This child's toy uses the principles of center of mass to keep balance on a finger

In physics, the center of mass or barycenter is the weighted average location of all the mass in a body or group of bodies. Various important calculations in mechanics become simplified when quantities are referenced to the center of mass, or when the entire mass of a body is treated as if it is concentrated at the center of mass.

In the case of a rigid body, the center of mass is fixed in relation to the body, and it does not necessarily coincide with the geometric center. Nor does the center of mass necessarily coincide with any point on the body, as is often the case for hollow or open-shaped objects, like a horseshoe. In the case of a loose distribution of particles or bodies, such as the planets of the Solar System, the center of mass of the entire group may not correspond to the position of any individual member.

The mass center often obeys simple equations of motion, and it is a convenient reference point for many other calculations in mechanics, such as angular momentum and moment of inertia. In many applications, such as orbital mechanics, objects can be replaced by point masses located at their mass centers for the purposes of several types of analysis. The center of mass frame is an inertial frame in which the center of mass of a system is at rest at the origin of the coordinate system.

Gravity[link]

Diagram of an educational toy that balances on a point: the CM (C) settles below its support (P)

The suspending chair trick makes use of the human body's surprisingly high center of mass

The center of mass is often called the center of gravity because any uniform gravitational field g acts on a system as if the mass M of the system were concentrated at the center of mass R. Specifically, the gravitational potential energy is equal to the potential energy of a point mass M at R,^[1] and the gravitational torque is equal to the torque of a force Mg acting at R.^[2] In a uniform gravitational field, the center of mass is a center of gravity, and in common usage, the two phrases are used as synonyms.

In a non-uniform field, gravitational effects such as potential energy, force, and torque can no longer be calculated using the center of mass alone. In particular, a non-uniform gravitational field can produce a torque on an object, causing it to rotate. The center of gravity, an application point of the resultant gravitational force, may not exist or not be unique; see centers of gravity in non-uniform fields.

Definition[link]

The center of mass Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{R}

of a system of particles of total mass Failed to parse (Missing texvc executable; please see math/README to configure.): M
is defined as the average of their positions, Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{r}_i

, weighted by their masses, Failed to parse (Missing texvc executable; please see math/README to configure.): m_i

^[3]

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{R} = \frac{1}{M} \sum m_i \mathbf{r}_i.

For a continuous distribution with mass density Failed to parse (Missing texvc executable; please see math/README to configure.): \rho(\mathbf{r}) , the sum becomes an integral:^[4]

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf R =\frac 1M \int \mathbf{r} \; dm = \frac 1M \int\rho(\mathbf{r})\, \mathbf{r} \ dV.

If an object has uniform density then its center of mass is the same as the centroid of its shape.^[5]

Examples[link]

• The center of mass of a two-particle system lies on the line connecting the particles (or, more precisely, their individual centers of mass). The center of mass is closer to the more massive object; for details, see below.
• The center of mass of a uniform ring is at the center of the ring; outside the material that makes up the ring.
• The center of mass of a uniform solid triangle lies on all three medians and therefore at the centroid, which is also the average of the three vertices.
• The center of mass of a uniform rectangle is at the intersection of the two diagonals.
• In a spherically symmetric body, the center of mass is at the geometric center.^[6] This approximately applies to the Earth: the density varies considerably, but it mainly depends on depth and less on the latitude and longitude coordinates.

