6 ms·

I chopped off around 3-4mm off the tip of my left index finger as a kid with a lawn trimmer. 20 years later, I punched a nice groove around 3mm deep into the ti

by lqet 5y ago

I chopped off around 3-4mm off the tip of my left index finger as a kid with a lawn trimmer. 20 years later, I punched a nice groove around 3mm deep into the tip of another finger tip while trying to get tea out of a tea tube [0] (don't buy these things). It took weeks, but both times, the tips grew back perfectly round and smooth, even the fingerprints are back. The regrown tips felt a bit numb for 1-2 months, but then everything was back to normal. The second time I asked a friend, who is a medical doctor, how the body "knew" the form of the fingertip and the fingerprints. Where was this information stored? His answer was basically: we have no idea, just be grateful it works. [0] https://www.hochland-kaffee.de/media/catalog/product/cache/1/thumbnail/600x600/9df78eab33525d08d6e5fb8d27136e95/5/1/514150_xl.png https://www.hochland-kaffee.de/media/catalog/product/cache/1...

pkaye 5y ago
My finger tip got pinched under a lid and a small chunk was torn off but somehow it all healed with matching fingerprints that blends in.
galangalalgol 5y ago
I caught my finges in the chain of a swing as a child and tore about half the pad of my pinkies away to a similar depth, one narrow strip was still attached so I held it on with bandaids after washing it. It grew back together but now there is an offset or fault line in my print.
- deleted 5y ago
  [deleted]
- johnwalkr 5y ago
  At first I thought you meant to write fingers, then I realized your must have been referring to the truncated fingers, that is “finges”. Did you just do that on your own without telling an adult? I totally did similar things. I cut my thumb to the bone when I was 10 by whittling a stick towards myself, and I also have a fault line there now.
GauntletWizard 5y ago
Pure wild speculation: I suspect that an awful log of our biological form is fractals formed from chemical gradients, with our DNA controlling the amounts of each chemical, both how fast they're produced and consumed. Included in this are some wild "Programs" were Chemical A causes Chemical B to be produced, Chemical B produces Chemical C and chemical C shuts off chemical A - In wild patterns that eventually form the beauty of our bodies. On a mass scale, with dozens of signaling chemicals and switches flipped - Organelle A produces chemical B and C and they osmose. B spreads far and wide, and an organ grows wherever B is concentrated. C doesn't spread, and eventually it grows concentrated enough to shut itself off. Thus, the physical limits of a body are formed. Fingerprints would then be where this all happens on a micro scale - Running the game of life in 3d on the cells of your body, until they reach an "end state" of a stable limit of your skin.
- nvrspyx 5y ago
  You might be interested in reading up on homeobox genes. https://en.m.wikipedia.org/wiki/Homeobox https://en.m.wikipedia.org/wiki/Homeobox
- Retric 5y ago
  There are several parts embryo development that does operate on chemical gradients especially the initial stages. But like most of biology it gets really complex and isn’t limited to any one approach. For example as you gain fat tissue you need to increase the number of capillaries feeding that tissue, which in tern needs to link up to arterioles and arteries on one side and veins on the other. https://www.ncbi.nlm.nih.gov/books/NBK53238/ https://www.ncbi.nlm.nih.gov/books/NBK53238/ This happens well into adulthood.
- lurquer 5y ago
  Turing’s diffusion/reaction algorithm involved this. As you intuited, it is a good system for making fractal-like designs and patterns. Cheetah spots, zebra stripes, maybe even 3D structures like capillaries... But, such a system can’t make discrete forms—like a nose. There’s something else going on. For instance... deer grow antlers every season (antlers are not horns; rather, they are complex structures with tissue, bone, skin, nerves, etc) Anyway, if a growing antler is nicked, scar tissue will form... no big deal, right? But, this is where it gets weird... When the antlers fall off and then grow the following year, the scar will be present on the new antlers. Let that sink in.
zck 5y ago
Any idea if your fingerprints are the same as before?
- tata71 5y ago
  Good point, is identical only an assumption?
  - BrazzVuvuzela 5y ago
    It seems somewhat plausible. Identical twins often have broadly similar, although still distinct, fingerprints: https://pubmed.ncbi.nlm.nih.gov/22558204/ https://pubmed.ncbi.nlm.nih.gov/22558204/
  - lostlogin 5y ago
    Maybe everyone should get their prints on record as a way of verifying in the future.
    - oynqr 5y ago
      Nice try.
    - ajuc 5y ago
      Aren't we already doing this (see smartphones).
akomtu 5y ago
Some time ago there was a post on HN about one scientist who made a simple organism to grow two heads by messing with the intercellular magnetic fields. No DNA changes, just magnetic fields. There's a way to check this hypothesis without cutting fingers. Salamanders can regrow tails. So get a salamander, cut its tail, use some magnetic field generator to mess with the regrowth process and see what happens.
- inglor_cz 5y ago
  The scientist is Michael Levin and his work, while absolutely legit, is so far from current mainstream that I am a bit afraid it might not be adapted for medical use in our lifetimes. Or possibly only after a major upheaval, much like mRNA deployment was accelerated by Covid. (mRNA co-pioneer Dr. Katalin Karikó ran into similar problems - the concept of mRNA was too revolutionary to be fully grasped by the PennU administration.) https://wyss.harvard.edu/news/mike-levin-on-electrifying-insights-into-how-bodies-form/ https://wyss.harvard.edu/news/mike-levin-on-electrifying-ins... https://www.newyorker.com/magazine/2021/05/10/persuading-the-body-to-regenerate-its-limbs https://www.newyorker.com/magazine/2021/05/10/persuading-the...
temp8964 5y ago
One of my finger nail was wrecked last year and it looked horrible. I thought it would never grow back. Now I can’t even tell which one had been wrecked.
frogulis 5y ago
> I punched a nice groove around 3mm deep into the tip of another finger tip while trying to get tea out of a tea tube Out of curiosity, how did this happen? Is the opening sharp?
- lqet 5y ago
  Its not that sharp, its a tube of brushed aluminium around, around 2cm in diameter, the walls ca. 1 mm thick. It's tapered at the top (which can be seen in the image). I put tea in there and coudldn't get it out after it had swollen in the hot water. I opened the bottom, put the handle of a wooden cooking spoon in, hold the cooking spoon with both hands and pushed the tea tube against a wall. The tea suddenly gave loose, and the tea tube shot down the cooking spoon to where my hand was holding it. It only hurt after the shock of seeing a groove in my fingertip was over, and it seemed like and eternity until there was blood (but then lots of it).
l2p 5y ago
Regarding how the body "knows" how to form missing pieces, might be worth checking out Michael Levin's research regarding bio-electricity. Most interesting finding to me is that once modified, the animal bodies continue to produce different parts as if there is some electrical "memory" in the cells. Here is an overview video: https://www.youtube.com/watch?v=XheAMrS8Q1c https://www.youtube.com/watch?v=XheAMrS8Q1c, though there are much longer lectures and papers which I would recommend if you are interested.
- lifeplusplus 5y ago
  even more crazy : https://phys.org/news/2013-07-flat-worms-retain-memories-decapitation.html https://phys.org/news/2013-07-flat-worms-retain-memories-dec...
- spyder 5y ago
  Another related article: https://knowablemagazine.org/article/living-world/2020/how-do-bodies-position-arms-legs-wings-and-organs https://knowablemagazine.org/article/living-world/2020/how-d...

