The content you've requested is available without charge only to active Sigma Xi members and American Scientist subscribers.
If you are an active member or an individual subscriber, please log in now in order to access this article.
If you are not a member or individual subscriber, you can:
Our universe is immersed in a weak bath of microwaves—short-wavelength radio waves that represent the afterglow of the Big Bang. These microwave photons are present everywhere in the sky, and for the most part they are very similar wherever one looks. But very sensitive instruments are able to detect slight differences in the temperatures of the photons, suggesting that the early universe wasn't perfectly uniform. It turns out that the microwaves from different points on the sky also have slightly different polarizations—the preferential orientation of their electric fields. Measurements of the polarizations should reveal fundamental properties of the cosmos, such as the dynamics and composition of the early universe and the presence of primordial gravitational waves.
Connect With Us:
An early peek at each new issue, with descriptions of feature articles, columns, and more. Every other issue contains links to everything in the latest issue's table of contents.News of book reviews published in American Scientist and around the web, as well as other noteworthy happenings in the world of science books.
To sign up for automatic emails of the American Scientist Update and Scientists' Nightstand issues, create an online profile, then sign up in the My AmSci area.
JSTOR, the online academic archive, contains complete back issues of American Scientist from 1913 (known then as the Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.
Receive notification when new content is posted from the entire website, or choose from the customized feeds available.