Chemistry Blog

Apr 14

A letter from a chemist to homeopaths

Dear Homeopaths,

Homeopathy awareness week is here again. And I’ve got some questions about this most popular of alternative therapies. The answers to which I’d very much like to be aware of.

Homeopathy, as I understand it (please correct me if I’m wrong), is based on a idea that ‘like cures like’. So if your hayfever causes runny eyes then onions may be be able to help (because onions cause similar symptoms). Or maybe you suffer from insomnia, in which case caffeine may be the solution. However a cup of strong coffee is likely to keep you wide awake. So you get around this through massive dilutions. This way, you claim, the beneficial effects are retained whilst the unpleasant side-effects are removed. 

Now before we go any further let’s make sure I understand the dilution process, again using the caffeine example. You might start with a solution of caffeine that’s about the same concentration as coffee. Then you perform a 1 in 100 dilution. The solution is shaken, often by hitting it against a leather bound surface (a process known as succussion). The result is known as a 1C solution. You perform another dilution, shake etc. resulting in a 2C solution. The process continues often 30 or more times. The net result is a solution that will not contain a single molecule of the original. In fact it might be the equivalent of diluting the cup of coffee in sphere of water the size of the solar system.

So far I hope we can agree. But it seems rather unlikely, to me, that this process might result in an effective remedy. Although you have explanations e.g. ‘water is capable of storing information relating to substances with which it has previously been in contact’. Or to put it another way the water can remember what was diluted in it.

There is no sound scientific evidence that water has any such memory storage capacity. However, homeopaths often tell scientist that we should be more open minded and not to be so wedded to the dogma that we have been taught. So here I am, putting my education and experience in chemistry to one side for a moment.

Nevertheless, even without everything that chemistry might tell me, I’m still left with what seems to be some logical holes in your therapy.  Hence my questions for you, and I really am interested in the answers.

How come the water remembers the starting substance (e.g. the caffeine) but not impurities?

The gold standard for water purity (used by analytical chemists, but not homeopaths) is just 10 parts impurity to 1 billion parts water. The concentration of these impurities is equivalent to a 4C solution. So in dilutions made beyond this point the impurities will outnumber the original substance. How then can the homeopathic solution know which molecules it is supposed to store information about?

How do you make an oxygen based homeopathic remedy?

There appear to be quite a few remedies based on oxygen. But oxygen from the air will continually dissolve in the water you use to dilute your solutions. So how do you actually manage to make a 30C dilution of oxygen, when at every step along the way you are just adding more of it to your remedy?  

How is the power of a remedy transferred from water to a dry pill?

You make pills by dropping a water remedy onto a sugar tablet and then drying it. How is the stored information (supposedly in the water) retained in the pill after the water has evaporated?

Why can’t I find a homeopathic contraceptive?

I looked and you don’t seem to make or sell any.

If the potency of a remedy increases the more it gets diluted why can this never be perceived as a strong taste?

If a remedy is to work then it must interact with our biology. Why does this never manifest to our sense of taste?

Why was homeopathy so ineffectual at combating infectious diseases before the advent of vaccines?

Your theme for this years homeopathy awareness week is infectious disease. Vaccinations have reduced the spread of infectious diseases to a tiny fraction of what they once were. Homeopathy was around long before most vaccinations were commonplace, so why did it fail to reduce the incidents of infectious diseases?

I hope by answering these you might be able to give me a greater awareness of how you believe your therapies work.

Yours sincerely,

Dr Mark Lorch

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Feel free to republish this letter. This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.

Mar 27

The Disney Periodic Table: Clever Hook or Abomination?

We’ve all seen the plethora of faux periodic tables. I’ve ranted written about them before.

And now Disney (not content with trying to taking ownership of every  story ever) has chipped in with its own version of the periodic table.

At least it resembles the original, all the symbols are their, numbered correctly and laid out in the familiar way. But no longer do the symbols represent elements. Instead manganese has become Mulan, neon has transmutated into Nemo, and lead has been replaced by Pooh Bear (at least they are both rather dense). The only element that survives intact is copper, all be it in dog form and where cobalt should be.

Now I’m in two minds about this one. On the one hand it might serve as a way to get a bit of chemistry onto the walls of Disney fans and maybe they’ll then graduate onto the real version. But on the other hand it just makes me feel a bit sick :-/

So what do you think? Is it a clever way to elicit an interest in chemistry in those that might otherwise be more interested in fairy tale princesses or is it just an abomination?


Mar 12

Sharing Science: Distilling Publications Into 5 Minute Videos

Aiming to make our research more accessible, the Hanson research group will post five minute videos recapping each of our papers after they are published. This probably sounds like a very time consuming undertaking, but our group is very lucky to have access to GEOSET studio, a creation of our local Nobelist Harry Kroto.

