The helium atom. Depicted are the nucleus (pink) and the electron cloud distribution (black). The nucleus (upper right) in helium-4 is in reality spherically symmetric and closely resembles the electron cloud, although for more complicated nuclei this is not always the case.

Helium-4 (4
2He or 4
He) is a non-radioactive isotope of helium. It is by far the most abundant of the two naturally occurring isotopes of helium, making up about 99.99986% of the helium on earth. Its nucleus is the same as an alpha particle, consisting of two protons and two neutrons. Alpha decay of heavy elements in the Earth's crust is the source of most naturally occurring helium-4 on Earth. Helium-4 is also produced by nuclear fusion in stars. Most of the helium-4 in the universe, however (including most of the helium in the Sun), was thought to have been produced by the Big Bang. Helium-4 makes up about a quarter of the ordinary matter in the universe, with almost all of the rest being hydrogen. However, this primordial helium is largely absent from the Earth, having escaped during the high temperature phase of Earth's formation, leaving radioactive decay to produce most helium on Earth, after the planet cooled and solidified.

When helium-4 is cooled to below 2.17 kelvins (–271 °C), it becomes a superfluid, with properties that are very unlike those of an ordinary liquid. For example, if helium-4 is kept in an open vessel, a thin film will climb up the sides of the vessel and overflow. Another name for this property of helium is Rollin film. This strange behaviour is a result of the Clausius-Clapeyron relation and cannot be explained by the current model of classical mechanics nor by nuclear or electrical models; it is only understood as a quantum mechanical phenomenon. The total spin of the nucleus (zero) is an integer, so it is a boson, as are neutral atoms of helium-4. The superfluid behavior is now understood to be a manifestation of Bose-Einstein condensation, which occurs only with bosons.

Helium-4 also exists on the moon, and as with on Earth, is the most abundant helium isotope.

The helium-4 atom[link]

The helium atom is the next least complicated atom after hydrogen, but the extra electron introduces a third body, so that solution becomes a three body problem which has no analytic solution. However, numerical approximations of the equations of quantum mechanics have given a good estimate of the key atomic properties (such as size and ionization energy) of helium-4.

The related stability of the helium-4 nucleus and electron shell[link]

The nucleus of the helium-4 atom is identical with an alpha particle. High energy electron-scattering experiments show its charge to decrease exponentially from a maximum at a central point, exactly as does the charge density of helium's own electron cloud. This symmetry reflects similar underlying physics: the pair of neutrons and the pair of protons in helium's nucleus obey the same quantum mechanical rules as do helium's pair of electrons (although the nuclear particles are subject to a different nuclear binding potential), so that all these fermions fully occupy 1s1s orbitals in pairs, none of them possessing orbital angular momentum, and each cancelling the other's intrinsic spin. Adding another of any of these particles would require angular momentum and would release substantially less energy (in fact, no nucleus with five nucleons is stable). This arrangement is thus energetically extremely stable for all these particles, and this stability accounts for many crucial facts regarding helium in nature.

For example, the stability and low energy of the electron cloud state in helium accounts for the element's chemical inertness (the most extreme of all the elements), and also the lack of interaction of helium atoms with each other, producing the lowest melting and boiling points of all the elements.

In a similar way, the particular energetic stability of the helium-4 nucleus, produced by similar effects, accounts for the ease of helium-4 production in atomic reactions involving both heavy-particle emission, and fusion. Some stable helium-3 is produced in fusion reactions from hydrogen, but it is a very small fraction, compared with the highly favorable helium-4. The stability of helium-4 is the reason hydrogen is converted to helium-4 (not deuterium or helium-3 or heavier elements) in the Sun. It is also partly responsible for the fact that the alpha particle is by far the most common type of baryonic particle to be ejected from atomic nuclei; in other words, alpha decay is far more common than cluster decay.

Binding energy per nucleon of common isotopes. The binding energy per particle of helium-4 is significantly larger than all nearby nuclides.