More generally, for any symmetry of a body, its center of mass will be a fixed point of that symmetry.^[2]

Properties[link]

Momentum[link]

For any system with no external forces, the center of mass moves with constant velocity. This applies for all systems with classical internal forces, including magnetic fields, electric fields, chemical reactions, and so on. More formally, this is true for any internal forces that satisfy Newton's Third Law.^[3]

The total momentum for any system of particles is given by

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{p}=M\mathbf{v}_\mathrm{cm},

where M indicates the total mass, and v_cm is the velocity of the center of mass.^[7] This velocity can be computed by taking the time derivative of the position of the center of mass. An analogue to Newton's Second Law is

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{F} = M\mathbf{a}_\mathrm{cm},

where F indicates the sum of all external forces on the system, and a_cm indicates the acceleration of the center of mass. It is this principle that gives precise expression to the intuitive notion that the system as a whole behaves like a mass of M placed at R.^[3]

The angular momentum vector for a system is equal to the angular momentum of all the particles around the center of mass, plus the angular momentum of the center of mass, as if it were a single particle of mass Failed to parse (Missing texvc executable; please see math/README to configure.): M

^[8]

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{L}_\mathrm{sys} = \mathbf{L}_\mathrm{cm} + \mathbf{L}_\mathrm{around\,cm}.

This is a corollary of the parallel axis theorem.^[9]

History[link]

The concept of a center of gravity was first introduced by the ancient Greek physicist, mathematician, and engineer Archimedes of Syracuse. He worked with simplified assumptions about gravity that amount to a uniform field, thus arriving at the mathematical properties of what we now call the center of mass. Archimedes showed that the torque exerted on a lever by weights resting at various points along the lever is the same as what it would be if all of the weights were moved to a single point — their center of mass. In work on floating bodies he demonstrated that the orientation of a floating object is the one that makes its center of mass as low as possible. He developed mathematical techniques for finding the centers of mass of objects of uniform density of various well-defined shapes.^[10]

Later mathematicians who developed the theory of the center of mass include Pappus of Alexandria, Guido Ubaldi, Francesco Maurolico,^[11] Federico Commandino,^[12] Simon Stevin,^[13] Luca Valerio,^[14] Jean-Charles de la Faille, Paul Guldin,^[15] John Wallis, Louis Carré, Pierre Varignon, and Alexis Clairaut.^[16]

Newton's second law is reformulated with respect to the center of mass in Euler's first law.^[17]

Locating the center of mass[link]

Plumb line method

An experimental method for locating the center of mass is to suspend the object from two locations and to drop plumb lines from the suspension points. The intersection of the two lines is the center of mass.^[18]

The shape of an object might already be mathematically determined, but it may be too complex to use a known formula. In this case, one can subdivide the complex shape into simpler, more elementary shapes, whose centers of mass are easy to find. If the total mass and center of mass can be determined for each area, then the center of mass of the whole is the weighted average of the centers.^[19] This method can even work for objects with holes, which can be accounted for as negative masses.^[20]

A direct development of the planimeter known as an integraph, or integerometer, can be used to establish the position of the centroid or center of mass of an irregular two-dimensional shape. This method can be applied to a shape with an irregular, smooth or complex boundary where other methods are too difficult. It was regularly used by ship builders to ensure the ship would not capsize.^[21]

Applications[link]

Estimated center of mass/gravity of a gynmast at the end of performing a cartwheel. Notice center is outside the body in this position.

Engineers try to design a sports car's center of mass as low as possible to make the car handle better. When high jumpers perform a "Fosbury Flop", they bend their body in such a way that it clears the bar while its center of mass does not.^[22]

Aeronautics[link]

The center of mass is an important point on an aircraft, which significantly affects the stability of the aircraft. To ensure the aircraft is stable enough to be safe to fly, the center of mass must fall within specified limits. If the center of mass is ahead of the forward limit, the aircraft will be less maneuverable, possibly to the point of being unable to rotate for takeoff or flare for landing.^[23] If the center of mass is behind the aft limit, the aircraft will be more maneuverable, but also less stable, and possibly so unstable that it is impossible to fly. The moment arm of the elevator will also be reduced, which makes it more difficult to recover from a stalled condition.^[24]

For helicopters in hover, the center of mass is always directly below the rotorhead. In forward flight, the center of mass will move aft to balance the negative pitch torque produced by applying cyclic control to propel the helicopter forward; consequently a cruising helicopter flies "nose-down" in level flight.

