Editor’s note: As we continue to invite bloggers out there in the wild to compose our monthly Blogroll column, Joshua Howgego penned the January 2014 column.
Mulling over the Mpemba effect, and a call to read more widely.
A recent post at The Physics arXiv Blog tells of a possible explanation for the ‘Mpemba paradox’: the observation, named after a Tanzanian student, that a hot glass of water will freeze more quickly than a cold one. This puzzling and counterintuitive phenomenon seems to fascinate scientists the world over, and was the subject of a 2012 competition run by the Royal Society of Chemistry that garnered more than 20,000 entries.
We learn that, according to a new theory, in warmer water hydrogen bonds expand further and — because of electron-pair repulsions — this compresses the molecules’ covalent bonds, leading to a net cooling effect. The calculated energy changes arising from hydrogen-bond stretching accurately predicts the observed differences in freezing speed for water at different temperatures. Yet the post notes that because the paper makes no new predictions, the researchers will still “probably need to work a little harder to convince everyone”. An interesting — if unproven — idea, nevertheless.
Elsewhere in the blogosphere there’s encouragement to keep reading in unfamiliar places, such as the arXiv blog. A guest post by Nilam Ashra-McGrath at The Thesis Whisperer (a blog encouraging PhD students through their endless toil) has exactly this advice for PhD students: read extensively. Ashra-McGrath says her PhD’s most frequent highs came when she was “devouring books and taking in ideas quickly […] making connections between my emerging data and the theories I was reading”. As one commenter put it “how do we expect ourselves to make new conceptual connections if we follow the same path as everyone else?”.