Tag: history of science

Natural Selection by Alfred Russel Wallace

Everyone knows about Charles Darwin, but hardly anyone remembers Alfred Russel Wallace, who came up with the idea of natural selection at the same time as Darwin. Darwin’s publication of the On the Origin of Species was spurred on by Wallace. Flora Lichtman and Sharon Shattuck shed a little light on Wallace with this video:

Indeed, from the introduction of On the Origin of Species:

I have more especially been induced to [publish], as Mr. Wallace, who is now studying the natural history of the Malay archipelago, has arrived at almost exactly the same general conclusions that I have on the origin of species. Last year he sent to me a memoir on this subject, with a request that I would forward it to Sir Charles Lyell, who sent it to the Linnean Society, and it is published in the third volume of the Journal of that Society. Sir C. Lyell and Dr. Hooker, who both knew of my work—the latter having read my sketch of 1844—honoured me by thinking it advisable to publish, with Mr. Wallace’s excellent memoir, some brief extracts from my manuscripts.

— Darwin, 1859. On the Origin of Species.

↬ The Dish

The History of Pharmaceutical Penicillin

For ten years after discovering penicillin, Fleming and his contemporaries could not get the penicillium mold to grow fast enough for mass production. Finally, in 1942, scientists isolated a strain of the mold from a piece of moldy cantaloupe in a garbage can.

Penicillium mold on mandarin oranges. Image by Wikimedia User:Bios.

Networks versus Trees: Ways of Analyzing the World

Manuel Lima contrasts the traditional, hierarchical, view of the world (evolution’s tree of life for example) to a more network oriented perspective.

One interesting part is the interpretation of the history of science as having three phases, dealing with Problems of:

  • Simplicity: Early scientific efforts (17th-19th centuries) was focused on “simple” models of cause and effect — embodied perhaps in Newton’s Laws, where every force has an equal and opposite force.
  • Disorganized Complexity: Think early 20th century nuclear physics — Heisenberg’s uncertainty principle for example — where the connections between events are complicated and sort of random/probabilistic.
  • Organized Complexity: Systems science sees the interrelatedness of everything: ecologic food webs; the Internet; horizontal gene transfer across the limbs of the tree of life.

ᔥ RSA Animate ↬ The Dish

Pictures from the Royal Society

Knap-weed or matfelon and cornflower or bluebottle, by Richard Waller (1689) from The Royal Society's Picture Library.

The Royal Society’s Picture Library is now available online. It contains images from some of the seminal scientific works of the last four centuries. It’s an excellent resource for teachers and students, who, with registration, can get free high-resolution images for presentations and unpublished theses.

I’m particularly attracted to the biological drawings at the moment because I’m trying to get students to practice their scientific drawing and diagramming.

The History of the Periodic Table

Fitted to a cylinder, the elements on this periodic table would form a spiral. Image via Wikipedia.

Spurred by Philip Stewart‘s comment that, “The first ever image of the periodic system was a helix, wound round a cylinder by a Frenchman, Chancourtois, in 1862,” I was looking up de Chancourtois and came across David Black’s Periodic Table Videos. They put things into a useful historical context as they explore how the patterns of periodicity were discovered, in fits and starts, until Mendeleev came up with his version, which is pretty much the basis of the one we know today.

The cylindrical version is pretty neat. I think I’ll suggest it as a possible small project if any of my students is looking for one. You can, however, find another interesting 3d periodic table (the Alexander Arrangement) online.