What physical ‘life force’ turns biology’s wheels? • Hacker News Board

Re: What physical ‘life force’ turns biology’s wheels?

#51

Post by zimpenfish » Fri, Apr 24, 2026, 8:22 AM UTC

mmooss wrote: post #48

ur-whale wrote: post #7

Earlier quoted context omitted.

> For some context, a billion years at a 20 minute breeding cycle is 26.3 trillion generations. Which if you want an actual feel for the true scale of things, must be multiplied by (order of magnitude) the number of bacteriums on the planet.

Is that true for evolution? If that math works, it seems that any one bacterium's mutation must become universal across the globe? Evolution works but not for every instance of a beneficial mutation. I wonder what the odds are for bacteria.

It's more the probabilities, I think[1] - even in one generation, (say) 26 trillion[0] bacterium are going to experience a lot of mutations.

[0] Which is an extremely low ball number for worldwide bacterium, even billions of years ago, I think, given your average human has around 30 trillion inside them.

[1] Like "anomalies in Minecraft" series - given how many seeds there are, how many people play it, and how big the worlds are, eventually even the rarest things generate naturally.

Re: What physical ‘life force’ turns biology’s wheels?

#52

Post by lucy_hnatchuk » Fri, Apr 24, 2026, 9:23 AM UTC

Beautifully written. This doesn’t just explain the flagellar motor — it feels like watching the very “life force” behind biology running on protons and entropy. Amazing how much of life boils down to such elegant physics.

Re: What physical ‘life force’ turns biology’s wheels?

#53

Post by imtringued » Fri, Apr 24, 2026, 10:56 AM UTC

mmooss wrote: post #48

ur-whale wrote: post #7

Earlier quoted context omitted.

> For some context, a billion years at a 20 minute breeding cycle is 26.3 trillion generations. Which if you want an actual feel for the true scale of things, must be multiplied by (order of magnitude) the number of bacteriums on the planet.

Is that true for evolution? If that math works, it seems that any one bacterium's mutation must become universal across the globe? Evolution works but not for every instance of a beneficial mutation. I wonder what the odds are for bacteria.

I'm not sure why you think "any one bacterium's mutation must become universal across the globe". That's a pretty strange takeaway in the presence of a mutation that is so advantageous it lets you become a predator and hunt other bacteria or run away from predators and gain a painfully obvious survivability benefit.

The takeaway should be "mutations that confer massive benefits can become universal across the globe even if they only happen once, no matter how unlikely they are", which is obvious and intuitive.

Re: What physical ‘life force’ turns biology’s wheels?

#54

Post by CGMthrowaway » Fri, Apr 24, 2026, 3:07 PM UTC

djokkataja wrote: post #15

This reminds me of a gem of a comment from about a month back, about a dead simple Russian guidance system from a Cold War-era missile: https://news.ycombinator.com/item?id=47389285 Actually, someone even commented in that thread about how it was similar to biological mechanisms: https://news.ycombinator.com/item?id=47390619

Would it not easily get sidetracked by the sun? Like a moth to a flame

Re: What physical ‘life force’ turns biology’s wheels?

#55

Post by mmooss » Fri, Apr 24, 2026, 4:10 PM UTC

imtringued wrote: post #53

mmooss wrote: post #48

Earlier quoted context omitted.

Is that true for evolution? If that math works, it seems that any one bacterium's mutation must become universal across the globe? Evolution works but not for every instance of a beneficial mutation. I wonder what the odds are for bacteria.

I'm not sure why you think "any one bacterium's mutation must become universal across the globe". That's a pretty strange takeaway in the presence of a mutation that is so advantageous it lets you become a predator and hunt other bacteria or run away from predators and gain a painfully obvious survivability benefit. The takeaway should be "mutations that confer massive benefits can become universal across the globe e…

I agree; I was talking about the math in the parent post. I think the math represents the probability of individual mutations and not of evolution.

Re: What physical ‘life force’ turns biology’s wheels?

#56

Post by estimator7292 » Sat, Apr 25, 2026, 7:49 PM UTC

I have always been super annoyed by the abstraction that ATP is a magical tiny battery that transports "energy" in some nonspecific way and that cells just hand-wave absorb that magic energy.

I learned recently that the actual mechanism of the energy transfer is one of the most interesting parts of molecular biology.

ATP doesn't just store chemical energy. ATP synthase constructs the molecules by literally mashing the two halves together and mechanically twisting them. ATP can later slot into proteins, releasing that energy by mechanically moving parts of a molecular machine. It can also be split for simple heat and participate in other chemical reactions more directly.

But I find it absolutely fascinating that ATP operates as a mechanical battery. Storing actual mechanical motion in a chemical bond that can be reversed to recover the motion and transform it into work. Molecular machines are one of the most incredible things in the universe.