Magnetic reversal

[Ninurta]

What does this mean? I really am NOT scientific at all... If someone could explain a bit, like you would explain to an 8 year old.

Earth has a magnetic field. That magnetic field is generated by a molten iron/nickel core of the planet differentially rotating, The field is what makes compasses work, and tells them which direction to point. It is also what creates the aurora borealis, as the magnetic filed "funnels" charged particles of the solar wind towards the poles.

Over geological time, that magnetic field has shifted, and swapped poles several times - about every 300,000 years or so, on average, so it's nothing new. The last time it happened was about 780,000 years ago, so we are overdue for a shift by roughly 480,000 years. It WILL happen again, and again, and again, but no one knows exactly when.

Will the compass work differently?

Yes. The north end of the needle will always point towards magnetic "north", and some current projections I've seen place the new magnetic north in the area of the South Pacific - but those are only projections. No one knows, with any degree of certainty, where it will settle in when it settles down.

During the shift, the field will get weaker and even disappear altogether at times, and during those times the compass will have no idea where to point. It is weakening right now, but not yet enough to affect compasses. A weakened or non-existent field during the shift will also expose the Earth's surface to bombardment by cosmic radiation, which is something the field currently protects us from, just as it funnels particles to the Northern Lights.

Life will survive, however. It has already managed to survive through numerous previous magnetic shifts.

Will the birds find their destination?

No. Most birds navigate by means of a magnetic organ in their head. In effect they have a built-in compass. They will likely go through a period of confusion before they become adjusted to the new "north". They will probably find new destinations as well.

Is it SURE that this will happen?

100% certain. It's not a matter of "if", it's just a matter of "when". It could be tomorrow, it could be 100,000 years from now. Current indications are sooner rather than later. Those indications include the current weakening of the field in combination with the "galloping" it has been undergoing for the last 20 or 30 years, huge shifts in where the north magnetic pole is located from year to year. Several years ago it started moving in huge bounds and in a straight line towards Russia from it's then current location. For the 400 years before that, it was just meandering in a relatively small area just north of Hudson's Bay in Canada. Then it suddenly set a course for Russia.