Archive for the ‘Science’ Category


Monday, April 7th, 2008

Some of the things that bacteria eat are … odd. There are bacteria that eat oil, for instance. But we might be more worried about some other bacteria – bacteria that actually eat antibiotics.

The researchers, led by George M. Church, a geneticist at Harvard Medical School, found hundreds of bacteria that can subsist on antibiotics as their sole source of carbon.

Fortunately, none of these antibiotic-eating bacteria cause disease in humans.


It all depends on your point of view

Tuesday, March 18th, 2008

Recently, the EPA announced some new ozone standards, lowering the allowable amount of ozone pollution from 80 parts per billion to 75 parts per billion. That doesn’t sound like a lot, and indeed the EPA’s scientists recommended a much tougher ozone standard – from 60 to 70 parts per billion:

Nearly a year ago, EPA’s Clean Air Scientific Advisory Committee reiterated in writing that its members were “unanimous in recommending” that the agency set the standard no higher than 70 parts per billion (ppb) and to consider a limit as low as 60 ppb. EPA’s Children’s Health Protection Advisory Committee and public health advocates lobbied for the 60-ppb limit because children are more vulnerable to air pollution.

EPA and other scientists have shown that ozone has a direct impact on rates of heart and respiratory disease and resulting premature deaths. The agency calculates that the new standard of 75 ppb would prevent 1,300 to 3,500 premature deaths a year, whereas 65 ppb would avoid 3,000 to 9,200 deaths annually.

There’s a bit of a scandal here, since the Bush administration forced the EPA to go against its own science and issue less strict ozone standards.

So the new standard is too lax and fails to adequately protect public health. But it’s better than nothing, right? Maybe. If you’re a lobbyist for the chemical manufacturing industry, you might think that even the old 80 parts per billion standard was too restrictive.

“The available science is largely unchanged since the 1997 standard was issued and demonstrates that there is no clear and substantial basis for making the standard stricter at this time,” [the American Chemistry Council] said in a statement. Lowering the ozone standard “unnecessarily will impose significant new burdens on states and others even as they continue to try and comply with the 1997 standard.”

It all depends on your point of view.

Studying the obvious

Thursday, January 3rd, 2008

Kellie sent me a link to a study recently conducted at Clemson. It’s more likely that you’ll swerve out of your lane if you’re text messaging or messing with your iPod while you’re driving:

Text messaging and using iPods caused drivers to leave their lanes 10 percent more often in a simulated driving study conducted by researchers in the Clemson University psychology department.


Drivers who simply talked on cell phones were distracted and had slower reaction times but tended to stay in their own lane, however drivers who looked away from the road to use electronics were significantly more likely to leave their lane, said Johnell Brooks, assistant professor of psychology.

It’s not the results of the study that I want to hilight. The study, after all, tells us exactly what we expect: it’s not smart to text while driving. If you click the link above, you’ll see that the site describing the study allows comments. As I’m writing this post, the comments all say about the same thing. Here’s a sample:

And this is the college everyone raves about? Sounds like the only thing this place can do right is get drunk. What a waste of money. Ho[ne]stly I don’t think they should have even admitted they were doing this study because common sense would have given them the answer.

Commenters complained that the study was a waste of money and effort because the results confirm “common sense”. The problem with that argument is simply this: Common sense is commonly wrong. Because of this, it’s a good idea to actually test out things we think are “obvious”. You don’t have to dig very deeply in science to find a good example of common sense failing. Just consider fire.

[Burning log cartoon]

When you burn a piece of wood, you get ash. The ash is lighter than the original wood. Common sense dictates that burning must be the loss of something within the wood.

During much of the eighteenth century, that something was called “phlogiston”, and the loss of phlogiston was obviously responsible for the difference in mass between wood and ash. Anything that burns must contain phlogiston, and that’s why ash is always lighter that the substance being burned.

We now know, however, that the sentence above is false. Burning doesn’t require the loss of anything. Instead, the burning process is the combination of a substance with oxygen from the air. How did we find that out? By actually testing the “common sense” idea!

More careful analysis of burning wood revealed that if you account for all of the gases given off, the gases and the ash together weigh more than the original wood.

