3 ms·

Excellent science. Of course, in retrospect, makes complete sense. Radiation is used to sterilize food, so it's not surprising that it is doing the same thing t

Excellent science. Of course, in retrospect, makes complete sense. Radiation is used to sterilize food, so it's not surprising that it is doing the same thing to the forest.

marcosdumay 13y ago
I'm surprised. I'd expect micro-organisms to adapt faster to radiation than plants, not slower.
- yk 13y ago
  My guess is, for a micro-organism death of a single cell is deadly. So the first photon that comes along kills. ( A bit more formal, irradiation effects are probably proportional to the surface area, while available cells, and thus ratio of destruction, is probably proportional to the volume. So relative damage is proportional to 1/size.)
  - Dylan16807 13y ago
    That doesn't make any sense to me. I can't imagine any quasi-realistic situation where irradiation would be proportional to surface area.
    - yk 13y ago
      Well cross section, which is in a quite handwaving way proportional to surface area.
      - Dylan16807 13y ago
        But radiation can go through without impacting anything. Absorption should be roughly proportional to total mass/volume. Even if it didn't penetrate then some cells/rocks/dirt would shade others from the danger and the average radiation would still be based on mass/volume. I mean it's not like treating a human body as individual cells, increasing surface area a millionfold, would change the dose.
  - dalke 13y ago
    All light is made of photons. I think you mean "ionizing radiation", which includes gamma rays (photons), as well as alpha particles, beta particles, neutrons, etc. I concur with Dylan16807; your physical model makes no sense. It means that viruses would be killed if a gamma ray sneezed nearby, and it doesn't explain D. radiodurans survivability. It's likely going to be a function of DNA size, ability to repair DNA, redundancy in the DNA, and lack of easily induced damaging side effects. None of which are strongly correlated to cell volume.
    - yk 13y ago
      I am not talking about cell volume, I am talking about number of cells. So if a single celled organism is hit by a gamma ray and a cell dies, it is dead. If a tree looses a single cell, it will probably survive.
      - dalke 13y ago
        A single gamma ray rarely kills any cell, just like a single gamma ray rarely kills a tree. If there is a ton of single celled organisms, and enough radiation to kill 1/2 of them, then 1/2 a ton of single celled organisms remain. If there is a ton of tree, and enough radiation to kill 1/2 of the cells, then the tree is almost certainly dead. And if I read the numbers correctly, you'll likely need more radiation to kill a single celled organism cell than a tree cell.

Excellent science. Of course, in retrospect, makes complete sense. Radiation is used to sterilize food, so it's not surprising that it is doing the same thing to the forest.

marcosdumay 13y ago

I'm surprised. I'd expect micro-organisms to adapt faster to radiation than plants, not slower.

yk 13y ago
My guess is, for a micro-organism death of a single cell is deadly. So the first photon that comes along kills. ( A bit more formal, irradiation effects are probably proportional to the surface area, while available cells, and thus ratio of destruction, is probably proportional to the volume. So relative damage is proportional to 1/size.)
- Dylan16807 13y ago
  That doesn't make any sense to me. I can't imagine any quasi-realistic situation where irradiation would be proportional to surface area.
  - yk 13y ago
    Well cross section, which is in a quite handwaving way proportional to surface area.
    - Dylan16807 13y ago
      But radiation can go through without impacting anything. Absorption should be roughly proportional to total mass/volume. Even if it didn't penetrate then some cells/rocks/dirt would shade others from the danger and the average radiation would still be based on mass/volume. I mean it's not like treating a human body as individual cells, increasing surface area a millionfold, would change the dose.
- dalke 13y ago
  All light is made of photons. I think you mean "ionizing radiation", which includes gamma rays (photons), as well as alpha particles, beta particles, neutrons, etc. I concur with Dylan16807; your physical model makes no sense. It means that viruses would be killed if a gamma ray sneezed nearby, and it doesn't explain D. radiodurans survivability. It's likely going to be a function of DNA size, ability to repair DNA, redundancy in the DNA, and lack of easily induced damaging side effects. None of which are strongly correlated to cell volume.
  - yk 13y ago
    I am not talking about cell volume, I am talking about number of cells. So if a single celled organism is hit by a gamma ray and a cell dies, it is dead. If a tree looses a single cell, it will probably survive.
    - dalke 13y ago
      A single gamma ray rarely kills any cell, just like a single gamma ray rarely kills a tree. If there is a ton of single celled organisms, and enough radiation to kill 1/2 of them, then 1/2 a ton of single celled organisms remain. If there is a ton of tree, and enough radiation to kill 1/2 of the cells, then the tree is almost certainly dead. And if I read the numbers correctly, you'll likely need more radiation to kill a single celled organism cell than a tree cell.