The unusual stability of the helium-4 nucleus is also important cosmologically: it explains the fact that in the first few minutes after the Big Bang, as the "soup" of free protons and neutrons which had initially been created in about 6:1 ratio cooled to the point that nuclear binding was possible, almost all first compound atomic nuclei to form were helium-4 nuclei. So tight was helium-4 binding that helium-4 production consumed nearly all of the free neutrons in a few minutes, before they could beta-decay, and also leaving few to form heavier atoms such as lithium, beryllium, or boron. Helium-4 nuclear binding per nucleon is stronger than in any of these elements (see nucleogenesis and binding energy) and thus no energetic drive was available, once helium had been formed, to make elements 3, 4 and 5. It was barely energetically favorable for helium to fuse into the next element with a lower energy per nucleon, carbon. However, due to lack of intermediate elements, this process requires three helium nuclei striking each other nearly simultaneously (see triple alpha process). There was thus no time for significant carbon to be formed in the few minutes after the Big Bang, before the early expanding universe cooled to the temperature and pressure point where helium fusion to carbon was no longer possible. This left the early universe with a very similar ratio of hydrogen/helium as is observed today (3 parts hydrogen to 1 part helium-4 by mass), with nearly all the neutrons in the universe trapped in helium-4.

All heavier elements (including those necessary for rocky planets like the Earth, and for carbon-based or other life), have thus had to be created since the Big Bang, in stars which were hot enough to fuse not just hydrogen (for this produces only more helium), but to fuse helium itself. All elements other than hydrogen and helium today account for only 2% of the mass of atomic matter in the universe. Helium-4, by contrast, makes up about 23% of the universe's ordinary matter—nearly all the ordinary matter that isn't hydrogen.

References[link]

Tur, Clarisse (2009), "DEPENDENCE OF s-PROCESS NUCLEOSYNTHESIS IN MASSIVE STARS ON TRIPLE-ALPHA AND 12C(α, γ)16O REACTION RATE UNCERTAINTIES", The Astrophysical Journal 702 

Ben Miller
Miller at the 2008 BAFTA Television Awards
Born	Bennet Evan Miller (1966-02-24) 24 February 1966 (age 46) London, United Kingdom
Education	Natural sciences
Alma mater	St Catharine's College, Cambridge
Occupation	Comedian, director, actor
Spouse	Belinda Stewart-Wilson (Divorced, 2011)
Partner	Jessica Parker
Children	Two sons

Bennet Evan "Ben" Miller (born 24 February 1966^[1]) is an English comedian, actor and director. He is perhaps best known as one half of comedy double act Armstrong and Miller, along with Alexander Armstrong. Together the pair wrote and starred in the Channel 4 sketch show Armstrong and Miller, and the more recent BBC television sketch show The Armstrong and Miller Show. As of 2011, he is starring in the crime drama series Death in Paradise.

Early life and education[link]

Miller was born in London, England, and grew up in Nantwich, Cheshire.^[2] His paternal grandfather was a Lithuanian-born tailor who lived in London's East End;^[3] his father, Michael Miller, was a lecturer in American Literature at the City of Birmingham Polytechnic; and his Welsh mother, Marion, taught English at South Cheshire College.^[3] He has two younger sisters, Leah and Bronwen.

He was educated at Malbank School and Sixth Form College, his local comprehensive school in Nantwich, Cheshire. He then studied natural sciences at St Catharine's College, Cambridge, where he acted with and dated Rachel Weisz.^[4][5] He remained at Cambridge to study for a Ph.D. in quantum physics, entitled "Novel quantum effects in low-temperature quasi-zero dimensional mesoscopic electron systems".

