Join PopSci+ to read science’s greatest stories. It’s just $1 per month »

Channels
- PopSci+
- Science
  - Archaeology
  - Ask Us Anything
  - Biology
  - Dinosaurs
  - Physics
  - Space
- Technology
  - AI
  - Aviation
  - Best of What’s New
  - Engineering
  - Internet
  - Military
  - Robots
  - Security
  - Vehicles
- Environment
- DIY
- Health
- Gear
  - Audio
  - Cameras
  - Computers
  - Fitness Gear
  - Gaming
  - Gift Guides
  - Home
  - Home Theater
  - Outdoor Gear
  - Phones
  - Tablets
  - Wearables
More
FIND US ON
- Social
  - Facebook
  - Twitter
  - LinkedIn
  - Instagram
  - Pinterest
  - Youtube
- Flipboard
- Apple News+
- RSS

SOCIAL

PopSci +

Popsci+

Subscribe
Log in

Science
- Archaeology
- Ask Us Anything
- Biology
- Dinosaurs
- Physics
- Space
Technology
- AI
- Aviation
- Best of What's New
- Engineering
- Internet
- Military
- Robots
- Security
- Vehicles
Environment
DIY
Health
Gear
- Audio
- Cameras
- Computers
- Fitness Gear
- Gaming
- Gift Guides
- Home
- Home Theater
- Outdoor Gear
- Phones
- Tablets
- Wearables
Newsletter Sign-Up
MERCH
PopSci +

Science

State Lines

| Published Feb 24, 2009 8:18 PM EST

Science

SHARE

httpswww.popsci.comsitespopsci.comfilesimport2013importPopSciBlankPagespops_obesity_mainmap2.jpg

Like science, tech, and DIY projects?

Sign up to receive Popular Science's emails and get the highlights.

LET'S GO

Links

Home
About Popular Science
Newsletter Sign-up
How We Test & Review Products
Editorial Standards
Contact
Privacy Policy
Terms & Conditions
Sitemap
DepositPhotos
Subscriber Login
Affiliate Disclosure

Follow us

DISCLAIMER(S)

Articles may contain affiliate links which enable us to share in the revenue of any purchases made.

Registration on or use of this site constitutes acceptance of our Terms of Service.

© 2023 Recurrent. All rights reserved.