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  • It’s that time of the year again: around October, the Nobel prize winners are announced,

  • and a few scientists around the world are specially honored for their discoveries.

  • Olivia talked about the Physiology or Medicine Prize last week, and now it’s Chemistry

  • and Physicsturn.

  • This year’s Chemistry prize was shared between three researchers, who all used molecules

  • to make tiny machines.

  • Over billions of years of evolution, nature has come up with lots of molecular machines,

  • from whip-like flagella that help cells move, to enzymes that catalyze chemical reactions.

  • These researchers haven’t had that kind of time, but their microscopic tools could

  • still have a big impact on the future.

  • First up is the chemist Jean-Pierre Sauvage, who wanted to see if molecules could be mechanically

  • connected.

  • Normally, different molecules are connected by covalent chemical bonds between their atoms.

  • But Sauvage and his team used copper ions to coax molecules into interlocking like links

  • in a chain, which they call a catenane.

  • This new way of linking molecules could be used as part of a bigger microscopic machine,

  • like a switch or a motor.

  • The researchers even created a simple mechanical system, where adding a bit of energy made

  • one ring revolve around the other.

  • The second winner, J. Fraser Stoddart, synthesized two different molecules that can be links

  • together as one machine: axles and rings.

  • The axle was basically a rod with bulky ends and two middle bits packed full of electrons,

  • while the slightly-open ring didn’t have many electrons.

  • Opposites attract, so the electron-poor rings threaded onto the electron-rich rods when

  • they were mixed.

  • Then, the team sealed up the rings with a chemical reaction to mechanically lock them

  • onto the axles, creating these structures called rotaxanes.

  • By adding some heat, the team could shuttle the rings along the rods, and make tiny machines

  • that worked like elevators, muscles, and even computer chips.

  • Lastly, the third scientist, Ben Feringa, built a tiny molecular motor.

  • Free molecules are always getting jostled around, so they tend to spin left and right

  • randomly.

  • But Feringa’s team built a molecule out of two flat structures that locks together,

  • so when they added UV light and heat, it only spun in one direction.

  • The group’s first attempts in 1999 weren’t all that speedy, but by 2014 they had a molecular

  • motor that spun at 12 million revolutions per second.

  • They even built a nanocar with four motors for wheels, which zipped forward across a

  • surface!

  • So, all these basic machines are neat ways to make molecules spin and slide, but theyre

  • still just the beginning.

  • As scientists work to combine them, or build entirely new structures, who knows what microscopic

  • technologies well be building the future?

  • Now, the Physics prize this year went to three theoretical physicists who are studying how

  • more extreme materials behave and change forms.

  • This involved lots of weird quantum phenomena, plus a branch of math called topology, which

  • looks at how objects can be arranged and manipulated.

  • Phase transitions describe how one state of matter becomes another, thanks to changing

  • conditions like temperature.

  • Youve heard of things melting, boiling, freezing, and condensingbut there are

  • other kinds of phase transitions, too.

  • If a magnetic substance gets hot enough, for example, the magnetic orientations of the

  • atoms get all randomized, and its overall magnetism is disrupted.

  • Two of the Nobel prize winners, Michael Kosterlitz and David Thouless, studied phase transitions

  • in stuff that’s really cold, and really thinjust a few atoms thick.

  • Here, things start getting weirdbecause quantum!

  • Quantum effects can be hard to study, since theyre tiny and hard to pick out from all

  • the normal atomic wiggling.

  • But if you lower the temperature enough, there’s a lot less energy making the atoms move around,

  • and quantum effects can be seen throughout whole materials.

  • Take quantum vortices, which are basically whirlpools of angular momentum in materials

  • like superconductors and superfluids, giving them strange properties.

  • Turns out, quantum vortices also involved in an entirely new topological phase transition

  • discovered by these two physicists!

  • Near absolute zero, the quantum vortices in ultra-cold, ultra-thin superconductor materials

  • were arranged in pairs.

  • But with a little bit of heat, the vortices spread apart over the surface.

  • This shift is now called the Kosterlitz-Thouless transition, and it’s turned out to be important

  • in other fields of physics too.

  • Thouless and the final winner, Duncan Haldane, are both also using topology to pave the way

  • for a new kind of material: topological insulators.

  • In a conductor like copper metal, electrons flow through the entire material.

  • And in an insulator, like rubber, electrons can’t really flow at all.

  • A topological insulator acts like both at the same time, which we used to think was

  • impossible!

  • Most of the material is an insulator, but its surface can carry an electric current.

  • Nowadays, scientists are working to develop topological insulators, and some think they

  • could be as important for future technologies as semiconductors are today.

  • So this year’s Nobel Laureates have pioneered some important research into molecular machines

  • and topological materials, and it looks like there’s a lot more on the horizon!

  • Thanks for watching this episode of SciShow News, brought to you by our patrons on Patreon.

  • If you want to help support this show, just go to pateron.com/scishow.

  • And don’t forget to go to youtube.com/scishow and subscribe!

It’s that time of the year again: around October, the Nobel prize winners are announced,

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The 2016 Nobel Prizes: Chemistry and Physics!

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    Kana kawai posted on 2017/11/15
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