Nobel prize part 2: Quantum dots, mRNA vaccines, and attosecond lasers

Nobel Prize in Chemistry: Quantum Dots

Things act weird when they get small. The electrons that make up materials run out of room and get squished together, resulting in odd properties that don’t match the normal-sized versions. These small particles are referred to as quantum dots and got the Nobel Prize in chemistry this year.

For example, nanoscale materials are a different color than their large counterparts. The exact same material has 2 completely different colors when they’re just a little smaller. A 12 nanometer particle (roughly 4,000 times smaller than a hair) can be a different color than a 4 nanometer particle.

This might not seem that strange or exciting to you, but it opens up an entire world of possibilities, because color isn’t the only thing that changes. As you might imagine, how electrons behave controls a lot of properties in the materials around us.

The nano-scale quantum dots quickly became their own field and have been used to track cells as they move through the body, as catalysts to speed up chemical reactions, and all around us in digital screens.

Moungi Bawendi, Louis Brus, and Alexei Ekimov were awarded the Nobel Prize in Chemistry for the discovery of quantum dots and their production methods.

Read more here.

Nobel Prize in Physiology/Medicine: mRNA modification for vaccines

mRNA vaccines helped slow the COVID pandemic and saved an estimated 14 million lives. But how’d we get them so fast? It turns out, we didn’t. Scientists had been working behind the scenes on developing the technology behind the mRNA vaccines for decades. This Nobel Prize was given to 2 of them: Katalin Karikó and Drew Weissman.

We’ve been making vaccines to fight diseases one way or another for centuries. To start, healthy people were exposed to small doses of actual diseases (namely smallpox). For obvious reasons we don’t do this anymore.

Recently, we’ve moved on to using inactivated viruses that have the same structure/markers as the original viruses but aren’t capable of making us sick. We also use specific fragments of viruses that don’t do anything but let the immune system recognize what they’d look like on the real virus.

These techniques are great, but are hard to scale up, hard to produce quickly, and are hard to change as viruses mutate. So, as scientists do, the medicine prize winners Katalin Karikó and Drew Weissman looked for alternatives.

They turned to mRNA, which tells your cells what proteins to make. They figured that if we could make mRNA that tells our cells to make harmless virus proteins, then the immune system would recognize those proteins and thus be prepared for the real virus.

One major benefit of mRNA is that the process to make it is much more scalable than making virus protein fragments or inactivated viruses (especially in the 1990s when this work started).

The major issue Karikó and Weissman solved was figuring out how to get our bodies to not attack the mRNA right when its delivered. It turns out that the immune system sees mRNA that’s just floating around outside of cells as a red flag. This makes sense; some viruses use RNAs to attack so it’s best not to have RNA just hanging out.

Among other things, Karikó and Weissman discovered that modifying a small part of the mRNA reduced the negative response to it significantly. A little tweak of changing a carbon to a nitrogen made a huge difference and was one of the first fundamental breakthroughs towards making mRNA vaccines a reality.

Read more here.

Nobel Prize in Physics: Attosecond light pulses for studying electrons

Electrons move fast. Ridiculously fast. So fast, it’s historically been impossible to measure much about them. In order to measure something as fast as an electron, we need to be able to create flashes of light that are just as quick.

Electrons change energy and speed every few attoseconds. An attosecond is about 1 billionth of a billionth of a second, or in other terms, an absurdly short time. An incomprehensibly short time. So short, that comparing 1 attosecond to 1 second is the same as comparing 1 second to the age of the universe.

That’s faster than we can make light pulses using just lasers. In the 1980s, it was considered impossible to make attosecond pulses.

However, this year’s Physics Nobel winners discovered some tricks to make it possible (Anne L’Huillier, Pierre Agostini, and Ferenc Krausz).

They discovered that putting lasers through certain gasses allowed the laser’s light pulses to interact with eachother and create quicker pulses as a result. At the same time, they developed methods for characterizing how different laser pulses combined and measuring the resulting light pulses.

This technology lets us measure things like how electrons move away from atoms, how they’re distributed around atoms, and other detailed physics questions.

Read more here.