![Secret Life of Scientists and Engineers | Danielle Whittaker: Roller Derby 101 | Season 2013 | Episode 37 | PBS Secret Life of Scientists and Engineers | Danielle Whittaker: Roller Derby 101 | Season 2013 | Episode 37 | PBS](https://image.pbs.org/video-assets/pbs/secret-life-of-scientists/107857/images/Mezzanine_905.jpg)
Secret Life of Scientists and Engineers | Danielle Whittaker: Roller Derby 101 | Season 2013 | Episode 37 | PBS
Roller Derby City on Twitter: "Our pro referee shirts are made 100% in house right here at RDC HQ 😁 They're velcro resistant, available in a range of fits and you can
![A Roller Derby referee in her striped shirt. Roller Derby is a contact sport which is played by more than 1200 amateur leagues worldwide and is dominated by all-female amateur teams Stock A Roller Derby referee in her striped shirt. Roller Derby is a contact sport which is played by more than 1200 amateur leagues worldwide and is dominated by all-female amateur teams Stock](https://c8.alamy.com/comp/KTWNCR/a-roller-derby-referee-in-her-striped-shirt-roller-derby-is-a-contact-KTWNCR.jpg)