

Care would have to be taken in ensuring that the rotational forces are evenly distributed, otherwise the structure could rip itself apart. Thankfully, as space is a frictionless environment, once it is spinning at the correct speed there will be little to slow it down.

The greater the diameter of the ringworld, the greater the shear forces that will be exerted upon it when the structure rotates. According to Mack, the strength of these shear forces acting upon a ringworld is dependent upon “how close you are to the star and how much gravity you need”.

Immense power

Assuming that the ringworld shares the same diameter as that of the Earth’s orbit (about 186 million miles, or 300 million km on average), and required approximately 1G of gravity, the ringworld would need to rotate at approximately 1,200,000mph. The shear forces would be so immense that Mack says we would “probably have to find a new way to bind atoms together that is stronger than anything we know”.

“The forces are bad enough when you are building a little space station” explains Reynolds, “but imagine them on something the size of a solar system.”

One theoretical solution to overcoming this engineering problem could be through some form of piezoelectricity. Put simply, that means a material could be artificially strengthened by running power through it.

However, given the size of ringworlds, and how much power would be required, this would, again, be a colossal undertaking and grossly inefficient. Likewise, using such a method also comes with the need to ensure an even distribution of power throughout the entire structure, and with it the risk of a catastrophic power failure.