A century after Albert Einstein said we would never be able to observe the instantaneous velocity of tiny particles as they randomly shake and shimmy (in so-called Brownian motion), physicist Mark ...

The instantaneous velocity of a Brownian particle has been measured for the first time, a result Einstein believed would be impossible. By trapping a micron-sized silica bead in air in an optical ...

Circular motion, instantaneous velocity of an object moving in a circle. When demonstrating circular motion, swing the ball in a vertical path to increase visibility. When demonstrating the ...

Particle Image Velocimetry is a state-of-the-art non-intrusive flow measurement technique. Small tracer particles advected by the flow are illuminated twice by very short pulses of a laser light sheet ...

But what is the difference? If you ask any person on the street, they might say there is no difference. In non-physics use, they would be correct. However, in physics we have very specific definitions ...

How short is an 'instant'? Is it a second? A tenth of a second? A microsecond? You might think all of these qualify. What about 100 years? That certainly doesn't seem like an instant, and to a human ...

One must get the methods of measuring position and time working together if we are to obtain a reliable representation of motion. To that end we have developed a unique system composed of elements ...