Alex McColgan

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And now, back to our fascinating discovery.

Nearly a century ago, Swiss-born astronomer Fritz Zwicky noticed that galaxies in the Coma Cluster moved too quickly for the amount of gravity that would be created by their visible matter alone.

Yes, including the missing stuff.

Instead, he thought another form of mass must be there, and in 1933, Zwicky dubbed this missing substance Dunkelmaterie, the German for dark matter.

In the 1970s, American astronomer Vera Rubin had a similar experience.

She was observing spiral galaxies and wondered how stars on the outer edge of the spiral galaxies were able to move so quickly without flying off into space.

Again, some unknown mass must have been pulling them back in, and she concluded the same as Zwicky.

There must be dark matter holding them together.

This new type of stuff interacts with its ordinary baryonic counterpart through gravity, but it doesn't interact with the electromagnetic spectrum, meaning that it doesn't absorb, reflect, or emit any light.

This makes dark matter extremely difficult to find, and seemingly impossible to observe, at least directly.

Yet, it influences the cosmos on a galactic scale.

it may even be helping to conceal our missing baryonic matter.

Since the 1980s,