by lqet 5y ago

pkaye 5y ago

My finger tip got pinched under a lid and a small chunk was torn off but somehow it all healed with matching fingerprints that blends in.

galangalalgol 5y ago

I caught my finges in the chain of a swing as a child and tore about half the pad of my pinkies away to a similar depth, one narrow strip was still attached so I held it on with bandaids after washing it. It grew back together but now there is an offset or fault line in my print.

deleted 5y ago
[deleted]
johnwalkr 5y ago
At first I thought you meant to write fingers, then I realized your must have been referring to the truncated fingers, that is “finges”. Did you just do that on your own without telling an adult? I totally did similar things. I cut my thumb to the bone when I was 10 by whittling a stick towards myself, and I also have a fault line there now.

GauntletWizard 5y ago

Pure wild speculation: I suspect that an awful log of our biological form is fractals formed from chemical gradients, with our DNA controlling the amounts of each chemical, both how fast they're produced and consumed. Included in this are some wild "Programs" were Chemical A causes Chemical B to be produced, Chemical B produces Chemical C and chemical C shuts off chemical A - In wild patterns that eventually form the beauty of our bodies. On a mass scale, with dozens of signaling chemicals and switches flipped - Organelle A produces chemical B and C and they osmose. B spreads far and wide, and an organ grows wherever B is concentrated. C doesn't spread, and eventually it grows concentrated enough to shut itself off. Thus, the physical limits of a body are formed. Fingerprints would then be where this all happens on a micro scale - Running the game of life in 3d on the cells of your body, until they reach an "end state" of a stable limit of your skin.

