Up to now, humans have only been able to observe four dimensions in the universe – height, length, width and time. But beyond these dimensions, collectively known as 'spacetime', there may be more ...

What are those unexplained objects zipping around in the sky? They could be aliens; they could be secret government aircraft; they might even be Superman. Or, if you believe the latest MAGA politician ...

It can be tempting to assume that your intuitions about three-dimensional space carry over to higher-dimensional realms. After all, adding another dimension simply creates a new direction to move ...