29 November, 2013

Chemophobia II

Chemical weapons are scary. I'm afraid of chemical weapons. But are chemical weapons more scary than other weapons?

The question, "Why are chemical weapons more scary than other weapons?" was posed by Mark Loach in his radio programme, "Chemophobia" (see yesterday's post), but he didn't seem to answer it fully. He gave the example of the horrific deaths in Syria from chemical warfare, and asked why this was worse than the greater number of deaths from conventional weapons. Of course, the terms "biological weapons" or "physical weapons" (or even just "weapons") are frightening too. Mark seems to suggest that "chemical weapons" is a worse prospect in the eyes of the general public.

Chemical weapons are devices that contain chemicals specially formulated to cause death or injury to humans. The properties of the chemical in the devices are the "weapon" rather than any physically destructive force of the device. The Organisation for the Prohibition of Chemical Weapons (OPCW, Nobel Peace Prize winners 2013 "for its extensive efforts to eliminate chemical weapons") administers the Chemical Warfare Control treaty, "an arms control treaty which outlaws the production, stockpiling, and use of chemical weapons and their precursors." (Wikipedia)

 Chemical weapons maybe are viewed as agents that cause irreversible damage, injuries that cannot be fixed and horrific deaths. It's clearly right for their use and manufacture to be banned. How should we reconcile banning these agents and not all weapons of all kinds? Biological weapons and "conventional" weapons perhaps can cause death and injury, of course, but maybe their effects are not seen as quite as bad, because there is an "antidote" or broken bones can be fixed, physical injuries can be healed, or chemicals (or drugs) can be used to cure a person. Chemical weapons can be non-lethal, but can leave someone "contaminated" or incurable.

Anyway, I feel like I'm getting out of my depth pretty quickly here. So I'll leave it there for now. If anybody would like to add anything or question me, leave me a message or a tweet.


*Edit 22/12/2013* Periodic videos (Brady Haran) posted a...video on 2nd Sept 2013 on the topic of chemical weapons. Link. "Discussing chemical weapons, including Sarin and Mustard Gas.
Featuring professors Rob Stockman and Martyn Poliakoff from the University of Nottingham.
" As usual the video is entertaining and informative, more than I could explain here!

*Edit 2 22/12/2013* Further footage on the chemical weapons video linked above. link. Fritz Haber, binary weapons, "...it's a little unfair to attack chemistry for chemical weapons...", "In the end, the use of military force to solve political problems is something which I hope is becoming more and more unacceptable across the world"

28 November, 2013

Chemophobia I

The topic of chemophobia (the fear of chemicals) has come up in the chemistry blogosphere quite often in recent times. Here, for example, is Janet D. Stemwedel at Scientific American, asking what's the problem with chemophobia and why should chemists care and what response we should have.

ChemBark has written on the topic several times and has also addressed the question "…is it[chemophobia] really a problem? Who cares if the public dislikes chemicals? So long as chemists know better, we will continue doing good science. Why should we be distracted by general ignorance?".
Answer. Quote: "For a democracy...to function efficiently, the electorate must be educated and informed. The steady decline of chemistry’s public image is a massive problem, because it erodes support for our field."

Plenty of other blogs touching on chemophobia here, here and here, and here.

The most high profile discussion of chemophobia is now up on the BBC website. Mark Loach has a 15minute radio programme (Hmmm not sure if readers outside the UK will be able to listen to that. Just read the article if you can't - it's pretty much word for word) and an article which go into areas such as the definition of chemophobia, the usefulness of "bang, crack, fizzzz" chemistry demonstrations in sparking an interest in chemistry amongst young people (see my previous post on crack bang wallop demonstration I attended in Cambridge), and why physics or biology, for example, do not elicit similar fears in the general public. One of his most interesting metaphors was that a "sodium + water = bang!" demonstration he saw carried out by his grandad, was only "fuel" for his interest in chemistry. It was not the "spark", which for him came later in life. This fuel alone is not sufficient to ignite an interest in chemistry, he argues. We should concentrate more on the "little girl at the back of the room with her hands over her ears" and not just on the "boys at the front cheering and applauding" (paraphrased).

17 November, 2013


Was competing in a challenge walk this weekend, and a set of general knowledge questions included naming the main ore of tin (I had no idea!). A quick Google (shhh! Anyway, we didn't win) revealed the answer as cassiterite. In various table quizzes I seem to remember these "what's the main ore of X" as common enough, but I still never have the correct answer. My question is, does anybody? Who is expert in metal ores? Are they social enough to communicate with others in a table quiz or online? Who makes this interesting?

Acanthite - Silver
Chromite - Chromium
Hematite - Iron (obvs!)
Ilmenite - Titanium
Magnetite - Iron
Cinnabar - Mercury (HgS)
Pentlandite - Nickel
Sphalerite - Zinc

12 November, 2013

"We'll start by making some gunpowder"

A quote from the lecture on Thursday evening, entitled "The Science of Fireworks and Explosives", which I attended with a few people from work. Prof. Chris Bishop was the master of ceremonies, and he did indeed make some gunpowder, firing a Brown Bess gun at the end of the lecture (loaded only with wadding)!

The lecture was advertised as a "family lecture", with "loud bangs, bright flashes, and some smoke". The fumehood used during the lecture just about dealt with the smoke, but did start giving out (beeping) towards the end of the lecture, when the accumulated smoke from the displays started to get too much. Even though it was aimed mostly at young people, I was engrossed by the displays, explanations and Bishop's red lab coat! The chemistry was explained in broad terms (sulphur=fuel, charcoal=fuel, saltpetre=oxygen), but there was interesting tidbits of information for those with a more in depth chemistry knowledge : Did you know a good ratio for gunpowder is 75:15:10 Saltpetre:Charcoal:Sulphur? It was explained that gunpowder produces quite a "soft" explosion (more of a "push", hence its use in fireworks, for example). But what if you want a proper bang/crack? The talk then moved on to metals, both in flash powder (metal fuel) and fireworks (colours). The predictable metal-salts-in-a-Bunsen-burner section was spiced up a bit by the use of methanol solutions of salts like SrCl (red), NaCl (orange), CaCl (orange) and CuCl (aquamarine). The MeOH spilled on to the floor at one stage, starting a small fire! Some of the parents looked a bit worried, but Chris's able assistant walked to the side of the stage to receive a fire blanket. (Waving it over the fire, rather than placing it carefully!)
Another picture from the lecture. This is of lycopodium powder being blown through a Bunsen flame.
 Then the main topic : fireworks. Types (four classes : 1. Indoor 2. Garden 3. Display 4. Professional), effects (white glitter, strobes, orange popping, screechers)

Finally nitrocellulose, dynamite, HMX tubing, nitrogen triiodide (very loud!)

This child exploded into just CO2 and water shortly after this photo