We see a lot of things! From plants or cells to planets, stars and galaxies, which are formed of visible matter.
The gravity of visible matter isn’t that strong to hold together entire galaxies or other complex structures, so there must be something else that doesn’t reflect light.
That something is known as Dark Matter. The problem is that we know pretty much nothing about Dark Matter. The only thing we know is that it exists, that it interacts with gravity and that there is probbably a lot of it.
Dark Energy is even wierder than Dark Matter. In 1929, Edward Hubble examined how the wavelength of light emited by distant galaxies, shifts towards the red end of the electromagnetic spectrum as it travels to space. Hubble determined that these galaxies shifted more and more, and that is because the Universe itself is constantly getting bigger and bigger.
This is thought to be a cause of Dark Energy. If that is so, Dark Energy is more powerful than any other energy or matter, and it would consist of a even bigger ammount as the Dark Matter.
Dark energy could not be a thing, but a property of the Universe. It could be something oposite to gravity, or could be a kind of energy that has an opposite effect as normal energy.
It is thought that the universe is made up of:
- 5% Visible Matter
- 25% Dark Matter
- 70% Dark Energy
These are just some theories we don’t know are true. For sure the scientist who will proof the existence of dark matter and dark energy will get the Nobel prise!
There is so much more to learn, and this is exciting!