Wikipedia:Reference desk archive/Science/2006 August 12

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[edit] Glow sticks, who invented them

My six year old son and I would like to know the chemist or inventor of the glow stick.

Glen

Hello Glen. Our article doesn't seem to mention the inventor. However, this google cache suggests:
In the early 1960s, some guy, a young chemist at Bell Labs in Murray Hill, N.J., was searching for a general way to explain chemiluminescence. Peroxides, with their potential to liberate large amounts of energy during some chemical reactions, seemed to be likely participants.
After a number of experiments, he found to his great excitement that oxalyl chloride mixed with hydrogen peroxide and a fluorescent dye produced chemical light. The efficiency was only about 0.1%, but it was the foundation from which sprang modern chemiluminescence. Chandross, unaware of the powerful potential of his discovery, never patented it.
At about the same time, chemist Michael M. Rauhut was manager of exploratory research at American Cyanamid in Stamford, Conn. He and his colleagues corresponded with Chandross about his oxalyl chloride chemistry, then went to work on the reaction--studying it and looking for avenues that would produce chemical light intense enough to be of practical use.
Rauhut and his colleague Laszlo J. Bollyky developed a series of oxalate esters. Ultimately, Rauhut designed a phenyl oxalate ester that, when mixed with hydrogen peroxide and a dye, gave a quantum yield of 5\--not as efficient as a firefly, but still brilliantly useful. They dubbed it Cyalume, and it became the trademark name for American Cyanamid's chemical light products.'
So there you have it, Edwin A. Chandross developed the chemistry and Rauhut & Bollyky applied it to make the first glowsticks. Rockpocket 01:10, 12 August 2006 (UTC)
Ed Chandross may have been doing research in the field around the time that glow sticks were commercialized, but credit is usually given to Naval Air Weapons Station China Lake for inventing the glow stick. Here is an article. -- C. S. Joiner (talk) 01:13, 14 August 2006 (UTC)
I've edited the article, with mentions of both theories. (NPOV in action ;) Ignoramibus 06:08, 16 August 2006 (UTC)
After communicating with Ed Chandross by e-mail, I withdraw my comment which was based on second-hand information from a former employee of China Lake. It does indeed appear that Ed Chandross holds the patent for inventing the glow stick. -- C. S. Joiner (talk) 01:45, 11 October 2006 (UTC)

[edit] Chemistry term

Sorry to edit, but here's your answer - Mark Wrighton, chancellor of Washington University in St. Louis was the chemist responsible for the glow stick. Orientation at WashU every year features a mile or so walk from the Athletic complex to the quad - the sidewalk is lined with faculty, administrators, etc. holding glow sticks to both commemorate the achievement and light the way (not that it's really needed). Harvard has their business review, we have the glowstick (ah the charm of the midwest v. the coasts). There you have it. :) www.wustl.edu

Hi

I've been trying desperately to remember a particular term I heard used a week or so ago in a 3rd year chemistry lab. We had made an oily substance from beta-pinene, and had it sloshing around in an aqueous solution as a blob kind of thing. The oil was still liquid because solvent was 'dissolved' in it, so we mushed it around with a glass rod. This was meant to push the solvent out of it. It turned to chewing gum consistancy, then solid.

Finally, I get to my question: the working it around with the glass rod had a term to describe it. Maybe it was something like titilation... anyone have any ideas what this word actually was?

Thanks for your help

Aaadddaaammm 01:14, 12 August 2006 (UTC)

Perhaps agitation? I think agitation is usually used for liquids, not gummy substances, though. --Bmk 01:18, 12 August 2006 (UTC)
Sorry - didn't read carefully enough - I guess it was liquid while you were ----itating the solution. Perhaps it was agitation then. --Bmk 01:22, 12 August 2006 (UTC)
Wow thanks for the quick reply, but that's not the word... We "X"ed the liquid until it became gummy and then kept "x"ing it until it was completely solid. It was a really weird word that I've never heard before Aaadddaaammm 01:26, 12 August 2006 (UTC)
Based on your guess, could it be Trituration? Rockpocket 01:35, 12 August 2006 (UTC)
YES! Thank you! Wikipedia comes to the rescue again! I'm impressed! Aaadddaaammm 01:37, 12 August 2006 (UTC)
Well, we're not really an encyclopaedia, but a small community of smart guys, here on the Reference Desk.

