When a massive star collapses under its own gravity, it forms a black hole that is so heavy that it captures everything that passes its event horizon. Not even light can escape. At the event horizon, time replaces space and points only forward. The flow of time carries everything towards a singularity furthest inside the black hole, where density is infinite and time ends (see figure).
Roger Penrose – awarded the 2020 Nobel Prize in Physics – invented ingenious mathematical methods to explore Albert Einstein’s general theory of relativity. He showed that the theory leads to the formation of black holes, those monsters in time and space that capture everything that enters them.
Not even Albert Einstein, the father of general relativity, thought that black holes could actually exist. However, ten years after Einstein’s death, the British theorist Roger Penrose demonstrated that black holes can form and described their properties. At their heart, black holes hide a singularity, a boundary at which all the known laws of nature break down.
To prove that black hole formation is a stable process, Penrose needed to expand the methods used to study the theory of relativity – tackling the theory’s problems with new mathematical concepts. Penrose’s ground-breaking article was published in January 1965 and is still regarded as the most important contribution to the general theory of relativity since Einstein.
The 2020 Nobel Prize in Physics has been awarded with one half to Roger Penrose “for the discovery that black hole formation is a robust prediction of the general theory of relativity” and the other half jointly to Reinhard Genzel and Andrea Ghez “for the discovery of a supermassive compact object at the centre of our galaxy.”
When viruses infect a bacterium, they send their harmful DNA into it. If the bacterium survives the infection, it inserts a piece of the virus DNA in its genome, like a memory of the virus. This DNA is then used to protect the bacterium from new infections.
During Chemistry Laureate Emmanuelle Charpentier’s studies of Streptococcus pyogenes, one of the bacteria that cause the most harm to humanity, she discovered a previously unknown molecule, tracrRNA. Her work showed that tracrRNA is part of bacteria’s ancient immune system, CRISPR/Cas, that disarms viruses by cleaving their DNA.
Charpentier published her discovery in 2011. The same year, she initiated a collaboration with fellow 2020 Nobel Laureate Jennifer Doudna, an experienced biochemist with vast knowledge of RNA. Together, they succeeded in recreating the bacteria’s genetic scissors in a test tube and simplifying the scissors’ molecular components so they were easier to use.
The 2020 Nobel Prize in Chemistry has been awarded to Emmanuelle Charpentier and Jennifer A. Doudna “for the development of a method for genome editing.”