What was once a dirty word in nuclear physics is garnering renewed attention from the world's most powerful military.

Today, the U.S. House of Representatives committee on armed services is set to be presented with a bill outlining the potential of cold fusion — a technology that used to be the poster child for scientific hoaxes. 

What is cold fusion?

Cold fusion is based on the premise that you can, at Earth-like temperatures, force the nuclei of two hydrogen atoms to fuse to make an atom of a larger size and, more importantly, create a bucketful of energy in the process. Nuclear fusion happens all the time in the sun, but that's millions of degrees hotter than anything we would see on Earth.

Solar Flare

Hot nuclear fusion is what powers the sun - millions of degrees hotter than anything we've ever seen on Earth. (Goddard Space Flight Center/Associated Press)

Cold fusion suggests you could accomplish the same thing at more normal temperatures — and in 1989, researchers claimed to have done it. The initial experiment was done by University of Utah scientists and it was heralded as an incredible breakthrough in clean energy technology. That was 27 years ago. 

The theory was widely discredited and is considered one of the worst blights on scientific integrity in recent history. The experiment proved to be completely irreproducible and many experts in the field suggested that the theory wasn't even valid and cold fusion shouldn't be possible at all.

So cold fusion went cold. Ice cold.

Why are we talking about it again? 

It turns out the Utah experiment wasn't a complete failure. It did produce a modest amount of heat — a surprising amount, actually. It wasn't nearly enough to claim that cold fusion was taking place, but enough to say that something else was going on.

That's when a man named Lewis Larsen got involved and proposed a very different explanation for the now-debunked experiment. He calls it Low Energy Nuclear Reactions (LENR).

The explanation is pretty simple — instead of two nuclei slamming together, the subatomic particles are bouncing around a bit and being shared between the hydrogen atom and the element palladium, which acts as a platform for the effects observed. The rest of the hypothesis involves quantum mechanics and entanglement, which I won't get too far into because we'll never get out of it. Needless to say, these little reactions are enough to release some energy and start a chain reaction.

Nuclear Fusion

This Dec. 10, 2015 file photo shows the nuclear fusion research centre at the Max Planck Institute for Plasma Physics. (Stefan Sauer/Associated Press)

"You can take energy from a lot of particles, transfer it to a smaller number of particles, without having to have high temperatures," explained Larsen. 

That's why the House of Representatives was presented with an LENR proposal — because this could be a massive disrupter for traditional energy sources.

How far along is LENR research? 

It depends on who you talk to. There is a lot, and I mean a LOT of discord in this field. All science is built upon differing opinions of theory, but there's none that run quite so deep as in the field of cold fusion. 

Italian entrepreneur Andrea Rossi claims he's invented a working machine that does LENR. But I should point out that this particular physicist's track record of academic integrity issues has made most people skeptical.

Andrea Rossi

Italian entrepreneur Andrea Rossi claims he's invented a working machine that does LENR, but most academics are sceptical. (andrea-rossi.com)

If you talk to Ethan Siegal, a blogger and theoretical physicist from the University of Portland, then you get a completely different story. 

"When you say it's theoretically possible, that depends on what theory you're listening to," said Siegal, "the way we understand [physics] today, no, that shouldn't be possible."

Why has it become so controversial? 

It was embarrassing to the nuclear physics community to have such a stain on the record. The controversy made research into cold fusion, or any low energy nuclear reactions, almost impossible for fear of being the laughing stock of your institution.

The scientists working on it have been working practically in secret. This isn't helped by a vast network of conspiracy theorists, skeptics and non-science supporters that unleash their theories online. I'm telling you, doing research for this column was very difficult to weed out the quacks from the experts.

So where do we sit? Right now, we have some very secretive work done by scientists that don't have the greatest track record. But there are countries getting into the LENR game — Japan is rumoured to be making advances in this field, which might be part of the reason the U.S. is trying to catch up. 

There is promise — promise that could basically make the petroleum industry obsolete — but, ultimately, cold fusion is further from reality than some would have us believe.