Nobel Prize in Chemistry 2026 to Henri B. Kagan and Kenso Soai | Hacker News Reader

Nobel Prize in Chemistry 2026 to Henri B. Kagan and Kenso Soai

nobelprize.org

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I remember first learning about chirality in my biochemistry course in college, and it was definitely a mind-blower. I had already started to understand that molecules had 3d structures, but the idea (and attempting to visualize it mentally) of mirror image molecules stretched my brain significantly.

It's also still amazing to me how people first recognized this: poking around looking at the crystals that form in the bottom of a wine under a microscope, noticing that some of them were mirror images of the other, and then seperating them manually with tweezer, dissolving them into two different solutions, and demonstrating that they rotated light in opposite directions.

Sodium-ammonium tartrate (I remembered what you were talking about, but had to look up the actual chemical!)

https://pmc.ncbi.nlm.nih.gov/articles/PMC9291139/

From that:

"To his surprise, he noticed that each crystal has a tiny facet on one of its edges oriented sometimes to the right and sometimes to the left. He could separate them by hand with a tweezer."

It's moments like that, and Kekule's story of the snake dream for benzene that make me feel unworthy of being a scientist. I sometimes wonder: in my career of looking at things, did I miss something fundamental and significant simply because my powers of observation and general intelligence were insufficient?

Well, I don't know that every scientist has to have poetic dreams about snakes (Kekule) or apples (Newton).

Weirdly I often have dreams where I am 'solving' some problem, however on waking I realise the details are nonsense - not just the solution, but the problem itself. I think dreams are often a way to just exercise and sort memories and ideas. There is no reasoning involved.

A lot of science is just process, or multiple careful experimentation. Preparing for getting lucky is another matter.

When I first learned about recursion I could not understand it (specifically, I didn't understand how eventually you reached a termination point and popped back up the stack). I spent all day thinking and thinking and thinking. As I was falling asleep- in that sort of lucid awake-but-not-awake state, the entire program I wanted to write appeared before me in glowing letters. Some deep part of my brain woke me up, I wrote the program down, and went back to sleep.

When I woke up the next day, I compiled it, ran it, and it worked on the first try (up to the stack limit on my computer... 6 function calls deep).

Since then I've noticed that if I get super-duper obsessive about things I don't understand, insights will start to pop into my head, but at the same time, I can't really talk to other people because the human interaction part of my brain is "paged out". I kind of understand tormented geniuses better knowing that many of them also walk a fine line between human life and discovery.

Newton didn't dream of the apple falling, it actually happened (as such things do) but it didn't hit him on the head.

https://www.newtonproject.ox.ac.uk/view/texts/normalized/OTH...

> after dinner, the weather being warm, we went into the garden, & drank thea under the shade of some appletrees, only he, & myself. amidst other discourse, he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind. "why should that apple always descend perpendicularly to the ground," thought he to him self: occasion'd by the fall of an apple, as he sat in a comtemplative mood: "why should it not go sideways, or upwards? but constantly to the earths centre? assuredly, the reason is, that the earth draws it. there must be a drawing power in matter. & the sum of the drawing power in the matter of the earth must be in the earths center, not in any side of the earth. therefore dos this apple fall perpendicularly, or toward the center. if matter thus draws matter; it must be in proportion of its quantity. therefore the apple draws the earth, as well as the earth draws the apple."

This is such quaint, clear, and beautiful writing. It deeply struck me. Thank you for posting it.

If you think Kekule's story is wild, you should read about how Kary Mullis came up with the idea for the polymerase chain reaction!

I already have :) don't forget he also dropped acid in Golden Gate Park and then wrote a Nature paper about time reversal!

He was on drugs. Right?

I assumed opium.

But I think if you are in the throes of a problem, pondering it constantly, day and night—it is in these times that an insight will make its way to your consciousness (drugs or otherwise).

In graduate school he had a reputation for being the best at synthesizing LSD.

Btw, all this is explained in the "popular information" tab on the Nobel page. Always very interesting and easy to follow:

https://www.nobelprize.org/prizes/chemistry/2026/popular-inf...

