I’m not an expert about, well… anything. I love space. I love science. I love learning about space and science, and I love talking about the stuff I learn (whether the people around me want to hear about it or not). Still, I’m not an expert. With that in mind, let me tell you about nuclear fusion.
Nuclear fusion is super easy. Here, let me show you.
The tricky thing is that you do need to squeeze really, really, really hard to make this work. Atomic nuclei have matching magnetic charges—positive and positive—so whenever you want to fuse atoms together, you have to overcome the force of magnetic repulsion. It takes enormous amounts of energy to do that. Like, in the demonstration above, when I squeezed those two atoms together with my hands, I burned a ton of calories doing that. Yes, the fusion reaction produced some energy at the end, but not as much energy as it took to make the reaction happen in the first place. All things considered, this was a net energy loss for me.
But on December 5, 2022, researchers at the National Ignition Facility (NIF) in California—i.e., actual experts on this topic—caused a nuclear fusion reaction where the energy output exceeded the energy input. How did they do it? For one thing, they didn’t squeeze atoms together with their hands. They did it with an elaborate system of lasers. Specifically, they focused 192 lasers on one tiny capsule full of hydrogen isotopes. It reportedly took 2.05 megajoules of energy to make the reaction happen, and 3.15 megajoules of energy came out of it.
This sort of nuclear fusion reaction, where hydrogen isotopes are fused together to make helium nuclei, does not produce radioactive waste. There’s no carbon footprint. If anything ever goes wrong, the reaction automatically stops itself; there’s no chain reaction that would lead to a Chernobyl-style or Three Mile Island-style nuclear meltdown. NIF researches say that they should be able to improve the lasers, design better reaction capsules, and generally refine and perfect their nuclear fusion technique. In a few decades, we should expect large scale nuclear fusion reactors to become commercially viable.
For anyone who (like me) worries about the climate and humanity’s growing energy needs, nuclear fusion sounds like a near perfect solution. But I have learned, both in my personal life and by being a citizen of this planet, that whenever you solve one problem you inevitably create new problems. You just have to hope your new problems are less problematic than the old ones. When nuclear fusion becomes a commercially viable technology, it will be economically disruptive. Companies will go out of business. People will lose their jobs. Also, one of the isotopes used in NIF’s experiment (a hydrogen isotope called tritium) is radioactive. So in the future, nuclear fusion reactors may still require radioactive fuel, even if they don’t produce radioactive waste.
All that being said, commercially viable nuclear fusion is one of those Sci-Fi pipe-dreams that I never really expected to see happen in my lifetime. Now, for the first time ever, I feel like there’s a light at the end of the tunnel when it comes to climate change and the energy crisis. We’ll still have to survive the next few decades, and nuclear fusion will create new problems for us even as it solves some of our old ones. But this is as near perfect a solution to our current problems as I can realistically imagine us finding.
However, as I said at the beginning of this post, I’m not an expert. There’s still a lot I need to learn about nuclear fusion, climate change, and all the other stuff I mentioned in this post. All I can say for certain right now is that I feel optimistic—more optimistic about humanity’s future than I have felt in a long, long time.
WANT TO LEARN MORE?
While researching this post, I saw a surprising amount of cynicism in the popular press. I guess some people think if fusion can’t offer an immediate and 100% perfect solution to climate change, then it doesn’t offer a solution at all. So if you want to learn more about this, I recommend watching this press conference from the U.S. Department of Energy and the following panel discussion with some of the researchers who were involved in NIF’s experiment. Together, the press conference and panel discussion are about an hour and a half long, but you’ll be hearing straight from the people who did the work what they did and what it means.