3 ms·
There is something off about the numbers. Ordinary, day to day auroras can locally reverse the magnetic field. So, maybe the average change was less than 10% of
by goodcanadian 5y ago
There is something off about the numbers. Ordinary, day to day auroras can locally reverse the magnetic field. So, maybe the average change was less than 10% of the average magnetic field, but I've no doubt that local variation can be much, much higher.
And reading further down, the article claims the change in magnetic field is slow. It's not. It's very fast.
The article does not get the basic physics correct. The one thing that is correct is that it is unlikely to damage your cell phone. What will happen is that massive currents will be induced in transmission lines blowing up transformers and possibly damaging anything plugged into mains.
- altcognito 5y agoThe more localized the change in the magnetic field, the less it matters.
- goodcanadian 5y agoLocalised is relative. We're still talking about currents circling a significant portion of the planet twisting back and forth.
- pfdietz 5y ago> And reading further down, the article claims the change in magnetic field is slow. It's not. It's very fast. The average speed of a CME is 500 km/s. I think they've been seen to go as fast as 3000 km/s. At 3000 km/s, that would take about 4 seconds to traverse the diameter of the Earth, and much longer to traverse the magnetosphere. I would call that slow, especially compared to the timescale of the EMP from a nuclear weapon.
- goodcanadian 5y agoYes, but it is not a single event, it generates currents in the ionosphere that move and jump around. Magnetic field lines break and reconnect. The event lasts for hours. The magnetic field at a particular place may reverse several times and the reverses can happen suddenly. But no, it is not like an EMP. That is the wrong way to think about it.
- deleted 5y ago[deleted]