It’s even more convincing to look at the burning of metals. No gases are released by the burning of metals like magnesium, so all you have to do to collect everything given off is to burn the magnesium in a container with a loose-fitting lid. It’s easy to show that the ash left behind weighs more than the original metal, and my intro chemistry students do this in lab.

The weight gain was eventually discovered by Lavosier to be due to oxygen.

So, don’t laugh too hard when some scientist seems to be testing something that’s “common sense”. It’s true that common sense isn’t very common, but it’s also true that common sense isn’t always … sense!

New Year’s Recycling: The many phases of iodine

Wednesday, January 2nd, 2008

For my first post of the new year, here’s an improved version of an old post. I’m using the images from the post in one of my chemistry classes this spring, and I thought I’d share the improved pictures.

Iodine is one of the more unusual things you can find at your family drug store. In pure form, it’s a somewhat shiny solid. From appearance alone, you might mistake solid iodine for some of the things you’d find in the rock bins at Black Market Minerals in Myrtle Beach.

[Solid iodine]
Solid iodine

What makes iodine unusual? Iodine’s a solid that goes easily from the solid to the gas phase. Also, once iodine gets into the gas phase, it is not colorless and invisible. Iodine vapor is bright purple in color. Solid iodine slowly sublimes (goes from the solid state to the vapor) at room temperature, but you can speed up the process quite a bit by supplying a little heat.If iodine vapor comes into contact with a cold surface, it will deposit (resolidify) on the surface, forming pretty crystals. The same thing happens when water vapor in the atmosphere comes into contact with an extremely cold car windshield – making frost.

To show the phase changes of iodine, I set up an experiment similar to a demonstration from one of my old chemistry books. I took some solid iodine and put it into a beaker, then set the beaker on a hotplate. On top of the beaker, I put a watch glass: a curved piece of glass shaped a little like a shallow bowl. On top of the watch glass, I put some ice. The ice cools the watch glass.

[Iodine experimental setup]

To speed up the production of iodine vapor, I turned the hotplate on “low”. After a few minutes, I could just see the color of iodine vapor in the beaker.

[Small amount of iodine vapor]
A little vapor is visible

Once the hotplate’s temperature gets to about 114 oC (237 oF), the iodine begins to melt, forming a dark purple liquid. The amount of iodine in the vapor state increases.

[More iodine vapor]
More vapor is visible. If you value your nose, keep it away from the vapor.

After more heating, you can see all three phases of iodine inside the beaker.
[Iodine: Solid, liquid, and gas]
Pick a phase, any phase!

There is a mixture of solid and liquid iodine at the bottom of the beaker. Since the hotplate is providing heat energy, some of the solid iodine melts, forming liquid. Some solid iodine also sublimes, forming vapor. The liquid iodine evaporates, forming more vapor.

Near the top of the beaker and on the cooler upper sides of the beaker, iodine vapor deposits, forming solid iodine crystals. Some iodine vapor condenses to liquid on the warmer lower walls of the beaker, and that liquid then freezes to solid iodine. That’s a total of six different phase changes going on all at once; and we haven’t even discussed the ice on top of the beaker.

The ice? The ice at the top of the beaker melts, removing energy from the iodine vapor and helping it deposit on the bottom of the cold watch glass.

[Deposited iodine crystals]
Deposited iodine crystals, forming from purple iodine vapor

The iodine crystals on the watch glass are flat and shiny – almost metallic in appearance. They look a bit like stalactites.

[Deposited iodine crystals, closer view]
Deposited iodine crystals, closer view

I advise against attempting this experiment yourself, since iodine looks more harmless than it is. Iodine won’t blow up on you – provided you keep it away from combustibles, but iodine can cause chemical burns on contact. Iodine vapors are harmful to the lungs. This sort of experiment needs a fume hood, and solid iodine shouldn’t be handled directly. Plus, buying lots of iodine might make some folks think you’re going to start a meth lab.

Target: Homeopathy

Wednesday, April 25th, 2007

Long-time readers of this blog – all three of you – know that I am no fan of homeopathy. I am, though, something of a fan of Target . This is largely due to the fact that Target’s only local competition is Wal-Mart. The shopping experience at Wal-Mart is only slightly less pleasant that being repeatedly hit on the head with a baseball bat. But I digress…

We were making our usual Target run the other day. This time, though, Patty was suffering from an earache. So, while I sifted through the clearance merchandise, Patty asked the pharmacist to suggest something to ease the earache pain.

