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Comment by dheera | Hacker News Reader

Why aren't there mugs with hydrophobic coating on the bottom? It seems like this should be an easy problem to solve compared to all the petaflop GPU's and spacecraft we're building.

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Normally, mugs are ceramic and thus the parts that had to touch the shelf in the kiln are unglazed.

Maybe we just need to make pottery in 0G.

Could you just suspend them on a cushion of air like indoor skydiving?

One of the primary motivations behind LK99 and other efforts to create room-temp superconductors is to fashion coffee mugs that harness the Meissner effect to levitate above journal print-outs.

How do you "just" suspend a mug on a cushion of air?

Maybe like indoor skydiving?

Obtaining the necessary laminar flow in the presence of the handle might be challenging.

Huh, TIL

The bare ceramic on the bottom of the mug is of those things I've always noticed about coffee cups but never really thought about.

Not all tableware is barefooted / dry-footed. You can use a stilt, which is a ceramic with sharp metal (eg Kanthal) pins on which the glazed ceramic is supported. Pieces fired this way have small marks on the bottom like the injection marks some moulded plastic has.

Fully glazed ware is good for wet areas when the ceramic may not be entirely vitrified, as this prevents water from soaking into the ceramic body.

Dry-footed ware that hasn't been high-fired will soak up moisture, eg when washing, and so cause problems - crazing, and getting very hot when used in a microwave oven (which can cause more crazing, but also burn your hand!

Source: am potter.

The foot ring on dry-footed mugs is a useful knife sharpener in a pinch.

That's a very low tech solution. What we need is an internet connected mug that senses with a camera if it's about to be set on top of a piece of paper and starts beeping uncontrollably.

With a firmware update and an additional charge to the customer a model for detecting polished wooden furniture could also be used.

It also needs a permanent internet connection, as the inference for the paper detection is run in the cloud, and a subscription to keep it working.

I call it No-SaaS, No Stains as a Service.

Because that is a hardware fix.

Why fix in hardware what can be fixed in software? A simple Latex package could add hydrophobic coating feature to the document file.

Next: the device driver team will be tasked with a software patch to correct for the burned out light bulb on the device.

Oh great, one more ink cartridge for printer manufactures to sell. And, of course, the printer will refuse to work if your hydrophobic coating cartridges is empty even tough all other cartridges are fine.

They tend to get destroyed when cleaning the items. It happens a lot with clothing that has hydrophobic coatings so I'd imagine a dishwasher would ruin it almost immediately, leading to complaints and returns.

Then how would we tell which papers have been read?

How would a hydrophobic coating help?

I can imagine two ways. First, on the very bottom, if you place the mug into a puddle of coffee, then no coffee will wet the bottom of the mug. Second, around the side, when coffee runs down the side of the mug, a hydrophobic coating might stop a drop in its path if it is not too heavy. Not sure if the second thing would actually work.

The coating around the side should form a V, with the handle being the lowest point, and make a little indentation on the bottom of the inside of handle to collect all the liquid...

So make a GoreTex sleeve that waterproofs the bottom of your coffee mug?

Aren't most hydrophobic coatings very toxic and wear easily?

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