What is the universe made of?
Scientists have determined that normal matter the stuff that makes up the earth the stars and [everything] we can see
Only makes up a small portion of the universe the rest is made up of two mysterious
components that are shaping our universe in Profound ways
Much of the mass of the universe is made up of something called Dark Matter which neither reflects nor emits light?
But like the matter we can see pulls things together with gravity
In space itself seems to be permeated by an unusual Force called Dark energy which is driving things apart
But the interesting thing is we don't know yet. What dark matter
Is that is to say we no ordinary matter is composed of fundamental particles [like] quarks electrons?
But we don't know what the dark matter is made of we're made of atoms atoms
Are the things we knew of until about 30 or so years ago?
They're just a small part of the story the two big actors in the story are dark matter and Dark energy
Based on current estimates scientists believe that only 5% of the universe is made up of normal matter
27% is made up of Dark matter and a whopping 68 percent is made up of Dark energy
So what are they and how do we know they exist?
Although we can't see dark matter
We can tell it is out there from the effect it has on regular matter such as galaxies and stars
Dark Matter is Matter which we infer to exist
Because we see its gravitational effect and in particular one example
Is that if you look at the rotation of Galaxies and this is how the discovery was really first made it turns out the galaxies
Are rotating much faster than they ought to be rotated at that speed?
That's just fly apart if the only thing taken together was the gravity the matter see
so the inference is that there must be more matter than
And that's what we call dark matter. We can track where dark matter is located through an effect called gravitational lensing
Relativity massive bodies bent the Fabric of space-time that means they bend the paths of light
Astronomers can see this like bending in places where there are no visible chunks of matter such as stars
It must be caused by Dark matter
Through these observations scientists have found a cosmic web of Dark matter
As clubs long threads of it to spread throughout the universe but tends to be concentrated in aliens around galaxies
Indeed it is considered [to] have been integral to the formation the large-scale structure of the universe in our universe not in ordinary life
But in our universe gravity really is the most important forms
For the first 10 billion years gravity was the master builder, and so it was the gravity of Dark matter that
pulled together matter into galaxies and clusters of Galaxies and
[eventually] into stars and solar systems like our own
so what is dark that are made of no one knows for sure yet, but there are a number of theories and
So one of the big questions about Dark matter is well first off. What is it?
[and] then secondly you know how if at all does it interact with normal matter
it doesn't give off light and
so that
Must mean that it's not made of atoms because atoms give off light if you kick them or tickle them or do something to them
And so this dark matter must not be made of charged particles
And we're now to the point that we believe that it's a new form of matter
Particles left over from the big bang, it's a new form of stable matter that we've yet to identify
There are a number of different experiments focused on finding dark matter trying to catch it as it occasionally bumps into normal matter
But none of them has been successful so far
Dark Matter particles might just be created in Earthly laboratories - at the large Hadron Collider in Switzerland
where particles smashed together near the speed of light there is some chance that dark Matter particles will pop out and
Astronomers using some of the world's largest telescopes [are] observing the cosmos with ever more precision to learn about where darlene is located
Image through their efforts in the late 1990s that scientists learned about the other mysterious force that is shaping our cosmos Dark energy
Astronomers studying distant Supernovae discovered it accidentally by observing that the expansion of the universe seemed to be speeding up
Michael Turner coined the term Dark Energy to describe the mysterious force that seemed to be pushing the universe apart
This could be the most profound mystery in all of science the fact that the universe is speeding up
hidden in Einstein's Theory of General relativity is the
possibility for
Very weird stuff, which we now call Dark energy
To have gravity than instead of pulling things together pushes things apart the idea that the universe could expand or contract
showed up in early drafts of Albert Einstein's theory of relativity
But Einstein himself believed the universe was of a fixed size
To get things to add up correctly he fudged his equations by inserting a fixed value. He called a cosmological constant
only later when it was shown the universe was in fact expanding that had become apparent that his equations were right to begin with
Einsteins cosmological constant might also end up accounting for Dark energy
No one knows what dark energy is exactly although many theories have been postulated. We know a lot about what dark energy isn't
So it's not particles. We can't break it down into individual particles. It's more like a medium or a substance
Unlike Dark Matter Dark energy doesn't clump up. It's uniformly
distributed
Suggestion is that it is energy folded into the fabric of space itself
Most likely is that it's simply vacuum
Energy the energy of empty space the vacuum is not a simple state at all
it's a very very complicated state in the vacuum particle and antiparticle pairs are constantly appearing and disappearing and
We also think there's at least one field what we call the higgs field
Which has a Nonzero value everywhere in space So Dark Energy is
It's actually not associated with matter
I mean one of the amazing things [onsen] taught us was that the absolute value [of] energy is meaningful
Because there's gravity associated with it
so even if there's no actual particles around the universe itself can carry energy in fact that's
Expected as space expands so does the amount of dark energy, so there will be more of it to push the universe apart
What astronomers don't know yet? Is if the rate of acceleration of the expansion will change over time if it does that could have profound?
Implications is the acceleration itself accelerating if it is
then
[Dark] Energy will rip apart the universe
it will rip apart clusters of galaxies and then galaxies and then solar systems and then planets and
Then eventually us
But the dominance of dark matter and dark energy have shifted over the lifespan of the universe
With dark matter playing a stronger role in the early years and dark energy [gaining] traction more recently
What will happen to our universe depends on the interplay between these two dark titans?
If dark energy becomes more dominant the universe may thin itself out of existence [in] what's called the big Rip
but if dark matters influence should increase that could collapse the universe back upon itself in a big [crunch] and
If neither force changes dramatically space may just [continue] expanding Outward indefinitely
For cosmologists trying to foresee the ultimate fate of the universe much remains in the dark