For me as early as high school it was easy to understand the concept of molecules having 3D structure (the standard textbook explanation of left glove versus right glove is easy), but it was really difficult for me to visualize it. I was not and am still not a visual thinker. This caused me a lot of problems when I needed to distinguish between enantiomers. For example I had a great deal of trouble when given two molecules that only differ in chirality, which one is levo and which is dextro, despite studying very hard.

At least for me (because I have aphantasia) I found that using molecular visualization apps (ideally with 3D stereo glasses) makes a huge difference. I can sort of rotate the molecules around and build up a working mental picture that way.

It was a 100 level O-Chem lesson for me: We had the physical ball-and-stick models.

Enantiomers and Diastereomers are one of the more interesting and challenging things in Organic Chemistry. It also makes carbohydrate chemistry challenging in Biochem.

The paths we all take to the same knowledge is hilarious to me. I learned about chirality in my mid twenties while playing mass effect lol

>Other than life itself, no one had achieved this feat.

Yeah, when you put it that way it sounds pretty impresive.

Chemist here. I read this and thought it was either lies or propaganda. But after a while of pondering , it would say that the word "homochiralic" (creation-from-nothing) does a lot of heavy lifting here to make their claim technically true, if at all:

Asymmetric synthesis was already well established before 1995. Chemists like Knowles, Noyori, Sharpless, and Evans could routinely produce highly enantioenriched molecules using chiral catalysts or auxiliaries.

What made Soai's reaction different was that it did not require an external chiral source. The chiral product catalyzes its own formation, so a tiny random imbalance can be amplified into a very large enantiomeric excess.

Other examples of abiotic asymmetry, such as Pasteur's crystallization experiments and circularly polarized light, were also known earlier.

So the Nobel press release is best understood as shorthand: Soai did not discover asymmetric synthesis, but demonstrated a remarkable form of self-amplifying, spontaneous chiral symmetry breaking in an abiotic chemical system.

That helps a lot! I'm a novice learning about enzymatic synthesis. I'm not there yet, but my assumption is the target molecules (And reactants/intermediate-products) will all have specific chiralities, unlike the chemical-synthesis ones which may produce 50/50. Everything in my data structures (And the pubchem CID / ChEBI ids they reference) are chiral.

Is it explained why, in this drawing, the right catalyst forms at a higher rate than the left? Or put another way why left/right catalyst gets formed at a higher rate than right? I’m trying to understand the why behind the amplification effect.

All reagents are symmetric, so how do you design a reaction where you produce more left or right? So starting from purely symmetric reagents and catalysts, how do you produce asymmetry?

When the chirality of the product is an autocatalyst to its own chirality. So if your reaction starts off with a little more left than right due to molecular randomness, the left is an autocatalyst which means there is a runaway process and you end up at the end of the reaction with a lot more left than right.

If you repeat the reaction from scratch, it is random if you end up with a left product or a right product. But the product of your reaction is not a 50-50 mix left-right! I.e. you created asymmetry in your solution from purely symmetric solvents.

As I understand it, the chirality problem is one of the big ones in abiogenesis - the beginning of life. How does some initial series of inorganic "accidents" lead to life? The necessary chemistry has to give the right chirality.

But maybe someone better informed can explain... I've only heard James Tour ranting about it

The chirality of biomolecules is also the source of the differentiation of left and right in a developing embryo.

Cilia form that are tilted toward the tail of the embryo. The chirality of the protein motors driving them causes them to turn clockwise, which creates a leftward flow of water.

https://pmc.ncbi.nlm.nih.gov/articles/PMC1180515/

https://hms.harvard.edu/news/telling-left-right-organ-develo...

In 2004, left-handed sugar was hyped as a way to eat junk food without absorbing the sugar. It turned out to be too expensive, but I think it's an interesting story (oddly involving Mars!). More here:

https://spinoff.nasa.gov/Spinoff2004/ch_4.html

Fun fact: his family name in kanji 硤合 is so rare that most people don't even know how to read it thus most japanese news sites using a hiragana translation そあい

Is it common for family names in Japan to be this rare? Like, collectively, is the percentage of Japanese people with rare family names greater than 1%? I ask because I know that many Italian people (myself included) have rare last names that are almost exclusively found in the city their family is from.