Astronomy[link]

Two bodies orbiting a barycenter internal to one body

The center of mass plays an important role in astronomy and astrophysics, where it is commonly referred to as the barycenter. The barycenter is the point between two objects where they balance each other; it is the center of mass where two or more celestial bodies orbit each other. When a moon orbits a planet, or a planet orbits a star, both bodies are actually orbiting around a point that lies away from the center of the primary (larger) body.^[25] For example, the Moon does not orbit the exact center of the Earth, but a point on a line between the center of the Earth and the Moon, approximately 1,710 km (1062 miles) below the surface of the Earth, where their respective masses balance. This is the point about which the Earth and Moon orbit as they travel around the Sun. If the difference in mass is smaller, e.g. Pluto and Charon, the barycenter will fall outside both bodies.

See also[link]

• Center of percussion
• Center of pressure (fluid mechanics)
• Center of pressure (terrestrial locomotion)
• Mass point geometry
• Metacentric height
• Roll center
• Weight distribution
• Expected value

Notes[link]

References[link]

External links[link]

Look up barycentre in Wiktionary, the free dictionary.

• Motion of the Center of Mass shows that the motion of the center of mass of an object in free fall is the same as the motion of a point object.
• The Solar System's barycenter Simulations showing the effect each planet contributes to the Solar System's barycenter

Richard Hammond
Hammond in May 2006.
Born	Richard Mark Hammond (1969-12-19) 19 December 1969 (age 42)[1] Solihull, Warwickshire, England
Residence	Weston under Penyard, Herefordshire, England
Other names	Hamster
Education	Solihull School Ripon Grammar School
Alma mater	Harrogate College of Art and Technology
Occupation	Broadcaster, journalist, author, media personality, talk and game show host, voice-over artist
Years active	1998, 2002–present
Employer	BBC, The Daily Mirror (prev. ITV & Sky)
Known for	Presenting: Brainiac: Science Abuse Crufts Should I Worry About...? The Gunpowder Plot: Exploding The Legend Richard Hammond's 5 O'Clock Show Top Gear Petrolheads Richard Hammond Meets Evel Knievel Total Wipeout Richard Hammond's Blast Lab Richard Hammond's Engineering Connections Richard Hammond's Invisible Worlds
Home town	Solihull, West Midlands, England
Height	5 feet 7 inches (1.70 m)[2]
Spouse	Amanda Etheridge (m. 2002) «start: (2002-05-04)»"Marriage: Amanda Etheridge to Richard Hammond" Location: (linkback:http://en-wiki.pop.wn.com/index.php/Richard_Hammond)
Children	2
Parents	Eileen and Alan Hammond

Richard Mark Hammond (born 19 December 1969) is an English broadcaster, writer, and journalist most noted for co-hosting the car programme Top Gear with Jeremy Clarkson and James May, as well as presenting series 1–4 of Brainiac: Science Abuse on Sky 1. Since 2009, Hammond has co-hosted Total Wipeout with Amanda Byram on BBC One which has since been cancelled.

Hammond is currently presenting Planet Earth Live alongside Julia Bradbury.

Early life[link]

Hammond was born in Solihull and is the grandson of workers in the Birmingham automobile industry.^[3][4] In the mid-1980s Hammond moved with his family (mother Eileen, father Alan, and younger brothers Andrew, writer of the 'Crypt' Series, and Nicholas) to the North Yorkshire cathedral city of Ripon where his father ran a probate business in the market square. Originally a pupil of Solihull School, a fee-paying boys' independent school, he moved to Ripon Grammar School, and from 1987 to 1989 attended Harrogate College of Art and Technology. After his graduation he worked for several radio stations, including Radio Cleveland, Radio York, Radio Cumbria, Radio Leeds, Radio Newcastle and Radio Lancashire, before auditioning for Top Gear.^[5]

Top Gear[link]

