Long Exposure Magic

Star trails

At first these spectacular swirls of color may look like clever computer graphics. Actually they are the product of hour after hour of painstaking night-time shooting by photographer Lincoln Harrison. His stunning pictures of star trails across the Australian night sky were taken over periods of up to 15 hours.
Source: http://www.lincolnharrison.com/#/0

Airplane takeoffs

By Terence Chang.
Source: https://www.flickr.com/photos/exxonvaldez/

Photos from ISS

This is a composite of a series of long exposure images photographed from a mounted camera on the Earth-orbiting International Space Station, from approximately 240 miles above Earth by Expedition 31 Flight Engineer Don Pettit.
Source: http://webodysseum.com/art/long-exposure-photos-from-iss/

Steel wool light painting

Steel wool grade 0 and finer (00, 000) are flammable. You can attach a pad to a wire or string and spin it around and create a shower of sparks. Here is the trick, it only showers sparks when you spin or move it so some kind of spin works best. The air gets in it and fuels it so the faster you swing the more sparks you get.
Source: http://wildammo.com/2011/05/10/insane-steel-wool-long-exposure-photographs/#14

Roomba paths

Roomba is a robotic vacuum cleaner that is able to autonomously vacuum the floor while navigating a living space and avoiding obstacles. It also comes equipped with color-changing LEDs that indicate things like remaining battery power and dirty spots. The LED lights combined with a seemingly random cleaning path has led some intrepid photographers to take long exposure photographs. The results are a kind of ‘light painting.’
- Seven Roombas operating simultaneously, by IBRoomba

9 dancers in flowing motion

By Bill Wadman.
Source: http://www.billwadman.com/motion/

Fireworks

By David Johnson.
Source: http://www.daveyjphoto.com/fireworks