Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced
About the Cover


Bell tower of First United Methodist Church in Chatham, Cape Cod, Massachusetts, at dawn (6:26 a.m. on 23 June 1986; solar elevation: 12°35.4′ above horizon; natural illuminance levels: 12,200 lux ambient and 6,300 lux in the line of gaze). Exposure to artificial light of comparable intensity can rapidly reset the human circadian pacemaker by about 6 hours. See page 667. [Charles A. Czeisler, Neuroendocrinology Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115]


[Table of Contents]

ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)