Now, two Canadian scientists think there is a good reason dark matter doesn't exist at all. No one has come up with a strong evidence that it exists.
Since I have yet seen one, I have no knowledge whether it exists. The universe has a lot of strange things. Scientists have yet understood many factors, especially with the Big Bang theory and how long the universe will continue to expand, possibly eternity.
Will we ever be around to determine whether the dark matter theory is valid or not? I doubt it but we will see! For further reading, click on the link below.
Scientists Say Dark Matter Doesn't Exist