Mohr smiles. ‘Rockets are okay for traveling to the moon or Mars, but you can’t use them for interstellar travel. The problem is the rocket’s fuel, or propellant. Unlike a plane, which pushes against air, a spacecraft has no mass to push against in the vacuum of space. Therefore, rocket ships must transport with them all the mass they’ll need to push against in order to move. Let’s say you wanted to use one of our newest Mars transports to reach Proxima Centauri, the closest star to our sun. Forget the fact that it would take you nine hundred years to arrive. In terms of propellant, there isn’t enough mass in the universe to get you there. Now, if you used a nuclear fusion rocket, something several space agencies are working on, you’d still need a thousand supertankers of propellant. Of course, if you wanted to get there sooner, it would require even more ungodly amounts of fuel.’

‘I saw a program about the new Mars cargo vessels. They’re going to use lunar-based lasers to push light sails.’

‘Correct, but the technology is still not feasible over great distances. Let’s say you were one light-year from Earth and wanted to make a course change. It would take two years just for the new commands to be radioed to ground control, received, and sent back.’

‘So what’s the solution?’

‘The solution is twofold: First, find a source of energy that is already in the vacuum of space; second, discover the means to manipulate the coupling or connection between mass and space-time.

‘Back in 1948, a Dutch physicist by the name of Hendrick Casimir completed an experiment using two metal plates. When brought close enough together, the plates attracted each other, revealing the presence of energy within the vacuum. The Casimir effect, as it was later named, was defined as zero-point energy—the random electromagnetic oscillations left in a vacuum after all the other energy has been removed.