[edit] Color in Complete Darkness

I clicked the random article button, as I usually do, to find new topics of interest. An article came up about how the color perceived in complete darkness is actually lighter than the color seen as black in a lit area because the brain relies partly on contrast, rather than solely on absolute color, to differentiate between objects and colors. A name was given for the color seen in complete darkness, and I should like to know what it was, but I can't figure out how to find the article. It would be greatly appreciated if an answer, or more helpfully, the actual article, could be sent to email redacted. Thank you,

Maverick —The preceding unsigned comment was added by 64.12.116.74 (talk • contribs) 01:42, 12 August 2006 (UTC)

De nuit tous les chats sont gris. (Did I get that right?) --Trovatore 01:47, 12 August 2006 (UTC)
La nuit, tous les chats sont gris. --LambiamTalk 06:46, 12 August 2006 (UTC)
In het donker zijn alle katjes grauw. Any more languages? DirkvdM 11:46, 13 August 2006 (UTC)
In der Nacht / bei Nacht / Nachts sind alle Katzen grau. --LambiamTalk 17:24, 13 August 2006 (UTC)
Even though complete darkness wouldn't have a color because color is a wavelength of the electromagnetic spectrum... yeah, I can't help you. — [Mac Davis] (talk)
Yeah. you must have light to percieve color. So there is no such thing as color in complete darkness. You may want to think a bit more about what you are asking, perhaps you mixed some facts. pschemp | talk 05:37, 12 August 2006 (UTC)
If you've forgotten the title of an article you visited recently, try looking through the history list of your browser. Could it have been Purkinje effect or scotopic vision?--Shantavira 07:01, 12 August 2006 (UTC)
Could it be eigengrau? Adambrowne666 11:53, 12 August 2006 (UTC)
Interesting. --Proficient 14:00, 12 August 2006 (UTC)
um if this is random color seen in perfect darkness due to the optic nerve firing or molecules in the cones (thus nothing is really actually seen) this statement in the article "the night sky looks darker than eigengrau because of the contrast provided by the stars." is odd since the night sky is nothing close to being in perfect darkness. Maybe the article needs some help.pschemp | talk 14:18, 12 August 2006 (UTC)
The claim is that the night sky with stars appears darker than eigengrau, not that the night sky is "perfect darkness." digfarenough (talk) 17:09, 12 August 2006 (UTC)


Eigengrau is exactly what I wass looking for, thank you. Also, for those of you who commented on complete darkness not having a color, you may notice that I asked about the color 'perceived' or 'seen' and opposed to the actual wavelength. Make sure you have _your_ facts straight and understand my question before you criticize, please.

[edit] central dogma

what are the situations where central dogma are not obeyed

Assuming you are referring to the Central dogma of molecular biology - (where DNA becomes RNA becomes protein) - then any retrovirus in the process of replicating violates this dogma. Raul654 04:51, 12 August 2006 (UTC)


[edit] Another crypsis question

Can anyone tell me the name of the creature, I think it's a spider, that has evolved to so resemble the creatures it preys on, I think it might be ants, that it is all but indistingishable from them?

Thanks, Adambrowne666 05:30, 12 August 2006 (UTC)

See our article on Ant mimicry. --LambiamTalk 05:43, 12 August 2006 (UTC)
Thank you, perfect. Adambrowne666 06:33, 12 August 2006 (UTC)

[edit] minto engine

  i want to know more about


Uhh?--Light current 05:40, 12 August 2006 (UTC)

Do you mean the Mentos eruption? InvictaHOG 05:45, 12 August 2006 (UTC)
The user probably means the heat engine; see this reference. Could it be that this is the same device as the "Minto wheel" mentioned in MythBusters (season 2)? --LambiamTalk

