article_snippet: Instead, a number of theories ranging from it being a fluid, to not existing at all, have been presented by researchers - who also say it is likely 'weirder than we first thought.'
article_snippet: 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: 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: Dr Richard Massey, one of the authors on the study, told MailOnline that it was most likely a different type of particle to what scientists had been looking for so far.
article_snippet: But there are those very weird theories that also might be able to replace this,’ he said.
article_snippet: it’s presence can be predicted based on these interactions.
article_snippet: We can’t observe wind, but you know it’s there because leaves are floating around,’ said co-author Dr Richard Massey from Durham University's Institute for Computational Cosmology.
article_snippet: What form it will take, though, or whether it is really there, remains to be seen.
highlights_snippet: This could instead be like a 'fluid', or something else entirely .
  