- Person
- Arthur Ashkin
- Lived
- 1922–2020
- Field
- Laser physics
- From
- American
The story
Arthur Ashkin was born in Brooklyn in 1922 to Jewish immigrants from the Russian Empire and Eastern Europe; his orphaned father had been smuggled out of Russia on a sealed train. He went to Brooklyn public schools, built radar components at Columbia during the Second World War, earned a PhD at Cornell in 1952 and spent forty years as a researcher at Bell Labs in New Jersey.
As a boy Ashkin had wondered whether light could push objects. When the laser was invented in 1960 he set out to find out. Shining laser light on microscopic transparent beads, he saw that they were pushed along the beam and also pulled toward its brightest part, because light bends as it passes through them. He published the first paper on optical trapping in 1970. With colleagues including Joseph Dziedzic, he then created a trap using a single tightly focused laser beam that holds a particle in place in three dimensions, described in 1986. It became known as optical tweezers, and the same ideas helped other Bell Labs scientists trap and cool atoms.
Ashkin found the biological uses almost by chance. A sample of virus he left open overnight became contaminated with bacteria, and his laser caught them. By switching to infrared light, which does not harm cells, he showed in 1987 that living bacteria and viruses could be trapped and moved without damage, and that the tweezers could even reach inside cells.
Optical tweezers let scientists hold a single molecule or cell and measure forces of a few trillionths of a newton. They were used to map kinesin, a protein motor that carries cargo through the cell one step at a time, and have since been used to stretch DNA, watch proteins fold, study how viruses pack their genes and test the stiffness of blood cells. Laser tweezers are now standard equipment in biophysics laboratories worldwide, and holographic versions with thousands of traps could help separate malaria-infected blood cells from healthy ones. Ashkin received half of the 2018 Nobel Prize in Physics at 96 and died in 2020.
Why it matters
Optical tweezers are used in laboratories around the world to study the molecules and cells behind health and disease, one particle at a time.
About Arthur Ashkin
Brooklyn-born Bell Labs physicist who invented optical tweezers, laser beams that hold living cells, viruses and DNA, now standard tools in biology and medical research. Nobel Prize 2018.
Sources
- The Nobel Prize in Physics 2018, Popular information NobelPrize.org
- Arthur Ashkin, Biographical NobelPrize.org
- Nobel-winning physicist Arthur Ashkin, Ph.D. ’52, dies at 98 Cornell Chronicle
- Arthur Ashkin Wikipedia
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.