“Just So Science” – The Fusion Conundrum

By Elf Eldridge 04/09/2011 3

After an altogether far-too-long hiatus due to Kiwipycon, the upcoming ‘Official Sciblogs Podcast’, a series of videoprofiles of MacDiarmid Institute Alumni, the 2011 NZ Datamixandmash competition, the Tell Us a Story Competition at Victoria University and gorgeous clear skies last night – I’ll get back to the story of stellar evolution! (You can find part 1 here)

When we last left our forming stars, their parent nebulae had just collapsed under gravity providing enough energy to ‘ignite’ the process of nuclear fusion that will fuel the stars for the rest of their lives. We could feasibly skip the details of this process by saying “the heat generated by this gravitational collapse allows the individual Hydrogen atoms to smash into each other with enough energy to fuse, forming Helium and producing large amounts of energy as light”. Certainly sounds reasonable enough.

But there’s a problem. Usually, when we heat things, they stick together less (think about butter melting when you heat it) – so why would the hydrogen atoms stick together MORE when they start moving faster? And furthermore WHERE DOES THE ENERGY COME FROM??!! It’s true that things emit more light the more you heat them (a process known as blackbody radiation) – but to emit as much light as stars do for billions of years these hydrogen atoms would have to be at temperatures much higher than what we actually see in stars. Essentially, there’s not enough energy in the movement of these atoms to produce the light that we see – so what’s going on!

Image of our Sun, Sol, taken with a filter enabling us to see below what we can see with our naked eyes. The colours indicate the temperature with red colour being about 2 million degrees and blue/green being about 1 million degrees.
Image of our Sun, 'Sol', taken with filters enabling us to see beyond what we can see with our naked eye. The colours indicate the temperature with red colour being about 2 million degrees and blue/green being about 1 million degrees.

Confused? Don’t worry. So was the entire scientific community for a number of years after making these realizations and to understand the process we need to delve into a little into bizarre quantum physics,  and Einstein’s famous equation: E=mc².

I’ll discuss the quantum detail in an upcoming nanotech post, as it certainly doesn’t just occur in the sun – but the energy problem can be answered simply. That equation above describes the equivalence between mass and energy – it says that under the right conditions they can be interchanged, but that’s certainly not what we see on a daily basis! Can you imagine being the middle of a conversation with a person,  and then having them spontaneously erupt into a massive wave of energy? And when I say massive – that is an understatement, and a huge one at that. The rest of Einstein’s formula is that c² term. That’s the speed of light squared, and light is quick. In fact, it’s the fastest anything can travel – 300 000 000 meters per second. So the formulae above can be simply stated thusly:

“There’s a LOT of energy in mass.”

By example – if you converted all of an average person’s mass into energy, you would end up with more than the combined total of every nuclear weapon every detonated on earth. A LOT of energy.

The reult of a nuclear fission detonation. The sun uses fusion. Its more powerful.
The reult of a nuclear fission detonation. The sun uses fusion. It's more powerful.

And that’s precisely what happens in stars. When two Hydrogen atoms fuse, they produce Helium – but Helium’s mass is just slightly less than that of two individual Hydrogen atoms; the extra mass has been converted to energy during the fusion process. That’s why stars are so bright and so long lived – they burn mass itself and convert it into energy. Take a moment to digest that statement – and if you’re out enjoying the sun this weekend, give thanks that the sun is as far away as it is.

I’m quite fond of my hydrogen atoms personally, and don’t relish the though of any part of me being turned into energy – no matter how beautiful the result may be!

3 Responses to ““Just So Science” – The Fusion Conundrum”

  • Nuclear physicists in 1989 were riding a bonanza of tens of billions in government research money for the development of hot fusion reactors. After several decades of hard work, they were still far from achieving break-even, where output energy exceeds input energy. Just as the next round of appropriations was assured, Fleischmann and Pons came along with the announcement that they had already achieved excess heat output without government support and on an inexpensive desktop setup.

    Denial was immediate. MIT and Caltech, who had been leaders in hot fusion work, immediately went to work “trying” to replicate the experiment. In just five weeks Caltech announced negative results. At a May 1st 1989 APS meeting in Baltimore, two thousand physicists gave a standing ovation to the Caltech team’s presentation. A lynch mob mentality, combined with denial, turned the exciting discovery of cold fusion into an enemy.

    MIT helped set the tone by arranging a front page story in the Boston Herald on the day of the meeting with the headline, “MIT bombshell knocks fusion “breakthrough” cold.” The story was an interview with leaders of the MIT fusion lab that accused Fleischmann and Pons of fraud. The charge was later denied but tapes of the actual interview confirm what was said.

    MIT further disgraced itself by altering data in its failure to replicate study. This was discovered two years later by MIT employee Eugene Mallove, who found copies of the July 10 and July 13 drafts of the paper. The July 10th version had a graph that clearly showed excess heat. In the July 13 version the graph was redrawn to show no excess heat. The atmosphere at MIT, as shown by a “Wake for Cold Fusion” party (before the data was analyzed) and t-shirts and mugs offered by the plasma fusion lab, was hardly impartial.

    To this day, denial reigns among most of the guilty parties of this travesty. The Department of Energy, Nature magazine, Scientific American, the American Physical Society, the U.S. Patent Office and many of the world’s top physicists still cling irrationally to the belief that cold fusion is junk science. Of course, this is how denial works: We protect our belief system by quietly stepping around the “elephant under the rug.” As long as a majority of our group backs us up, our view of reality remains grossly distorted to preserve the group-think consensus. Global warming deniers do this every day.

    The Fleischmann-Pons announcement should have been the start of a new era of cheap, clean energy that would have saved us from the financial and environmental disasters and wars caused by fossil fuel energy. Instead, denial and dirty tricks caused us to waste 23 years and tens of billions of dollars on failed nuclear projects as though nothing had happened. The Presidents 2012 budget includes $2.5 billion for such projects. The first DEMO hot fusion plant is currently scheduled for 2033.

    A surprising natural process was discovered in 1989 that can provide us with clean, essentially free energy. It clearly conflicts with the current consensus understanding of quantum mechanics that works nicely for hot fusion reactions. It seems reasonable to try to improve the theory to accommodate this new reality, but denial has instead tricked many good scientists to try to “shoot the messenger.”

    The time has come to admit the mistake and get busy trying to improve our understanding so that we can perfect this amazing new technology. We have spent $20 billion and 55 years trying to reach break-even with hot fusion. Time to give cold fusion a chance.