Emerging Technology from the arXiv

A View from Emerging Technology from the arXiv

Spiral Arms Did Not Cause Climate Change on Earth

A new map of the Milky Way galaxy proves that the sun’s motion through the spiral arms could not have caused a well-known climate-change cycle.

  • June 26, 2009

The evidence that Earth’s climate was different in the past is overwhelming, but there is little agreement on what caused these changes.

One of the more exotic theories is that past changes in the earth’s climate have been caused by the sun’s gradual passage through the spiral arms of the galaxy. The thinking is that in regions of denser star populations, supernovas would have been more common, bathing the earth in cosmic rays more often. These cosmic rays would then have seeded the formation of clouds, which cools the planet.

There is even evidence to back this claim. It turns out that the sun seems to move between spiral arms every 140 million years or so, and a similar 140-million-year cycle also crops up in climate change on Earth.

Today, Adrian Melott at the University of Kansas and a couple of buddies put the idea to rest once and for all. They point out that in recent years, astronomers have mapped out the structure of our galaxy in increasing detail. How does this new information sit with the galactic theory of climate change?

Not well. Melott and co have compared the times of transit between regions of the new galactic map with changes in Earth’s climate and found that the 140-million-year correlations simply disappear.

You might say that this could be explained if the movement of the sun had not been regular during this period. But no, Melott says that the cycle cannot be made to match for any reasonable change in the motion of the sun through the galaxy.

So whatever caused the 140-million-year climate-change cycle on Earth, it wasn’t the sun’s passage through the galaxy.

Ref: arxiv.org/abs/0906.2777: Testing the Link Between Terrestrial Climate Change and Galactic Spiral Structure

Want to go ad free? No ad blockers needed.

Become an Insider
Already an Insider? Log in.

Uh oh–you've read all of your free articles for this month.

Insider Premium
$179.95/yr US PRICE

Want more award-winning journalism? Subscribe and become an Insider.
  • Insider Premium {! insider.prices.premium !}*

    {! insider.display.menuOptionsLabel !}

    Our award winning magazine, unlimited access to our story archive, special discounts to MIT Technology Review Events, and exclusive content.

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

    Access to the Magazine archive. Over 24,000 articles going back to 1899 at your fingertips.

    Special Discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

    First Look. Exclusive early access to stories.

    Insider Conversations. Listen in as our editors talk to innovators from around the world.

  • Insider Plus {! insider.prices.plus !}* Best Value

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus ad-free web experience, select discounts to partner offerings and MIT Technology Review events

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

    Access to the Magazine archive. Over 24,000 articles going back to 1899 at your fingertips.

    Special Discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

  • Insider Basic {! insider.prices.basic !}*

    {! insider.display.menuOptionsLabel !}

    Six issues of our award winning magazine and daily delivery of The Download, our newsletter of what’s important in technology and innovation.

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

/
You've read all of your free articles this month. This is your last free article this month. You've read of free articles this month. or  for unlimited online access.