result it looks more red
and the universe slowly turns red as you
go away from us this is called redshift
and this is technically how we find out
how far away things are yeah I didn't
mess that whatsoever so we must be
getting close to the size of the
universe right nope as we zoom out to
the Laniakea super cluster which is a
cluster of clusters of clusters hmm yeah
this weirdly named group has over 300 to
500 super clusters and a hundred
thousand galaxies each with billions of
stars and all of them are out there
right now yeah also in the Laniakea
super cluster is the rather ominously
named Great Attractor
which is kind of ominous in real life as
well it's this thing that we can't see
that has a mass tens of thousands of
times more than our own galaxy but in
theory with all that mass we should be
upset right well we probably could if it
weren't for the Milky Way's core being
in the way so we can't see it thanks a
lot Milky Way I know we owe our
existence to you but you do get annoying
sometimes okay so here we go zooming
further out and we've stopped why have
we stopped becoming here already
oh it seems we've reached the edge of
the observable universe and we can't see
any further it's kind of in the name the
light coming from there was emitted 13.8
billion years ago and that light we are
seeing now but in that time that object
has moved away from us to the point
where it's 47 billion light years away
now so that's how we get the radius of
everything we can see known as the
observable universe we can't see any
further as those objects that emit light
have been around long enough for the
distance from further away to reach us
so in a system in a cloud in an arm of a
galaxy in the cluster and a cluster in a
cluster in the universe we are here I'll
also talk about the start of everything
what came before that and the depressing
but inevitable end to the universe so
see you then
try not have an existential crisis in
the meantime
you
you
