The discovery of dark energy #shorts

In the 1920s it was Edwin Hubble that first noticed that galaxies further away from us, appear to be moving away from us faster than those close by. That was eventually interpreted as not the galaxies themselves moving, but the space between us and the galaxies expanding, i.e. the Universe is expanding. It also led to the development of the Big Bang theory for how the Universe has evolved. That took decades of endless scientific debate though, and it wasn't until the cosmic microwave backgrou