Repeating Crumley: Tobacco Seed Growth in D2O

<p>In 1950 Crumley et al did a series of experiments where they tested the growth rate of several plants in differing amounts of D2O (heavy water or deuterium oxide). They used H2O, 33% D2O, 63% D2O, and 99% D2O (mixtures with H2O) and discovered that growth rates were drastically slower in increasing amounts of D2O. I was asked to repeat their experiment with just tobacco seeds and for the most part I validated their claims with one crucial exception: tobacco seeds in 99% D2O don't grow at all! Their original data is enclosed here (figure3-crumley.png).</p> <p>All experimental information is kept in an open notebook online where the experiments are organized (see link 2). The first link below takes you to the original Crumley et al paper (starting on page 7). Link 3 takes you to the introduction of the experiment. Link 4 refers to a conversation on Google+ between Steve Koch and myself.</p> <p>From link 2, you will find links to each experimental trial, the results of each trial (hosted on Google Docs), and time-lapse slideshows of seed growth.</p> <p>Note: Trial 2 is omitted from this data set because the experimental conditions caused the trial to fail. Explanation can be found in link 2 as well. Growth images for this trial are hosted in my notebook and here on FigShare.</p>