# Would life be any different if the Earth's poles weren't magnetic? **URL:** \ **Category:** Factual Questions\ **Created:** [September 25, 2012, 6:31am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753 "2012-09-25T06:31:16Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [September 25, 2012, 6:31am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/1 "2012-09-25T06:31:16Z")
I know some animals, mostly birds, use the magnetic field of the Earth as an aid in navigation, but am not sure if it has other important uses. If, by chance, the Earth did not have this magnetic field, would life have evolved any differently? Are there things that wouldn’t have happened, like maybe it affects the rotation of the Earth, or the weather, or something? Basically I’m asking, what does it actually do? ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [September 25, 2012, 6:42am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/2 "2012-09-25T06:42:26Z")
If not for the Earth’s magnetic field, there would probably be no life at all. One of its important tasks is to shield the Earth from the solar wind, which would strip the Earth of much of its atmosphere. Earth would become much like Mars, which has no magnetic field and a very thin atmosphere. ---
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [September 25, 2012, 8:48am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/3 "2012-09-25T08:48:44Z")
Huh. Okay then. Why are we looking for life on Mars if it’s impossible without a magnetic field? ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [September 25, 2012, 8:53am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/4 "2012-09-25T08:53:01Z")
> [@GuanoLad](#): > > Huh. Okay then. Why are we looking for life on Mars if it’s impossible without a magnetic field? They are not looking for life on Mars, they don’t have the equipment - they are looking for _the conditions that may have supported life_. Also, while Mars no longer has a magnetic field, this may not have always been the case. And Mars is a long way out from Earth - the Solar Wind is less intense out there (but it has stripped most of the Martian Atmosphere away). Si ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [September 25, 2012, 8:54am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/5 "2012-09-25T08:54:13Z")
Life _as you commonly think of it_ \*\*may \*\*be impossible without a magnetic field to shield it. But in recent times we’ve discovered life almost everywhere on earth we’ve looked - kilometres deep underground, under the antarctic ice, in boiling hot water deep in the ocean, you name it. Places like that would be shielded from solar wind. ---
**Author:** ![BMax](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bmax/32/4267_2.png) [@BMax](https://boards.straightdope.com/u/BMax)\ **Post date:** [September 25, 2012, 9:17am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/6 "2012-09-25T09:17:14Z")
Isn’t the earth’s magnetic field a result of the inner molten core? > **[Earth's magnetic field](https://en.wikipedia.org/wiki/Earth's_magnetic_field)** > > Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo. > The ma... Isn’t it tied in with plate tectonics, vis a vis the crust floating on the mantle? ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [September 25, 2012, 9:35am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/7 "2012-09-25T09:35:35Z")
> [@BMax](#): > > Isn’t the earth’s magnetic field a result of the inner molten core? Yes. Mars is smaller and has less iron, and the core has now solidified. It has not had a Magnetosphere for 4 billion years. Si ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [September 25, 2012, 10:36am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/8 "2012-09-25T10:36:38Z")
> [@cochrane](#): > > If not for the Earth’s magnetic field, there would probably be no life at all. One of its important tasks is to shield the Earth from the solar wind, which would strip the Earth of much of its atmosphere. Earth would become much like Mars, which has no magnetic field and a very thin atmosphere. Not only that, surely, but the Earth’s surface would be bombarded with a lot more radiation than it is, both from the Solar wind and cosmic rays. Currently, the magnetic field serves to deflect a lot of the radiation, which is largely charged particles many of which get trapped in the [van Allen belts](http://en.wikipedia.org/wiki/Van_allen_belt). ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [September 25, 2012, 1:34pm UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/9 "2012-09-25T13:34:14Z")