Hammond became a presenter on Top Gear in 2002, when the show began in its present format. He is sometimes referred to as "Hamster" by fans and his co-presenters on Top Gear due to his name and comparatively small stature.^[6] His nickname was further reinforced when on three separate occasions in series 7, Hammond ate cardboard,^[7] mimicking hamster-like behaviour. A running gag is Hammond's supposed use of teeth whitener.^[8] In a series 7 episode, co-presenter Jeremy Clarkson claimed to have found a pack of teeth whiteners in a Marcos TSO GT2 that Hammond had tested. Hammond objected, claiming it was a set-up. In a series 10 episode that featured the Peel P50, Clarkson was seen supposedly talking to Hammond on the phone about him considering a tooth whitening treatment costing £4000. Later, during a series 13 episode that featured the presenters in their office searching for car insurance prices, a teeth whitening kit was pictured on his desk. It was staged to appear that he was caught looking at a website on teeth whiteners on Richard Hammond's 5 O'Clock Show.

In the first episode of series 9 broadcast on 28 January 2007, having recovered from his high speed crash Hammond returned to a hero's welcome, complete with dancing girls, aeroplane style stairs and fireworks. The show also contained images of the crash, which had made international headlines, with Hammond talking through the events of the day after which the audience broke into spontaneous applause. Hammond then requested that the crash never be mentioned on the show again, though all three Top Gear presenters have since referred to it in jokes during the news segment of the programme. He told his colleagues, "The only difference between me now, and before the crash, is that I like celery now and I didn't before".^[9]

During the third episode of series sixteen, Hammond suggested that no one would ever want to own a Mexican car, since cars are supposed to reflect national characteristics and so a Mexican car would be a "lazy, feckless, flatulent, overweight oaf." Hammond finished with the remark "I'm sorry, but can you imagine waking up and remembering you're Mexican?!"^[10] Following complaints, the BBC defended the broadcast of this segment on the grounds that such national stereotyping was a "robust part" of traditional British humour.^[11]

Brainiac: Science Abuse[link]

In 2003, Hammond became the first presenter of Brainiac: Science Abuse; he was joined by Jon Tickle with Charlotte Hudson joining in series 2.^[12] After the fourth series it was announced that Hammond was no longer going to present the Sky1 show after he signed an exclusive deal with the BBC. Vic Reeves took his place as main presenter.^[13]

Other television work[link]

Early in his career, as well as his radio work, Hammond presented a number of daytime lifestyle shows and motoring programmes such as Motor Week on Men & Motors.

He presented the Crufts dog show in 2005, the 2004 and 2005 British Parking Awards, and has appeared on School's Out, a quiz show on BBC One where celebrities answer questions about things they learned at school. He has also presented The Gunpowder Plot: Exploding The Legend.^[14] Along with his work on Top Gear, he presented Should I Worry About...? on BBC One, Time Commanders on BBC Two and the first four series of Brainiac: Science Abuse on Sky One. He was also a team captain on the BBC Two quiz show, Petrolheads, in which a memorable part was one where Hammond was tricked into smashing his classic Ferrari while trying to parallel park blindfolded in another car.

From 3 January 2006 until 10 February 2006, Hammond was the eponymous star of Richard Hammond's 5 O'Clock Show with his co-star Mel Giedroyc of Light Lunch fame.^[15] The programme, which discussed a wide range of topics, was shown every weekday on ITV between 17:00 and 18:00.^[15]

In July 2005, Hammond was voted number one in a Heat magazine poll of top "weird celebrity crushes". Also in 2005 he was voted one of the top 10 British TV talents.^[16]

He presented Richard Hammond and the Holy Grail in 2006. During the special, he travelled to various locations around the world, including the Vatican Secret Archives, exploring the history of the Holy Grail.^[17]

In one episode of Top Gear, fellow presenter James May was mocked by both Hammond and Clarkson for being named the celebrity with the worst hairstyle, while Hammond was named the celebrity with the best.

