Re: nincs cím

Háttt az a forásmunka úgy érzem nem a topot képviseli mondjuk itt kivágva a lényeg ami adatot is tartalmaz, ami nem árt ha okoskodunk :)

"Earth's magnetic field is thought to be generated deep inside the planet. An inner core of solid iron is surrounded by an outer core of molten iron. They rotate at different rates, and the interaction between the regions creates what scientists call a "hydromagnetic dynamo." It's something like an electric motor, and it generates a magnetic field akin to a giant bar magnet.

The process is not completely understood. In fact, one study suggests the planet's mantle, which surrounds the core, also plays a role.

However it works, the setup has been in place for at least 3 billion of Earth's 4.6 billion years, scientists figure. But the field is shifty, periodically growing stronger and weaker, moving around, and even flipping its polarity entirely.

In the past 15 million years, there have been four reversals every 1 million years, or about one shift each 250,000 years, Clement explained. The last one, however, was 790,000 years ago. That might suggest we're overdue for a big change. Not necessarily so, Clement says. The flips are not periodic, meaning they don't adhere to a schedule of even intervals.

Yet the intensity of the magnetic field has been dropping for the last 2,000 years, and "it has dropped significantly" during the past two decades, Clement said. One recent study shows the decline in strength amounts to 10 percent over the last 150 years.

"

Tehát a mágneses mezőben komoly változások vannak ez előjel is lehet, de kétségtelen h csúszhat 2-3000 évet ami minket megment :), de a föld korához mérve apró bizonytalanságot jelent csak :)

Akkor hajrá hajrá szelektiv hulladékgyüjtés :), nem hiszem h erről bárki lebeszélne, én biztos nem :)