A NASA -backed scientist has claimed his light-speed engine could help humans travel in space – but many other experts are sceptical.

Among the hundreds of exoplanets discovered this century, there are 45 "Earth-like" planets which could potentially sustain life as we know it.

But even the closest of them is around 25 trillion miles away.

The fastest spacecraft yet built would take nearly 20,000 years to reach another Earth and there's the additional problem of where all the fuel would come from.

One man thinks he might just have the answer.

Physicist and historian Jim Woodward has built an experimental engine which uses vibrating crystals to generate thrust.

While the forces involved are comparatively small the important part is that the device will continue to accelerate as long as electricity is available.

Jim Woodward, inventor of the MACH drive
Jim has spent over 50 years chasing the dream of a fuel-free spacecraft

Theoretically the engine could continue to accelerate almost indefinitely – reaching a speed approaching that of light.

Because all that's required is an electric current, there's no need for a massive fuel tank.

Instead a small nuclear reactor would provide all the power needed for a voyage to the stars.

While the Mach-effect gravitational assist (MEGA) drive sounds too good to be true, NASA is interested enough in the idea to provide Jim and his collaborator Hal Fearn with a grant to fund their research.

The current generation of spacecraft are weighed down by the enormous quantity of fuel they need to carry

And just before the coronavirus pandemic shut down almost all of California, the research seemed to at last yielded a positive result.

The idea for the MACH drive dates back to 1967, when Jim was living in Spain and studying Flamenco guitar. He was staring up at the sky one night when he saw what he thought at first was a satellite .

But Jim knew enough about physics to work out that whatever he was looking at wasn’t obeying the laws of physics.

He felt sure that NASA or the Soviets couldn't have launched something so groundbreaking in secret and concluded that he was looking at a ship from another world.

Jim Woodward MACH engine
Jim's experimental engine is currently being tested by other physicists around the world

“Critters at least as clever as us had figured out how to get around spacetime far better than we are capable of doing,” he told Wired.

And then he thought if interstellar flight was possible, he should work out exactly to do it.

He added: “If somebody figured out how the hell to do something like that, they probably aren’t an awful lot smarter than I am.

“So I thought maybe I should devote a little time to trying to do that.”

That “little time” turned into over half a century. But the dream seems finally to be paying off, even though many rival physicists are sure Jim’s results are down to wishful thinking.

Even colleague Hal Fearn says he approached the idea with scepticism: “I haven't been able to disprove it, and believe me, I've been trying to disprove it for the last 10 years.”

The engine could power the next generation of deep space probes – and one day, perhaps a manned starship

Jim’s “vibrating crystal” theory isn’t completely out of left field. It was predicted in work published by Einstein in 1915.

Right now, versions of Jim’s drive are being tested in labs around the world to see if his results can be duplicated. If those peer review experiments prove successful, the next step would be a test in orbit.

The next generation of long-range space probes could well be sent to the stars propelled by Jim's MACH engines.

Asked if now he has created a working MACH engine he feels vindicated for all those times that fellow physicists rubbished his ideas, Jim says he doesn't, or at least not yet: “Do I feel vindicated? No, not really.

“I’ll feel vindicated if I live long enough to see someone publicly say, ‘Yes, these things really work.”