Friday, December 21, 2012

Royal Institution Christmas Lectures

With Christmas approaching, my attention naturally turns to the Royal Institution Christmas Lectures. The Royal Institution (Ri) website states:
“The Ri is an independent charity dedicated to connecting people with the world of science. We're about discovery, innovation, inspiration and imagination. You can explore over 200 years of history making science in our Faraday Museum as well as engage with the latest research, ideas and debates in our public science events.

We run science programmes for young people at our Young Scientist Centre, present exciting, demonstration-packed events for schools and run mathematics masterclasses across the UK.

We are most famous for our Christmas Lectures which were started by Michael Faraday in 1825. Check out the 2011 Lectures here and don't miss them this Christmas on BBC Four.

Anyone can join the Ri. If you're interested in how the world works, or how to make it work better through science, the Ri is the place for you.”
The 2012 Christmas Lectures, 'The Modern Alchemist' will be broadcast on BBC Four on December 26, 27, and 28 at 8pm. Don’t get BBC Four? Neither do I. But that is OK, because you can watch the Christmas Lectures at the Ri website. In fact, you can watch the Christmas Lectures from past years too. You will have to open an account, which means you will need to give them your email address and other information, but you don’t need to pay anything; it’s free. Kind of like a Christmas present.

My favorite lecture is from 2010. Mark Miodownik stars in “Why Elephants Can’t Dance but Hamsters Can Skydive”. He talks about an issue discussed in Homework Problem 28 in Chapter 2 of the Fourth edition of Intermediate Physics for Medicine and Biology. Russ Hobbie and I ask the reader to analyze how fast animals of different sizes fall. In Why Elephants Can’t Dance, Miodownik performs a brilliant demonstration using two spherical animals--one about the size of a hamster, and the other about the size of a dog-- made of some sort of jello-like gel. Suffice to say, the hamster-sized blob of gel does just fine when it hits the ground after a fall, but the dog-sized blob has some problems. The audience for the lecture is mostly children, but as Dickens wrote “it is good to be children sometimes, and never better than at Christmas”. The entire lecture is about why size matters in the animal kingdom.

Miodownik then talks about another topic in animal scaling that Russ and I don’t mention in our book, although I often bring it up when I teach Biological Physics at Oakland University. In two animals with the same shape but different sizes, the weight increases as the cube of the linear size, but the cross-sectional area of its legs increases as the square of the size. Therefore, a large animal has a harder time supporting its weight than a small animal does. Miodownik demonstrates this with two rubber pig-like spheres with rubber legs attached. The small sphere easily stands on its legs, while the large sphere just collapses. As the video says, size really does matter. Of course, elephants solve this problem by making their legs thick, which is why they can’t dance.

I recommend watching Why Elephants Can’t Dance while reading Chapter 2 of Intermediate Physics for Medicine and Biology. It will help you understand animal scaling.

Enjoy the Royal Institution Christmas Lectures, and have a Merry Christmas.

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