Cool, brings back some memories from grad school. Always found these types of reactions with self-reenforcing quite interesting.

Reminds me of another paper where just stirring a solution or not would determine the chirality of crystals formed and gives an idea how highly chiral environments can arise from "nothing":

Chiral symmetry breaking in sodium chlorate crystallizaton https://doi.org/10.1126/science.250.4983.975

I remember an offhand comment from a professor in grad school about the origin of chirality in life, he said some people had speculated it had to do with parity of the electroweak force (https://ui.adsabs.harvard.edu/abs/1985Natur.318..172T/abstra...) or something like that, but it always seemed unlikely because the energy difference due to that is so tiny that it would be hard for a single or small number of events to be biased significantly in one direction.

Yeah, I believe the estimates from parity breaking where on the order of 10^-10 J/mol or something, so almost completely irrelevant for anything near room temperature energy scales.

So some random self-enriching chiral process seems much more likely to be the origin. But who knows! :)

Congratulations to Professor Soai on winning the Nobel Prize. The discovery of asymmetric autocatalysis is truly groundbreaking, and as a fellow Japanese, I am incredibly proud of this achievement.

Yes, that should be evident from the first paragraph of each article.

Mirror-image life obviously depends on chirality. But chirality is very relevant without it. It is a fundamental aspect of chemistry (and biology).

Yes, this sounds like a situation where progress in that field may have led them to go back and give more credit to the original experiments going in that direction

This is a plot point in one of my most favourite science fiction novels by Roger Zelazny... bit of a spoiler, so ROT13:

_Qbbejnlf va gur Fnaq_

which still has my favourite life situation for a protagonist (room, board, tuition and generous stipend so long as he attends his uncle's alma mater until such time as he graduates....)

The popular information is always a great read for non-experts! https://www.nobelprize.org/prizes/chemistry/2026/popular-inf...

As a right-handed person, I find this deeply offensive and request all left-handed life be destroyed at once!!

That said, would it be possible to make "right-handed" food that is safe to eat, satisfies the psychological urge to consume food in every sensory measure, but still contributes 0 calories?

I thought that sort of how artificial sweeteners work

We have matter-antimatter asymmetry in physics... and now I just learned there's a similar concept in chemistry (one variant frequently occurs in life while the other mirrored variant is rarely found in nature)

Do I understand correctly that Kagan has been working on his part for (more than) 40 years?

Reading Wikipedia it seems he also didn't win another Nobel because the max number of recipients is 3. It's not that unusual that people get the prize a loooong time after their actual work though.

I have to admit that when I read the intro header of the piece on the page, “They made chemistry choose a mirror image,” it struck me as LLM-speak and I immediately lost interest. I have no idea whether the authors used one to draft that phrase, which seems like an innocent summary of their contributions, but somehow I feel like if it were three years ago we would have never seen that in the title.

Does this fall under the Tetris effect?

Does this imply a parity violation (and thus that the weak force must somehow ultimately be in involved in the reaction)?

No, in this case neither isomer is inherently preferred, i.e. if you repeat the reaction you could end up with the opposite isomer, but in each run the symmetry is broken leading to an excess of just one.

(Though what you're saying is not impossible per se, I think I read an experimental proposal a while ago which suggested achieving just that, iirc by using parity violation to generate chiral photons which then initiate some kind of reaction!)

No. Even in the absence of parity violations you can imagine a reaction that has a 50% chance of producing only left handed products and a 50% chance of producing only right handed products. This discovery is more like that.

See also this discussion about this in the sci-fi series The Expanse, where a planet has bi-chiral organisms (able to use both versions of these molecules): https://www.reddit.com/r/TheExpanse/comments/i4e187/a_small_...

Going to fire up Death Stranding 2: On The Beach

Chirality is quite interesting!

For 1m I thought I would re learn chemistry. Then I remembered how diff it was at the uni.

Throughout my life as a student from elementary school to university, I’ve had so many teachers with an extremely diverse ability to actually teach that I no longer think of any subject as inherently hard or easy. I always think it’s a bad teacher or a bad textbook. When I self-studied chemistry I switched textbooks three times before I found one that really matched the way I think.

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