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Who cares about Earth's magnetic field and ozone layer?

  1. Jul 12, 2010 #1
    It seems to me that concern occasioned by the risks attendant on loss of the Earth's magnetic field is very nearly totally misplaced. Could someone please help me worry?:cool:
    I realise that popular science is largely hooey, but some items are so widely circulated that it is hard to find anything authoritative to debunk it. We are told that with out the Earth's magnetic field deflecting radiation from space, we would all be dead anyway, and if we were dead we wouldn't even be alive because there would be nothing for us to breathe, or something like that.:bugeye:!!)
    Now, I am sure that this makes good sense; how could it not, given that everybody knows it? And yet, the more I think about it, the more worried I am about not dying and all that. First of all, what radiation do we get from outer space? Neutrons? I hardly think so! There are not many fast neutron sources out there, especially not very close to the Earth. It would take a very, very fast neutron from say, the Sun to reach us in less than a few days, and a neutron’s half life, last time I didn't measure it, probably was around eight or 10 minutes. Never mind neutrons from neutron stars or anything like that!
    So let's accept (unless you know different!) That neutrons from space are not much of a worry. The rest of the nuclear zoo have even shorter half lives, except for the commoner nuclei, especially hydrogen (a.k.a. protons, and if you like, antiprotons), helium (a.k.a. Alpha particles), electrons (and of course positrons, a.k.a. beta particles if you like), and neutrinos. Am I forgetting any of note?
    Oh yes! And let's not forget all those photons bulleting at us! Mustn't forget the photons!
    Now, far be it from me to be negative, positronic though my brain is not, but I find it very difficult to get excited about the protective effect of our geomagnetic field on say, neutrinos, photons and the like. They may not be indifferent to magnetic fields, but I cannot imagine their being seriously affected by Earth's magnetic field. If they were going to hit us, it would not be the geomagnetic field that would deflect them, but the atmosphere. There are certain complications of course, such as ozone, but neutrinos pass through us routinely. Quite a few sneaked through while I was writing this, and serve me right no doubt! Gammas, x-rays, and most ultraviolet rarely get very far through the troposphere; in fact, most don't get very far through the stratosphere, geomagnetic field or no geomagnetic field.
    Not to make too much of a meal of it, non-charged intruders either get stopped in the atmosphere or hit us anyway.
    Now the charged particles. Protons and electrons currently (suit yourself about puns) get deflected by the geomagnetic field, and spiral in to entertain us with auroras in reds or blues and greens, depending on how far north or south we might be watching them. That is all very nice for people living on the equator, but for those near the poles it amounts, not so much to protection, as to concentrated incoming. Not much to thank our magnetic field for! What is it that makes me think that with out the field we would get more (and more diffuse) auroras and more diffuse exposure to charged particles. And then in any case, how many protons, electrons and alphas will get through the atmosphere except as hydrogen and helium? In which form they might be expected to do exactly what harm?
    I remark in passing that very likely our planet has had something like one or two thousand magnetic reversals since we (certain of our ancestors anyway) originally crawled out onto land. Each time, as far as we can tell, our projection was severely compromised at least, and yet none of our major extinctions seems to have had anything to do with space radiation. (Not that I was there to check, so if you know different, please tell us!)
    Bottom line to that bit: apart from homing pigeons and Boy Scouts with pocket compasses, who should care what happens to our magnetic field? (Actually, I would, but mostly because I like homing pigeons and scouts (Girl Scouts for preference!)) and in particular I love auroras.)
    Some people say that without our magnetic field, our atmosphere would be stripped away by charged particles. Perhaps, but I would love to see a cogent defence of that assertion. Surely it would be rather a slow process? After all most of the particles would simply be sopped up by the atmosphere, charged or not.
    And then again, what about the ozone layer? If we removed it, as some people claim we very nearly did, that would have no effect on our ultraviolet C in the stratosphere. How much effect would it have on our flux of ultraviolet B? And ultraviolet A? One hears such dread pronouncements on how sheep will be blinded and plants will be destroyed and plankton will be wiped out, and yet all of those sound to me like rubbish!
    Please correct me and tell me why I should run, not walk, to the nearest nuclear bomb shelter.
    Jon
     