As part of Red Nose Day 2007, Hammond stood for nomination via a public telephone vote, along with Andy Hamilton and Kelvin MacKenzie, to be a one-off co-presenter of BBC Radio 4's Woman's Hour on 16 March 2007.^[18] However, he was defeated by Andy Hamilton.

In April 2007, Hammond presented a one off special on BBC Radio 2 for Good Friday followed by another in August 2007 for the Bank Holiday. He is scheduled to present more Bank Holiday specials for the station.

Hammond recorded an interview with the famed American stuntman Evel Knievel, which aired on 23 December 2007 on BBC One, and was Knievel's last interview before his death on 30 November 2007.^[19]

In September 2008, Hammond presented the first episode of a new series; Richard Hammond's Engineering Connections on the National Geographic Channel.^[20] In this show, Hammond discovers how the inventions of the past, along with assistance from nature, help designers today. Episodes include the building of the Airbus A380, Taipei 101 and the Keck Observatory.^[20] Series 2 of Richard Hammond's Engineering Connections began in May 2010 and has included the building of the Wembley Stadium and the Sydney Opera House.

Hammond also filmed an advertisement for Morrisons supermarkets in 2008,^[21] and joined the cast of TV show Ashes To Ashes for a special insert on the 2008 Children in Need special.

While in New Zealand for Top Gear Live 2009, Hammond filmed several television commercials for Telecom New Zealand's new XT UTMS mobile network. Telecom claimed that the new network was "faster in more places", compared to its competitors and its existing CDMA network. After the network repeatedly failed in late 2009 and early 2010, Hammond became the butt of a joke when he did not return to New Zealand for Top Gear Live 2010. His fellow Top Gear co-hosts said he was too embarrassed to come back to New Zealand, and in a supposed live feed back to Hammond, the feed suddenly drops out as the "XT Network had crashed".^[22] Hammond was later given the right of reply to his colleagues during an interview with Marcus Lush on RadioLIVE's breakfast show in New Zealand.^[23]

Hammond is currently hosting the UK version of the US series Wipeout, called Total Wipeout. It takes place in Argentina, and is co-presented by Hammond and Amanda Byram. Hammond presents and does the voiceover for the clips in a London studio, and Byram is filmed at the obstacle course in Buenos Aires.^[24]

Hammond also presented a science-themed game show for children, Richard Hammond's Blast Lab which aired on BBC Two and CBBC.^[25]

In March 2010, Hammond presented a 3 episode series called Richard Hammond's Invisible Worlds, which looked at things too fast for the naked eye to see, things that are beyond the visible spectrum (e.g. ultraviolet and infra-red light), as well as microscopic things.

One of Hammond's lesser known television roles was as presenter of the BBC2 'gameshow' Time Commanders, a sophisticated warfare simulator which used a modified version of Creative Assembly's Rome: Total War game engine.^[26]

Since February 2011, Hammond has presented a online technology series "Richard Hammond's Tech Head".^[27]

In July 2011, Hammond presented a two-part natural science documentary Richard Hammond's Journey To The Centre Of The Planet, focused on Earth geology and plate tectonics.^[28][29]

Hammond will also host the upcoming BBC America programme Richard Hammond's Crash Course.^[30]

Personal life[link]

Hammond has been married to Amanda Etheridge (mostly known as Mindy)^[31] since May 2002; the couple have two daughters.^[3] The family lives in a mock castle in Herefordshire and also has an apartment in London. Hammond also plays the bass guitar, on which he accompanied the other Top Gear presenters when they performed alongside Justin Hawkins on Top Gear of the Pops for Comic Relief in 2007. Hammond likes to ride his bicycle in cities, for which he is mocked mercilessly by fellow presenter Jeremy Clarkson.^[32]

