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Space Science

New Ice Age Theory 272

Posted by samzenpus from the why-is-it-so-cold dept.
amigoro writes "Most believe that the ice ages are the result of subtle changes in Earth's orbit, known as the Milankovitch cycles. According to one scientist, that is not the case. Robert Ehrlich of George Mason University in Fairfax, Virginia, has developed a model which hypothesizes a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 or 41,000 years, exactly the same period as between ice ages on Earth. The main problem with Milankovitch cycles is that they can't explain how the ice ages go from 100,000 year cycle to 41,000 year cycle. The cycles predicted by Ehlrich's model line up with the observations."
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New Ice Age Theory More

New Ice Age Theory

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  • I Hope (Score:5, Funny)

    by Zonnald ( 182951 ) on Wednesday January 24, 2007 @08:57PM (#17746712)
    No one tries the old venerable "Frost Post"

  • Human Caused (Score:5, Funny)

    by _Sharp'r_ ( 649297 ) <sharper AT booksunderreview DOT com> on Wednesday January 24, 2007 @08:58PM (#17746726) Homepage Journal
    This guy's theories are all wrong. Obviously people are causing the 100,000 - 41,000 year cycles. Someone should take away his meterology license...

  • Old News (Score:5, Funny)

    by tignom ( 562076 ) on Wednesday January 24, 2007 @08:59PM (#17746730)
    So the new model is heliocentric instead of geocentric. I thought we made this switch centuries ago.

    • Re: (Score:2, Funny)

      by Anonymous Coward
      We did, but it wasn't until we declassified Pluto as a planet that all of the astrology star charts started to line up. Now they're actually accurate. Today my horoscope read: "things should be going quite well in many parts of your life." Hit the nail on the head right there!

      I've heard that some expert astrologers have predicted that "the weather may get colder for a period and then warm up at a later date or it might get warmer first and then cool off at a later date." It sounds like they've got a bet
    • So when is a new model going to look past the edges of our solar system?

      • Re: (Score:3, Funny)

        by nmb3000 ( 741169 )
        So when is a new model going to look past the edges of our solar system?

        The guy's on crack.

        The real reason behind the ice ages is the Sun's evil sister-star: Nemesis [wikipedia.org].

        According to my scientific analysis, it just so happens that Nemesis orbits our solar system once every 100,000 or 41,000 years, exactly the same period as between ice ages on Earth. As the rouge star passes closest to the Sun, it triggers an influx of neutrino emissions in the star's inner core of dark matter. This results in an ion-theta flu

        • Re:Old News (Score:5, Funny)

          by Jesus_666 ( 702802 ) on Thursday January 25, 2007 @12:29AM (#17748096)
          As the rouge star passes closest to the Sun, it triggers an influx of[...]

          ...lipstick emmissions and mascara protuberances in what is known as a coronal makeup ejection (CME). This causes gothmagnetic storms, during which our planet goes through a goth phase and clothes mainly in black clouds, thus keeping sunlight from the planet's surface and everything becomes cold.
  • Could it be that the inner shells of the sun are bouncing a bit? Perhaps a resonance building up from fast "shell quakes" where localised fuel combinations are changing ?
    • "Could it be..."

      Who the hell knows...

      From TFA: "In an article appearing in the journal Nature, Ehrlich describes..."

      Click the nature link and you end up at NewScientist.

      Even if this guy has a viable mechanisim for his "dimmer switch", I can't see that it has any implications for our current climate problems. Wake me up again iff someone finds an abstract.
      • Since when is pointing out a broken link a Troll? Did I miss a memo somewhere? Did the mod try the link? Are the details NOT missing? Is there another reference in TFA that shows where this work has been "published".

        Not to put too fine a point on it but there IS a noticeable difference in credibility between an article in nature and an article in New Scientist, also "articles" are not the same as "peer-reviewed papers".

        My guess is the mod is an anti-science freak who didn't like my oblique reference t

  • 70500 +/- 29500 years, easy! (Score:2, Funny)

    by Anonymous Coward
    See, I learned something in all those science experiment classes.

    OTOH the check word says the "contrary". Maybe the author should use this system to find the solution.

  • Combination (Score:4, Interesting)

    by dohzer ( 867770 ) on Wednesday January 24, 2007 @09:05PM (#17746788)
    Could it not be a combination of both Milankovitch cycles and the dimming of the sun?

