Light, Time and Space

I watched an illuminating program about the development of the telescope.  Every improvement in telescope technology has resulted in man’s greater understanding of the universe.  When man watched the planets in the sky by eye they saw them going through strange circuitous orbits.  It was Copernicus who realized that the planetary orbits could be greatly simplified if the sun and the planets did not rotate around the earth, but rather that the earth and the planets rotated around the sun (heliocentrism).  At the time this was a deeply dangerous heresy because the Church had decreed that the earth was central.  It was the development of the telescope by Galileo in 1610 that enabled him to prove that Copernicus was correct.  But, the Church could not accept that, and so they forced him to recant.  But, we now take heliocentrism for granted; religion was wrong, as it is about many features of the natural world.

Einstein forever dispelled the notion that there is a universal clock in the universe and that time is the same everywhere.  It was one of Einstein’s revelations that when we look at the stars, we see them not as they are now, but as they were millions of years ago,  because it takes a very long time for light to travel the huge distances from the stars to the observer on earth.  When I look at you in a room or further away, I see you not now but a few nanoseconds later.  The concept of not being in the same time is the same as not being in the same space.  According to Einstein time and space form a continuum, so everything takes time.  We take it for granted that an experiment takes place in space, but it also takes place in time, something that the early physicists took for granted.

Edwin Hubble was the American astronomer who through diligent observation proved that the universe was far larger than the Milky Way, and that there are in fact billions of galaxies each with billions of stars.  But, there are large volumes of the sky which appear to be blank.  The launch of the James Webb space telescope, named after the first director of the US space agency,  (if everything goes according to schedule) will open up even greater regions of observation, since it will be a million times more sensitive than the current Hubble space telescope.   It will be located a very long distance from earth, and its huge telescope is collapsed so that it can be launched on a rocket.  It requires ca. 300 separate mechanical movements in order to open it up.  If any one of them fails the telescope won’t work, and there is no way to repair it.  This will be a great human adventure.