A picosecond (abbreviated as ps) is a unit of time in the International System of Units (SI) equal to 10−12 or 1⁄1 000 000 000 000 (one trillionth) 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 approximately 31,689 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]
One picosecond is equal to 1000 femtoseconds, or 1/1000 nanoseconds. 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 vacuum to travel approximately 0.30 mm
- 1 picosecond – half-life of a bottom quark
- ~1 picosecond – lifetime of a single H
3O+
(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 Bang – electromagnetism separates from the other fundamental forces
- 34 picoseconds – signal rise time (20% to 80%) of a SFP+ transmitter for 10 Gigabit Ethernet.[6]
- 10–150 picoseconds – rotational correlation times of a molecule (184 g/mol) from hot to frozen water[7]
- 100 picoseconds – Unit Interval of a 10 Gbps serial communication link, such as USB 3.1.[8]
- 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 complete a processing cycle
See also[edit]
References[edit]
- ^ "Trillion-frame-per-second video". Massachusetts Institute of Technology. Retrieved 2014-03-06.
- ^ "Ultra high speed CCD cameras capture the motion of light". Stanford Computer Optics. Retrieved 2014-03-06.
- ^ "Lifetime of single hydronium (H3O+) ion at 20°C". BioNumbers. Retrieved 2011-10-10.
- ^ James E. Kloeppel (2006-12-11). "World's Fastest Transistor Approaches Goal of Terahertz Device".
- ^ Lankhorst, D.; Schriever, J.; Leyte, J. C. (1982). "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.
- ^ SFF Committee. "SFF-8431 Specifications for Enhanced Small Form Factor Pluggable Module SFP+" (PDF).
- ^ 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: 89–92. doi:10.3891/acta.chem.scand.29a-0089.
- ^ "Universal Serial Bus 3.1 Specification" (PDF).
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction