4 ms·

In rough agreement with you, but have a quibble about your second point. As far as I understand it, while the lower atmosphere does provide significant protecti

by ktizo 14y ago

In rough agreement with you, but have a quibble about your second point. As far as I understand it, while the lower atmosphere does provide significant protection, the ionosphere does have a substantial role to play as well. Here is a very brief outline of this from everyone's favourite experimental nutter-magnet/atmospheric testing facility, HAARP: http://www.haarp.alaska.edu/haarp/ion3.html http://www.haarp.alaska.edu/haarp/ion3.html [edit] Just thought and realised that the ionosphere is very little to do with the issue. I should really be talking about the magnetosphere and how it helps protect us from highly energetic particles in the solar wind. So my quibble still stands, but my reasoning was a big steaming pile of monkey poo.

Retric 14y ago
Charged particles are the only thing affected by the earths magnetic field and they tend to be absorbed easily. Especially when they would need to get though 10+ miles of dense atmosphere to get to us. Alpha Radiation can travel a few inches in the air. Beta Radiation can travel a few feet in the air but far less than 50% can make it though 100 feet of air. So for 1 mile of atmosphere you would leave 1/2^52 of them.
- ktizo 14y ago
  But at ground level, cosmic radiation accounts for apparently an average of around 11% of ionising radiation exposure and this is measurably affected by the interaction of the solar wind with the magnetosphere according to experiment, or at least according to the nice graph on this page - http://www.sievert-system.org/WebMasters/en/contenu_rayonnement.html http://www.sievert-system.org/WebMasters/en/contenu_rayonnem... [edit] I think I remember reading somewhere that a strong magnetosphere also reduces the erosion of the atmosphere, but I suspect that this would not be a particularly important effect over the timespan of a magnetic flip, otherwise we would not be here to worry about it. [edit] Have just gone and had a good look at this and it would appear that while there is an increase in cosmic rays at the earth's surface when the magnetic field is reduced, this basically has negligible effect when compared to other sources of ionising radiation exposure - http://www-istp.gsfc.nasa.gov/Education/FAQs7.html#q104 http://www-istp.gsfc.nasa.gov/Education/FAQs7.html#q104 - so I was talking monkey poo all along. Oh well. Quibble revoked. However I did learn a little bit about oh-my-god particles while looking into this - http://www.fourmilab.ch/documents/OhMyGodParticle/ http://www.fourmilab.ch/documents/OhMyGodParticle/ - which are really, really cool. :)

by ktizo 14y ago

Retric 14y ago

Charged particles are the only thing affected by the earths magnetic field and they tend to be absorbed easily. Especially when they would need to get though 10+ miles of dense atmosphere to get to us. Alpha Radiation can travel a few inches in the air. Beta Radiation can travel a few feet in the air but far less than 50% can make it though 100 feet of air. So for 1 mile of atmosphere you would leave 1/2^52 of them.

ktizo 14y ago
But at ground level, cosmic radiation accounts for apparently an average of around 11% of ionising radiation exposure and this is measurably affected by the interaction of the solar wind with the magnetosphere according to experiment, or at least according to the nice graph on this page - http://www.sievert-system.org/WebMasters/en/contenu_rayonnement.html http://www.sievert-system.org/WebMasters/en/contenu_rayonnem... [edit] I think I remember reading somewhere that a strong magnetosphere also reduces the erosion of the atmosphere, but I suspect that this would not be a particularly important effect over the timespan of a magnetic flip, otherwise we would not be here to worry about it. [edit] Have just gone and had a good look at this and it would appear that while there is an increase in cosmic rays at the earth's surface when the magnetic field is reduced, this basically has negligible effect when compared to other sources of ionising radiation exposure - http://www-istp.gsfc.nasa.gov/Education/FAQs7.html#q104 http://www-istp.gsfc.nasa.gov/Education/FAQs7.html#q104 - so I was talking monkey poo all along. Oh well. Quibble revoked. However I did learn a little bit about oh-my-god particles while looking into this - http://www.fourmilab.ch/documents/OhMyGodParticle/ http://www.fourmilab.ch/documents/OhMyGodParticle/ - which are really, really cool. :)