Nobel Prize in Chemistry and Physics
The Nobel Prizes were announced last week, and history was made in the Physics and Chemistry categories.
The Nobel Prize in Physics was awarded to three people this year, with half of the award going to Donna Strickland and Gérard Mourou for their method of generating high-intensity ultra-short optical pulses, and the other half of the award going to Arthur Ashkin for his work on optical tweezers and their application to biological systems.
Donna Strickland, an associate professor at the University of Waterloo in Canada is only the third woman to be awarded the Nobel Prize in Physics in the 117-year history of the prize. The last woman to receive a Nobel Prize in Physics was Maria Goeppert-Mayer in 1963 and before that was Marie Curie in 1903.
Donna Strickland and Gérard Mourou invented the technique of creating ultrashort high-intensity laser pulses without destroying the amplifying material, called chirped pulse amplification (CPA). This technique soon became standard for subsequent high-intensity lasers. Its uses include the millions of corrective eye surgeries that are conducted every year using the sharpest of laser beams.
Arthur Ashkin invented optical tweezers that grab particles, atoms, viruses and other living cells with their laser beam fingers. This enabled these molecules and organisms to be studied without touching them, holding them in place with laser light.
The Nobel Prize in Chemistry was also split this year with one half awarded to Frances H. Arnold for her work in the directed evolution of enzymes and the other half awarded jointly to George P. Smith and Sr Gregory P. Winter for their work on the phage display of peptides and antibodies.
Frances H. Arnold, a professor of chemical engineering, bioengineering, and biochemistry at the California Institute of Technology, is only the fifth woman to be awarded the Nobel Prize in Chemistry in the 117-year history of the prize.
In 1993, Frances H. Arnold conducted the first directed evolution of enzymes, which are proteins that catalyse chemical reactions. Since then, she has refined the methods that are now routinely used to develop new catalysts. The uses of these enzymes include more environmentally friendly manufacturing of chemical substances, such as pharmaceuticals, and the production of renewable fuels for a greener transport sector.
George P. Smith developed a method known as phage display, where a virus that infects bacteria can be used to evolve new proteins. Sir Gregory P. Winter used phage display for the directed evolution of antibodies, with the aim of producing new pharmaceuticals.
The First “Exomoon” May Have Been Found
Scientists have published a study in Science Advances providing evidence of what could be the first “exomoon”, orbiting the exoplanet Kepler-1625b. Scientists have been looking for exoplanets, planets that are beyond our solar system, in the hopes of finding one that is suitable for supporting life. However, exomoons could also support life if they fall within the “habitable zone” of the star.
The discovered exomoon, called Kepler-1625b-i, has a radius of around four times that of Earth and is roughly 16 times heavier, making it much more similar in size to Neptune. Its corresponding exoplanet is Jupiter-sized, and both are located about 8,000 light-years away from Earth.
As this is the first discovery of a possible exomoon, it is hard to say if it is unusually big, and how it came to be a moon has also yet to be explained. There are three main mechanisms covering the most likely reasons behind the formation of a moon, the first is an impact scenario, which explains the existence of our moon. The second mechanism is moons coalescing out of a disk of materials swirling around the planet in the early days of the planetary system, this is how the moons of Jupiter, Saturn, and Uranus were formed. Lastly, a capture scenario, which explains Neptune’s largest moon Triton, as it was captured from the Kuiper Belt.
The exoplanet was found using the transit method; when a planet passes in front of a star from our point of view, it blocks out a little bit of the starlight that we can see. We can then measure this slight dip in the intensity of the starlight. This discovery hints at the potential discovery of an exomoon, which the study’s authors cautioned should not be taken as conclusive evidence. It was made because if there is a moon orbiting around the planet then we would expect to see a big dip in the light intensity corresponding to the planet crossing the star and then a smaller dip when the moon crosses the star. The gravitational influence of the moon on the planet can also cause the planet to wobble as it orbits the star, and this can cause the planetary transit to come through early or late.
Written by Jeanne Kroeger