By the 1980s, our view of the Universe was pretty close to what it is today. We had confirmed the Big Bang Theory and even had some understanding of what must’ve caused the Big Bang. There were some mysteries around, such as dark matter, the age of the Universe, and the solar neutrino problem, but all in all, we were on pretty solid ground.
One of the things astronomers had been waiting for was a supernova to go off in our galaxy. We expect about one per century in our galaxy, and we hadn’t seen one since 1604! It’s 2009 now, and we still haven’t seen one, but in 1987, we got closer than any other time since 1604. Take a look at our nearby galactic neighborhood:
While our Milky Way is certainly the most dominant thing until we get out to Andromeda, more than 2 million light years away, many of these dwarfs and clouds actually have a lot going on. The Large Magellanic Cloud (LMC), for example, has over 10 billion stars in it! And in 1987, something fascinating happened over there in the Tarantula Nebula:
In the outskirts of this nebula, one of the more massive stars in this cloud simply ran out of fuel, collapsed, and created a giant supernova explosion. Can you spot the supernova in this Hubble Space Telescope picture?
Look in the middle. There’s one small part that’s brighter than the rest. I can’t zoom in on the image above, but the Hubble Space Telescope, thankfully, did. Let’s take a look at what it sees:
(And click here for the full size shot.) Now, this was interesting to people who studied stars, supernovae, nuclear physics, and many others for all sorts of reasons. But sometimes, the greatest discovery is the one you weren’t planning on.
Let me explain, and let me do it by taking you over to Kamioka, Japan.
What’s this? It’s a huge, underground tank being constructed! There was a popular theory in the early 1980s that, as one of its consequences, predicted that the proton would decay! In order to look for this, the Japanese, led by Masatoshi Koshiba, build a huge tank of water with detectors all around the edge to look for decaying protons. The experiment was called Kamiokande, for the Kamioka Nucleon Decay Experiment. In fact, here’s a modern-day picture of the current detector at Kamioka:
In 1987, it had 3000 metric tons of water inside of it, or about 10^34 protons. Well, this detector was going for awhile, and it didn’t see any decaying protons. You watch 10^34 protons for a year, none of them decay, and what do you conclude? That protons live for at least 10^34 years! (This is incredibly long, considering that the Universe is only about 10^10 years old!) But in 1987, the supernova above went off in the LMC. It was the first time that any event this destructive and energetic occurred so close to us since the dawn of modern technology. Kamiokande happened to be running, and you know what happened?
The detector went off! Not just with one event like this, but with 11 events, all coming from the direction of this supernova! You see, this Nucleon Decay Experiment also functioned as a Neutrino Detector Experiment. Koshiba and his team had just detected the first astrophysical neutrinos from anything other than the Sun.
For this discovery and the work that grew out of it, Koshiba won the Nobel Prize in 2002. This work led directly to the discovery of neutrino oscillations and the fact that neutrinos have a mass, which is pretty profound for particle physics. But Koshiba has a claim to infamy as well as a claim to fame. Just one year prior to winning the Nobel Prize, Koshiba caused the greatest science disaster in Japanese history, where thousands of these detectors around the edge exploded in a chain reaction. This was about a 30 million dollar mistake, and Koshiba was the one blamed.
So you see, you can make a groundbreaking discovery, change our view of the laws of nature forever, win a Nobel Prize, and still do one of the dumbest things in history. Sometimes, it’s better to be lucky than good, and in Koshiba’s case, he was in the right place with the right equipment at the right time.