How Do We Know That Dark Matter Makes Up 27%?

Well I divided the post, bc it was toooo big this morning (oh no😮‍💨, I joked even didn't realize I did it).

Next time I will show it with the Friedman equation.


Dark matter is not directly observable, but its influence can be measured through various astrophysical observations. The main methods confirming that dark matter constitutes about 27% of the total mass-energy of the universe include:
1. Cosmic Microwave Background (CMB)
2. Gravitational Lensing
3. Dynamics of Galaxies and Clusters


Today, I’ll focus on the first point, because otherwise, you’ll die reading all of this. :)

Cosmic Microwave Background (CMB)

The CMB is light that has traveled freely since the early hot phase of the universe(of course, not as hot as i am, kidding). When the universe was only 380,000 years old (VERY hot MILF, forgive me, Christ), its temperature dropped enough for photons to stop scattering off free electrons and start traveling freely
through space(like independent women now, like me for example, haha). These photons now form the cosmic microwave background.

They detected small temperature fluctuations.
These fluctuations correspond to variations in density in the early universe. In other words, photons interacted differently with regions of varying density, leaving an imprint that can be detected today.
Ordinary matter creates shock waves, while dark matter provides additional gravitational pull, influencing the shape of these waves.

To determine how much dark matter exists in the universe, scientists analyze the intensity and frequency of these fluctuations. Usually scientists just compare theoretical models with observational data. If there is only ordinary matter - the structure of these fluctuations would be different.