Skip to Content
Uncategorized

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.

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

Deep Dive

Uncategorized

Embracing CX in the metaverse

More than just meeting customers where they are, the metaverse offers opportunities to transform customer experience.

Identity protection is key to metaverse innovation

As immersive experiences in the metaverse become more sophisticated, so does the threat landscape.

The modern enterprise imaging and data value chain

For both patients and providers, intelligent, interoperable, and open workflow solutions will make all the difference.

Scientists have created synthetic mouse embryos with developed brains

The stem-cell-derived embryos could shed new light on the earliest stages of human pregnancy.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.