Most of us have experienced using a lens in some way, whether it was using glasses, cameras, or our favorite, telescopes. A lens is a piece of glass or other transparent substance with curved sides for concentrating or dispersing light rays. They have the ability to bend light! Did you know that gravity can bend light in the same way? We call this gravitational lensing; when a large massive object, like a blackhole or galaxy, passes in front of our view of a distant light source and a distant galaxy. It bends the distant light in different ways, sometimes creating two or more images or creating an Einstein ring, a complete ring of the image.
The glass shape at the bottom of the stem of a wine glass, and looking straight through the glass has almost exactly the same optical properties as a massive galaxy or blackhole!
When you pass the glass over a light source or picture, it distorts the light into an Einstein Ring. This is one way Astronomers know about dark matter! According to Einstein’s theory of general relativity, the presence of matter (energy density) can curve spacetime, and the path of a light ray will be deflected as a result.
Written by: Mimi Garai