Hammond is a fan of Porsche 911s and claims the Pagani Zonda to be the ultimate supercar. He once owned a 1982 Porsche 911 SC (sold in the mid-2000s),^[33][34] and later purchased a 2006 Porsche 911 (997) Carrera S.^[35] In 2004, Hammond purchased a Porsche 928 for the purpose of daily driving.^[36] Much unlike Clarkson and May, he also has an interest in American muscle cars. Hammond has owned a 1969 Dodge Charger R/T,^[36] a 1967 Ford Mustang GT 390,^[37] and a 2008 Dodge Challenger SRT-8 (which was purchased in the United States on a Series 12 episode of Top Gear).^[38]

Hammond had also owned a Morgan AeroMax, in which he was involved in a car accident on 9 August 2009. He also owns a Jaguar E-Type^[39] and is also a fan of monster trucks, having attended Truckfest '07.

An interview with The Sunday Times in February 2008 reported Hammond as having moved briefly from Gloucestershire to Buckinghamshire, then back again because he missed the country life.^[40]

Hammond is a keen motorcyclist^[41] and Land Rover Defender fan. He spent over £70,000 rebuilding his 110 "Buster" in 2008.^{[citation needed]}

During the news segment of Top Gear's 2010 USA Road Trip special, Hammond openly expressed his dislike of the band Genesis. This fact was later exploited by his co-presenters in two special episodes: during the Middle East Special, when they installed a secret second stereo unit in his Fiat Barchetta that only plays the band's Live over Europe 2007 concert; in the India Special, Clarkson played the same song used in the previous special through the megaphone mounted in his Jaguar XJS, despite Hammond driving a different car (a Mini Cooper Sport).

In October it was reported he had spent over £2 million buying Bollitree Castle which is situated near Weston under Penyard, Ross-on-Wye. It has been rumoured he has also bought a large house in the small town of Wantage, Oxfordshire^{[citation needed]}.^[42][43]

On Top Gear in 2007, Hammond went to Africa on an 'Epic Road Trip' across Botswana. While there he found a 1963 Opel Kadett, in which he drove across Botswana. Hammond named it Oliver. On Top Gear a week after the special was aired, Hammond announced during the news, that he had shipped Oliver back to the UK, where it was restored by a team from Practical Classics magazine. Oliver features on Hammond's children's science television show Richard Hammond's Blast Lab and in another episode of Top Gear as a kind of "Hill-holder" in the trailer truck challenge (after it acquired the personal plate "OLI V3R"). Oliver is also mentioned in Hammond's second autobiography As You Do.^{[citation needed]}

In 2010, Hammond was the President of the 31st Herefordshire Country Fair held at Hampton Court in Hope under Dinmore. His involvement caused unprecedented attendance with "nearly 15,000 people" drawn to the event to meet the presenter.^[45]

In 2010, Hammond gained a private pilot licence PPL(H) in an R44 helicopter.

During season 18 of Top Gear it was revealed that he owns a Fiat 500 TwinAir.

Charity work[link]

Richard Hammond is a Vice-President of UK children's brain injury charity The Children's Trust, Tadworth.^[46]

[edit] Vampire dragster crash

During filming of a Top Gear segment at the former RAF Elvington airbase near York on 20 September 2006, Hammond was injured in the crash of the jet-powered car he was piloting.^{[47][48][49]:1} Hammond was travelling at 288 mph (463 km/h) at the time of the crash.^[50]

His vehicle, a dragster called Vampire, was theoretically capable of travelling at speeds of up to 370 mph (595 km/h).^[48] The vehicle was the same car that in 2000, piloted by Colin Fallows, set the British land speed record at 300.3 mph (483.3 km/h).^[49]:3[51] The Vampire was powered by a single Bristol-Siddeley Orpheus afterburning turbojet engine producing 10000 hp (7.5 MW).^[48][50]