Miller's interest in comedy began when a friend asked him to help ferry around the judges of the National Student Drama Festival, which was being held that year in Cambridge.^[6] Having already finished his undergraduate degree, he then joined the Footlights in 1989 alongside the likes of Andy Parsons, David Wolstencroft and Sue Perkins and went on to direct a revue.^[7]

Career[link]

Miller decided not to continue his doctorate studies and moved to London to pursue a career in comedy.^[8] He was introduced to fellow Cambridge graduate Alexander Armstrong in 1992, at the TBA Sketch Comedy Group, a comedy club which ran at the Gate Theatre Studio, Notting Hill throughout the 1990s. They performed their first full-length show at the Edinburgh Fringe in 1994, and returned in 1996, whereupon they were nominated for the Perrier Comedy Award.^[9]

Their success resulted in the commissioning of the television series Armstrong and Miller, which ran for four series in total from 1997 to 2001 – one on the Paramount Comedy Channel, and three on Channel 4. The duo had their own radio show with the same name on BBC Radio 4 in 1998, which featured many of the sketches and characters from their TV series, and a second show, Children's Hour with Armstrong and Miller, later in the same year. After a six-year break, the show was recommissioned for Hattrick Productions as The Armstrong and Miller Show and is currently in its third series.^[10]

In 2001, Miller starred in Steve Coogan's first feature film, the British comedy The Parole Officer.^[11] In 2003 he played the role of 'Bough', sidekick to Rowan Atkinson's title character in the film Johnny English. In 2004 he co-starred in The Prince and Me. In 2004 and 2005, he starred in two consecutive series of the BBC television series The Worst Week of My Life,^[12] alongside Sarah Alexander,^[2] followed in 2006 by a three-part Christmas special, The Worst Christmas of My Life. Since 2007 he is starring as James Lester in ITV's sci-fi drama Primeval,^[9] and as Mr Jonathan in the Australian film Razzle Dazzle: A Journey Into Dance.^[6]

From 2001 until 2007, Miller provided the voice for the ITV Digital and now PG Tips Monkey, in a popular series of television advertisements featuring Johnny Vegas.^[13]

In 2008, he appeared in three ITV1 series, as television producer Jonathan Pope in Tony Jordan's series Moving Wallpaper. He also starred in Thank God You're Here.

In 2010 he made his directorial debut with the film Huge.

In 2011 (as revealed by Miller on Twitter), he will reprise his role as James Lester in Primeval.

One of his more recent successes, is starring in the hit BBC TV Series Death in Paradise, where he plays DI Richard Poole.

Since November 2011, he has been in The Ladykillers at the Gielgud Theatre playing Louis Harvey.

Production[link]

Miller directed a television pilot, which subsequently became the first episode of Steve Coogan's 2006 British BBC TV Comedy series Saxondale. With Armstrong, he has formed a production company named Toff Media.

Awards[link]

Miller was awarded a Judges' Commendation for his portrayal of Hamlet at the 1990 National Student Drama Festival. He co-wrote MindGym, winner of the first BAFTA Interactive Entertainment Award for comedy in 1998, with Tim Wright and Adam Gee. He and Armstrong won a BCA Award for The Armstrong and Miller Show. In 2010 they also won a BAFTA for The Armstrong and Miller Show.

^[14]

Personal life[link]

Miller was married to Belinda Stewart-Wilson (who guest-starred with him in Series 3 of Primeval), Miller eventually divorcing Stewart-Wilson (2011) after a 2 year separation. The couple lived in Maida Vale. They have a son, Jackson a.k.a Sonny, (born 2006). Miller also has a son, Harrison born late 2011, with his partner, production executive Jessica Parker.^[15][16]

A talented musician, Miller plays the guitar and drums^[2] and likes yoga.^[12] At school Miller played in a band called Aquilae which performed Eagles covers translated into Latin.^{[citation needed]} His fictitious school band, Slide Rule, which featured in sketches from the first A&M TV series, is believed to be an affectionate homage to the legendary Section B.^{[citation needed]} At St Catharine's, he played in a band called the Dear Johns, with Andy Edwards and Eoin Patterson.^{[citation needed]} They released one 7 in single, entitled "Shame".^{[citation needed]}

Miller is often mistaken for Rob Brydon,^[4][12] with whom he appeared on an episode of QI, first broadcast on 20 February 2009 (Series 6. 9). As a joke, they dressed in similar shirts and shared a narcissistic kiss.^[17][18]

Filmography[link]

References[link]

External links[link]

• The Armstrong & Miller Show official website
• Ben Miller at the Internet Movie Database
• Ben Miller hands out his very own BAFTAs