Hacker News Reader

Comment by jschveibinz | Hacker News Reader

Fun fact: The average replacement rate of cells in our bodies (generally speaking) is around 7 to 10 years. So all of our parts have been replaced several times over...

View on HN

Neurons live much longer than that, also not everything is cells. Parts of your teeth for example can be 80+ years old if you keep em that long.

Are teeth closer to exposed bone or enlodged rocks?

if teeth were simply rocks it’d be a helluvalot easier to get them replaced

if teeth were exposed bone we’d be able to regrow them

teeth are their own special thing; toughened enamel with an alive inside

So what I’m hearing is that they’re rocks that are alive.

But we can regrow them. We just evolved an anti-teeth-regrowth substance/molecule that's in our blood and shuts down teeth growth once adult teeth are finished, because adult teeth roots are so deep that they require surgery to pull the old teeth out to make space for new. Also historically humans didn't live that long, compared to the decade it takes adult teeth to grow.

They're doing phase 2 trials in Japan right now, on children with a birth defect that blocked some teeth from spawning.

The medicine is a monoclonal antibody "antiserum" that neutralizes the teeth-growth-blocker.

When we replace them, we do use rocks though.

It’s not the hard part that’s hard to replace but rather the rooting to the alive part.

Teeth are the proof that God doesn't exist, no celestial being could be dumb enough to create teeth which if not brushed regularly with semi-annual dentist checks rot because of.... foood.

Only the type of food we eat in an “advanced” society

And what food do we eat in advanced society, titanium?

I eat meat, vegetables, some sugary things ofc but they had honey back then. Honey also rots teeth.

People "back then" didn't have access to an industrial quantity of honey

Regardless, most people in the westen world dont eat like you. Most of their calories come from ultraprocessed garbage (look up the nova food system)

There's a difference between the food that's been eaten over the past thousands of years and the food that we all eat today. I suppose if you look at this the right way, it's another argument in favor of evolution. Teeth are optimized for hunter/gatherer diet and lifespans. Doesn't matter if your teeth rot out by 50 if you die in your 30-40s

30-40 is plenty if you’re having offspring by 13-17 and seeing them to the same age. Teeth need not last any longer.

Bones are alive. Teeth are dead. So more like rocks.

Is a wave the particles of water in it at any given instant, or something else entirely.

Its the energy.

In what way can you say that the forces acting on the particle in the western pacific is the same force acting on a completely different particle in that same wave 1000s of miles away when it hits California? It's not by any physical definition. The relationship is purely through the chain of causation over time. In our defining that network of causation as a cohesive system. When a wave interferes with another wave, why do we say both waves died, those energies still exist, when two waves join and magnify each other or cause child waves to branch off in different directions, where does the identity of the wave go?

Speak for yourself, old man

lol, thanks.

Reply on news.ycombinator.com