Some accounts suggested that the accident occurred during an attempt to break the British land speed record,^[47][52] but the Health and Safety Executive report on the crash found that a proposal to try to officially break the record was vetoed in advance by Top Gear executive producer Andy Wilman, due to the risks and complexities of such a venture.^[49]:4 (The report stated: "Runs were to be carried out in only one direction along a pre-set course on the Elvington runway. Vampire’s speed was to be recorded using GPS satellite telemetry. The intention was to record the maximum speed, not to measure an average speed over a measured course, and for [Hammond] to describe how it felt.")^[49]:1

Hammond was completing a seventh and final run to collect extra footage for the programme when his front-right tyre failed,^[49]:8[53] and, according to witness and first responder Dave Ogden, "one of the parachutes had deployed but it went on to the grass and spun over and over before coming to a rest about 100 yards from us."^[54] The emergency crew quickly arrived at the car, finding it inverted and partially embedded in the grass.^[52] During the roll, Hammond's helmet had embedded itself into the ground, flipping the visor up and forcing dirt into his mouth and left eye, damaging the eye. Rescuers felt a pulse and heard the unconscious Hammond breathing before the car was turned upright.^[52] Hammond was cut free with hydraulic shears, and placed on a backboard.^[49]:9 "He was regaining consciousness at that point and said he had some lower back pain".^[52] He was then transported by the Yorkshire Air Ambulance to the neurological unit of the Leeds General Infirmary.^{[47][49]:9[55]} Hammond's family visited him at the hospital along with Top Gear co-presenters James May and Jeremy Clarkson.^[54][55] Clarkson wished Hammond well, saying "Both James and I are looking forward to getting our 'Hamster' back", referring to Hammond by his nickname.^[47][54]

The Health & Safety Executive report stated that "Hammond's instantaneous reaction to the tyre blow out seems to have been that of a competent high performance car driver, namely to brake the car and to try to steer into the skid. Immediately afterwards he also seems to have followed his training and to have pulled back on the main parachute release lever, thus shutting down the jet engine and also closing the jet and afterburner fuel levers. The main parachute did not have time to deploy before the car ran off the runway."^[49]:13 The HSE notes that, based on the findings of the North Yorkshire Police (who investigated the crash), "the accident may not have been recoverable", even if Hammond's efforts to react were as fast as "humanly possible".^[49]:13

The crash was shown on an episode of Top Gear on 28 January 2007; this was the first episode of the new series, which had been postponed pending Hammond's recovery. Hammond requested at the end of the episode that his fellow presenters never mention the crash again, a request which has been generally observed by both Hammond and the other presenters, although occasional oblique references have been made. On The Edge: My Story, which contains first hand accounts from both Hammond and his wife about the crash, immediate aftermath, and his recovery was published later that year.

In February 2008 Hammond gave an interview to The Sunday Times newspaper in which he described the effects of his brain injuries and the progression of his recovery.^[56] He reported suffering loss of memory, depression, and difficulties with emotional experiences, for which he was consulting a psychiatrist.^[56] He also talked about his recovery in a 2010 television programme where he interviewed Sir Stirling Moss and they discussed the brain injuries they had both received as a result of car crashes.^[57]

After the car crash the BBC website Have Your Say received more than 10,000 messages of good wishes and sympathy for Richard Hammond from people around the world.

Works[link]

TV shows[link]

Books[link]

Car books[link]

• Hammond, Richard (13 October 2005). What Not To Drive. Weidenfeld & Nicolson. pp. 276 pages. ISBN 978-0-297-84800-4. 
• Hammond, Richard (5 October 2006). Richard Hammond's Car Confidential. Weidenfeld & Nicolson. pp. 144 pages. ISBN 978-0-297-84445-7. 
• Hammond, Richard (28 May 2009). A Short History of Caravans in the UK. Weidenfeld & Nicolson. pp. 144 pages. ISBN 978-0-297-84446-4. 
• Hammond, Richard (20 May 2010). Richard Hammond's Caravan Confidential. Weidenfeld & Nicolson. pp. 144 pages. ISBN 978-0-7538-2671-3. 

