Is time different to observers moving at different speeds? For more information, see the World Year of Physics 2005 feature. http://www.nsf.gov/news/mmg/mmg_disp.cfm?med_id=55655&from=vid A RealPlayer streaming version of the video also is available. To see the clip with the captions on, you will need to select Tools > Preferences > Content > Use Supplemental text captioning when available, or deselect it if you do not wish to see the captions. Then re-start the video....

Hardware demonstration and explanation of an inverted pendulum, stabilized by two independently controlled reaction wheels connected to DC motors. Made as part of a master's thesis at the System and Identification and Control Laboratory at the University of California, San Diego.

This video shows an experiment involving a mobile robot, an IR-camera vision system, and a wireless network. The robot queries the vision system for position information. The robot uses this position information to simulate a potential function in its environment. The hybrid controller uses these measurements in a coordination of vehicle steering and an optimization algorithm to drive the vehicle to the minimum of the function (shown as a blue 'x').

Using hybrid control a two link planar robot, called the pendubot, is stabilized to its upright equilibrium from any initial condition despite large disturbances in a robust globally asymptotic fashion. This video shows the pendubot being stabilized from a few different positions. The current controller being applied to the pendubot is indicated by variable q. When q is positive an open-loop control effort is being applied to move the pendubot from one equilibrium point to another...

TIME DILATION: an experiment with mu-mesons This classic film documents an experiment done in 1963 the results of which can only be explained when one accepts the consequence that moving clocks run slow. This phenomenon is known as time dilation. The timekeeping device is the mu-meson, a subatomic particle with origins away from the Earth moving at relativistic speed. What follows here is an explanation of the experiment described in that film. Many mu-mesons rain down every hour on the...

2D cut of complete 3D simulations of gold tip and gold surface (tip-to-surface distance is 10 nm) excited by a laser pulse at 652 nm. Laser pulse propagates towards the screen and is polarized along tip's longer axis. Intensity is plotted in logarithmic scale and is normalized to it's maximum. Maximum intensity enhancement in this example is 4 orders of magnitude.