hckrnws
We used to joke in my biophysics grad program that basically everything was determined by its surface area to volume ratio.
"First, assume a spherical chicken."
> even though evolution is contingent at a local level (such as a specific protein sequence or the shape of a flower), it is remarkably predictable at a global level (such as the very existence of proteins and flowers across many species)
to be fair... flowers are a very recent invention that appeared only after the dinosaurs got wiped out and clean slate allowed co-evolution of flowers and pollinators to occur
Flowering plants (angiosperms) appeared during the Cretaceous before dinosaurs got wiped out, and there is fossil evidence of insects pollinating non-flowering plants (gymnosperms) like ferns and confers even earlier than that: https://repository.si.edu/server/api/core/bitstreams/152b12d...
>an estimated 70 percent of viral capsids known to date are icosahedral, shaped like tiny soccer balls.
Soccer balls are not icosahedra. The archetypal soccer ball is a truncated icosahedron: https://en.wikipedia.org/wiki/Truncated_icosahedron
There are a few pictures of truncated icosahedra in the article, alongside several other shapes that are not icosahedra. The point is that they have icosahedral symmetry. The L is important.
I was going to comment pedantically that soccer balls were dodecahedrons not icosahedrons, but in reading the article, I came to realize that truncated icosahedrons are the same as truncated dodecahedrons.
This was such a delightful realization I felt the need to comment anyway.
that is indeed a delightful realisation! akin to when I noticed that a cube and an octahedron both had a cross section that was a regular hexagon.
Hmm. I'm sorry, but truncated dodecahedra are different from truncated icosahedra.
Truncated dodecahedra are made from twelve 10-gon and twenty triangular faces. Truncated icosahedra are made from twenty hexagonal and twelve pentagonal faces.
And that archetypal soccer ball design is called the Telstar and named for a communications satellite, fun fact. I think before 1968 the volleyball shape was more popular https://en.wikipedia.org/wiki/Adidas_Telstar
do you know what the modifier "like" means in the sentence you quoted, or are you just being annoyingly pedantic
eh but also organic chemistry only does well 30 and 60 degrees
The universe seems perfectly happy to have, for example, 5-member rings tho.
See buckyballs as a trivial refutation of your point.
Are buckyballs organic?
Formally, yes. "Organic chemistry" is not too far off a synonym for "chemistry with carbon involved".
"Not too far off" = "exactly defined as".
I wasn't sure if there were any weird edge cases, but yeah.
I mean, I don't think diamonds are considered "organic"; same for graphite. But that's where the term "organic" itself starts to break down as a category.
I was also thinking carbonates in a geologic context.
Yes! Not sure why you're asking- things don't have to be created by biological processes to be organic (this concept is totally unrelated to "organic" in the supermarket).
Not in 3D.
That image just demonstrates what was mentioned in the article, that the sphere cannot be covered only with regular hexagons, but a part of them must be replaced with regular pentagons, so the angles that are multiples of 30 degrees are not sufficient.
So the previous poster was right.
An angle projected on a plane is not the same as a 3D angle.
Also see the structure of diamond (109 degs).
Crafted by Rajat
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