I used the astronaut and the skeptic because it’s a simple analogy, but the problem with it is that to many people, the answer is extremely clear cut. I am one of these people. The Earth is just round, so arguments to the contrary make the business of evaluation difficult to separate from the evaluation itself. Asking questions like, ‘How do I know this is true?’ is the business of evaluation. ‘Is the Earth round or flat?’ is the argument itself. They’re not the same.

So let’s talk about the complete opposite example: Pons and Fleischmann. They claimed to have discovered cold fusion. They didn’t.

Let’s talk fusion.

E=mc^2, energy equals mass times the speed of light squared. In short, energy and mass are the same things, and they can be converted into each other via well-known processes.

Take it like 2 + 2 = 4. A 2 and another 2 are the same things as 4, provided the 2s are combined via a well known process, that being addition. Mass and energy can be converted into each other equally. It’s not the case that all uses of mass give energy any more than 2/2 equals 4. But if you do one of the appropriate processes, like addition, you can get 4 from combining a pair of 2s. Likewise if you do one of the right things, like fusion, you can get energy from mass.

You can also go the other way, but I’m not getting into that.

Suppose you’ve got some hydrogen. It’s the most common element in the Universe. Some of your hydrogen is Deuterium, hydrogen 2, with one proton and one neutron, and some of it is Tritium, hydrogen 3, with one proton and two neutrons. Ignore the rest. If you put one atom of each very close to each other, they will stick together forming helium 4 (2 protons and 2 neutrons) and a spare neutron. That neutron will go shooting off. You have completed fusion. It’s how the sun makes light and energy. We write this D + T -> He + n + g

The trick here is that an atom of helium plus a neutron is a little less massive than an atom each of D and T individually. What’s left? The g. The g is a gamma ray photon (you might have more than one). Gamma rays are massless. So the equation doesn’t balance in mass. For specificity’s sake:
D mass = 2.014u
T mass = 3.016u
He mass = 4.003u
n mass = 1.009u
g mass = 0

D+T = 5.030u
He + n = 5.012u
5.030 =|= 5.012u

There was more mass to begin with. Where did it go?

Well, some of it went into the gamma ray and the rest was converted to energy that binds the He together. Why does that happen?

Like charges repel. Two positively charged things, like protons, repel each other. When the two protons are pushed together, they push back, and to keep them together requires energy. That energy is the mass conversion.

With me? That’s vastly-oversimplified how fusion works.

Coincidentally, why do we care? Because hydrogen is the most common element in the universe, D and T are fairly easy to get, and there are no long-term radioactive byproducts except for the reactor. The outputs are Helium, which is inert and harmless in any normal concentration, a neutron, which decays into regular hydrogen in about 11 minutes, and a gamma ray, which is deadly by only lasts until it hits something. So in theory we could wrap the fusion reactor in a bunch of concrete, and it would be perfectly safe. There are no greenhouse gas products.

We would still have the reactor, and the secret of fission is that most nuclear waste isn’t the fuel, it’s the reactor. This is non-trivial, but people think they can solve it. Maybe. In an accident situation, say a tidal wave hits a reactor like what happened at Fukushima, it doesn’t seem like a meltdown is possible.

There are three ‘forms’ of fusion, and these terms regard how you do it. Hot fusion works by getting everything to a few million degrees. Hot atoms vibrate, so when a bunch of hot atoms are vibrating together, they may whack into each other hard enough to overcome the two protons repelling each other. This is how we think the Sun works. Muon-catalyzed fusion works in the extreme low temperature regime. It does work, but it doesn’t make energy because the energy required to do it is much greater than the energy you get out (the gamma rays). Cold fusion is what Pons and Fleischmann claimed to have discovered.

There’s also warm fusion and a few others, but they’re generally weird cases of the above.

Anyway, these two guys Pons and Fleischmann said they had created cold fusion and could do so whenever they wanted. Basically room temperature reactions, which are cold compared to the Sun, that produce evidence. They still have supporters today. They claimed they did it by putting water filled with the two forms of D and T in a tube with an electrode. They put voltage across the electrode. Allegedly, fusion then happened.

Pons and Fleischmann wouldn’t let anyone see their work. They wouldn’t let anyone examine their tubes. They wouldn’t share their electrodes. They claimed they had done fusion, but they wouldn’t duplicate the experiment where other people were watching, and they wouldn’t tell other people how to do it such that those other people could duplicate the experiment.

(When I worked at the patent office I had a rule. I won’t believe your perpetual motion machine exists unless I can look at it and take it apart. Unfortunately I worked in copiers, so I never had a perpetual motion machine application, but I still think it’s a good rule.)

So now we’ve got an astronaut and a skeptic situation. There is no way for the skeptic, me, to duplicate the astronaut’s claims. I think it’s all garbage. But I can’t prove it because I can’t attack the evidence. There is no evidence to be had!

Hence the Dangerous Play Fallacy, the assertion is invalid because there’s no way to interrogate it without another logical fallacy.

There’s a rabbit hole of quibbling here, the first item being that the reason the skeptic can’t go into space and look at the shape of the Earth is no fault of the astronaut’s. It’s economics, engineering, and so on. Whereas Pons and Fleischmann COULD have shared their data and just didn’t. That makes them the bad guys.

But that’s an ad hominem attack. Logically, there’s no reason someone has to share their data to be correct. I like Coca Cola, and they won’t tell me how to make it.

Come to Denver, have a beer, and we can argue this. We will not accomplish much other than running up a bar tab.

My Dangerous Play Fallacy is itself a manifestation of the common logical position that the one making the assertion shoulders the burden of proof.

However I said before I’m a scientist, not a philosopher, and more meaningfully, I’m an experimentalist. Why do I reject the Pons and Fleischmann theory when under similar circumstances I hew to the global Earth?

Because I can look at the Moon. I can do trig. I can stick sticks in the ground or stare at obelisks, and back calculate. All the other factors support the round-Earth. NOTHING hard and fast supports room temperature fusion under any methodology I’ve yet read. P&F’s cold temperature scheme had input energies on the order of eVs per atom. Nuclear binding energies, the amount of energy you would need to do something, are on the order of MILLIONS of eVs per atom. Yes, tunneling exists, but that’s an energy function as well. We know that function! It doesn’t yield the frequencies necessary!

The tunneling argument is absurd. I have a Subaru. I’ve taken it to about 120 mph on a track. With more straightaway, I could probably hit 140 before I hit the air resistance limit or blow my engine. The tunneling argument is like saying I could hit 10,000 miles per hour if I was just going downhill.

Yes, I might be able to go a little faster downhill, but not 10,000 mph. It ain’t happening. These are all known factors. 10,000 mph isn’t a possibility.