In spite of the emotion and turmoil of my hearing Trump take the US out of the Paris Climate accord and also the storm of new information daily about Trump and the Russians ( I personally feel that these leaks are payback from Trump having insulting the entire intelligence community), I want to calm myself and write a little about several recent exciting science discoveries. In spite of having retired and closed my lab in 2014, I have tried (I admit with some difficulty) to keep up with papers and discussions in Nature and Science. And I also subscribe to a fascinating magazine for the educated layman (and retired molecular biologists) called The New Scientist.
Discovery of gravitational waves.
These are non-electromagnetic waves traveling at the speed of light produced by the deformation of space-time by massive accelerating gravitational objects. Einstein had predicted these in 1916 in his General Theory of Relativity but it was thought that they were faint to be ever observed. In 1974 however, these waves were indirectly detected by observing a binary neutron star system over a 2 year period by radio astronomy. Hulse and Taylor found that the period of rotation was decreasing exactly as predicted by Einstein’s theory if gravitational waves were being radiated.
To actually detect gravitational waves requires an instrument that can measure a movement of 10-19 meters (a distance of 1/10,000 of a proton)! The best way to measure small distances is still to use interferometry, as used by Michelson in 1880 to show that the speed of light was constant in any direction and therefore a hypothetical medium in which light moved called the “ether” did not exist. This led directly to Einstein’s relativity theories. To detect gravitational waves required a series of truly incredible engineering advances: production of an extremely powerful and stable 200 watt laser, seismic isolation systems that sense ground movements and make corrections, passive movement damping system involving pendulums supporting the 40 kg mirrors, production of extremely high quality vacuums in the two L-shaped 2.5 mile long tunnels in both the Hanford and Livingston sites, and finally a network of supercomputers to process and archive the terabytes of data produced every day. The project initiated in 1990 and was upgraded in 2010. The first detection of gravitational waves at both sites occurred in 2015, just a few days after the installation of upgraded detectors.
And suddenly there was a new window on the universe not based on electromagnetic waves! To date there have been three separate observations of gravitational waves.
In order to clear my head of Trump nonsense, I plan to discuss several additional major advances in science in upcoming blogs. These include:
2. Dark matter
3. Dark energy
4. The multiverse and the quantum universe.
5. Growth of brain organoids from stem cells.
6. The role of micro RNAs in gene regulation
7. Development of the CRISPR/Cas gene editing system