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Comment by vharuck | Hacker News Reader

Soda cans also have a counterintuitive efficiency feature: concave bottoms. If a can with a flat bottom held the same amount of soda, it would be shorter and have less surface area, but its metal body would need to be thicker to withstand the same pressure. In the end, it'd require more aluminum.

https://www.csmonitor.com/Science/Science-Notebook/2015/0414...

^Probably not the best article for this, but it was easy to find and has a link to a chemical engineer's video.

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Engineer Guy (Bill Hammack) has a great video about this.

https://www.youtube.com/watch?v=hUhisi2FBuw

Edit: Just realized this is the same video you referenced. All of his work is fantastic.

I really liked this video when I watched it. I may have watched it twice.

I've encountered a few of his videos on wikipedia (creative commons license.) Pretty neat.

His 'drinking bird' video is used on the wikipedia page for the same: https://en.wikipedia.org/wiki/Drinking_bird#Physical_and_che...

> All of his work is fantastic.

Even that is an understatement, I love those videos

Same about waviness on plastic bottles.

https://www.riverkeeper.org/wp-content/uploads/2018/04/bottl...

The waviness around makes it easier to hold them too. Although to some degree it might be marketing as well?

It's a combination of structural variation, like with the bricks, and branding. Because as long as it's "waving" it doesn't matter how exactly it waves except in some critical areas, like where you hold it, the bottom and the top.

Standard video:

"The Ingenious Design of the Aluminum Beverage Can"

https://chbe.illinois.edu/news/stories/engineer-guy-ingeniou...

https://www.youtube.com/watch?v=hUhisi2FBuw

I think that's also why a pretty small kink in the can will make it tremendously easier to crush against your forehead as a party trick :-)

Or, more likely, it's a similar principle also at place in the design.

Same with cans, corrugated sides, tops and bottoms are for strength and pressure resistance. Actually most corrugated anything is done so for strength.

I think the Christian Science Monitor is perfectly fine. https://mediabiasfactcheck.com/christian-science-monitor/

The religious group that funds it has a questionable relationship to science including and despite "Science" being in its name. (It was started as a 19th Century anti-hospital group. We'd consider them "proto-anti-vax" in today's concerns and terminology.) They may be unbiased in reporting the news, generally, but there's still concerns about their relationship to reporting science given their name and the known beliefs of their church.

...being anti-hospital in the 19th century sounds fairly rational to me?

Sure, you can't fault them for not having some good reasons behind their beliefs, based on what they knew and experienced at the time. You can certainly fault them for calcifying those beliefs into an entire church with rituals/rites devoted to such beliefs that then became somewhat obstinate in the face of later scientific progress and technological advancement (and then because of that also complicit in later struggles of science versus pseudo-science and conspiratorial thinking).

Treating a hospital as an absolute last resort in the 19th century would be rational, but I'm not sure being "anti-hospital" would be.

> there's still concerns about their relationship to reporting science

Can you provide any credible examples of concerns regarding their reporting on science topics?

Also in the current design you can stack them. This is probably worth something in terms of wrapping of pallets of cans.

Same principle as concave bottoms on wine bottles (though the concern there is more about jostling and impact during transport than pressurized contents).

Aluminium's also more expensive than steel but experiences sufficiently less breakage to justify the price.

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