    • Re:Combination (Score:5, Informative)

      by toby34a ( 944439 ) on Wednesday January 24, 2007 @10:53PM (#17747564)
      Yeah, it definitely could be a combination of all manners of cycles. That's the thing about climate shifts- there are so many variables interacting, that some interact in very different ways. I wrote a summary paper a few years ago for a seminar about a theory of frequency modulation of the Milankovitch cycles to help solve some of the classic Milankovitch "problems". Here's a link for it: http://www.sciencemag.org/cgi/content/abstract/285 /5427/564 [sciencemag.org]. Looking at the followup research, Dr. Rial has done both frequency modulation to see what he can do with the three main Milankovitch cycles (that being orbital eccentricity (changing in how "oval" the Earth's orbit is, every 100,000 and 400,000 years), planetary precession (changing the location of the seasons, so that the Northern Hemisphere winter moves from January to January over the course of 21,000 years) and the planet's obliquity (changes in the tilt of the earth from 22.5 degrees to 24.5 degrees, over a course of 41,000 years). Through this frequency modulation, he was able to produce a signal very close the delta-O 18 ratios found for the Vostok core in Antartica. His theory also was able to "demodulate" the Vostok core to get peaks at 41kyr (kyr = 1000 years), 100kyr, and 21kyr as predicted by the classic Milankovitch cycles. While these solar fluctuations may exist (and I'm not an astronomer, just a meteorology/atmospheric science/climatology PhD student) I'd prefer to firm them up before they replace the classical orbital mechanisms that we know exist. Whether they cause the Ice Ages or not, they are present in the orbital path.

      • Re:Combination (Score:4, Interesting)

        by radtea ( 464814 ) on Thursday January 25, 2007 @12:05AM (#17747952)
        While these solar fluctuations may exist (and I'm not an astronomer, just a meteorology/atmospheric science/climatology PhD student) I'd prefer to firm them up before they replace the classical orbital mechanisms that we know exist. Whether they cause the Ice Ages or not, they are present in the orbital path.

        We do know the orbital fluxuations to exist, but we don't know that they cause terrestrial climate fluxuations. The problem is real: the dominant frequencies in the orbital fluxuations do not match well with the dominant frequencies in the climate fluxuations. Something more is going on, probably in our understanding of the global climate, which may impose frequencies of its own, like a resonant system excited by a non-resonant driving force.

        Unfortunately, the kind of step-function we are giving the planet, and which it has had in the past from other natural occurences, is a pretty powerful excitation at all frequencies.
      • I tried to raise some interest in providing EdGCM with variant insolation input, but it was deemed not a useful idea because the old Model II collapses for any simulated periods of longer than a couple of thousand years.

        Do you know of any open-source simulator covering the various orbital parameters of Milankovitch and/or others? It could be handy for plugging into other simulation frameworks, like ESMF.
    • Could it not be a combination of both Milankovitch cycles and the dimming of the sun?

      Anything is possible. But two (completely independent) phenomenon that happen every 100,000 years, just happening to match-up, seems extremely unlikely.

      It would be much more concievable if, instead, there were two phenomenon that occured every 1,000 years, and only resulted in a major event (eg. ice age) on the 1-in-100 times they happen match-up.

  • Socrates would be disappointed (Score:5, Insightful)

    by Volfied ( 307532 ) on Wednesday January 24, 2007 @09:09PM (#17746830)
    sophism [sof-iz-uhm] -noun
                  a specious argument for displaying ingenuity in reasoning or for deceiving someone, e.g. beginning with a conclusion and finding reasons to justify it, regardless of where the evidence points.

  • Er, what? (Score:2, Insightful)

    by mqduck ( 232646 )
    Man... Where have I been? I'm no science geek and I guess it shows. What happened to that big asteroid that was supposed to start the Ice Age?

  • Misleading grammar (Score:5, Insightful)

    by p0ss ( 998301 ) on Wednesday January 24, 2007 @09:14PM (#17746872)
    Ice ages are not caused by planet Earth's orbital variations as once thought, but by the dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years which is exactly the same period as between ice ages on Earth, according to a radical new theory proposed by renowned astrophysicist Robert Ehrlich of George Mason University.

    shouldn't that be:
    According to a radical new theory proposed by renowned astrophysicist Robert Ehrlich of George Mason University, Ice ages are not caused by planet Earth's orbital variations as once thought, but by the dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years which is exactly the same period as between ice ages on Earth.


    that's like writing
    THE EARTH IS FLAT!!!! according to some guy somewhere.
    instead of
    some guy somewhere thinks the earth is flat!!

