How do scientists know dark matter is there? Although dark matter does not interact strongly via electromagnetism, it does interact with another fundamental force: gravity.
It is through the interaction with gravity that astronomers were first able to discover dark matter and, later, accurately map it..
Understanding dark matter is important to understanding the size, shape and future of the universe.
The amount of dark matter in the universe will determine if the universe is open (continues to expand), closed (expands to a point and then collapses) or flat (expands and then stops when it reaches equilibrium)..
Dark matter and dark energy are one of the central mysteries in modern physics, although modern astrophysical and cosmological observations and particle physics experiments can and will provide vital clues in uncovering its true nature..
Unlike normal matter, dark matter does not interact with the electromagnetic force.
This means it does not absorb, reflect or emit light, making it extremely hard to spot.
In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter..
Unlike normal matter, dark matter does not interact with the electromagnetic force.
This means it does not absorb, reflect or emit light, making it extremely hard to spot.
In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter..
The success comes at a price:
Although simple, this standard model is strange.
The model implies that most of the matter in our Galaxy is in the form of “dark matter,” a new type of particle not yet detected in the laboratory, and most of the energy in the universe is in the form of “dark energy,” energy associated with empty space.
Meanwhile, dark energy is a repulsive force — a sort of anti-gravity — that drives the universe’s ever-accelerating expansion.
Dark energy is the far more dominant force of the two, accounting for roughly 68 percent of the universe’s total mass and energy.
Dark matter makes up 27 percent.
Dark energy comprises 69% of the mass energy density of the universe, dark matter comprises 25%, and “ordinary” atomic matter makes up 5%.
There are other observable subdominant components:
Project to measure the expansion of the universe
