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Physics
The matter made of atoms only accounts for 5% of the total matter in the universe
Everything we see around us is made up of the normal building blocks called atoms but this only accounts for 5% of the total matter in the universe. Dark matter makes up 23% and dark energy makes up about 72% of the total matter.
Without dark matter the stars in a galaxy would not have the speeds they rotate at regardless of their distance from the centre of the galaxy.
The astronomer Vera Rubin produced rotation curves for galaxies such as the Andromeda galaxy from observations made at the kitt peak Observatory Southern Arizona 1968. Because the rotation curves were flat it indicated that stars on the edge of a galaxy rotated at the same speed as those close to the centre. This suggested that there was more matter than could be accounted for otherwise the enormous speeds of the stars on the edge of a galaxy would simply cause them to be flung out. You could say 'she bought dark matter to light'.
Evidence of dark matter is due to an effect called gravitational lensing first described by Albert Einstein. The intense gravity of dark matter causes light from distant galaxies to bend. Distorted images of galaxies can be seen that would normally be hidden from view if it were not for gravitational lensing.
Dark energy is thought to be responsible for the increasing rate of expansion of the universe. The ever increasing expansion of the universe was discovered by the Nobel Prize winning physicist at the University of California in Berkley, Saul Perlmutter. Could empty space be creating more matter?
Neither dark matter or dark energy have been detected but only their effects have been observed. Proving the existence and nature of both dark matter and dark energy have now become the holy grail of Physics.