> [@Askance](#): > > Life _as you commonly think of it_ \*\*may \*\*be impossible without a magnetic field to shield it. But in recent times we’ve discovered life almost everywhere on earth we’ve looked - kilometres deep underground, under the antarctic ice, in boiling hot water deep in the ocean, you name it. Places like that would be shielded from solar wind. life may exist there but it might not have evolved there. it might have needed the surface to evolve. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [September 25, 2012, 2:42pm UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/10 "2012-09-25T14:42:18Z")
> [@cochrane](#): > > If not for the Earth’s magnetic field, there would probably be no life at all. One of its important tasks is to shield the Earth from the solar wind, which would strip the Earth of much of its atmosphere. Earth would become much like Mars, which has no magnetic field and a very thin atmosphere. Not necessarily; Venus has a much thicker atmosphere than Earth yet [doesn’t have a magnetic field](http://en.wikipedia.org/wiki/Venus#Magnetic_field_and_core). However, this resulted in the loss of lower molecular weight molecules like water, although I don’t know how relevant this would be to Earth, which is much cooler and has very little water vapor in the upper atmosphere. Radiation would still be a problem, but I imagine the presence of an atmosphere blocks some of it (gamma rays, x-rays and ultraviolet aren’t influenced by magnetic fields and energetic cosmic rays can penetrate Earth’s magnetic field). Also, Earth’s magnetic field periodically weakens in reversals and [there is no reliable evidence of adverse effects on life](http://en.wikipedia.org/wiki/Geomagnetic_reversal#Effects_on_biosphere_and_human_society) occurred during these periods (which have happened hundreds of times); one possibility is that the solar wind is enough to induce a magnetic field strong enough to prevent harmful radiation from reaching the surface (it should also be noted that this is only referring to the dipole component; weaker fields still exist): > [@](#): > > Detailed calculations confirm that, if the Earth’s dipole field disappeared entirely (leaving the quadrupole and higher components), most of the atmosphere would become accessible to high energy particles, but would act as a barrier to them, and cosmic ray collisions would produce secondary radiation of 10Be or 36Cl. There is evidence that this occurs both during secular variation[37][38] and during reversals… > > …Even if the magnetic field disappeared, the solar wind may induce a sufficient magnetic field in the Earth’s ionosphere to shield the surface from energetic particles… > > …Statistical analysis shows no evidence for a correlation between reversals and extinctions. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 25, 2012, 10:47pm UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/11 "2012-09-25T22:47:22Z")
Loss of atmosphere due to solar wind isn’t an instantaneous thing-- It takes a while. That’s why Earth doesn’t lose it all during the occasional field reversal, and why Mars seems to have had a significant atmosphere earlier in its history. ---
**Author:** ![Grrr](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/grrr/32/146_2.png) [@Grrr](https://boards.straightdope.com/u/Grrr)\ **Post date:** [September 26, 2012, 9:20am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/12 "2012-09-26T09:20:28Z")
Even if we could get past the solar winds sweeping away our atmosphere, we wouldn’t have any magnets, thus no electricity. (I’m going off of my memories of freshmen science class nearly 30 years ago. I could be wrong here.) ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [September 26, 2012, 11:39am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/13 "2012-09-26T11:39:34Z")
> [@Shakes](#): > > Even if we could get past the solar winds sweeping away our atmosphere, we wouldn’t have any magnets, thus no electricity. > > (I’m going off of my memories of freshmen science class nearly 30 years ago. I could be wrong here.) You are. Artificial magnets and magnetic fields aren’t dependent on the Earth’s magnetic field at all. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 26, 2012, 11:46am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/14 "2012-09-26T11:46:34Z")
> [@Shakes](#): > > Even if we could get past the solar winds sweeping away our atmosphere, we wouldn’t have any magnets, thus no electricity. > > (I’m going off of my memories of freshmen science class nearly 30 years ago. I could be wrong here.) Permanent magnets can and do exist independently of the earth’s magnetic field. ---
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [September 26, 2012, 11:51am UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/15 "2012-09-26T11:51:29Z")
> [@Shakes](#): > > Even if we could get past the solar winds sweeping away our atmosphere, we wouldn’t have any magnets, thus no electricity. Even though “how do magnets work?” was what originally inspired my train of thought to ask this question, I did know that bar magnetism has nothing to do with the Earth’s magnetic field. ---