    Last edited: Jul 12, 2010
  2. jcsd
  3. Aug 9, 2010 #2
    I think there is more to it then complete death or nothing. Its more about how humans' everyday life, effects on weather, technology etc. would have to change. There are studies that show Earth's magnetic field affects our brain's functionality/internal communication on the neuron level, not just birds and boyscout compasses. Shifts have happened multiple times through out Earth's history. Its just that man has never been here when it did. Whats more alarming IMO, is that atmospheric conditions are changing fast on all the planets in our solar system with our sun now towards the peak for sun spots and entering into an area of the galaxy that it hasn't been in for 26K years. A lot of debate on that too, near an energized cloud in space and what that means.

    In the recent years there was a solar flare that was the size of Jupiter (then separated into smaller ones) that reached the earth in 30 mins. Thats 97% the speed of light, scientists never thought it was possible or how it happened. Electronic signals on Earth were only disrupted. Now research shows the sun's solar flares could be even more powerful as it enters this new place in our galaxy and Earth at the weakest magnetic field in its history and/or ready to flip polls.

    The Magnetic field has to do with what happens at the center of the Earth's core as much as it does in space, maybe more...

    "In the center of the Earth, a di-pole magnet known as the Geo-Dynamo powers a magnetic current which, among other things, shields life from some lethal solar and cosmic rays, guides migration for many species, and protects our telecommunication systems. Between the gravitational tides of the moon (80%) and the sun (20%), the Earth gyrates in one direction. The core has two layers of molten Nickel Iron, spinning in opposite directions. Part of the problem is scientists have many competing theories why the Geo-Dynamo behaves the way it does. Some believe, since the moon moves further and further away from us every year that our core may slow down. Others speculate that when the Sun’s magnetic field aligns with Earth’s (North facing South) that this further destabilizes the magnetosphere.



    By measuring the magnetic polarity of sub-ocean volcanoes solidifying lava to rock, paleo-magnet-ologist determined that our planet’s poles reverse every few hundred thousand years. Although humans have never witnessed such an event, many believe that, since the last one occurred 780,000 years ago, a Geomagnetic Reversal is long overdue. According to the Associated Press,
    http://www.space.com/scienceastronomy/earth_magnetic_031212.html



    Now, if the magnetic poles swapped places, the magnetosphere would never vanish at near ground level. Although the currents may shrink in size due to entangling and destabilization for roughly 2,000-10,000 years, scientist have never correlated a pole switch to a mass extinction.

    (computer model of what a poll shift would look like in limbo) http://www.brighthub.com/science/space/articles/20617.aspx?image=47800



    That said, even just the weakening of the magnetosphere has already caused problems around the globe. Almost all life possesses magnetite in their brains to orient themselves, even human beings (though we seem to have lost the ability to use it). The process already wreaks havoc on the humpback whales, according to NOVA: Magnetic Storm—Impact on Animals:
    http://www.pbs.org/wgbh/nova/magnetic/animals.html

    Our technology in Earth’s orbit may be at risk as well. The Hubble Space Telescope, among other satellites, now must shut down when crossing over Brazil to compensate for the intense pocket of radiation known as the South Atlantic Anomaly. If the magnetosphere dips any lower, the weakening could affect international flights next.



    Much speculation follows the scenario of full-blown magnetic reversal. Conservatives argue not much will change at all, that it will happen so gradually that we will adapt. Others believe Earth would be susceptible to solar flares short-circuiting our power grid and that New York City may see its own aura borealis. Still, even more radical, some pseudo-scientists claim that a field inverse may trigger the release of the natural psychedelic molecule, Dimethyltryptamine (or DMT). Regardless, nobody wants the magnetic field to change anytime soon.



    Though the ebbs and flows of the magnetic currents may be natural, I feel it is unwise to leave it there and move on. Without causing doomsday panic, the general public should know more about the Geo-Dynamo that sustains them. Public awareness leads to pressure on the scientific community to understand polar shifts and the magnetosphere’s numerous implications.

