article_snippet.sent: If physicists only take visible matter into account, physicists equations simply don't add up; the elements that can be observed are not sufficient to explain the rotation of objects and the existing gravitational forces.
article_snippet.sent: From this physicists deduced that there must be an invisible kind of matter that does not interact with light but does, as a whole, interact by means of the gravitational force.
article_snippet.sent: Called 'dark matter', this substance appears to make up at least 80 per cent of the matter in the known universe.
article_snippet.sent: ‘Dark matter could equally be called “transparent matter”, because we see things behind it that gets distorted by gravity,’ Dr Bridle told MailOnline.
article_snippet.sent: Dark matter, the mysterious substance that makes up 85 per cent of all matter in the universe, is invisible to even the most sensitive astronomical instruments because it does not emit or block light.