The pharmacist recommended the Target-brand generic version of this Similisan product. So, Patty put it in the cart, we bought it, and we took it home. Here’s the front of the package:

Target’s homeopathic ear drops (front of package)

Looks like normal medicine, right? A little later into the evening, Patty told me that the ear drops from Target didn’t work very well – not nearly as well as the drops she had gotten from the doctor the last time she had an earache. So, we looked at the label again to see what sort of things were in the drops. Here’s what the back of the label looked like.

Target’s homeopathic ear drops (back of package)

The first thing that caught my eye was the list of ingredients.

  • Chamomilla HPUS 10X (calmative, pain reliever).
  • Mercurius sol. HPUS 15X (anti-inflammatory).
  • Sulphur HPUS 12X (pain reliever, anti-itch)

That’s an odd list of ingredients, isn’t it? it soon hit me that the Target pharmacist had just sold us an expensive bottle of quackery: homeopathic ear drops. Here’s the list of ingredients in plain English.

“10X”, “15X”, and “12X” are homeopathic dilutions. Suffice it to say that there’s very little of these ingredients in the drops. Considering the toxicity of mercury, that’s a very good thing.

I admit that I don’t make a habit of scouring the over-the-counter drug aisles looking for quackery, but I was surprised that this normal looking bottle of “medicine” was being sold at Target. I’m highly disappointed in Target and its pharmacist for ripping us off, and I was tempted to take my business elsewhere. However, I checked several other stores and pharmacies and they all carry either the Similisan product or their own generic version. Unfortunately, I can’t single out Target for pushing nonsense. Everyone’s doing it.

Let me add a few things here about homeopathic drugs. As I pointed out in my earlier post, there’s practically no theoretical (or experimental) support for homeopathy. In addition, homeopathic drugs don’t undergo the efficacy testing or several parts of the safety testing that conventional drugs do. Manufacturers of homeopathic drugs don’t have to prove their drug works, nor do they have to “release test” the final product (test it to make sure it is what the label says it is) before distribution.

What a racket!

Rock your desktop!

Friday, March 9th, 2007

A while back, I posted about amethyst. That post included some images, but none really large enough for use as desktop wallpaper. I’ve been testing out with the new family camera, and I’ve taken a few more pictures of my amethyst samples. These new pictures are a little more suitable for wallpaper. Here they are:

Amethyst image #1 (1024×768 JPG)
Amethyst image #2 (1024×768 JPG)
Amethyst image #3 (1024×768 JPG)

Each image is approximately 150K in size. #1 and #2 are the same stone from different angles, and #3 is a different (darker) stone. Enjoy!

The beauty of imperfection

Friday, January 12th, 2007

Take a look at the ground around you. Chances are you’ll find some sand. Sand, quite frankly, is boring stuff. It’s rather dull looking, and it’s … pardon the pun … common as dirt.

One of the major components of sand is silica or quartz – known chemically as silicon dioxide, SiO2. Regular quartz can form pretty crystals, but these crystals are still rather dull in terms of color.

When quartz crystals form, they generally don’t do so in a chemically clean environment. In other words, there’s an awful lot of other stuff around. That other stuff can get trapped inside the quartz crystals, leading to imperfections in the quartz structure.

When these impurities are large enough to be seen with the naked eye, they’re called inclusions. Often, inclusions make crystalsl less valuable.

Sometimes impurities get into a crystal at the atomic level. These impurities (called interstitial impurities or substitutional impurities depending on where in the crystal structure they are) can’t be seen with the naked eye. But … if there are enough of them, these impurities affect the crystals properties in a way that can be easily detected.

Take that silicon dioxide – boring ol’ sand – we mentioned earlier. If silicon dioxide crystals form in such a way that the crystal contains trapped iron or manganese ions**, the crystals will look like this:

[A sample of amethyst]
A sample of amethyst

Quite a difference! This is amethyst, an impure (but much prettier) form of quartz.

[Amethyst close-up!]
A different sample of amethyst, up close. Click to see a high resolution image of the whole stone (378K).

Just keep in mind that the impurities in the silicon dioxide crystal that transform it from boring quartz to beautiful amethyst!

