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Comment by tlb | Hacker News Reader

If this ends up being the right design for fusion, it may be the most weirdly shaped human artifact, where the shape is fundamental to its operation and not decorative. It's far more complex than a mere turbine blade or venturi. Or can anyone suggest a weirder one? (Define weirdness as the Kolmogorov complexity of the shape, within the precision needed to work properly.)

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David Gelernter has a book on (mostly? not sure if I remember correctly) industrial and software design, in which he brings up the bakelite telephone as an example of such an object. Weird shape - check, functional - check (the handset's size and placement matches the distance between the ears and the mouth). It became a literal icon of itself.

https://en.wikipedia.org/wiki/Model_302_telephone

https://en.m.wikipedia.org/wiki/Evolved_antenna looks weird. Source 1 has another image of a more complex antenna.

Both images for lazy: https://i.imgur.com/ROhfMXb.jpg

> Define weirdness as the Kolmogorov complexity of the shape, within the precision needed to work properly.

Well, if the shape is the output of an optimization program, as long as the program itself and its inputs can be simply specified, the shape actually has low Kolmogorov complexity.

True, but you can still formalize the sense in which the object is weird in terms of how long it takes the optimization routine to run. See Bennett's notion of Logical Depth: https://en.wikipedia.org/wiki/Logical_depth

Does a CPU count? The functional part is a very precise, complex and intricate shape.

CPUs also have some iterative weirdness in that successive generations do, to a certain degree, depend upon the computation of the previous iteration to calculate the layout.

I nominate the latest Ubuntu Desktop or Windows install DVD for title of the most complex item in the known universe.

(For comparison, the human genome is under a GiB.)

The weird design makes me as a layman skeptical of the tech's potential, but I'd love to hear why I'm wrong:

- The randomness and lack of symmetry suggest that we are lacking insight into the problem, like an inelegant physics explanation or an over-fitted model. It's not just that it's complex, but it doesn't even seem to have "parts" that work together. Conceptually fusion seems pretty simple: why in principle does harnessing it require super-human complexity?

- If such extreme contortions and micro-optimizations are required to get this far, how much potential can there still be on this path? In software, if you are replacing divisions with bit shifts, maybe you really need a different algorithm. I understand this is just a research project, but if everything is so finely tuned already, how do you make improvements?

I don't know anything about fusion power, but those are the intuitions I feel when I see the plasma vessel photo and read how it was designed.

It's extremely symmetrical!

It's all about the magnetic surfaces. Some pictures:

https://images.slideplayer.com/33/10482660/slides/slide_9.jp...

https://www.nature.com/articles/ncomms13493/figures/1

https://imgur.com/gallery/eikBLMX

why state 'I don't know anything about fusion power' but expect that fusion is simple.

nothing is simple, nothing is elegant. Everything is hideously complex, we are just standing on the shoulders of giants. e.g. Try making common things that we take for granted, like building a plane or glider or even writing a text editor from scratch (including the font rasterization code and display driver).

> The randomness and lack of symmetry suggest that we are lacking insight into the problem

No, it doesn't.

> Conceptually fusion seems pretty simple: why in principle does harnessing it require super-human complexity?

Because having 2e30 kg ball of hydrogen within a powerplant is extremely unwieldy here on Earth.

> In software, if you are replacing divisions with bit shifts, maybe you really need a different algorithm.

Huh? If your algorithm says "divide by 4", why would you need a different algorithm.

Plasma dynamics isn't simple. You're trying to confine fast-moving charged particles with a magnetic field. Those charged particles generate their own magnetic field when they move, and that field creates forces on all the other moving charges. Most configurations are unstable, because tiny asymmetries in the shape get amplified.

> Conceptually fusion seems pretty simple: why in principle does harnessing it require super-human complexity?

All your useful materials melt at 2000 degrees.

The fusion takes place at 20000000 degrees.

Mystery solved.

(Yes I know these numbers are grossly oversimplified.)

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