Mother Earth News built a gigantic 20 foot high Minto Wheel in 1976. It was disappointing in that it rotated VERY slowly and had low efficiency. Perhaps better design could improve on their experience. See: http://my.voyager.net/~jrrandall/MintoWheel.html Edison 02:57, 15 August 2006 (UTC)

Follow this link for a video of a working Minto Wheel: http://www.youtube.com/watch?v=-fUlKBH1sY8

The MintoWheel Yahoo group has active discussions and an archive of information and internet links: http://tech.groups.yahoo.com/group/MintoWheel/

[edit] Drugs producing synaesthesia

Sir, could you, please, elaborate a list of drugs that produce synaesthesia with some limited additional information about them? Thanks.

I don't believe any chemicals produce true synaesthesia, which is a specific neurological condition. Some chemicals, the most well-known of which is LSD, are said to produce something akin to synaesthesia, though. Psychoactive mushrooms might produce such an effect (not sure) or perhaps peyote or other cacti, but I don't know much about those. In general though, I think it's safe to say that no chemical is going to alter your brain in such a way as to give you true synaesthesia. digfarenough (talk) 17:15, 12 August 2006 (UTC)

Thanks.


Myself and others have experienced synesthesia while under the influene of the research chemical DOC, u can find out more about it on erowid.com

[edit] Insecticides --- as Preservatives

Hello! Why do soft-drinks companies use insecticides in their products as preservative? Are there no alternatives to this? Often, it is beyond permissible limit... and regular consumption of which may lead to fatal disease. I want to know why can't this use be discarded altogether... There must be some other chemicals(i don't know though),which can replace insecticides. Or is the alternate one too expensive for the companies to use (it will definitely prevent them from making those dazzling ads.)??? Thanks,--Pupunwiki 09:00, 12 August 2006 (UTC)

unless you can produce a specific example, i'd say they don't. Xcomradex 09:40, 12 August 2006 (UTC)
This could be about the India cola thing ([1], see google news for more). There are a number of possible explanations: there is a farm within some kilometers of a cola bottling plant, and microscopic amounts of insectiside get carried around by wind. And/or local cola manufacturers have found a neat trick to kick Pepsi and Coke in the groin by spreading rumors. You'll probably eat more pesiticide in your daily bread and milk because they are produced on farms that handle pesticides. Weregerbil 12:44, 12 August 2006 (UTC)

Yes, this is concerning the India-cola thing. It's evident from here. .Looking forward for a better answer... Thanks,--Pupunwiki 13:37, 12 August 2006 (UTC)

an answer to what? he's already explained they do not add pesticides as preservatives. Xcomradex 13:43, 12 August 2006 (UTC)
Weregerbil is correct. Pesticides have been used heavily by indian farmers for a long time. As a result, there are significant levels of pesticides in ground water throughout India. Therefore, when Coca Cola and Pepsi add Indian water to their product, it contains some pesticides. You must have misread whatever you read if you think that they purposefully put pesticides in their products as "preservatives". It's a contamination issue. And by the way, you might be a bit more polite to people who have taken the time to answer your question. --Bmk 14:21, 12 August 2006 (UTC)

Sorry,I didn't mean to hurt anyone.Actually, both the print & electonic media in India have mentioned of pesticides being used as preservatives Like Dr. Ashish Tiwari of Bombay Hospital said, “These pesticides are used by the cola companies to preserve their products for a longer period as compared to other countries. "Some city medical experts believed the pesticides were in the form of preservatives that ensured a longer shelf life for the products, but this too was harmful for health they said".Though,the cola companies diagree to it.Even though, a question arises : Why can't the water used, be filtered properly during processing the products? These apart,I really want to know what are the preservatives used worldwide ? Again,if i have been rude to anyone untentionally, I apologize. Pupunwiki 18:02, 12 August 2006 (UTC)