nvrspyx 5y ago
You might be interested in reading up on homeobox genes. https://en.m.wikipedia.org/wiki/Homeobox https://en.m.wikipedia.org/wiki/Homeobox
Retric 5y ago
There are several parts embryo development that does operate on chemical gradients especially the initial stages. But like most of biology it gets really complex and isn’t limited to any one approach. For example as you gain fat tissue you need to increase the number of capillaries feeding that tissue, which in tern needs to link up to arterioles and arteries on one side and veins on the other. https://www.ncbi.nlm.nih.gov/books/NBK53238/ https://www.ncbi.nlm.nih.gov/books/NBK53238/ This happens well into adulthood.
lurquer 5y ago
Turing’s diffusion/reaction algorithm involved this. As you intuited, it is a good system for making fractal-like designs and patterns. Cheetah spots, zebra stripes, maybe even 3D structures like capillaries... But, such a system can’t make discrete forms—like a nose. There’s something else going on. For instance... deer grow antlers every season (antlers are not horns; rather, they are complex structures with tissue, bone, skin, nerves, etc) Anyway, if a growing antler is nicked, scar tissue will form... no big deal, right? But, this is where it gets weird... When the antlers fall off and then grow the following year, the scar will be present on the new antlers. Let that sink in.

zck 5y ago

Any idea if your fingerprints are the same as before?

tata71 5y ago
Good point, is identical only an assumption?
- BrazzVuvuzela 5y ago
  It seems somewhat plausible. Identical twins often have broadly similar, although still distinct, fingerprints: https://pubmed.ncbi.nlm.nih.gov/22558204/ https://pubmed.ncbi.nlm.nih.gov/22558204/
- lostlogin 5y ago
  Maybe everyone should get their prints on record as a way of verifying in the future.
  - oynqr 5y ago
    Nice try.
  - ajuc 5y ago
    Aren't we already doing this (see smartphones).

akomtu 5y ago

Some time ago there was a post on HN about one scientist who made a simple organism to grow two heads by messing with the intercellular magnetic fields. No DNA changes, just magnetic fields. There's a way to check this hypothesis without cutting fingers. Salamanders can regrow tails. So get a salamander, cut its tail, use some magnetic field generator to mess with the regrowth process and see what happens.

inglor_cz 5y ago
The scientist is Michael Levin and his work, while absolutely legit, is so far from current mainstream that I am a bit afraid it might not be adapted for medical use in our lifetimes. Or possibly only after a major upheaval, much like mRNA deployment was accelerated by Covid. (mRNA co-pioneer Dr. Katalin Karikó ran into similar problems - the concept of mRNA was too revolutionary to be fully grasped by the PennU administration.) https://wyss.harvard.edu/news/mike-levin-on-electrifying-insights-into-how-bodies-form/ https://wyss.harvard.edu/news/mike-levin-on-electrifying-ins... https://www.newyorker.com/magazine/2021/05/10/persuading-the-body-to-regenerate-its-limbs https://www.newyorker.com/magazine/2021/05/10/persuading-the...

temp8964 5y ago

One of my finger nail was wrecked last year and it looked horrible. I thought it would never grow back. Now I can’t even tell which one had been wrecked.

frogulis 5y ago

> I punched a nice groove around 3mm deep into the tip of another finger tip while trying to get tea out of a tea tube Out of curiosity, how did this happen? Is the opening sharp?

lqet 5y ago
Its not that sharp, its a tube of brushed aluminium around, around 2cm in diameter, the walls ca. 1 mm thick. It's tapered at the top (which can be seen in the image). I put tea in there and coudldn't get it out after it had swollen in the hot water. I opened the bottom, put the handle of a wooden cooking spoon in, hold the cooking spoon with both hands and pushed the tea tube against a wall. The tea suddenly gave loose, and the tea tube shot down the cooking spoon to where my hand was holding it. It only hurt after the shock of seeing a groove in my fingertip was over, and it seemed like and eternity until there was blood (but then lots of it).

l2p 5y ago

Regarding how the body "knows" how to form missing pieces, might be worth checking out Michael Levin's research regarding bio-electricity. Most interesting finding to me is that once modified, the animal bodies continue to produce different parts as if there is some electrical "memory" in the cells. Here is an overview video: https://www.youtube.com/watch?v=XheAMrS8Q1c https://www.youtube.com/watch?v=XheAMrS8Q1c, though there are much longer lectures and papers which I would recommend if you are interested.

lifeplusplus 5y ago
even more crazy : https://phys.org/news/2013-07-flat-worms-retain-memories-decapitation.html https://phys.org/news/2013-07-flat-worms-retain-memories-dec...
spyder 5y ago
Another related article: https://knowablemagazine.org/article/living-world/2020/how-do-bodies-position-arms-legs-wings-and-organs https://knowablemagazine.org/article/living-world/2020/how-d...