Children's books[link]

• Hammond, Richard (29 June 2006). Can You Feel the Force?: Putting the Fizz Back into Physics. Dorling Kindersley Publishers. pp. 96 pages. ISBN 978-1-4053-1543-2. 
• Hammond, Richard (2 June 2008). Car Science (Hardback). Dorling Kindersley Publishers. pp. 96 pages. ISBN 978-1-4053-3200-2. 
• Hammond, Richard (1 September 2008). Car Science (Paperback). Dorling Kindersley Publishers. pp. 96 pages. ISBN 978-0-7566-4026-2. 

Biographies[link]

• Hammond, Richard (20 September 2007). On The Edge: My Story (Hardback). Weidenfeld & Nicolson. pp. 308 pages. ISBN 978-0-297-85327-5. 
• Hammond, Richard (29 May 2008). On The Edge: My Story (Paperback). Phoenix. pp. 308 pages. ISBN 978-0-7538-2404-7. 
• Hammond, Richard (7 August 2008). On The Edge: My Story (Abridged). Phoenix. pp. 256 pages. ISBN 978-0-7538-2330-9. 
• Hammond, Richard (18 September 2008). As You Do: Adventures with Evel, Oliver and the Vice-President of Botswana (Hardback). Orion Publishing Co. pp. 268 pages. ISBN 978-0-297-85520-0. 
• Hammond, Richard (28 May 2009). As You Do: Adventures with Evel, Oliver and the Vice-President of Botswana (Paperback). Orion Publishing Co. pp. 314 pages. ISBN 978-0-7538-2562-4. 
• Hammond, Richard (1 October 2009). Or Is That Just Me? (Hardback). Phoenix. pp. 256 pages. ISBN 978-0-297-85521-7. 
• Hammond, Richard (20 May 2010). Or Is That Just Me? (Paperback). Phoenix. pp. 352 pages. ISBN 978-0-7538-2562-4. 

DVDs[link]

1. Top Gear Interactive Challenge Quiz (2007, 2|Entertain).
2. Top Gear Interactive Stunt Challenge Quiz (2008, 2|Entertain).
3. Top Gear Uncovered: The DVD Special (2009, 2|Entertain).
4. Richard Hammond's Engineering Connections: Series One (2009, Nat Geo DVD).
5. Richard Hammond's Invisible Worlds (2010, 2|Entertain).
6. Top Gear: Apocalypse (With James May) (2010, 2|Enertain).
7. Richard Hammond's Engineering Connections: Series Two (2010, Nat Geo DVD).
8. Hammond Meets Moss (2010, Acorn Media UK).
9. Richard Hammond's Journey To The Centre Of The Planet (2011, 2|Entertain).
10. Top Gear: At The Movies (With James May) (2011, 2|Entertain).
11. Richard Hammond's Engineering Connections: Series Three (2011, Nat Geo DVD).

Television advertisements[link]

1. Morrisons (2008)
2. Morrisons (Christmas 2008)
3. Morrisons (2009)
4. Morrisons (Christmas 2009)
5. Top Gear Turbo Challenge Trading Cards Test Set (2009)
6. Top Gear Turbo Challenge Trading Cards (2010)
7. Top Gear Interactive Challenge DVD (2007)
8. Top Gear Interactive Stunt Challenge DVD (2009)
9. Top Gear Uncovered DVD (2009)
10. Top Gear [Re-Runs On Dave] (2009)
11. Telecom XT network NZ (2009)

References[link]

External links[link]

Wikiquote has a collection of quotations related to: Richard Hammond

• Official website
• Richard Hammond on Twitter
• Richard Hammond at the Internet Movie Database
• Donations to Yorkshire Air Ambulance double as a result of their life-saving rescue of Richard Hammond
• Richard Hammond on Top Gear
• Q&A – The Guardian – 2009-1-3. Hammond questions about himself. Retrieved 2009-6-29.