Most of the universe is made up of stuff we can’t directly see. When we look up at the night sky, billions of stars are visible. In our galaxy alone, the Milky Way, there are an estimated 100 billion stars. And there are about 100 to 200 billion galaxies in our universe, each containing hundreds of billions of stars. An analogy to the number of stars in the universe is to count the grains of sand on all the beaches on earth.
But all those billions of stars and galaxies account for just 4.6 per cent of the universe. Thus, almost 96 per cent of the universe is invisible to us!
What we see is comprised of protons, neutrons, and electrons. But it turns out there is evidence of dark matter and dark energy that make up most of our universe.
How can we say something is there when we can’t see it? It’s about how it interacts with other objects.
Dark matter neither emits nor absorbs light or radiation. We know it’s there because of how it interacts with other things in the universe.
A piece of evidence for the presence of dark matter is something called gravitational lensing. The light from a distant galaxy will be bent by the gravitational pull of dark matter. It helps astronomers better understand the presence of dark matter in our universe. by everythinginterestinghd