    ~D. Neumann"


    So no, there is no need to "run for the hills" That would just be silly. All you can do is watch, wait and hope you have good seats.
     
    Last edited by a moderator: Aug 9, 2010
  4. Aug 9, 2010 #3

    Evo

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    Welcome to the forum timewasted.

    Due to copyright violations, when you quote from a published source, you must clearly show the quoted material and then please provide a link back to the original article. I have fixed two quotes for you and provided links so that you can see how it should be done. Please make any further changes needed to your post and follow this procedure going forward.

    Very nice post btw, nicely thought out, well researched, and informative. I look forward to seeing more contributions from you.
     
  5. Aug 11, 2010 #4
    Could you provide a citation please.

    What alarms you about this? What do you suggest is unusual about weather patterns on the planets? I am not aware of any evidence that would support your contention. Could you offer some citations please? For reference this is how I see it:
    Mercury: No significant atmosphere, so irrelevant.
    Venus: Minor changes that may be due to active volcanism
    Mars: Some suggestion of warming, but nothing that is beyond what might be reasonably expected
    Jupiter: Loss/intermingling of one of the zones. This has been observed at others times in the past and is quite normal.
    Saturn, Neptune, Uranus: No changes I am aware of.
    Pluto: Unexpected warming when it should be cooling. But we know so little of this former planet that it would not be surprising if our model was wrong.

    What do you mean by saying we are about to enter an area of the galaxy we have not been in for 26,000 years? That makes no astronomical sense whatsoever.Can you explain it please?

    I'm not sure where you got this quote, but it is simply wrong.
     
  6. Aug 11, 2010 #5
    I guess a bit too much ground is covered in these posts and a lot is indeed questionable.

    About the core having two layers of molten Nickel Iron, spinning in opposite directions, in some models it is assumed that convection currents in the liquid outer, originate on the surface of the solid inner core, if that's where the core heat is generated. That could be causing the misinterpretation. Furthermore this convection would generate counterrotating convexion cells, somewhat comparable to the Hadley cells along the equator. That could cause the confusion about counter rotating.

    See also Gary Glatzmaier's model

    Moreover, considering that the geomagnetic field has been highly (unusual) variable in the recent geologic Pleistocene past ( Guyodo and valet 1999 ), it would be rather premature to draw all kind of conclusions about biota being dependent on a more or less stable earth magnetic field.
     
  7. Aug 11, 2010 #6
    I agree with this Andre. I think it is more likely bad phrasing rather than a grossly incorrect statement. Regardless it is at best very misleading.

    As to much of the rest I am just perpelexed by what smacks of pop-pseudoscience. I hope I am mistaken and timewasted will return with some intriguing citations, but I am not optimistic.
     
  8. Aug 11, 2010 #7
    Sorry TW, a lot of stuff has hit my fan, so my response is at once tardy and cursory, if you will forgive the confusion of concepts. I did not intend to suggest that it is a binary matter of death-or-dismissal (though a lot of popular screeds on the subject suggest nothing less dramatic.)

    I regard the plausibility of Earth's magnetic field affecting our brain's functionality/internal communication on the neuron level practically dismissively. Those studies had better be pretty brass-bound to convince me that a half-Gauss change of field would have significant physiological effects on most mammals for a start.

    Sure. And?:uhh:

    Errr... Really? TW, would you excuse me if I found that a bit Velikovskian, as proposals go? I really would need you to present something cogent even for me to take it seriously, never mind look on it kindly.:rolleyes:

    I am not sure what you had in mind here. In fact, solar flares do actually cause far greater damage to large electrical distribution networks than I read into "Electronic signals on Earth were only disrupted" but for example, do you have any firm evidence that the effects would have been any worse if our magnetic field had been off at the time? After all, the electric fields are mediated by the motion of electrons and protons, neither of which penetrate the atmosphere very well. In fact, one might wonder whether, by concentrating the showers around the poles, the field was not concentrating and increasing the intensity of the damage as well. Did your studies evaluate that? If not, why not?:bugeye:

    Sure. That is where the field is generated after all, not in space.

