As I understand the way X-Rays work, some of the particles make it through your body and some don’t. It’s determined by the density of that part of your body. Bone and skin deflect a certain amount of X-Rays and they don’t hit the detector which reveals information about the structure contained therein.
How small of a particle would you have to use (and how many), to get the same effect for the whole planet? Is there a particle small enough that would allow us to scan the earth like this? I understand that some particles are so small they can pass right through our planet without hitting anything.
It sure would be a useful tool for geologists, but Big Brother would have some serious powers. It’s all hypothetical, I’m just wondering if such a thing is possible theoretically.
Well, x-rays wouldn’t work, they don’t pass thru 99+% of the earth’s material. Neutrinos wouldn’t work either, they pass thru everything. You need a particle that will pass easily thru some of the earth’s structure, less easily thru others, and not at all thru still more. You’d also need a really, really big particle collector (analogous to x-ray film) on the back side of the planet.
Oh yeah, you’d have to use non-ionizing radiation, or the action of taking the picture could wipe out all life on earth.
Don’t geologist not already do something very like this using sound waves? They measure the noise from earthquakes and volcanoes as it reaches all other parts of the world. This tells them a lot about the intervening rock.
Don’t neutrinos occaisionaly hit something. Like a single atom in a water tank in a cave somewhere? Maybe you could use them, you’d just have to use a whole hell of alot of them.
The detector on the back-side of the planet would probably have to be some sort of magnetic/energy field which would be able to detect neutrino (or whatever particle is suitable) hits.
We definately don’t want to kill everyone. maybe I should hold back for a little while till I get the kinks worked out.
Yep, acoustic waves, transmitted, reflected or refracted, are our primary means of remotely imaging the interior of the earth.
On a global scale they allow us to to track and pinpoint seismic and volcanic events, and the inability of shear waves to propogate through liquids were a key to our divining the molten outer core of the earth. Recording of acoustic energy is also used extensively on a local scale to map subsurface geology within the crust.
Other methods, such as potential fields studies (gravity and magnetics) and surface mapping, are integrated into the whole picture, but the transmission of acoustic energy is the greatest contributor, so far, to our understanding of the earth’s interior.