Harry, a 2006 Nobel Prize winner for the discovery of the Buckminster Fullerene and current faculty member at Florida State University, has been heavily involved in outreach activities encouraging children and public involvement in science. Global Educational Outreach for Science, Engineering and Technology (GEOSET) is one branch of this effort. GEOSET is a free, online service that allows users to upload and view science-related videos. GEOSET videos mirror what students see in a seminar or classroom. Its dual-window format shows side-by-side views of the presenter and his or her presentation slides (or you can click to expand one or the other).

The process for creating a video is very user-friendly. All I need to bring to the GEOSET studio are myself and my presentation slides (quick aside: I don’t mean to underplay what may be a stressful activity for those who are camera-shy. It takes a lot to be a comfortable presenter. Thankfully, GEOSET makes it as easy as possible). The studio camera has a teleprompter that shows your presentation slides as you present. It’s a wonderful set-up that makes it look like you are presenting off the top of your head. After giving your presentation, just like you would at any group meeting, the in-studio software couples the recording with the presentation file and then the GEOSET staff post the video online.

There are numerous partner institutions around the world that have dedicated studios for creating GEOSET videos. At FSU the GEOSET studio is located on campus in the Dirac Library. Any student/faculty/staff can schedule an appointment, bring their presentation file (Keynote, PowerPoint, etc.) and quickly record a video.

The first GEOSET video from our research group is presented by second year graduate student Jamie Wang. Jamie recently published her paper “Modulating Electron Transfer Dynamics at Dye–Semiconductor Interfaces via Self-Assembled Bilayers”, in the Journal of Physical Chemistry C. Her research is focused on controlling electron transfer events at dye-semiconductor interfaces particularly for application in dye-sensitized solar cells.

I want to send a special thanks to Jamie for being the first group member to pioneer this Hanson Research group practice. She did a wonderful job and will serve as a solid example for future videos – a few of which will be available soon.

Jan 24

23 Million Times Slower than Molasses

I have the pleasure of teaching general chemistry II for the first time ever this semester. It is fun to go back and revisit concepts that I have not spent time with since taking general chemistry ~13 years ago. Our first few classes will focus on intermolecular forces (dipole-dipole, London Dispersion, etc.) and some of their macroscopic manifestations. Some examples covered in the book include surface tension, capillary action and viscosity. Searching these topics online led me to my new favorite experiment: the Pitch Drop Experiment.
Pitch Drop

In 1927, Professor Thomas Parnell started the Pitch Drop experiment in which he sought to measure the viscosity of pitch. Pitch is a general term used to describe a highly viscous solid polymer, but this material is often a complex mixture of phenols, aromatic and long chain hydrocarbons. Unfortunately, I could not find the exact composition of the pitch used in this specific experiment, but needless to say this sample does meet the description of a highly viscous material.

The experiment was initiated when Prof. Parnell heated up a sample of pitch and poured it into a conical piece of glass. The pitch was then left to sit for three years, presumably the length of time it needed to cool and completely settle into the cone shape. Immediately after the bottom of the funnel was cut open the pitch came rushing out. Just kidding. The pitch ever so slowly began dripping out of the funnel. How slowly? At a rate of approximately one drop every 10 years. In fact, the most recent drop—the 9th drop ever– fell on April 17th 2014.

The first report on this experiment was published in the European Journal of Physics in 1984. In that manuscript they calculated the pitch (2.3 x 108 Pa s) to be 230 billion times more viscous than water (1.0 x 10-3 Pa s). That means it’s more than 23 million times slower than molasses (5-10 Pa s). The longevity and creativity of this experiment won Thomas Parnell and John Mainstone (the caretaker of the experiment for more than 50 years) an Ig Nobel Prize in 2005. The experiment has also been officially included in the Guinness World Records as the world’s longest continuously running laboratory experiment.

Despite this experiment’s epicness, or maybe because of it, no one has ever been in the room to watch one of the pitch drops fall. The closest anyone has come is a time-lapse video below.

The video is unfortunately anticlimactic. It shows the 9th drop making contact with the 8th drop in the beaker. It isn’t the spectacle of a full ‘drop’ event, but don’t worry. The next occurrence is right around the corner: about 14 years away. In anticipation of this event the University of Queensland has set up three webcams and a continuously streaming live feed on a website called The Tenth Watch. Regardless of where you find yourself, you can keep a constant eye on the experiment as it progresses. And even if you miss the 10th drop, don’t worry, it’s estimated that there is enough pitch in the funnel to produce several more drops over the next 100 years.

Jan 19

New manufacturer of NMR instruments to enter the market

With the exit of Agilent from the NMR instrument market there’s a gap that is in desperate need of filling. Now it looks like a rather unusual group is considering plugging the hole. The company, usual associated with construction but also happens to be the largest manufacture of tyres in the world, is conducting a poll to see whether NMR is a viable option for them.

If you think the chemistry community needs a new NMR instrument manufacturer then please pop over to their website and let your thoughts be known.





The lego NMR instrument now comes with mini figures!



Nov 10

How LCDs work

A little video I put together to explain how liquid crystal displays work, using pasta, stair gates, wool, a hair dryer and some polarizing filters.

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