You might own or rent a flat, maybe even a big house with a garden. You are the center of your life,
you have a family and friends you visit.
Maybe you have to drive for long or even have to fly around the globe and get the feeling
that they are living really far away.
But how far is it really? Where exactly do we live?
It is the only planet, we know of, where life exists and we call it Earth.
It is a small blue dot, circling a Star we call the Sun,
in between 25 – 27 thousand lightyears from the center of a Galaxy which we call the Milky Way,
in our supercluster, called Virgo, on the edge of an even bigger Supercluster,
we are calling
Lainakea,
immeasurable heavens. And that, still, is not everything!
Are you feeling small right now? Who are we and where do we come from?
As long as the earliest human records, we have focused our view on the stars.
All these little Stars, so far away! A view into our past, into the past of the origin of everything.
Over 100 Scientists, gathered Information for over 20
years, covering a gap of knowledge of
11 billion years,
creating the most accurate map of the universe.
They collected data from more than 4 million galaxies and Quasars.
Using various methods and telescopes and summarizing
all our understanding of the Universe and how it looked like for the past 12 billion years.
And now we can look at it, the map of our spacetime, the history of our universe.
And soon we might even be able to tell how everything might come to an end.
But how have they been able to create a map like that?
Basically, they looked around into every direction and discovered as many galaxies as possible, comparing them with the cosmic
microwave background radiation and trying to point out their exact position.
When we look at this picture, you can notice, that there are still two black parts where no galaxies or quasars were seen.
That is, because our Milky Way is hiding them from us, with its foreground patches of galactic dust and clouds…
in the so-called Zone of Avoidance.
It makes up around 20% of the extragalactic sky at visible wavelength. Meaning that we can not visually catalogue
galaxies due to our galaxy blocking the view.
But let’s move slowly from the outer ring to earth, as our viewing point. You can see the outer line of the huge bubble,
that’s where we could read the first light of the cosmic microwave background! And then, comes the huge gap, of blank….nothingness… the
dark ages of space…Look
at this huge gap, you see more of what we don’t know, than we know! And then, the Extended Baryon Oscillation
Spectroscopic Survey or eBoss was able to measure the spectral line of hydrogen,
the Lyman-alpha emitter galaxies. They are among the oldest objects in space, we know of, very early active galaxies.
Let’s look at the yellow dots here, they are kind of my favorite, because I LOVE Quasars,
they are really fascinating to me and here, on this picture, we’re able to see millions of various types of Quasars.
They’re really bright and are covering around five billion years of the existence of Now
let’s move closer in on our home planet. Here
we can see the bright light of young, blue Galaxies, discovered within the past six years of observing the universe.
These young folks are the future of our Universe!
And here is an older part of the universe, the luminous, old, red Galaxies, shown in red and violet.
Covering a time into the past, of about 6 billion years! And that’s the time around when the universe’s expansion started to
accelerate and is picking up ever since!
Scientists don’t have all the answers yet, they do not have a physical explanation of why acceleration is picking up!
But they are assuming, that the phenomenon called dark energy is responsible for that.
Dark energy makes up around 68% of our Universe. Plus 27% of Dark matter, leaving us with only 5%
of visible matter. Meaning, everything we know and see makes up only 5%
of what’s out there. And scientists were able to ask a lot more questions whose answers must be found again.
One instrument to find the answers will be DESI, the Dark Energy
Spectroscopic Instrument will measure the effect of dark energy on the expansion of the universe.
Observations already started in 2019 and we can be looking forward to its results of measuring the light of about 35 million galaxies!
Will we be able to see the true picture of the universe one day? Of everything there is? And yet again,
everything we’re able to see on this map, as big as it seems already, makes up only about one thousandth of a percent,
0.001
% of the existing universe we are thinking exists so far, only a tiny fraction of everything
there is, 4 million galaxies, out of possibly trillions and trillions more out there.
Let’s take another look at the Map, the green dots in the middle,
this is our home, with our nearby galaxies and our own Super cluster, called Virgo.
Super clusters are the biggest known structures in the universe, regions of space, that are densely packed with galaxies.
Right next to the dark voids in the intricate net of Galaxies,
the cosmic web. Its gravitational center is the Virgo-cluster and it’s first member was discovered in
1771 by Charles Messier. Not too long ago we thought that our supercluster would be about the size of our universe...
until someone came up with the idea to look even further and we discovered the Laniakea Super Cluster!
Laniakea means immeasurable heavens in Hawaiian and is one of the biggest structures discovered by humans! Its size is
approximately 500 million lightyears across and about five times bigger than the Virgo
Supercluster. Still, you’ll find 100 thousand more galaxies around it.
Recently, analysis suggested, contrary to first assumptions of this supercluster being a relatively stable structure,
that within the next few billion years, some of these clusters will separate and drift away. Everything
you can see here,
all of the
superclusters are interconnected with each other and even moving together, and Scientists have struggled to define where one ends and another begins.
Astronomers at the university of Hawaii, led partly by Brent Tully, started to study the motion and
gravitational forces to find out exactly that.
While the universe is expanding rapidly,
this is an unusual area with an unusual gravitational pull. And most
superclusters and local groups are being attracted towards this mysterious great attractor. Everything inside
Laniakea is organized around this area.
This Great Attractor is said to have localized concentration of mass, thousands of times more massive then our own Milky Way!
Causing most of the Galaxies to move towards it.
Scientists created a map of cosmic flow, to visualize the path, of the movement from all these different galaxies.
Every single dot is a galaxy, you can see the distribution of motion in Laniakea. They
were able to first define a super cluster whilst following its flow and boundaries in this cosmic map. Here
you can see Laniakea, in black and our neighbor Supercluster Perseus-Pisces, in red.
You can tell where the flow of Galaxies diverges and that is the area where neighboring clusters sheer apart. And in this
Supercluster, called Laniakea is our Virgo cluster, containing about 2.000 Galaxies within a diameter of around
150 to 200 million lightyears and the shape of a flat disc. … Flat Galaxy society, … anyone?
While zooming in further, you can find our Milky Way in our local group, consisting of minimal 54 neighboring galaxies.
Our neighboring Galaxies are mostly dimmer and smaller than the Milky Way.
The nearest bigger ones being the Triangulum Galaxy and Andromeda. We and Andromeda are moving towards each other at a speed of
120km per Second, meaning one day, it will be as bright in our night sky as the Milky Way
and both will partly form a new, giant, elliptical galaxy. In around 4 billion years.
But until then, our home address will remain at an outer spiral arm in the Milky Way,
around a Star, called Sun, on the third planet moving around it, Earth.
Our home and the only place we know of, where life exists.
I hope you enjoyed this journey through our universe, if so, remember to like and share!
What are your thoughts about our flat Galaxy and are you looking forward to the discoveries by DESI?
Will we be able to get a complete map of everything there is? Tell me in the comments,
have a wonderful week and remember to check in next week for more, exciting News!