  • Real source (Score:3, Interesting)

    by edwardpickman ( 965122 ) on Wednesday January 24, 2007 @09:16PM (#17746886)
    It doesn't explain the cycles but the ice ages are generally believed to be caused by a shift in the jet stream that was caused by the Himalayan Mountains. The cycle's start parallels the rise of that mountain range cutting into the jet stream and causing the shift. The trigger is still up for debate but the cold air is being caused by the jet stream shifting south.

    • Re:Real source (Score:4, Interesting)

      by edwardpickman ( 965122 ) on Wednesday January 24, 2007 @10:52PM (#17747560)
      I went from a five to a troll? Some people need to read more. The jet stream is the likely source. Check maps of the Glaciers and you'll see they matched the position of the jet stream during the last ice age. The jet stream acts as a wall to the cold arctic air. Other factors keep the frost line in northern Canada but during an ice age the Jet Stream marks the limit the cold will shift. A study of glacerial sediments helped prove the process began around the time the Himalayan Mountains started to form. Maybe the theory is wrong but it's not my theory. I felt like I just got trolled because I made a pro evolution post on a Christian web site. Might help to do some reading before you troll. Another FYI the earth isn't flat and evolution isn't just an unlikely theory.
    • Uhhh, soooo, every 50 million years or so, the Himalayas appear or disappear?

  • Luckily... (Score:4, Funny)

    by jpellino ( 202698 ) on Wednesday January 24, 2007 @09:28PM (#17746956)
    there's a Home Depot just an a.u. down the road - we should ve able to swap that out with a longer cycle dimmer and all will be well.

  • Conclusion! (Score:4, Funny)

    by Xybot ( 707278 ) on Wednesday January 24, 2007 @09:31PM (#17746978)
    Obviously mans careless use of the environment on earth is the root cause of this heliocentric dimming phenomenon. I call for an immediate halt to deforestation and burning of fossil fuels that initiate the anti-dimming process via subatomic sympathetic astrological particles (SSAP)!!

  • hmm (Score:2, Funny)

    by minus_273 ( 174041 )
    natural global cooling? with scientific backing? this sounds like a global warming denier. he should lose his licence and prosecuted in nuremberg style war crimes courts! quick, someone tell al gore!

    • Re:hmm (Score:5, Funny)

      by Daniel Dvorkin ( 106857 ) * on Wednesday January 24, 2007 @10:36PM (#17747454) Homepage Journal
      Since folks like you think the earth is only 6000 years old, I'm surprised you're paying any attention at all.
    • Fry: Who are you people?
      Al Gore: I'm Al Gore. And these are my vice presidential action rangers. A group of top-nerds, whose sole duty is to prevent disruptions in the space-time continuum. Fry: I thought your sole duty was to cast the tie-breaking vote in the Senate.
      Al Gore: That, and protect the space-time continuum. Read the Constitution.

    • Re: (Score:2)

      by Goaway ( 82658 )
      he should lose his licence

      Do you also get all righteously indignant if an engineer loses his license because he denies newtonian mechanics and starts building bridges based on his own alternate theories?

  • Ice Age Frequency (Score:5, Interesting)

    by Convector ( 897502 ) on Wednesday January 24, 2007 @09:33PM (#17746994)
    It's a neat idea. Are there any observations to support it? Peter Huybers from MIT just presented an alternative model which explains the 40 ky - 100 ky switch nicely without resorting to solar fluctuations. The basic idea is that you start out with ice ages every 40 ky, but at some point the ice accumulation retards heating, and one or even two thawing cycles get skipped. This gives you longer cold periods and a warm period every 80 ky or 120 ky. If you randomly distribute cycles with these two intervals, you can get a peak at 100 ky (but you can't just superimpose the sine curves with those two frequencies). He suggests that the 100 ky cycle isn't real, and just an effect we see from skipping some thaws. This is supposedly supported by oxygen isotope measurements, but I'm not enough of a geochemist to verify that.

