# Picosecond

Jump to: navigation, search

A picosecond is an SI unit of time equal to 10−12 or 1/1,000,000,000,000 of a second. That is one trillionth, or one millionth of one millionth of a second, or 0.000 000 000 001 seconds. A picosecond is to one second as one second is to 31,700 years. Multiple technical approaches achieve imaging within single digit picoseconds. For example the Streak camera or intensified CCD (ICCD) cameras are able to picture the motion of light. [1] [2]

The name is formed by the SI prefix pico and the SI unit second. It is abbreviated as ps.

One picosecond is equal to 1000 femtoseconds, or 1/1000 nanosecond. Because the next SI unit is 1000 times larger, measurements of 10−11 and 10−10 second are typically expressed as tens or hundreds of picoseconds. Some notable measurements in this range include:

• 1.0 picoseconds (1.0 ps) – cycle time for electromagnetic frequency 1 terahertz (THz) (1 x 1012 hertz), an inverse unit. This corresponds to a wavelength of 0.3 mm, as can be calculated by multiplying 1 ps by the speed of light (approximately 3 x 108 m/s) to determine the distance traveled. 1 THz is in the Far infrared.
• 1 picosecond – time taken by light in a vacuum to travel approximately 0.30 mm
• 1 picosecond – half-life of a bottom quark
• ~1 picosecond – lifetime of a single H
3
O+
(hydronium) ion in water at 20°C[3]
• picoseconds to nanoseconds – phenomena observable by dielectric spectroscopy
• 1.2 picoseconds – switching time of the world's fastest transistor (845 GHz, as of 2006)[4]
• 1.7 picoseconds - rotational correlation time of water[5]
• 3.3 picoseconds (approximately) – time taken for light to travel 1 millimeter
• 10 picoseconds after the Big Bangelectromagnetism separates from the other fundamental forces
• 10–150 picoseconds – rotational correlation times of a molecule (184 g/mol) from hot to frozen water[6]
• 108.7827757 picoseconds – transition time between the two hyperfine levels of the ground state of the caesium-133 atom at absolute zero
• 330 picoseconds (approximately) – the time it takes a common 3.0 GHz computer CPU to add two integers

## References

1. ^ "Trillion-frame-per-second video". Massachusetts Institute of Technology. Retrieved 2014-03-06.
2. ^ "Ultra high speed CCD cameras capture the motion of light.". Stanford Computer Optics. Retrieved 2014-03-06.
3. ^ "Lifetime of single hydronium (H3O+) ion at 20°C". BioNumbers. Retrieved 2011-10-10.
4. ^ James E. Kloeppel (2006-12-11). "World's Fastest Transistor Approaches Goal of Terahertz Device".
5. ^ Lankhorst, D.; Schriever, J.; Leyte, J. C. "Determination of the Rotational Correlation Time of Water by Proton NMR Relaxation in H217O and Some Related Results". Berichte der Bunsengesellschaft für physikalische Chemie 86 (3): 215–221. doi:10.1002/bbpc.19820860308.
6. ^ Bulla, I.; Törmälä, P.; Lindberg, J. J.; Mikalsen, Ø.; Southern, J. T.; Edlund, K.; Eliasen, M.; Herskind, C.; Laursen, T.; Pedersen, P. M. L. (1975). "Spin Probe Studies on the Dynamic Structure of Dimethyl Sulfoxide-Water Mixtures". Acta Chemica Scandinavica 29a: 89. doi:10.3891/acta.chem.scand.29a-0089. edit