The physics of time travel is still in its infancy. While all physicists today admit that time travel to the future is possible, many still believe time travel to the past will never be easily attainable. Don't believe anyone who tells you that humans will never have efficient technology for backward and forward time travel. I think there is a world market for maybe five computers. The device is inherently of no value to us.
Airplanes are interesting toys but of no military value.
The wireless music box has no imaginable commercial value. Professor Goddard does not know the relation between action and reaction and the need to have something better than a vacuum against which to react. He seems to lack the basic knowledge ladled out daily in high schools. Science fiction spurred humans to go to the moon. Physicists, who once considered this an intellectual exercise for armchair speculation, are now seriously studying advanced branches of mathematics to create practical models of our universe.