4 ms·

We should be able to find the impact geological records and build a probability model.

javajosh 5y ago
Did even Tunguska have a geological impact? And also, since 75% of the Earth is covered in water, it stands to reason that 75% of bolides exploded over an ocean, with literally no impact we could meaningfully measure. My point is that human cities are "bolide sensors" and unevenly distributed in time and space, so the "measurements" are necessarily fewer than what occurs in nature.
- staplung 5y ago
  Best definition of a city ever: “bolide sensor”. Love it
- jacquesm 5y ago
  trees flattened in a radial pattern might show up in the geological record somehow.
  - gota 5y ago
    Unlikely after several years, let alone several thousands, right?
  - bell-cot 5y ago
    It would require coordinated excavation over how many square miles, to spot the radial pattern? (Assuming, as gota points out, that the fallen trees were somehow preserved.) Then there's bolides over desert, savanna, tundra, ice sheets, etc.
- heavyset_go 5y ago
  Yes, there is geological evidence that the Tunguska event was a bolide explosion.
dogma1138 5y ago
Impacts of this size don’t leave enough evidence for you to know where to look, especially after 1000’s of years of man caused and natural erosion. An air burst impact that’s large enough to take out a city won’t leave a major impact crater. And back in the day it might even be the case of the perceived cause contributing more to the decline of a city or even an empire than the physical damage. If a meteor hit blows up your town when you have no ability to comprehend what just happened other than god/gods are angry you gonna move to a less cursed place. It can also cause social impacts such as the toppling of a given religious or leadership class because they angered the gods.
- koheripbal 5y ago
  OP's analysis demonstrates that it's very possible to detect theses events 1000s of years later, if you examine areas near the explosion.
  - gota 5y ago
    Yes, but they are testing the area because we know a settlement there was destroyed. We'd have to test random uninhabited (or at least currently uninhabited) areas for which there are no indications of anything special to get a better picture And not even that guarantees a complete picture - what if a tsunami event erases or conceals the record of something like this? Volcanic activity? Desertification? My point is that we can't reason about the rarity or uniqueness of these events as a main factor for accepting or refuting the hypothesis

Did even Tunguska have a geological impact? And also, since 75% of the Earth is covered in water, it stands to reason that 75% of bolides exploded over an ocean, with literally no impact we could meaningfully measure. My point is that human cities are "bolide sensors" and unevenly distributed in time and space, so the "measurements" are necessarily fewer than what occurs in nature.

staplung 5y ago
Best definition of a city ever: “bolide sensor”. Love it
jacquesm 5y ago
trees flattened in a radial pattern might show up in the geological record somehow.
- gota 5y ago
  Unlikely after several years, let alone several thousands, right?
- bell-cot 5y ago
  It would require coordinated excavation over how many square miles, to spot the radial pattern? (Assuming, as gota points out, that the fallen trees were somehow preserved.) Then there's bolides over desert, savanna, tundra, ice sheets, etc.
heavyset_go 5y ago
Yes, there is geological evidence that the Tunguska event was a bolide explosion.

dogma1138 5y ago

Impacts of this size don’t leave enough evidence for you to know where to look, especially after 1000’s of years of man caused and natural erosion. An air burst impact that’s large enough to take out a city won’t leave a major impact crater. And back in the day it might even be the case of the perceived cause contributing more to the decline of a city or even an empire than the physical damage. If a meteor hit blows up your town when you have no ability to comprehend what just happened other than god/gods are angry you gonna move to a less cursed place. It can also cause social impacts such as the toppling of a given religious or leadership class because they angered the gods.

koheripbal 5y ago
OP's analysis demonstrates that it's very possible to detect theses events 1000s of years later, if you examine areas near the explosion.
- gota 5y ago
  Yes, but they are testing the area because we know a settlement there was destroyed. We'd have to test random uninhabited (or at least currently uninhabited) areas for which there are no indications of anything special to get a better picture And not even that guarantees a complete picture - what if a tsunami event erases or conceals the record of something like this? Volcanic activity? Desertification? My point is that we can't reason about the rarity or uniqueness of these events as a main factor for accepting or refuting the hypothesis