**I’ve seen the purple color of amethyst described as being caused by both iron and manganese impurities

Maybe if we turned it to gold first …

Thursday, December 7th, 2006

Scientific American has a brief article about industry’s request to have lead removed from the EPA’s list of regulated pollutants.

The EPA said that from 1980 to 2005 the national annual lead concentrations have dropped more than 90 percent. Lead levels in air have mostly fallen because it was banned as a gasoline additive starting in the 1970s.

This is good news, since exposure to lots of lead is no good thing.

But I am puzzled. How will removing lead from the list of regulated pollutants lead to less lead in the environment? (Sorry, couldn’t resist the pun!)

Who wants lead off the list?

In a letter last July to the EPA, industry group the Battery Council International urged the agency to “delete lead from the criteria pollutants.”

Who’s this “Battery Council International”?

Battery Council International is a not for profit organization with the mission to promote the interests of the international lead-acid battery industry.

Surely, the lead-acid battery industry will not pollute the environment with lead if we remove the regulations! Right?

They probably just want to turn it to gold. 🙂

Bowling a 118 (with atoms)

Tuesday, October 17th, 2006

Nuclear chemistry really isn’t my specialty, but how can I not be iinterested in the news that scientists have produced a new element? It’s element 118.

Scientists said they smashed together calcium with the manmade element californium to make an atom with 118 protons in its nucleus.

The new element would be one of the noble (inert) gases – so it wouldn’t be all that interesting to play with in our introductory chemistry laboratories.

[Element 118]

You wouldn’t want to play with element 118, anyway. Like most of the heavier elements, element 118 is extremely unstable.

The new element lasted for just one millisecond, […]

… so don’t go looking for it at your local chemical supplier anytime soon!

But wait a second … doesn’t the story of the discovery of element 118 sound just a bit familiar? Sure does!

At a meeting of LBNL employees in June of this year, director Charles Shank announced that the laboratory had recently disciplined one of the members of the team for “scientific misconduct.” A yearlong internal investigation had convinced the laboratory’s directorate that the evidence for the creation of element 118 and its decay sequence through element 116 in the 1999 experiment had, in fact, been surreptitiously fabricated by one of the experimenters.

(emphasis mine)

I can only hope that – this time – someone has very carefully checked over the data. Otherwise, we will have to name this as-yet-unnamed new element “unobtainium”.

On the positive side, the scandal over the original “discovery” of element 118 does illustrate, yet again, the self-correcting nature of science. A reseracher was able to fool people with suspect data for a time, but it was only a short time.

Canadian bakin’

Thursday, September 28th, 2006

Via CHEMED-L (the chemical education list), here’s an article on a recent Canadian drug bust.

Actually it’s only sort-of a big drug bust. The person charged had some marijuana plants, but the big news is that he was accused of:

selling and possessing “precursor chemicals” for meth

These “precursor chemicals” were the makings of, according to the article, nine million Canadian dollars of meth.

She said the seizure, the result of months of investigation, is the RCMP’s biggest ever in the national capital region.

“It is huge,” Beauchamp [of the Canadian police] said

The chemicals? Red phosphorus and iodine. (Stop laughing.)

Red phosphorus is one of the forms of the element phosphorus. White phosphorus is the other form. It’s nasty stuff, and you’d be well-advised to avoid it.

Red phosphorus, on the other hand, is usually considered non-toxic. Extremely flammable, but non-toxic. Got a match? Well, you’ve quite likely got red phosphorus.

Then there’s iodine. Well, iodine’s just neat stuff. However, it’s actually a lot more toxic than red phosphorus is, in pure solid form. Solutions of iodine, on the other hand, are commonly used as disinfectants – check your local drugstore or your medicine cabinet.

Without making any additional commentary on the various “wars on drugs” and their usefulness, I’ll just say this: If you want to bust someone for meth, bust them for actually having or distributing meth. Busting someone for “precursors”, many of which are extremely common substances, will not lead us anywhere we as a technological society want to go. (See here for what sort of things you could be considered a criminal for having in a certain large US state. Scroll down to see the silliest of the stuff.)

(Edited to add: Or bust the guy for having a ton of highly flammable material in a residential neighborhood, perhaps. But not because it’s a “precursor”.)