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  • Scientists claim that the earth's magnetic poles will reverse within the next few thousand

  • years.

  • So why does that happen?

  • And what exactly does it mean for us?

  • Hey guys, Tara here for Dnews - and something that's always fascinated me, is the earth's

  • magnetic field.

  • Maybe it's because we can't see it with our own eyes, so it's this elusive thing

  • that we pretty much assume to be constant.

  • Believe it or not though, the north and south poles we know today, weren't always that

  • way.

  • 786,000 years ago - the earth's magnetic field flipped - and it's remained constant

  • ever since.

  • But before that happened, south was actually north - and what we now know as north, was

  • south.

  • According to scientists, every half million years or so - the earth's dipole magnetic

  • field, which you can imagine like a bar magnet with a north end and a south end, starts to

  • weaken, before eventually reversing completely.

  • No one is really sure why it happens, but it's thought to be caused by changes in

  • the fluid portion of the earth's iron core.

  • Up until recently, scientists presumed this reversal process took a few thousand years

  • - but new evidence suggests that the most recent major reversal 786,000 years ago - actually

  • happened in less than 100 years - roughly the span of a single lifetime.

  • Obviously, flips like this have occurred several times throughout Earth's history.

  • But the next one, scientists say, may happen within the next few thousand years.

  • New evidence indicates that the intensity of the Earth's magnetic field is decreasing

  • at a rate 10 times faster than normal, leading many geophysicists to believe that we're

  • on the brink of another reversal.

  • So what would happen if that did occur?

  • Would there be any noticeable changes?

  • Well, the good news is - there are no documented catastrophes associated with past reversals.

  • So you shouldn't expect the human race to immediately die out.

  • But that doesn't mean nothing bad could happen.

  • A magnetic reversal would almost surely wreak havoc on our electrical grid, which could

  • potentially bring it down.

  • It would also make us vulnerable to energetic particles from the sun and cosmic rays - both

  • of which can cause genetic mutations.

  • And that could happen before the reversal even takes place.

  • Like I described earlier, there's a period prior to reversals where the magnetic field

  • gets progressively weaker, and the genetic mutations that arise from that, could potentially

  • increase cancer rates.

  • So the longer it takes for that reversal process to complete, the more harmful it would be

  • to us.

  • Also worth mentioning, is the fact that even though the last reversal only took 100 years

  • - it was preceded by a period of magnetic instability that spanned over 6,000 years.

  • Meaning if the next reversal happens within a few thousand years, we could start seeing

  • the effects of it - very soon.

  • Kinda scary to think about it.

  • But at the same time - it's not likely that any of this will affect us in our lifetime.

  • So, before you start packing up your family and moving off the grid, Doomsday Preppers-style,

  • just remember that.

  • It's probably not worth it.

  • What do you guys think though, are you worried about this?

  • You can lay it all out for us in the comments right down there - or if you wanna get in

  • touch with me on Twitter, you can do so at @TaraLongest.

  • That's it for me, but as always - thank you guys for watching.

Scientists claim that the earth's magnetic poles will reverse within the next few thousand


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B1 中級 美國腔

当地球的磁极反转时会发生什么?(What Happens When Earth’s Magnetic Poles Reverse?)

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    joey joey 發佈於 2021 年 04 月 28 日