quokka

I found some on sale for around $300 on Etsy. Shipping is very expensive, so they would probably make sense only if you can manage local pickup.

I saw this via Lobsters yesterday and enjoyed reading it. The animations helped me understand bidiBFS.

But I'm confused by the example showing the buggy version of the algorithm fail. This is in the section "Finding the Wrong Path".

Consider the state of the algorithm after the first step. We've explored S and added its neighbors to the queue, Q = [T, a1, b1].

In the next step we explore T, the first node in the queue. We add its neighbors , a3 and b2, to the queue.

Now, I would expect the new value of Q to be something like [a1, b1, a3, b2] (depending on the order we add T's neighbors). In this case we would process a1, and b1 next, notice that b1 is adjacent to b2, and correctly find the shortest path S-b1-b2-T.

But the animation actually shows that after step 2, Q = [a1, a3, b1, b3]. In other words, a3 didn't join the back of the queue but jumped in front of b1. This is what leads to the buggy behavior that is shown.

So as I understand the example, this would have worked fine if Q were actually a queue. But as shown it is not.

Why is this?

Merlin is fantastic!

But it it's not 100% accurate and currently focuses on birds from Canada, the US, and Europe.

There is an email address to send errors and such. A secretary prints them and he marks up the hard copy (if necessary) which is returned with a reward check (when appropriate).

I have received one actual email from him, when I pointed out an error in the balances at the Bank of San Serriffe (https://www-cs-faculty.stanford.edu/~knuth/boss.html).

The email looks like it was typed by him - the style is right and it is signed "Don" - but the From: address has someone else's name.

He fixed the issue quickly after I sent an email.

I'm somehow on that list twice, which looks like a bug. I wonder if there is a reward for finding an error in the reward list.

Agreed. I posted a lot in the 90s, especially to groups like sci.math and rec.arts.books.tolkien, and there is almost no trace of any of it in Google groups.

When Google bought the Dejanews archives I thought it was good, because Google was good at search and I naively still believed that the company actually wanted to make all information accessible. It's a real shame that all of the old Usenet stuff is gone.

Years ago I had one of these. It slowly stopped working and my wife got sick of it. Without any way to fix it I got rid of it, which I now regret. The toaster we have now browns unevenly and is wildly inconsistent from run to run.

I just checked, and it is on by default for me, too.

Apparently floating these monsters is now a solved problem. But doing maintenance on a 200 m tower bobbing in the waves is still a challenge.

I'm a subscriber so I don't know how soft the paywall is:

https://www.economist.com/science-and-technology/2021/07/21/...

BirdNet has been around for several years now, while Merlin just got sound-id recently. Merlin has coverage for about 450 birds of North America, while BirdNet can id around 1000 birds of N Am. and Europe.

With BirdNet you make a recording, highlight the interesting section of the sonogram, and upload that section to the BirdNet servers. With Merlin you start recording and the software ids birds in real time, popping up species as it goes.

My assumption is that, because it runs locally on the device, Merlin is going to be less accurate than whatever BirdNet is able to do on its beefy servers. But it is has the advantage of working without a data connection. Merlin can also id from photos and descriptions.

So the one isn't a replacement for the other. It's great to have options.

That is true, and why to the solution to the US's slow internet providers isn't "get Google fiber to everyone". It should be "make it easy for new companies to provide service, even if another fast service is already available".

The writer is suggesting that the "FCC can mandate right-of-way rules similar to those granted Google Fiber to all credible competitors".

He isn't saying that the "free market" will fix things by itself. He observes that there isn't a free market in providing internet access because the incumbents control things like telephone poles (to hang optical cable on) and municipalities are so addicted to the kickbacks they get from cable franchisees that they won't let anyone else in. The magic of the invisible hand only works if there is actual competition. Those supply and demand curve charts only describe reality if there aren't monopolists.

His claim is that if the FCC mandated right of way to anyone wanting to hook homes up then a company like Google would already be serving many more homes as incumbents wouldn't be able to block them as AT&T is doing in Austin.

This is true, but I'm not convinced that it is the right way to get proper competition here. Is the solution really to have 5 companies each run optical fiber down a street? Better would be for one company to run super-fast tubes, and then sell the bandwidth in bulk to ISPs. Maybe that is the business model that would emerge, but maybe not.

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

"... securing for limited Times to Authors and Inventors the exclusive Right...".

The weasels in Congress get around this by retroactively extending copyrights every time Mickey Mouse is about to enter the public domain. Such extensions are thefts from the public domain and destroyers of wealth, but the Supreme Court has ruled it constitutional.

Oh, good lord. The definition uses max, but I was thinking of min. Face palm.

I don't understand. The definition of order is

  s = score(ups, downs)
  order = log10(max(abs(s), 1))