I doubt if pesticides can be removed from water just by filtering the water. Also note that actions like the one taken by the gov of India are frequently just excuses to protect their own local industry from competition, without running afoul of WTO rules. StuRat 19:28, 12 August 2006 (UTC)
Yeah, sounds to me like it's just an excuse, like 'Yes, the pop contains pesticides, but they were put there on purpose because as a nation we don't drink our pop fast enough.'Anchoress 22:50, 12 August 2006 (UTC)
indeed, especially when one considers the mechanism of action of insecticides (eg. chlorpyrifos) and preservatives (eg. sodium benzoate) are completely different. Xcomradex 12:00, 13 August 2006 (UTC)

[edit] Vicodin HP Tabs vs. Lorcet 10/650

ṬìňàHi, I have a pretty simple question if anyone could be of assistance. I have used search engines but haven't been able to find out anything helpful. I truly appreciate any assistance that someone would offer. My husbands' Doctor has been prescribing Lorcet 10/650 for his spinal problems for quite some time now. He has no problem with this medication as he normally only takes 1/2 tablet when his pain is difficult. He has never been one to take much medication but will;when necessary, take only 1/2 of a pill when needed. He doesn't have a high tolerance for pain meds but has been doing okay with the Lorcet. However; his last Dr. appt., he was written the exact same prescription, but upon having it filled at the pharmacy, we noticed the tablets looked different. We just assumed this was some form of generic. However; my husband was suffering with his pain a little more than usual last night and he took one (1) of the "different" tablets. It wasn't long before he began sweating, feeling nauseated, difficulty breathing, and finally vomiting. Now; I have looked at one of his prior prescription bottles vs.the new one and it does have different name. The new, white tablet has "Vicodin HP" whereas the older ones have Lorcet 10/650. It has now been quite a few hours and he still feels pretty bad. Is there anyone who could tell us what the HP stands for and what is the difference in the two? I know there has to be something different between the two and I sure do appreciate any assistance you could offer. Thanking you in advance, TH

Vicodin HP contains 10 mg of hydrocodone bitartate ("vicodin") and 660 mg of acetaminophen ("tylenol"). Judging by the numbers, Lorcet 10/650 contains the same amount of hydrocodone, but 10 mg less acetaminophen (a negligible difference if you're just taking 1 or .5 pills). So the pills are effectively the same, by my reckoning. The sweating, breathing difficulties, and vomiting are concerning and you should speak with your doctor rather soon about those. digfarenough (talk) 18:12, 12 August 2006 (UTC)
The most obvious problem is that he took double his usual dosage. I would avoid doing that again. However, even if the active ingredients are the same, there could be other diffs, like the rate at which the active ingredients are dispersed, or the inactive ingredients (which may be causing an allergic reaction). I recommend you try to get the old meds, unless they are no longer available. Your doctor or pharmacy should never change your medication without your permission, even when they claim "it's exactly the same". StuRat 19:18, 12 August 2006 (UTC)


[edit] Saving Private Ryan - white powder stuff stops bleeding

In the movie Saving Private Ryan, the squad attacks a machine gun nest. During this attack, Wade, the medic gets shot in the stomach. While the rest of the squad is trying to help him, I noticed they were ripping open packets of white powder and sprinkling it over the wound. What was that stuff? Where can I get it? I bet it would come in handy in a first aid kit. I assume it had something to do with stopping the bleeding.

I searched coagulant but didn't find anything, then looked in first aid kit, fustrated. I figured maybe someone just knows what it is.

Thanks. --69.138.61.168 21:14, 12 August 2006 (UTC)

Take a look at Sulfanilimide#History. --JWSchmidt 21:19, 12 August 2006 (UTC)
Also see styptic, if you are looking for something for your first aid kit.Tuckerekcut 22:03, 12 August 2006 (UTC)
Sodium hydroxide. — [Mac Davis] (talk)
I doubt that. --82.207.254.93 02:18, 13 August 2006 (UTC)
In the movie: sulfa antibiotic to prevent infection. To stop bleeding, a surgeon would now use something like microcrystaline collagen, but that was not available in WWII, and really is more for directed application than "sprinkling". - Nunh-huh 02:22, 13 August 2006 (UTC)
Sulfa for infection; pressure for the bleeding. B00P 21:31, 17 August 2006 (UTC)