OT: They're back

[Lobby Dosser]

Might want to re-assess the dog's diet. Needs more protein & fat! :o)

["<<<]

No way ... the dog has canine epilepsy, which makes him susceptible to having seizures. He takes Phenobarbitol twice daily to control them and is on a very specialized diet as recommended by his vet. You can second guess the vet's advice all day long, but I'm not changing a thing on this end.

[Morgans]

"">>"" wrote

My dog, on the other hand, has been running around for days, eating them like popcorn. YUCK !!!!

Yup. My dog didn't hardly touch her dog food for a month when they were here.

-- Jim in NC

[Morgans]

"Lobby Dosser" wrote

Are they still around up there, or have they been wiped out due to pollution/insecticides?

I have been know to have a chirping cricket in the house wake me, which caused me to get up, locate the cricket, find a pry bar and hammer, and remove the piece of baseboard he was hiding behind.

-- Jim in NC

[Lobby Dosser]

I'll have to ask my son, he lives down the valley. I haven't seen any around Portland.

By the time I'd find and kill it, I'd be so wired I'd just stay up ...

[Lobby Dosser]

Those extra snacks must be playing hell with that diet ...

[Drew Lawson]

General thought is that it avoids preditors getting adapted to them. Cicadas aren't agile and they aren't stealthy. So it helps that nothing is used to eating them on a regular basis.

Now why those *specific* time spans, I have no clue.

And I'll correct myself. It seems the 13 and 17 year broods *are* the same species. Just different populations.

[Doug Miller]

Because they're prime numbers. A predator that's around every year will catch them only every 13 (or 17) years; a predator that's around every other year will catch them only every 26 (or 34) years; a predator that's around every 3 years will catch them only every 39 (or 51) years; and so on. It makes it

*much* more difficult for a predator to co-evolve a synchronous hatching period: suppose they appeared every 12 years instead of every 13 -- then they'd be vulnerable, potentially, to predators that hatched every 12, 6, 4, 3, 2, or 1 years.

[Lobby Dosser]

Wow, that makes sense!

[Swingman]

Damn! Learn something new every day. That is absolutely awesome!

The implications of that mechanism, and it's origins, is absolutely mind-blowing!!

Thanks, Doug!

[Upscale]

Certainly makes one wonder if mother nature really is that mathematically inclined.

[Swingman]

Not religious, but maybe I oughta be ... Makes you wonder. A bug using prime numbers for survival ... Sheeeeeesh!

[Swingman]

Farkin' iPad speel checquer added an apostrophe!?! WTF?

[chaniarts]

most things with spiral based shells are based upon the fibinocci sequence

[Bill]

I'd say shells came first. According to Wikipedia: The Fibonacci sequence is named after Leonardo of Pisa, who was known as Fibonacci. Fibonacci's 1202 book Liber Abaci introduced the sequence to Western European mathematics.

It sounds familiar, but, since you brought it up, How are shells related to the Fibonacci sequence? It surprises me that all shells would have this commonality. I would have expected the kind of variance that you see in the growth rings of trees.

Bill

[Bill]

Answering my own question (by copying from Wikipedia):

It is sometimes stated that nautilus shells get wider in the pattern of a golden spiral, and hence are related to both ? and the Fibonacci series. In truth, nautilus shells (and many mollusc shells) exhibit logarithmic spiral growth, but at an angle distinctly different from that of the golden spiral.

Bill

[Lobby Dosser]

As is the Sunflower ...

[Bill]

You didn't read my other post? Sweeping generalizations like that, sweet as they may be, are often wrong. Can you cite a reference for your claim about the Sunflower?

Bill

[Drew Lawson]

Um, y'all have this slightly backward.

It isn't that nature knows advanced math. It is that advanced math is what it takes for humans to describe nature. Fibonacci didn't define a sequence just to amuse college freshmen. He did it to make sense of the way that plants tend to be formed -- one stem, two leaf groupings, three leaf groupings, five petals, eight petals, etc..

Maybe there's a Great Mathematician drawing on the chalkboard. Maybe there's mathematical structure making us imagine a chalkboard. Ether way, it is pretty amazing how things tend to fit/work together.

[Swingman]

I don't have it backwards, mon ami ... that is exactly what I am in awe of!!