    Do tell. Do tell. Which rays would these be? I can't think of any that would be affected by the magnetic field that could get through the atmosphere anyway. :zzz:

    This all sounds very learned, but lacks the more conviction, the more one analyses it. Maybe it is as well that I am rushed.:rolleyes:

    This too sounds terribly glib. Such work as I have seen was far less confidently assertive.

    Maybe, but it doesn't sound very alarming. We have a lot of options before planes start falling out of the sky or gyro-compasses stop working. Always assuming they do. If the stratosphere won't stop the charged particles, then flying a little deeper in that troposphere should fix it, no?:cool:



    Would you settle for "almost nobody"? It sounds very interesting to me, and not very threatening. I reckon it is high time we gave some serious attention to technologies that are a bit less electromagnetically vulnerable for a start. My bet is that magnetically navigating species would manage better than we suspect too. After all, some seem to be following quite ancient migration paths, compared to the dates of recent magnetopolar reversals.
    No?

    May be...??? :bugeye:

    There are alternatives?

    Errr... right. The general public should lean on the general scientist and shake him out of his ignorance and make him understand how vital it is and make him find out these important things. (Tsk! These stupid, irresponsible scientists!) :grumpy:



    Well, that sounds very reassuring, although it sounds a lot more reassuring than the material you quoted.

    What I still am wondering though, is why we should be worrying about the extraterrestrial threats that our current magnetosphere has been averting all our lives so far. Which are the ones that matter? Have our ozone layer and magnetosphere been doing more good or more harm?

    And while your quotes have been very interesting, I must admit that before I took that source at all seriously, he would have to tighten up his logic and erudition pretty radically!:cool:

    Any ideas?

    Cheers,

    Jon
     
  9. Aug 11, 2010 #8

    Evo

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    Thanks guys, the moderators had all agreed to delete or fix the rest of wasted's post the yesterday since they didn't return to fix it, and none of us got around to it.
     
  10. Aug 11, 2010 #9
    Well after all is said and done, I haven't heard of anyone that cared to read your original thread-header much less post a reply. So I thought I'd post some food for thought to make it less of a ghost-thread and it now actually has activity. I'll research what is said to be wrong and grow from here, but with so much sarcasm to read through it might be awhile. Oh and when I use "IMO" (In My Opinion) its not meant for rebuttal ffs just fyi.

    thx again for the lol,

    Timewasted, where my name says it all
     
    Last edited: Aug 11, 2010
  11. Aug 11, 2010 #10
    Without a magnetic field, the solar wind would interact directly with the upper atmosphere. Would this cause the ionosphere to be closer to the surface like it is on Venus? If so, would that have any effect on atmospheric pressure? Would lighting interact differently with the ionosphere? Would increased solar wind buffeting raise the earth's temperature?
     
  12. Aug 12, 2010 #11
    Very likely.
    I don't see how it could or why it should; it would neither increase nor decrease the mass of gas in the air column.

    I suppose lightning might, but just how would be a complex question. There might for example be less lightning because it discharged more easily nearer the ground where pressures were higher, and dissipated more easily in the conductive air at lower altitudes.
    Or there might be more lightning of lower intensity because it discharged more easily. I wouldn't bet it either way.
    Hmmm... I would not expect the effect to be very strong, but it would be conceivable. Whether it would be only at high altitudes if it occurred at all, I am not at all sure.
    Sorry to be so vague!:smile:
     
  13. Aug 12, 2010 #12
    TW,
    I definitely appreciated your contribution, and for much the same reasons as the monitor did. You do however present some of us with something of a dilemma. This forum certainly is intended to be serious, but hardly solemn. It is intended to be courteous, but not formal. It is intended to be polite, but not hypocritically so.
    Now, you presented some points of view and quoted some material in apparent good faith. For that, much thanks. However some of us, including myself, had our reservations on your opinions and were largely nonplussed by the material you quoted. This was not, please note, in snotty reaction to a newcomer having the utter gall to present an opinion (believe me, newcomers are more than welcome, and not just as a matter of form!) It was rather in reaction to some of the claims and declamations in the quoted material. You will note that I was not the only one to react sceptically, if not actually dismissively.
    If this forum had been a formal debate under parliamentary rules, no doubt the chairperson might have wrapped us over the knuckles for informality, but really, the exchanges are supposed to amount to a friendly general discussion of matters at issue. If every time that anyone felt sceptical, he were required to formulate his reactions in diplomatic language, lest it be interpreted as sarcasm, both the value and the tone of the forum would suffer.
    So, not to make too much of a meal of it, I request that you take the replies more lightly and less personally. Having seen several other contributions from the others who added their remarks and evaluations, I think I can safely vouch for their friendly and constructive spirit.