  • Comment removed (Score:4, Funny)

    by account_deleted ( 4530225 ) on Wednesday January 24, 2007 @09:44PM (#17747058)
    Comment removed based on user account deletion
    • I have three words for you: Being Steve Developers

    • (Drops onto New Jersey Turnpike)

      Insert Jersey Joke:

      Leela: "Who would have thought that hell really exists? And that it would be in New Jersey?"
      Fry: "Actually..."

      Geena Davis: Easy, sport. Got myself out of Beirut once, I think I can get out of New Jersey.
      Sam Jackson: Yeah, well don't be so sure. Others have tried and failed. The entire population, in fact.

      "The DEA is reporting that New Jersey's heroin is the purest in the country. It's 71 percent pure. That's gotta be at least a bit embarrassing, don't you

  • Models, Theories & Proof (Score:5, Insightful)

    by BoRegardless ( 721219 ) on Wednesday January 24, 2007 @09:51PM (#17747112)
    I thank God the scientists keep looking for patterns and physics to try to explain what we see in the geologic and solar record & current observations of the sun, as that is the ONLY WAY we will ever have a chance of really knowing what long term cycles are caused by. There may be 50 models and theories, but it will likely be a stew of dozens of researchers that finally get a theory that is solid enough to be verified and called a Proof, or tentative Proof.

    Fact is, no one can yet show a proof of why, but we do know that Ice ages occurred dozens of times and when, but we can not yet prove what the underlieing factor is that causes the repetition (excluding the major "accidental" supermassive volcano or mega-asteroid).

    That is what true science is for, which is to keep digging, sometimes literally, until you uncover the data and principals that can be independently verified and eventually acknowledged as fact.

    But that is not convenient for politicians who want power, and bureaucrats who can manage whole new divisions of government if they get funding to try to act on something with the citizens money, when there is only speculation as to what is going on and to what degree, let alone whether we can actually do anything about it.

    • Re: (Score:2)

      by jonabbey ( 2498 ) *

      But that is not convenient for politicians who want power, and bureaucrats who can manage whole new divisions of government if they get funding to try to act on something with the citizens money, when there is only speculation as to what is going on and to what degree, let alone whether we can actually do anything about it.

      Amen, and amen.

      I just pray to God that the scientists keep looking for patterns and physics to try to explain what we see in atmospheric carbon dioxide concentrations as well, while

    • Re: (Score:2, Insightful)

      by qralston ( 131596 )

      There may be 50 models and theories, but it will likely be a stew of dozens of researchers that finally get a theory that is solid enough to be verified and called a Proof, or tentative Proof.

      You are making the classic mistake: you are assuming that science is about trying to prove that something is true. It's not. Science cannot prove anything; science can only disprove.

      If you want a concise definition of science, it is this: science is the methodology by which we identify and discard beliefs and theories that are false. This process does not produce facts; it does not produce proof. At best, it produces theories that have withstood enough attempts to knock them down that for now, we

    • With all the "weird weather" over the past 12 months or so, are we experiencing another El Nino or is the world just going to hell in a handbasket yet again if we don't Do Something About It?

  • Dimmer switch...a competing viewpoint. (Score:5, Funny)

    by nixkuroi ( 569546 ) on Wednesday January 24, 2007 @09:58PM (#17747162)
    One competing viewpoint with this theory is that these events were caused by a solar "Clapper" which flipped the sun when bombarded with echoes and reverberations from the big bang. This non-viewpoint is endorsed by non-dimmer switch oriented non-scientists but these non-scientist find it more plausible...in lots of ways.

  • This is an inference -- not a prediction (Score:5, Informative)

    by stephanruby ( 542433 ) on Wednesday January 24, 2007 @10:10PM (#17747228)
    "The cycles predicted by Ehlrich's model line up with the observations."

    Shouldn't this be? The cycles predicted by Ehlrich's model were inferred from observations. Implying that a prediction is lining up with observations is not the same as a prediction that's inferred from observations. And besides, the article is claiming it's an inference based on past observations, not a prediction which has been verified with observations.

    The article itself makes no such wild encompassing claim.

