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Solar System's Path May Have Spurred Ice Ages

Posted by michael on from the tan-don't-burn dept.

ImproperShutdown writes "Space.com reports that a physicist has found a correlation between the amount of cosmic rays reaching the Earth, as it passes through the spiral arms of the Milky Way, and the planet's ice ages over the last billion years. Apparently, as the Solar System passes through the higher density spiral arm regions, it receives more cosmic rays from the higher density of supernovae that have occurred in the region. This larger flux of cosmic rays ionizes the Earth's atmosphere more, which makes it more cloudy and cools down the Earth."

34 comments

  1. Supernova by slug359 · · Score: 2, Interesting
    I remember seeing this interesting program on a Discovery program ~ 2 years ago, covering exactly the same topic.
    It also explained the effects of cosmic rays on space missions, from supernovas, and how more older stars are present in the 'arms' of the galaxy.

    It also went into great detail about the effects cosmic rays had on the early space missions, leaving very very very tiny dents (albeit all over) the spacecraft.

    1. Re:Supernova by no+reason+to+be+here · · Score: 2, Interesting

      I saw something recently (i.e. sometime in the last three months) on discovery (or possibly the learning channel) that explored the connection between average global temperature and deep sea currents. apparently, so long as the deep sea currents continue on un abated, avg. temperatures stay stable from year to year, and temperatures don't get too extreme in different areas of the globe.
      the last major disruption began around the end of the last ice age, and we humans have had an usually steady climate during our reign as king species.

      --
      my pet machine
  2. See, there they go again. by Snafoo · · Score: 4, Funny

    Once again our 'scientists' have managed to
    misintepret perfectly clear statistical
    data by imposing a faulty chain of causality.

    Obviously, things are back-to-front. Ice ages
    cause changes in the path of the solar system.

    Duh.

    --
    - undoware.ca
    1. Re:See, there they go again. by Anonymous Coward · · Score: 0

      This loose causality reminds me of rolling the bones and reading tea leaves. Not based on anything solid but relying entirely on the prestige and aura of the profession. They have to make some noise every once in awhile to validate their existence.

      Here i am dissing the scientists. A profession which I for so long thought to be entirely nobel...But they are not really that noble these days. If they're not pooping out stories like this, they're pimping themselves out as marketers to promote classes of products.

      Nay scientists, you are fast approaching the respectability of used car salesman or trip[le pane window pusher. Will the men painting old ladies roofs be wearing lab coats in the future?

  3. Global warming? by EvlG · · Score: 2

    Is the inverse true? Does the current path through the universe mean fewer cosmic rays are hitting us, and leading to global warming?

    Could this be a factor?

    1. Re:Global warming? by dankelley · · Score: 2, Interesting

      Probably not. The timescale is wrong. Besides, the warming trend [difficult as it is to measure] seems to be consistent with CO2 emissions, linked through climate models in which we have [some, of not great] confidence.

    2. Re:Global warming? by anthony_dipierro · · Score: 3, Interesting

      Besides, the warming trend [difficult as it is to measure] seems to be consistent with CO2 emissions, linked through climate models in which we have [some, of not great] confidence.

      It is also consistent with changes in the magnetic flux of the sun.

      The question of global warming is still out.

    3. Re:Global warming? by Planesdragon · · Score: 3, Insightful

      The question of global warming is still out.

      Really? We know two things.

      1: The world is getting hotter.

      2: We're spitting out pollutants that, among other things, can theoretically raise the tempature of the world.

      Let's do the prudent thing and reduce them first; even if the world still gets hotter, at least it'll be a mite bit cleaner.

    4. Re:Global warming? by g4dget · · Score: 3, Insightful

      There are many factors that influence climate. But we know for certain that CO2 levels have increased dramatically already, due to human activity, and that increase continue. If we don't stop that, that will lead to massive, unpredictable changes in our climate and that just can't be good. Looking at temperature records is secondary.

    5. Re:Global warming? by anthony_dipierro · · Score: 3, Insightful

      The world is getting hotter.

      So?

      Let's do the prudent thing and reduce them first; even if the world still gets hotter, at least it'll be a mite bit cleaner.

