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24 August 2001
Thermochromic bacteria?
Hello,
My name is Joshua Bierman and I recently became a member of SAS. First off I want to congratulate you and everyone else who works at SAS for doing a wonderful job. Secondly I need some help. I am doing some intensive reading (its not exactly research, I'm not doing anything new, just reading on what is known) on Thermochromic materials and Chromoforms (chromomorphs?) in general. I have done a great deal of online research and know considerably more than I did when I started. However I still feel there are some questions that the available literature is just not answering for me. Is there anyone in the lists of members who works in color change chemistry that would be willing to speak to (or trade email with ) me? The other related problem I am having is tracking down a tiny article from a year or so ago about a bacteria that had color change properties (pale yellow and dark purple, thats about all I remember about it) and research was being done into using it for signs and other forms of information dissemination devices. So far the search engines have been useless. Any suggestions?
I'm sorry if your not the person to ask these questions to. If that is the case please forward this on to the appropriate person, and thank you for your time.
From the Forum
The following piece is part of the ongoing forum discussion concerning Walter Alvarez's article in the previous E-Bulletin on using amateurs to collect geological data from the air (see Geology at 30,000 Feet: A proposal for a new citizen scientist initiative).
"As it happens I have been doing something similar during summer travels with a Gremlin eTrex. As Dr. Alvarez found, mine works only in the airplane window, only far from the wing. Together with a Nikon Kool-Pix, I thus have the means to record all I need about any interesting feature noted when there is no cloud cover, then I can look it up upon return to home. This has been fun along major air routes in the arid SW of USA, and a couple weeks ago in a traverse of SA en route to Buenos Aires. For example we happened to fly right over the Campo de Cielo site of the major meteorite fall 4000 years ago.
"For more quantative fun I undertook to pretend the GPS provides me a long carpenter's string that I can stretch taut between airports, and note the length and the bearing relative to a fixed remote landmark, viz Polaris. (I pretend not to know latitudes and longitudes, not to know the GPS is only calculating my distance and bearing from those readings, and not to have a globe from which I might have measured everything without a GPS.) It is of interest that bearing AB is not the complement of bearing BA, as it must be on a plane surface. Evidently the pancake-like appearance of the landscape is deceptive on a large scale. Here we have opportunity for compulsive do-it-yourself-ers to personally check the intrinsic geometry of the landscape without leaving that surface for a look from space, and without necessarily taking on faith what our 4th grade geography teachers told. My own travels provided by last week a network of stretched lines that I tabulated in an Excel spread sheet (attached: this is just my personal notes, done last week with no intent anyone else would ever see, but then today came Alvarez' 17 Aug letter and so I post it unedited as I left it some days ago). I have only bearings back to places I had already been during the summer, so most triangles remain incomplete, but there are a couple of biggies, like 15 million square miles. The sum of their internal angles exceeds pi by about half, suggesting positive curvature.
"I checked this by cutting long plastic strips half an inch wide, scaling them 1 inch per 1000 miles, and pasting their ends on xeroxed compass cards. Each card is an airport and the strips connect airports at the observed distances and bearings. The whole network proves not to be flat. It looks like a part of a sphere. The radius might be 7-9000 miles.
"Guessing this curvature might indeed be isotropic, a little spherical trig added to the spreadsheet enables quantitative estimation of radius: one triangle gave me 3981 miles, another 3961, compatible with hear-say.
"It has also been fun to do crude astronomy with GPS during night flights. Noting above overcast the full moonrise over the south tip of Greenland (known from GPS), it was fun to decipher the orientation of features on the Moon's disk in relation to the horizon, it curiously persistent low altitude, and the time of its rise: fun and games with geometry that would not be possible without GPS, yielding a satisfying feeling of knowing where I am and what's going on around me, not just being locked in a box for transport through nowhere, from one familiar universe (Tucson) to another (Bristol) with nothing sensible lying between. "
Cheers from Art Winfree
More on Mold
I have one of my usual experiments underway in my refrigerator.
A nice big metal can of Canadian maple syrup WILL get moldy if it isn't refrigerated soon enough after opening.
Maybe the sugar is fructose instead of sucrose? Anyway, it DOESN'T stop the mold growth!!!
I'm wondering if filtering it through a micron sized filter will 'claen it up' so the moldy taste is removed. I've got a sterile filter element and will report the results later.
The New E-Bulletin Format
Shawn,
I would like to request that the E-bulletin return to the old format. The new format does not allow me to simply scan through the E-bulletin using the browser slider bar as before. Now I must click on each topic that might be of interest and I can not scan to see if it would be of interest. Even worse, every clicked item ends up in a new window that has to be manually closed down later.
Reply: Others have complained about pages opening in new windows, so we have configured this issue of the E-Bulletin to keep everything in the same window. Please write and let us know what you think. Otherwise, the new format has been well-received by our readership, and we will continue to develop and improve it in subsequent issues. --Sheldon.
