The Nobel Prize in Physics 2020 (https://www.nobelprize.org/prizes/physics/2020/)

The Nobel Prize is a prestigious annual international award given by The Royal Swedish Academy of Sciences to recognize academic, cultural, or scientific advances. It is initiated by an engineer and industrialist from Sweden, Alfred Nobel, in 1895. The first prizes in Chemistry, Literature, Peace, Physics, and Physiology or Medicine were awarded in 1901.

The first Nobel Prize laureates in Physics was awarded to Wilhelm Röntgen for the discovery of X-rays. In 1940–1942, there were no Nobel Prizes laureates because of World War II. Some laureates in Physics Novel Prize were awarded for their discovery in finding a new particle of physics.

In 2019, three astronomers won the Nobel prize in Physics to understand the evolution of the Universe and Earth’s place in the cosmos. James Peebles for theoretical discoveries in physical cosmology. He predicted that if the Universe is an adiabatic system, we could find the artifact of this in the microwave wavelength. We call it the Cosmic Microwave Background (CMB) with a temperature of about 2.7K.

One of CMB’s interesting is it is a perfect example of the Plank distribution system and the Normal distribution if we analyze it in more detail. The other half jointly to Michel Mayor and Didier Queloz for discovering an exoplanet orbiting a solar-type star, 51 Pegasi. They spotted the Jupiter-like planet, called 51 Pegasi b.

This year, the Nobel prize also awards three astronomers for their discovery about the black hole. Roger Penrose discovered that black hole formation is a robust prediction of the general theory of relativity. He proved the nature of a black hole mathematically.

“… while Einstein’s general theory of relativity predicts the existence of black holes, Einstein didn’t himself believe they really existed. Penrose was the first to prove mathematically, in 1965, that they are a natural consequence of relativity theory and not just science fiction,” Jim Al-Khalili told the SMC.

For the next two laureates, Reinhard Genzel and Andrea Ghez, I had an engaging experienced when I took the course “Physics of Galaxy.” One of the projects we should present is how we can prove a black hole, a supermassive black hole (SMBH) in the heart of our Galaxy, Milky Way. My partners and I analyzed two papers. The surprise is the authors of the two papers we read are Ghez and Genzel. They are rivals in determining the mass of SMBH in the heart of Milky Way.

In the view of phenomenology, scientists had known that there is an SMBH in the Galactic Center for the several last decades. But they have not proven it confidently. Scientists call the SMBH in the Galactic Center as Sagittarius A* (Sgr A*). Genzel and Ghez determine the mass of the SMBH using Kepler’s second law, in simple explanation. But, it is very complex research. If you are interested in reading their papers, you can read a paper from Ghez here and from Genzel here.

They determine the mass of SMBH by monitoring the stellar orbits around SMBH. Scientists called the stellar around SMBH as the S-type star. There are at least 103 S-type stars. The most popular we know is S2. Genzel and Ghez analyze the orbit of S2 (in very detailed) using different data. Genzel analyzes data from Very Large Telescope (VLT), whereas Ghez analyzes W.M. Keck telescopes data.

S2 orbits Sgr A* in about 16 years. If we have observational data of S2 in 16 years simultaneously, we can determine the orbital elements of S2. Genzel and Ghez did it. You can see the orbit of S2 in Figure 1.

Figure 1. S2 orbit from Genzel’s paper (Gillessen et al.) at the below panel and Ghez (above panel).

The visualization of S2 is shown in the following video.

After they get the orbital elements of S2, they calculate the mass of Sgr A*. They got similar results, about 4 million times of solar masses. From these results, scientists can infer that Sgr A* is a supermassive black hole.

You can also see the orbit from other S-type stars in Figure 2.

Figure 2. S-type stellar orbits (Gillessen et al.)

Conclusion

I hope you can be inspired by what laureates have done in revealing the mystery of our Universe. Maybe some results do not directly affect our lives, but humans have nature on curiosity. I will give you a quote from Ghez, the fourth woman to be awarded a Nobel prize in Physics. She said

“I hope I can inspire other young women into the field. It is a field that has so many pleasures, and if you are passionate about the science there is so much that can be done,”

In the future, I think the Nobel prize will be awarded to they who detect the gravitational waves. Just my opinion. :D