Re: [math-fun] More good news: Luciferin Exists!
When I was a kid in the 50s, rather greenish "lightning bugs" were rife in the Camden & Philadelphia areas, despite massive anti-mosquito DDT spraying. (Are there multiple color variants of luciferin?) Despite the DDT ban, they're gone now. Probably habitat destruction. But they were trivial to catch, so maybe an invasive predator? E.g., northern California has lately become infested with little black phorid(?) flies. They attack your food in restaurants. And they (painfully) attack scratches and cuts. Probably came in on an Asian freighter. Or maybe something is wiping out the dragonflies. —rwg On Sat, Jun 29, 2019 at 12:34 AM rwg <rwg@ma.sdf.org> wrote:
-------- Original Message -------- Subject: [math-fun] More good news: Luciferin Exists! Date: 2019-06-28 12:21 From: Brad Klee <bradklee@gmail.com> To: math-fun <math-fun@mailman.xmission.com> Reply-To: math-fun <math-fun@mailman.xmission.com>
A very nice young woman from California recently told me she was floored to witness, for her first time ever, the beautiful flashing of fireflies in the dusk of Illinois.
If fireflies are not native to your home land, It's certainly worth travelling to see. In Kansas and Arkansas these bugs are well loved by just about everyone. I have never travelled to Japan, or any other part of Asia, but have heard from travellers that fireflies also exist in those locales--as well as Brazil.
In case you can not travel to look and wonder what type of math and science the yellow lights may be intimating, here are some nice blog articles I found for starters:
https://www.inhs.illinois.edu/resources/inhsreports/autumn-01/firefly/
http://www.mostlycolor.ch/2012/08/firefly.html
Cheers,
Brad
RWG: "When I was a kid in the 50s, rather greenish 'lightning bugs' were rife in the Camden & Philadelphia areas, despite massive anti-mosquito DDT spraying... Despite the DDT ban, they're gone now." A 2018 Drexel University article suggests that "Fairmount Park in Philadelphia is a great place to find and observe fireflies" so they are still there. https://www.anspblog.org/fireflies-in-your-backyard/
Dinoflagellates have their own luciferin, which emits in the visible blue. A loose measurement can be done by most human eyes, in person or from video recordings. In fact, It's worthwhile to take a closer look at the chemical geometry of Dinoflagellate Luciferin, especially next to that of Chlorophyll: https://biolum.eemb.ucsb.edu/chem/detail2.html https://en.wikipedia.org/wiki/Chlorophyll#/media/File:Chlorophyll_d_structur... Chlorophyll's magnesium ligand is well-known to act as a quantum antenna during photoabsorption, mostly in the blue. Dino. Luciferin has a similar structure, but without a magnesium atom at the center of approximate dihedral symmetry. Here we have an astounding example of the inversive relation between emission and absorption. The two phenomena are essentially similar under time-reversal symmetry. It could take a lot of high-power math to try and prove such a statement, see for example: http://bohr.physics.berkeley.edu/classes/221/1112/221.html ( Notes, 20, 32 & 41 ) One objection is that entropy favours emission over absorption, but this is not too difficult to get around. Absorption/emission is usually said to occur in the ultrafast regime, i.e. on the order of a femtosecond. Meanwhile, radiative lifetimes indicate a bound for the time scale where entropy is a more relevant concept. A lifetime figure written in nanoseconds, would be roughly six orders of magnitude slower than the instantaneous time of an emission or absorption event. ++Brad On Sat, Jun 29, 2019 at 3:03 AM Bill Gosper <billgosper@gmail.com> wrote:
Are there multiple color variants of luciferin? —rwg
participants (3)
-
Bill Gosper -
Brad Klee -
Hans Havermann