      It's a question of cost and benefit. Time spent figuring out ways to limit CO2 emissions is time not spent on other things, like figuring out the cure for cancer. Nothing is free, everything has positive and negative effects.

      Personally, I think yes, we should tax products which generate CO2 emissions and tax cutting down trees which also increases the CO2 in the atmosphere. Spend the money researching the problem, fixing it, and planting trees. But the jury is still out on whether or not there even is a problem in the first place.

    6. Re:Global warming? by Anonymous Coward · · Score: 0
      Really? We know two things.
      1: The world is getting hotter.

      • Some measurements actually indicate cooling. The latest "global warming" statistic also claimed temps were up a little...but would have been up a lot more if the planet hadn't actually been cooling.
      • Look up the term "Little Ice Age". We've been warming up since medieval times...because European weather was unusually cold then.
      • Look at the planet's temperatures over millions of years. We're usually warmer than this -- and we had an Ice Age recently enough that parts of the planet are still rising now that the weight of the ice is gone (making ocean level measurements way too much work).

      2: We're spitting out pollutants that, among other things, can theoretically raise the tempature of the world.

      • It's obvious that we are emitting gases which cause over 90% of the Earth's greenhouse effect. Actually, in recent decades our cars have been spewing out even more of this greenhouse gas, water vapor.
      • We've been collecting carbon that's been leaking upward through the crust and making use of it, instead of letting it eventually reach the surface and make tar pools or catch fire. Testing of these surface leaks is how engineers knew the types of materials which could be found in oil deposits.

      It certainly is nice to simply know. And what do you know about Christmas?

    7. Re:Global warming? by yzquxnet · · Score: 2

      There are many factors that influence climate.

      You've got that right, Solar cycles, water vapor, dust, ?cosmic rays?, CO2. Lots of stuff.

      But we know for certain that CO2 levels have increased dramatically already

      Yeah, we can see that. This is pretty much a given.

      due to human activity

      Now, this is where things get ugly. As of to date, no one has conclusively shown that the dramatic increase in CO2 is soley caused by us. As natural fluctuations are easily shown in proxy records. The question is how much have we added to the change. Lets say that C02 levels have risen 100% in the last 10 years (just as an example). So, maybe we have contributed 99% of that, or maybe we are responsible for only 1%. Who knows?

      If we don't stop that, that will lead to massive, unpredictable changes in our climate and that just can't be good.

      The reverse may just as well be true as well. As the biosphere becomes more in tune with higher CO2 levels (a greening perhaps) a sharp reduction may cause just as much unpredictable change.

      For as long as I can remember, and read about, people have been living on the banks of the rivers around my area. Every spring the flood waters flow through and there are always a few houses that get washed away. In the last half decade or so, from what I have noticed, every spring now after the waters receed there is a cry. More like a plee. 'We must stop the greenhouse gasses', 'SUV's are flooding my land'. It has become so easy to place blame on CO2. It doesn't do anything when you pick on it. It just stays there and takes. The river banks have flooded in the past, they will flood again.

    8. Re:Global warming? by Anonymous Coward · · Score: 0
      Time spent figuring out ways to limit CO2 emissions is time not spent on other things, like figuring out the cure for cancer.
      Not it's not.
    9. Re:Global warming? by Anonymous Coward · · Score: 0

      Mod this guy up !

    10. Re:Global warming? by fluffy666 · · Score: 1

      Some measurements actually indicate cooling. The latest "global warming" statistic also claimed temps were up a little...but would have been up a lot more if the planet hadn't actually been cooling

      Well, I wouldn't expect actual temperature measurements to be conclusive for at least the next 20 years. On the other hand, once things take off, there's precious little we can do to stop it.

      Look up the term "Little Ice Age". We've been warming up since medieval times...because European weather was unusually cold then.

      Yes there is natural variation in the weather. Which shows that the climate does undergo changes in response to small forcing factors (i.e. minor changes in solar output). Which strongly indicates that the extra carbon dioxide will cause problems

      Look at the planet's temperatures over millions of years. We're usually warmer than this -- and we had an Ice Age recently enough that parts of the planet are still rising now that the weight of the ice is gone (making ocean level measurements way too much work).