    • Re: (Score:3, Informative)

      by doubletruncation ( 939847 )
      I guess it's a bit of a symantics issue, whether it's a prediction or a post-diction. It's true that this "prediction" was made after the cycles themselves were observed in the temperature. However, the theory itself makes no reference to these observations, that is it doesn't use them for calibration (it's calibrated with observations of the sun only). The theory, instead, is that there is an oscillation in brightness that should be present in the Sun and other stars that hasn't been considered before. Ehr

    • Re: (Score:2, Interesting)

      by mdsolar ( 1045926 )
      One problem with asking for predictions in this case is that it would be very hard for you to confirm that the next two cycles occured or not. So, one is pretty much stuck with trying to account for the past. This is in the nature of observational science as opposed to experimental science. However, it is possible that the model will have consequences which explain other observations, or which suggest new observations which could help to test the validity of the theory. This is a theory about the solar

    • Re: (Score:2)

      by suv4x4 ( 956391 )
      Shouldn't this be? The cycles predicted by Ehlrich's model were inferred from observations.

      You know, I noticed my TV program guide lines up almost perfectly with the TV programs, but I never quite felt how this phenomenon is called.
    • In pattern recognition, this is called training on the test set. When you don't have enough data to make separate training and test sets, you're almost sure to get models that perfectly fit the data yet have no predictive ability. That's not to say the theory is wrong, just that it we have no way of knowing that it's right.

      Devon

  • I'm no scientist... (Score:3, Insightful)

    by KKlaus ( 1012919 ) on Wednesday January 24, 2007 @11:08PM (#17747654)
    But come on. "The cycles predicted by Ehlrich's model line up with the observations." The summary says that like its some type of verification. They line up (duh) because he picked the cycles that way. What a stupid end to the summary.

    Fwiw, I like the line of thinking - that the ice ages are an action of the sun rather than the earth, but its entirely unsubstantiated and to go _holy crap_ the model that he crafted to fit historical data fits historical data is fantastically disingenious.

  • Dimmer Switch theory would explain . . . (Score:5, Funny)

    by StefanJ ( 88986 ) on Wednesday January 24, 2007 @11:11PM (#17747684) Homepage Journal
    . . . that damn annoying hum.

  • What about Mars? (Score:4, Interesting)

    by tjl2015 ( 673427 ) on Thursday January 25, 2007 @12:07AM (#17747972)
    It seems that this theory should be fairly testable. If the orbital theory is correct, only Earth should display climate cycles of similar periods. If it's caused by the sun, then the whole inner solar system would be affected. Granted, it would be nearly impossible to see such evidence on Mercury and Venus, but perhaps evidence of some form would be left on Mars. I'm not quite up to speed on my astrogeology, does anyone know if we have any kind of reliable record of the ancient Martian climate?

  • Another Theory (Score:2, Interesting)

    by Philotic ( 957984 )
    Try this on for size:

    Picture the Earth in a glacial period. At this time most of the landmass is covered in ice. This prevents nutrients from being eroded and washed into the sea by rivers. This in turn causes phytoplankton populations to decline. As we know, phytoplankton are a major CO2 sink. The small plankton population results in rising CO2 levels, thus increasing temperature.
    Melting ensues.
    Now picture the Earth in an interglacial period. Most of the landmass is open to the elements. Rive

  • A Dimmer Switch?!?! (Score:5, Funny)

    by Anne_Nonymous ( 313852 ) on Thursday January 25, 2007 @12:58AM (#17748274) Homepage Journal
    >> a model which hypothesizes a dimmer switch inside the sun

    No, seriously? That must be how they get it to be all dark and stuff at night.
  • Looking at the majority of posts, I gotta say... I've the feeling, that the jokes that poke fun at theories of global warming caused by human activity will get less and less funny each year.

    I just hope we won't cry when we hear one in 10 years.

    I guess it's human nature to oversimplify things into two categories of black and white. As always, real life is a lot more complex than this.
  • I only rent here, I never knew what that darn switch did.
  • About the people who keep posting "The sun goes through dimmer cycles! So it can't be we are causing the global warming!"

    Let's try this one. I have the fire going in the house. The weather gets warmer. My wife asks why I have the fire going. I say "The heat is nothing to do with the fire, it's caused by the weather getting warmer. There's nothing I can do about it"

    Why is it so hard for these people to understand the idea that several factors can contribute to the same phenomenon, and if we don't want it to

  • Most believe that the ice ages are the result of subtle changes in Earth's orbit, known as the Milankovitch cycles.

    Whereas I believe that the ice ages are the result of subtle changes in John Malkovich's moods, known as the Malkovich cycles.

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