Please make sure you are signed in to ScientificAmerican.com.
Visitors to our website need a subscription to view our magazines. Readers without a subscription will have access to three complimentary articles per month before they are asked to subscribe. With a subscription to Scientific American or to Scientific American Digital, you get online access to the publication as well as news, videos, blog posts and podcasts.
If you have a print subscription and would like to get access behind the paywall, click here for full instructions.
Please see our Editorial post for more information, or email us if you have questions or feedback.
We support the latest operating systems, and the latest versions of the following browsers, set to accept all cookies:
Internet Explorer version 11
Please keep your browser and operating system up-to-date for the best experience using ScientificAmerican.com. If you receive an error signing in, first perform a sign out from ScientificAmerican.com, then restart your browser.
We also recommend clearing your browser's history and cache if you experience further difficulty. Of course you can always email us if you need further help.
Scientific American welcomes your feedback! Follow us on Twitter, Facebook, Instagram, LinkedIn and YouTube to comment on articles, news and videos. Where a comments forum is offered, we ask that you follow our Community Guidelines.
Scientific American reserves the right to delete comments and revoke commenting privileges from the site and social media pages without notice.
Letters to the Editor can be sent in an email, or to the following address:
Letters to the Editor
1 New York Plaza
New York, NY 10004