defatigable

Most things my body consumes (even the ones it doesn't use) don't fall in to that category. And most of what you're describing our bodies are very good at ignoring. I'm bathed in radiation constantly and I'm fine (unless I stay out in the sun too long without sunscreen...). I wouldn't want to live in a house with asbestos or lead paint, but I wouldn't be too bothered visiting a friend who lived in one. And so on.

It may absolutely be that nanoparticles of plastic are so harmful that eating off of plastic plates is a really bad idea, but my heuristic would be to not worry too much about it.

I just ate a dinner off of a plate that's been sitting on my shelf for a few days, using utensils that have been sitting in my drawer for a few days, accumulating whatever residual particles have been floating through the air settling on them.

Like most people I lick my fingers after eating chips and don't sterilize my hands in advance, hands covered with whatever I've recently been touching (including the plastic bag that the chips came in...).

I have an air purifier at home, but there's all sorts of detritus kicked up in the air from materials around the house that my body is constantly inhaling (not to mention the exhaust and tire particulates that I get from cars driving by me or whatever is being produced in the construction site down the street).

I absolutely agree that there are plenty of things out there that are bad for you, at least in sufficient concentration. But every breath you take and every bite you eat is consuming at least some trace amounts of particles that your body doesn't need, from all sorts of sources.

It may well be that nanoparticles of plastics are particularly bad for you (in the concentrations that are normally consumed) but my heuristic is to not worry too much about things like this unless given concrete reason to.

My basic mental model is that my body is constantly consuming chemicals that it doesn't use, be it particulates in the air or substances in the foods I eat or drink. My body is very good at incorporating the substances that it finds useful and ignoring (or killing) the ones that it doesn't, so I don't find myself worrying too much about any particular substance it might take up.

To your point, I don't have any particular reason to think that trace quantities of plastics going through my digestive system are going to cause any harm to me. Obviously if I have specific reason for concern I'll be careful (I'm not, like, going to eat off of asbestos plates...) but otherwise I'm not going to think about it much.

I like Alfred but I'm not a huge power user. It does have a bunch of other functionality. Out of the box it lets you do a bunch of stuff like filesystem manipulation, clipboard history management, a simple calculator, and stuff like that.

It's also extensible. For example there's a very useful add-on workflow [0] that makes it really quick to open up the next Zoom meeting you have scheduled in your calendar.

[0] https://github.com/caleb531/open-conference-url

Hey, this looks awesome. Thanks so much for the pointer.

Quick plug for a Chrome extension I wrote that gets rid of the _blank target on links, if that behavior annoys you as much as it does me:

https://goo.gl/4D1ONu

It appears as though just installing the APK doesn't get you all of the Google Voice integration -- you need to wait for some server-side changes to your account as well. (Discovered this after a frustrating hour or so of trying to get GV features to work...)

Ah. Yes, in frontier A* you definitely need a consistent heuristic, although I'd be surprised if frontier A* is the most popular form of the algorithm used, particularly for grid search. You really only want it in a very large implicit domain where the closed list would be too large to fit in memory. If the problem space is small enough then the traditional form of A* with an explicit closed list is much easier to think about.

A nitpick: "breadth-first heuristic search" is an algorithm developed by Zhou and Hansen and, while it's related to A* (in that it uses an admissible heuristic to prune the search space), it's not actually a variant of A*. (It's not a best-first search algorithm, since it doesn't expand nodes in increasing order of f cost.)

If you use an inconsistent heuristic, it may be possible to revisit a node a second time via a cheaper path. And thus, as you say, if you generate a node a second time but with a cheaper path, you may not find the optimal solution if you discard the regenerated node.

So if you do A* with an inconsistent heuristic, you need to revisit nodes if you explore them a second time with a cheaper cost (i.e., you can re-expand nodes in your closed list). If you do this, you will find optimal solutions even with an inconsistent heuristic.

The only requirement on your heuristic if you A* to find optimal solutions is that it be admissible.