James Webb Telescope proves Einstein right (again)
With each technological advancement, the human race is getting a clearer picture of the cosmos. The latest contribution to the clarity of our universe comes from the James Webb Space Telescope.
The image accompanying this month’s column is of a tiny dot in the sky about the size of a grain of sand held at arm’s length. If we looked at this area even with ground-based telescopes, we’d see nothing but the blackness of space. Yet, thanks to the ability of the most sophisticated telescope ever made, we see dozens of galaxies that are so far away that they represent the first of their kind. The depth of this picture is incomprehensible, but I will try to give you at least a hint of what you’re looking at.
The bright dots with six spikes of light emanating from them are foreground stars in our Milky Way galaxy. The spikes are artifacts from the physical structure of the telescope’s optical design. These stars are “only” a few dozen to a few thousand light years away. The rest of the objects are way-distant galaxies that existed billions of years in our past. These galaxies may not even exist in our “now.” Some of them are red — not because of the color of the stars within them — but, rather, because the light from these objects is stretched like taffy to the lower-energy (red) band of the electromagnetic spectrum. This stretching or shifting of light toward the red is called “redshift.” It can only happen by a known phenomenon called “the Doppler effect,” where the frequency of light is stretched by an object speeding away from us at extreme velocities approaching the speed of light itself! How can objects move that fast? Well, they don’t. Instead, what you’re observing is space itself expanding and carrying these galaxies away with it.
There’s another interesting feature in this image. Several of the reddish galaxies are distorted and curved. This is due to gravitational lensing. Gravity causes space and time (what Albert Einstein referred to as “spacetime”) to curve. The light from the reddish galaxies is curved to match the “shape” of spacetime curved by the gravity of the massive whiteish foreground galaxy clusters. You are literally seeing curved spacetime. Once again, Albert Einstein’s theory of relativity is proven to be true.