In the macroscopic world these disturbances make very little difference. For example, if the temperature of a flask of liquid is measured, the thermometer will absorb a small amount of energy as it heats up. This will cause a small error in the final reading, but this error is small and not important.
In quantum mechanics things are different. Some measurements are made by looking at the pattern of scattered photons. One such example is Compton scattering. If both the position and momentum of a particle is being measured, the uncertainty principle states that there is a trade-off between the accuracy with which the momentum is measured and the accuracy with which the position is measured. The equation that describes this trade-off is:
where
In the electric circuit shown on the right, the voltage drop across the light emitting diode (LED) depends on the material of the LED. For silicon diodes the drop is 0.6 V. However for LEDs it is between 1.8 V and 2.7 V. This information enables a user to calculate the Planck constant.
The energy needed for one electron to jump the potential barrier in the LED material is given by
where
When the electron decays back again, it emits one photon of light. The energy of the photon is given by
the same equation used in the photoelectric effect. If these equations are combined, the wavelength of light and the voltage are related by
The table below can be calculated from this relationship.
Since its discovery, measurements of h have become much better. Planck first quoted the value of h to be erg·sec. This value is within 5% of the current value.
As of 3 March 2014, the best measurements of h in SI units is  J·s. The equivalent figure in cgs units is  erg·sec. The relative uncertainty of h is .
The reduced Planck constant (ħ) is a value that is sometimes used in quantum mechanics. It is defined by
Planck units are sometimes used in quantum mechanics instead of SI. In this system the reduced Planck constant has a value of 1, so the value of the Planck constant is 2π.
Plancks constant can now be measured with very high precision. This has caused the BIPM to consider a new definition for the kilogram. The international prototype kilogram is no longer used to define the kilogram. Instead the BIPM defines the Planck constant to have an exact value. Scientists use this value and the definitions of the metre and the second to define the kilogram.
The Planck constant can also be mathematically derived:
formula_11
Here, formula_12 is the permeability of free space, formula_13 is the speed of light, formula_14 is the electric charge of electron, formula_15 is the Bohr's radius, and formula_16 is the frequency of revolution of the electron in a hydrogen atom formula_17. When these constant values are substituted to the theoretical Planck constant, the theoretical Planck constant value is exactly equal to the experimental value.
The Planck's constant elementary formula in terms of proton-to-electron mass ratio, the charge of electron, speed of light and vacuum permittivity is derived in. It is expressed as follows:
formula_18
where formula_19 is the elementary charge of an electron, formula_20 the mass of a proton, formula_21the mass of an electron, formula_22 the vacuum permittivity, and formula_13 the speed of light.
Sebastian Coe
Sebastian Newbold Coe, Baron Coe (born 29 September 1956, and often nicknamed "Seb Coe") is a former athlete and politician from the United Kingdom. A middle distance runner, Coe won the 1500 m gold medal at the Olympic Games in 1980 and 1984, and set eight outdoor and three indoor world records. He is widely considered to be amongst the greatest middle distance runners of all time. Following his retirement from athletics, he served as a Member of Parliament for the Conservative Party from 1992-97. He became a life peer in 2000. He is the head of the London bid to host the 2012 Summer Olympics. After the International Olympic Committee awarded the games to London, he became the chairman of the London Organising Committee for the Olympic Games. In 2007, he was also elected a vice-president of the International Association of Athletics Federations.
Coe was born in Hammersmith, London. He grew up in Warwickshire and Sheffield. His mother, Tina Angela Coe, died in Hammersmith and Fulham, London, in 2005, aged 75. His mother was half Indian, born to a Punjabi father Sardari Lal and an English mother Vera. His father, Peter Coe (born Percy N. Coe in Kingston upon Thames), died on 9 August 2008, aged 88, while Coe was in Beijing.
Coe married Nicky McIrvine, a former Badminton three-day-event champion, in Surrey, in 1990. They have two sons and two daughters, all of whom were born in Surrey:
The marriage ended in divorce in 2002 after twelve years and Coe moved out of the family home. Coe married Carole Annett in summer 2011.
On 12 February 2010, Coe was the 19th runner on the 106th day of the Vancouver Olympic Torch Relay. Coe's leg was along the Stanley Park Seawall, and he exchanged a "torch kiss" with the previous runner, Arnold Schwarzenegger, and the next runner, a 19 year old member of the Squamish community.
He was awarded with the first Prince of Asturias Award in sports category in 1987.
Coe was appointed a Member of the Order of the British Empire in 1982 and an Officer of the Order of the British Empire in 1990. He was created a life peer in 2000 as Baron Coe, of Ranmore in the County of Surrey.
In December 2005, Coe was given a Special award at the BBC Sports Personality of the Year awards ceremony. He was appointed a Knight Commander of the Order of the British Empire in the 2006 New Year's Honours List for services to sport.
Theme restaurant
Theme restaurants are.restaurants in which the idea for the restaurant takes priority. It influences the architecture, food, music, and overall "feel" of the restaurant. The food usually takes a backseat to the presentation of the theme. These restaurants generally attract customers only because of the theme itself.
One example is the "Rainforest Cafe" restaurants which have the obvious theme of a "Tropical Rainforest". "Medieval Times" has its theme of "Medieval Europe". The "Jekyll & Hyde Club" has an atmosphere of Jack the Ripper and Victorian horror novels. One strange but famous theme restaurant in Berlin, Germany is called "das Klo" (German for "The toilet"). It shows the insides of a toilet.
Many people consider the Rainforest Cafe to be biggest example of a theme restaurant. They also consider it the restaurant which kicked off the theme restaurant trend. Theme restaurants may be experiencing a decline in popularity, given the closings of several Planet Hollywood, Jekyll & Hyde Club, and Wilderness Cafe locations in recent years. Theme restaurants often depend on tourist business, since the theme soon becomes stale to locals. The focus is not necessarily placed on good food and service. Certain tourist destinations such as the Mall of America or Orlando, Florida have better chances of supporting theme restaurants. Theme restaurants are generally common at theme parks, such as Universal Studios.
John Laing plc
John Laing plc is a British developer and operator of privately financed, public sector infrastructure projects such as roads, railways, hospitals and schools. Before being bought by Henderson Private Equity in December 2006, John Laing plc was listed on the London Stock Exchange and was part of the FTSE 250 Index.
The business started in 1848. James Laing (born in 1816), along with his wife Ann Graham, and some employees whom they had hired, built a house on a plot of land that they had bought for £30 in Cumberland. The £150 proceeds from the first house financed the building of the next two houses on the same plot of land. One of these houses was kept by the Laing Family to live in. The family and the business later moved near Carlisle.