      Yes, the planet IS usually warmer than this. That's a major part of the problem; the very large scope for temperatures to increase.

      It's obvious that we are emitting gases which cause over 90% of the Earth's greenhouse effect. Actually, in recent decades our cars have been spewing out even more of this greenhouse gas, water vapor.

      Water vapour cannot act as a forcing factor as it is always in close equlibrium - it can only ever respond. Which means it'll tend to magnify any trend that crops up - if it didn't, then it would be hard to imagine the earth's climate ever changing.

      We've been collecting carbon that's been leaking upward through the crust and making use of it, instead of letting it eventually reach the surface and make tar pools or catch fire. Testing of these surface leaks is how engineers knew the types of materials which could be found in oil deposits.

      You'd do well to think before you wrote things like this, esepcially if an ex-oil industry geologist happens to be looking. Surface seeps of oil do happen, but their volume is vastly less than the amounts pumped out (or we wouldn't need to pump...). Surface seeps have usually spend enough time near the surface to have undergone bacterial degredation and fractionation, and are hence a poor indicator of subsurface oil composition. In a steady state oil field, where all traps are filled, the volume of surface seeps should loosely approximate to the oil production rate - which is always much less than the extraction rate, since the refilling of reservoirs is rarely even a consideration in commercial oil extraction.

      I find the large scale usage of fossil fuels by the west - and the poor rates of investment in long term alternatives like nuclear fusion - appallingly short sighted even *without* factoring in the cost of environmental change. It puts our economies in the hands of middle eastern zealots; the fuels will run out anyway; and our cities will be polluted.

  4. Wait a second... by Anonymous Coward · · Score: 0

    Ionizing the atmosphere cools down the Earth? Redirect energy from air conditioning to that and we can continue using cheap fuel and greenhouse gases! Science rocks!

  5. This is not his first bad theory. by Peter+T+Ermit · · Score: 4, Informative
    Here at the APS site, there's an abstract. It looks like a bad paper -- one of a zillion theories that make mountains out of correlations. It's not even this author's first proposal of this sort. Five years ago, he suggested that the cosmic rays caused extinction events.

    Sounds like this guy has a favorite hammer, and he's now convinced that everything looks like a nail.

  6. YAFWCCWC by Krapangor · · Score: 1

    Yet another fool who confuses correlation with causality.

    --
    Owner of a Mensa membership card.
  7. this could be good... by skydude_20 · · Score: 3, Funny

    for geeks that is... see since we tend to like sci-fi, space exploration, etc... we just have to let the environuts know about this, then they lobby for us to build massive space structures to shield us from the cosmic rays or generate more... cuz comeon, really, save the environment! stop cosmic rays!

    --
    Jesus saves souls and redeems them for valuable cash prizes
    1. Re:this could be good... by Quiet+Hatred · · Score: 1

      Don't be too sure we "environuts" will do anything for you.

  8. How can the solar system do this??? by Anonymous Coward · · Score: 0

    For the solar system to pass thru arms of the
    galaxy, doesn't it have to be moving at a
    different velocity than those arms? I thought
    all components of a galaxy rotated as a unit -
    or is this not true? If stars within a galaxy
    do not move at the same rate and direction,
    this would increase the chances of collisions.
    (By move at the same rate, I mean adjusting for
    distance from the center, so that all stars at
    a certain distance move in a circle around the
    center and at the same rate, so the whole thing
    moves like a wheel on an axel.)

    1. Re:How can the solar system do this??? by CheshireCatCO · · Score: 2

      First of all, the orbits of stars about the galaxy are Keplerian. They don't orbit as a solid body (like a record) but more like the planets.

      What makes this more interesting still is that the spiral arms are not composed of specific stars all the time. The spiral pattern propogates through the stars and gas in the galaxy (triggering star birth along the way). A given star will enter and leave the arms as the star comes up from beind the arm, passes through, and leaves. (Or from the other direction, depending.)

      I'm skeptical that we know the pattern speed of the sprial arms that well. When I was doing a paper on the "rare Earth" idea, I was looking up the co-rotation radius (the place where a star would always been inside or outside of a spiral arm because it orbits at the same speed as the pattern) for our galaxy. I found very conflicting numbers quoted in papers.

    2. Re:How can the solar system do this??? by Tablizer · · Score: 2

      What makes this more interesting still is that the spiral arms are not composed of specific stars all the time. The spiral pattern propogates through the stars and gas in the galaxy (triggering star birth along the way). A given star will enter and leave the arms as the star comes up from beind the arm, passes through, and leaves. (Or from the other direction, depending.)

      The "arms" are often described as "waves" rather than a physical collection. It is a density compression and decompression pattern of some sort.

      My understanding is that there are still many rough spots in the theories regarding knowing exactly what causes these spiral waves and how they move.

      It might all be tied into the mystery of what the dark matter is that is helping to hold galaxies together.

      --
      Table-ized A.I.
  9. It does lend credence to another theory by theolein · · Score: 2

    There was this book by a scientist/philosopher called Fritjof Capra that I read many years ago that claimed that one cannot be objective as everything is part of some system. This sort of makes some kind of sense in that direction in that the solar system is not isolated from it's galaxy and is part of the "process" in our milky way.

  10. 2-D vs. 3-D by PhreakOfTime · · Score: 1

    To start off, let me say I am not a professor in celestial mechanics, just a backyard amatuer astronomer. However, you bring up an interesting point not addressed at all in the artice.

    Although it sounds strange that the solar system 'passes through' arms of the galaxy, the motion that is being referrerd to is not contained within the same 2-D plane. The actual path that has been 'guessed' more resembles a sine wave oscillating in 3-D. In doing so the earth can 'pass through' the central plane of the galaxy several times, without being in danger of hitting anything

    1. Re:2-D vs. 3-D by Peter+T+Ermit · · Score: 1
      I think you're confused on this one. A plane can look like a sine wave if you're tilted with respect to it -- for instance, the sun seems to move in a sine wave between the tropics of Capricorn and Cancer, but the solar system is a plane, and all motion within it is pretty much planar. (And the paths are great circles on the celestial sphere that are inclined with respect to the equatorial plane.)

      The Earth passes through the central plane of the galaxy without hitting anything because even in that plane, there ain't much stuff there. Space is big.

  11. Oceanic Ice Age trigger by Anonymous Coward · · Score: 0
    Perhaps you're referring to the Arctic Ocean circulation.
    1. The theory is that the Arctic Ocean is the Ice Age trigger:
    2. the Arctic warms
    3. the ice vanishes and stops reflecting sunlight
    4. the Arctic Ocean warms
    5. a lot more water vapor (the major greenhouse gas) is released
    6. the global atmosphere which is much more humid starts producing a lot more precipitation
    7. huge amounts of snow fall across the Arctic area
    8. the Arctic suddenly starts reflecting sunlight again
    9. the amount of snow is much more than it is now, so it covered a larger area than it does now and is deeper
    10. snow survives a summer over a larger area then it does now, so more sunlight is reflected
    11. the Earth cools more than it does now, causing a larger area to remain snow covered next summer
    12. a new Ice Age is under way...until the air becomes dry enough to shrink the continental glaciers and enough water is locked in the polar icecap to keep the air as dry as it has been recently.

    While that has been going on, because the Arctic Ocean is warm..the cold deep ocean currents spilling down the Atlantic have stopped. This stops sucking the Gulf Stream current to the north. The U.S. southeast and Europe suddenly become cooler...as the snow begins to fall..and fall..and fall...

  12. Physics? by CSZeus · · Score: 1

    So, we gain cosmic energy and we get colder.... does anyone else sense a violation of thermodynamics here?

    1. Re:Physics? by Stoutlimb · · Score: 2

      I give energy to my car's heating system when I flip the switch to the "off" position. (The act of flipping the switch requres energy). By your reasoning, this should also violate thermodynamics.

