The lecture was on the importance of observing the Universe using the whole electromagnetic spectrum, from the shortest wavelengths (Gamma rays) to the longest (Radio waves). The discovery that our sky emits radio waves was primordial to our understanding of the expansion of the Universe through the discovery of the cosmic microwave background radiation (CMB). On May 20, 1964, American radio astronomers Robert Wilson and Arno Penzias discovered this CMB, the ancient light that began saturating the Universe 380,000 years after its creation. It was a complete surprise discovery. The Bell Labs' Holmdale Horn Antenna in New Jersey picked up an odd buzzing sound that came from all parts of the sky at all times. The noise puzzled Wilson and Penzias, who did their best to eliminate all possible sources of interference, even removing some pigeons nesting in the antenna. As a result, the two got the Nobel Prize in Physics in 1978.

Another major discovery is the discovery of pulsars by Bell Burnell. In 1967, she was working with Anthony Hewish, an astronomer at Cambridge who wanted to find more quasars, which are the distant, extremely bright cores of massive galaxies. To do that, Hewish was scanning the sky and looking for radio waves produced by those quasars. But to really succeed, he needed a new radio telescope. Luckily, he had just the graduate student for the job: Bell Burnell, one of the few women pursuing astronomy there at that time, was sharp, willing, and extremely capable of building a telescope that basically looked like a field full of wire fences. Bell Burnell ran the telescope for its first six months and discovered about a hundred more quasars—which she did by carefully studying paper readouts (Cambridge only had one computer for the entire university that had essentially no memory and was mostly occupied doing non-astronomy tasks). Although Bell noticed a strange "bit of scruff" in the data coming from her radio telescope, she and her advisor Anthony Hewish initially thought they might have detected a signal from an extraterrestrial civilization. Instead, she established that the signal was pulsing with great regularity, at a rate of about one pulse every one and a third seconds. Temporarily dubbed "Little Green Man 1" (LGM-1), the source (now known as PSR B1919+21) was identified after several years as a rapidly rotating neutron star.