**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\ **Post date:** [September 26, 2012, 2:37pm UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/16 "2012-09-26T14:37:24Z")
> [@Machine\_Elf](#): > > Permanent magnets can and do exist independently of the earth’s magnetic field. Not only that, but from what I can tell based off a quick google search, natural lodestone magnets don’t depend on the earth’s field to form. Most often they’re induced via lightning strikes on magnetite deposits. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [September 26, 2012, 3:22pm UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/17 "2012-09-26T15:22:50Z")
Even with no naturally occurring magnets at all, we could still produce electromagnets using electricity generated by chemical means. We’ve discovered a thousand year old battery: [Baghdad Battery - Wikipedia](http://en.wikipedia.org/wiki/Baghdad_Battery) it’ll probably delay our technology by several centuries though. I wonder what else we’re missing out on because they don’t occur naturally? Magnetic monopoles, hmm? ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [September 26, 2012, 4:09pm UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/18 "2012-09-26T16:09:02Z")
Well, this wouldn’t work: > [@](#): > > Archaeomagnetic dating is the study and interpretation of the signatures of the Earth’s magnetic field at past times recorded in archaeological materials. These paleomagnetic signatures are fixed when ferromagnetic materials such as magnetite cool below the Curie point, freezing the magnetic moment of the material in the direction of the local magnetic field at that point in time. The direction and magnitude of the magnetic field of the Earth at a particular location varies with time, and can be used to constrain the age of materials. In conjunction with techniques such as radiometric dating, the technique can be used to construct and calibrate the geomagnetic polarity time scale. This is one of the Dating methodologies used for sites within the last 10,000 years. > **[Archaeomagnetic dating](https://en.wikipedia.org/wiki/Archaeomagnetic_dating)** > > Archaeomagnetic dating is the study and interpretation of the signatures of the Earth's magnetic field at past times recorded in archaeological materials. These paleomagnetic signatures are fixed when ferromagnetic materials such as magnetite cool below the Curie point, freezing the magnetic moment of the material in the direction of the local magnetic field at that time. The direction and magnitude of the magnetic field of the Earth at a particular location varies with time, and can be used to... ---
**Author:** ![Grrr](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/grrr/32/146_2.png) [@Grrr](https://boards.straightdope.com/u/Grrr)\ **Post date:** [September 26, 2012, 4:29pm UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/19 "2012-09-26T16:29:17Z")
> [@GuanoLad](#): > > Even though “how do magnets work?” was what originally inspired my train of thought to ask this question, I did know that bar magnetism has nothing to do with the Earth’s magnetic field. OK. I believe you, but perhaps you (or somebody) can help refresh my memory. I vaguely remember that the magnetic rock got to be that way because the mineral (or whatever the hell it was) got to be that way because the Earth’s magnetic feild had permeated it for so long that the the magnetic poles _inside the mineral_ had aligned, thus causing it to be magnetic. What am I not remembering right? ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 26, 2012, 4:51pm UTC](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753/20 "2012-09-26T16:51:33Z")
> [@Shakes](#): > > I vaguely remember that the magnetic rock got to be that way because the mineral (or whatever the hell it was) got to be that way because the Earth’s magnetic feild had permeated it for so long that the the magnetic poles _inside the mineral_ had aligned, thus causing it to be magnetic. > What am I not remembering right? Yes, it’s true that some [lodestone](http://en.wikipedia.org/wiki/Lodestone) was naturally magnetized, and was at first the only source for magnets that could be used for making compasses. But they weren’t nearly strong enough for useful electric motors, so we make our own permanent magnets these days by exposing magnetizable materials to very strong electromagnets. If we lived on an earth with no magnetic field, it’s possible it might have taken us a bit longer to discover magnetism, but we would have figured it out eventually. [Next page](https://boards.straightdope.com/t/would-life-be-any-different-if-the-earths-poles-werent-magnetic/635753.md?page=2)