Oops 1 - Cold Fusion — How Knowledge Works

In particle physics there's fission, and then there's fusion. Sometimes there's confusion but never confission. There's no such word. These two things are similar in some ways and completely different in others, which is probably why there's confusion. Both describe how an element changes to another element and in so doing releases energy. What makes them do this and the circumstances in which they are able to do it is what makes them so very different.

Fission

The word fission means a splitting or breaking up into parts. In atomic fission this entails heavy elements like uranium breaking down to a less heavy element, like lead, and turning the difference into energy. This is the principle behind the atom bomb that was first used on Hiroshima and Nagasaki, and much less violently in nuclear power stations. Neither of these things happen naturally because uranium decays to lead incredibly slowly. It takes 4.5 billion years for half of a sample of uranium to decay to lead and another 4.5 billion for half of the remainder. Scientists had to coax uranium to be more active.

The two isotopes of hydrogen (deuterium and Tritium) fuse to helium and release energy in the form of a neutron. One gram releases the energy equivalent of 15 tonnes of coal. Source Wikimedia, Padsohot1

Fusion

Fusion is the other way around, light elements fusing to form heavier ones. The new element, like helium from two isotopes of hydrogen is less heavy than the original two elements combined, so again energy is released and, weight for weight, quite a bit more than for fission. This process only occurs naturally in one place, the core of the sun. It is only at the centre of the sun that the combination of temperature and pressure are high enough to force hydrogen atoms to fuse. These numbers are immense. Temperature is 15.6 million degrees celsius and pressure is 250 billion times the atmospheric pressure here on Earth. The highest natural pressure accessible on Earth is in the deepest part of the ocean, at the bottom of the Challenger Deep. This is only 1000 times atmospheric pressure.

To get an idea of how difficult it is to create these conditions on Earth, consider the hydrogen bomb. To set a hydrogen bomb off you need a trigger that will momentarily recreate the conditions at the core of the sun, so that a chain reaction can get started. Only one thing is capable of doing this and that's an atom bomb. It is numbing to think that a hydrogen bomb needs the energy released at Hiroshima and Nagasaki to be triggered. I should probably write about how we don't always use our knowledge in our own or the planet's best interest, but this one is much too obvious, so I'll save that for other essays.

A simplified schematic of the Fleischmann-Pons experiment. Source, Wikimedia - Pbroks13

Cold Fusion

So imagine the reaction when two scientists, Martin Fleischmann of Southampton University and Stanley Pons of Utah University published a claim in 1989 that table-top room-temperature and pressure fusion had been achieved. This was the holy grail in energy physics. If it was true it would open a new era of clean and cheap energy without dangerous by-products.

Scientists around the world rushed to replicate the Fleischmann and Pons experiment without success. Part of the problem was that Ohio University, anxious to be the first to publish had pressured Fleischmann and Pons to publish quickly. The first the world knew about it was by a press release. It soon became clear that, even with the detailed paper describing the experiment published after the press release, most researchers couldn't replicate the results, which were supposed to show an unidentified energy release that could only be explained as a fusion event.

Cold fusion had obviously not been clearly demonstrated, but research on the Fleischmann and Pons principle continued in different places without success and was terminated in 1998. It is still believed that cold fusion will eventually be achieved, just not the Fleischmann and Pons way. Research continues and some commentators think the solution is only a decade or so away.

So what lessons can be drawn from this?

There is no doubt that the two men were genuine in their belief that they had discovered cold fusion, but It was published in haste. Carl Sagan said that extraordinary claims require extraordinary evidence. This was certainly an extraordinary claim and much more time should have been taken to check and recheck equipment, possibly run it again with new equipment. Experiments of this kind are complex and high reliance has to be place on sensitive apparatus, especially measuring devices like thermometers and their placement, which appears to have been the problem here.
On the upside it was a vindication of a particular element of the scientific method, or the rules of evidence. Whenever an experimental result is announced, especially one of importance to our understanding or is unexpected, scientists around the world try to replicate it. Replication is a basic first check on the validity of a claim and in this case it worked a treat.
I think it is important to recognise that researchers should not be discouraged from being innovative and trying out new ideas, provided the rules of evidence are followed. The rules cover both the conduct of the experiments and the checks that follow. Its better to have a go and be wrong than not have a go for fear of failure. There are a few quotes that relate to this.

Albert Einstein - A person who never made a mistake never tried anything new.
Carl Sagan - Somewhere something incredible is waiting to be known.
Isaac Newton - I know not how I seem to others, but to myself I am but a small child wandering upon the vast shores of knowledge, every now and then finding a small bright pebble to content myself with while the vast ocean of undiscovered truth lay before me.
Stephen Hawking - I am just a child who has never grown up. I still keep asking these 'how' and 'why' questions. Occasionally, I find an answer.
Aristotle - Criticism is something we can avoid easily by saying nothing, doing nothing, and being nothing.

This is a model of the ITER fusion reactor. The construction has started in Southern France. Source - Wikimedia, N509FZ

Will it happen?

ITER is the International Thermonuclear Experimental Reactor. Its mission is to show that it is possible to create the conditions at the core of the sun, contain it safely and generate energy that is 10 times the energy input, for at least 8 minutes. They hope to achieve this by 2025 and start producing reliable energy by 2035. They will achieve this by using 10,000 tonnes of superconducting magnets to safely contain a vacuum where the high temperature and pressure environment can be maintained. This is exciting stuff and if successful will be the single most significant technological breakthrough so far this century, and will have a massive impact on our future.

You can see a wonderful graphic of this on the the ITER website at www.iter.org/mach. By clicking on the right hand menu the different elements of the reactor are highlighted.