Todd Helmenstine


About Todd Helmenstine

Todd Helmenstine is the physicist/mathematician who creates most of the images and PDF files found on sciencenotes.org. Nearly all of the graphics are created in Adobe Illustrator, Fireworks and Photoshop. Todd also writes many of the example problems and general news articles found on the site.


Today in Science History – February 25 – Theodor Svedberg

February 25 marks the passing of Theodore H. E. Svedberg. Svedberg was a Swedish chemist best known for the invention of the ultracentrifuge. Svedberg was a colloid chemist studying the various physical properties of particles suspended in solution such as diffusion, light absorption, and sedimentation. His work helped prove Einstein’s […]

Theodor Svedberg (1884 - 1971)

Friedrich Sertürner

Today in Science History – February 20 – Sertürner and Morphine

February 20 marks the passing of Friedrich Sertürner. Sertürner was a German pharmacist who was the first to isolate the active ingredient from opium poppies. The small crystals he extracted would be later called morphine after Morpheus, the Greek god of sleep because of the way it caused drowsiness. Sertürner […]