    All the best,
    Jon
     
  14. Aug 12, 2010 #13

    Gokul43201

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    Those of these issues that involve short time-scale responses (to the terrestrial field - solar wind interaction) can be examined by looking at the windward and leeward sides of the magnetosphere, which are very different from each other. For instance, is there a difference in atmospheric pressure between the two halves?
     
  15. Aug 12, 2010 #14

    Gokul43201

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    And that could be a good thing, but it does not relieve you of the responsibility of conscientiously sourcing your claims. There are so many unsourced claims in your post that it may be more dangerous than helpful to leave it open. I can help by pointing out where citations are needed. (see next post)
     
  16. Aug 12, 2010 #15

    Gokul43201

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    Needs citation.

    Need citations.

    Needs either a citation or a better description.

    97% is a miscalculation. 1AU is about 8 light-minutes. The part about what scientists thought was possible or not possible needs citation.

    Needs citation.

    Beyond this point, I can not tell which part of the post is your own writing, and which is a quotation, so I'm stopping here. But this should be sufficient to show you how to proceed.
     
  17. Aug 12, 2010 #16
  18. Aug 12, 2010 #17
    The solar wind.

    http://en.wikipedia.org/wiki/Solar_wind

    The Earth's magnetosphere http://en.wikipedia.org/wiki/Magnetosphere protects us from the solar wind, by deflecting, slowing, and trapping damaging particles from the solar wind.

    Don't believe the particles are damaging? Look up the damage done by the solar flare in March 1989, which evidently broke through the magnetosphere, and toasted a transformer in a nuclear powerstation causing millions of dollars worth of damage.

    Have you done any research?
     
  19. Aug 12, 2010 #18
    Maybe not. Taylor columns don't seem to rely on convection mechanisms. The idea was to explain convection cells, which transport heat like a conveyer belt. In the Earth atmosphere this is done for instance by the Hadley Cells.

    But certainly the currents in the fluid outer core are a bit hard to model especially since there seems to be some discussion about the real heat source in the core and it's location, see for instance the attempts of James Vanyo

    http://www.me.ucsb.edu/dept_site/vanyo/computational.pdf [Broken]
    http://www.me.ucsb.edu/dept_site/vanyo/core_mantle.pdf [Broken]
     
    Last edited by a moderator: May 4, 2017
  20. Aug 12, 2010 #19
    Andre, I have looked through the links you posted, but I cannot find the bit that talks explicitly about outer core convection, nor any mention of Hadley Cells. Please could you bring them to my attention.

    The key difference between the core and the atmosphere is that at the core you do not get a bias towards equatorial heating.

    Taylor Columns are well documented convection mechanisms, that arise in rotating annuli, which is the situation we have in the outer core. Here is a video of Taylor Columns. http://www.youtube.com/watch?v=FETUoik9Yd4&feature=player_embedded
     
    Last edited by a moderator: May 4, 2017
  21. Aug 13, 2010 #20
    I don't think we disagree. I may have explained poorly.

    http://www.lbl.gov/Science-Articles/Archive/Phys-earth-core.html

    http://www.es.ucsc.edu/~glatz/geodynamo.html
    The reference to the hadley cell was merely intending to illustrate the counter-rotating of the northerly and southerly convection cells, albeit that hypothetical outer core convection cells are assumed to be orientated North-South.

    more about the core convection:
    http://www.nature.com/nature/journal/v454/n7208/full/nature07227.html


    Note that the references do not talk about taylor colums and that the wikipedia article about Taylor Columns does not mention convection. So all the elements of misunderstanding are here.
     
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