  13. 100's of millions of years, not thousands. by apsmith · · Score: 5, Interesting

    Some of the other posts (not having read the actual article presumably) and the space.com report itself seem a bit confused about the way the term "ice age" is being used here. Based on estimates (somewhat shaky, as was pointed out in another comment) of the galactic rotational speed of the spiral arms relative to stars like our Sun, this paper shows a surprising correlation over the past billion years between times our solar system was within a spiral arm, and periods of significant glaciation lasting 10's or 100's of millions of years.

    According to the calculations in the article, the solar system has passed through the four spiral arms ("Orion" or Sagittarius-Carina, Scutum-Crux, Norma, and Perseus) a total of seven times over the last billion years, or roughly once every 150 million years. We've actually only recently left the Orion arm (heading for Perseus) so the cosmic-ray flux is still quite high, and according to the author's diagram, we are STILL experiencing a major glaciation period. Since the last "ice age" as we know them ended just over 10,000 years ago, that time scale is WAY to short to show up on the scale of this article. In other words, we're still in the middle of an ice age, as far as this paper is concerned.

    While the thickness of the spiral arms is such that we pass through them in about 30 million years, the cosmic ray effects last 50-60 million years or more, depending on the level of star-formation within the arms at any given time. The author also notes that it is believed our galaxy had a peak in star production about 300 million years ago, and had much lower star production prior to about 1 billion years ago (until you get back to the 2-3 billion year period and earlier, for which we don't have much in the way of geologic records). In addition to the ice age records, the author also looks at records from iron meteorites radio-isotope dating to get another measure of cosmic ray flux in those periods, which also seems to correlate.

    Anyway, interesting stuff, but on a time scale much bigger than we normally think about when we think of ice ages. The ice age before the current one according to this model dates to before the rise of the dinosaurs; go back a couple more and it's before we have any evidence of complex life on Earth!

    --

    Energy: time to change the picture.

    1. Re:100's of millions of years, not thousands. by ManitobaMoose · · Score: 1

      well, i remember i read somwhere that the galactic year for the sun is around 250 million years. so that would make around 4 complete rotations in 1 billion years. how could the sun pass through the arms 7 times? i suppose they are rotating too with roughly aequivalent velocities and in the same direction. even if the arms would stand still the sun could've passed perseus for example, max 4 times in the last 1 billion years. or am i missing something here?

    2. Re:100's of millions of years, not thousands. by aug24 · · Score: 1

      The original poster mentions that input flux of cosmic rays 'makes it more cloudy and cools the earth'. It should, of course, be observed that in fact this raises the albedo of the planet, and that this is presumed to be the significant cooling effect: lack of effective insolation.

      However, the 'white earth' problem shows the hole in this conjecture. If the insolation changes caused by clouds caused by cosmic rays were sufficient to start ice ages, then the presence of surface ice over the globe would also be sufficient to continue it - we should never have warmed up again!

      No-one has ever come up with a good explanation for the *end* of significant ice ages - until and unless this chap's theory can do that, his observation is just 'interesting'.

      J.

      --
      You're only jealous cos the little penguins are talking to me.
    3. Re:100's of millions of years, not thousands. by Proaxiom · · Score: 1
      Since the last "ice age" as we know them ended just over 10,000 years ago, that time scale is WAY to short to show up on the scale of this article.

      This is correct. It's also easily apparent just by looking at climate evidence.

      Considering the 'recent' Ice Age started 2 million years ago, the 10,000 year period of warmth we are experiencing could easily be an anomaly, or a brief thaw, and not a definitive end.

      This does put the scope of the paper into better perspective. Of course, it also reminds us that we may not be as important as we think. On a greater scale, the worst Global Warming scenario we can think of might only appear as a slight blip in the Earth's climate history.

  14. missing the point by f00zbll · · Score: 1

    Reguardless of whether there is global warming, (which no real scientist can prove beyond reasonable doubt) does not negate the fact humans are majorly F_ _ _ing up this planet. Using resources too quickly, poluting the air/water we breathe/drink and basically killing every freakin thing in site. Any body stupid enough to buy into this whole global warming argument is falling into a political brain trap. Instead of arguing about how to actually change society in measurable ways, the debate ends being about global warming, which typically results in more fossil fuels/resources being used to try to prove something unprovable.