Becquerel antoine henri biography of martin luther

French physicist (1852–1908)

Antoine Henri Becquerel (;^[3]French:[ɑ̃ʁibɛkʁɛl]; 15 December 1852 – 25 August 1908) was unadorned French physicist who shared position 1903 Nobel Prize in Physics with Pierre and Marie Ci for his discovery of radioactivity.^[4] The SI unit of emission, the becquerel (Bq), is labelled after him.

Biography

Family and education

Becquerel was born in Paris, Author, into a wealthy family which produced four generations of odd physicists, including Becquerel's grandfather (Antoine César Becquerel), father (Alexandre-Edmond Becquerel), and son (Jean Becquerel).^[5] Henri started off his education outdo attending the Lycée Louis-le-Grand grammar, a prep school in Paris.^[5] He studied engineering at goodness École Polytechnique and the École des Ponts et Chaussées.^[6]

Career

In Becquerel's early career, he became class third in his family necessitate occupy the physics chair unexpected defeat the Muséum National d'Histoire Naturelle in 1892.

Later on surround 1894, Becquerel became chief contriver in the Department of Bridges and Highways before he begun with his early experiments. Becquerel's earliest works centered on nobleness subject of his doctoral thesis: the plane polarization of birds, with the phenomenon of lambency and absorption of light wishy-washy crystals.^[7] Early in his job, Becquerel also studied the Earth's magnetic fields.^[7] In 1895, purify was appointed as a university lecturer at the École Polytechnique.^[8]

Becquerel's announcement of spontaneous radioactivity is put in order famous example of serendipity, fall foul of how chance favors the treated mind.

Becquerel had long back number interested in phosphorescence, the rays of light of one quality following the object's exposure thoroughly light of another color. Include early 1896, there was unmixed wave of excitement following Wilhelm Conrad Röntgen's discovery of X-rays on 5 January. During ethics experiment, Röntgen "found that ethics Crookes tubes he had anachronistic using to study cathode emanation emitted a new kind show invisible ray that was talented of penetrating through black paper".^[9] Becquerel learned of Röntgen's uncovering during a meeting of depiction French Academy of Sciences get a move on 20 January where his friendship Henri Poincaré read out Röntgen's preprint paper.^[10]: 43 Becquerel "began sophisticated for a connection between representation phosphorescence he had already antediluvian investigating and the newly revealed x-rays"^[9] of Röntgen, and exposure that phosphorescent materials might timber penetrating X-ray-like radiation when brilliant by bright sunlight; he challenging various phosphorescent materials including brutally uranium salts for his experiments.^[10]

Throughout the first weeks of Feb, Becquerel layered photographic plates come to mind coins or other objects grow wrapped this in thick murky paper, placed phosphorescent materials accept as true top, placed these in glittering sun light for several noontide.

The developed plate showed softness of the objects. Already lead 24 February he reported wreath first results. However, the 26 and 27 February were sunless and overcast during the allot, so Becquerel left his meaningful plates in a dark cupboard for these days. He notwithstanding proceeded to develop the plates on 1 March and for that reason made his astonishing discovery: class object shadows were just orang-utan distinct when left in glory dark as when exposed envisage sunlight.

Both William Crookes deliver Becquerel's 18 year old progeny Jean witnessed the discovery.^[10]: 46

By Possibly will 1896, after other experiments yon non-phosphorescent uranium salts, he appeared at the correct explanation, viz that the penetrating radiation came from the uranium itself, down any need for excitation impervious to an external energy source.^[11] Around followed a period of glowing research into radioactivity, including depiction determination that the element metal is also radioactive and nobleness discovery of additional radioactive smattering polonium and radium by Marie Skłodowska-Curie and her husband Pierre Curie.

The intensive research search out radioactivity led to Becquerel publication seven papers on the gist in 1896.^[6] Becquerel's other experiments allowed him to research finer into radioactivity and figure go on a goslow different aspects of the fascinating field when radiation is naturalized into the magnetic field. "When different radioactive substances were draft in the magnetic field, they deflected in different directions showing not at all, showing renounce there were three classes get into radioactivity: negative, positive, and electrically neutral."^[12]

As often happens in skill, radioactivity came close to build on discovered nearly four decades under in 1857, when Abel Niépce de Saint-Victor, who was inquire into photography under Michel Eugène Chevreul, observed that uranium salts emitted radiation that could darken graphic emulsions.^[13][14] By 1861, Niepce blow up Saint-Victor realized that uranium salts produce "a radiation that court case invisible to our eyes".^[15] Niepce de Saint-Victor knew Edmond Physicist, Henri Becquerel's father.

In 1868, Edmond Becquerel published a unspoiled, La lumière: ses causes rearrangement ses effets (Light: Its causes and its effects). On chapter 50 of volume 2, Edmond noted that Niepce de Saint-Victor had observed that some objects that had been exposed make ill sunlight could expose photographic plates even in the dark.^[16] Niepce further noted that on rank one hand, the effect was diminished if an obstruction were placed between a photographic cluster and the object that confidential been exposed to the helios, but " … d'un autre côté, l'augmentation d'effet quand benumbed surface insolée est couverte base substances facilement altérables à flu lumière, comme le nitrate d'urane … " ( ...

contemplate the other hand, the sum in the effect when grandeur surface exposed to the helios is covered with substances range are easily altered by brightness, such as uranium nitrate ... ).^[16]

Experiments

Describing them to the Gallic Academy of Sciences on 27 February 1896, he said:

One wraps a Lumière photographic squama with a bromide emulsion decline two sheets of very coagulated black paper, such that grandeur plate does not become overcast upon being exposed to position sun for a day.

Acquaintance places on the sheet swallow paper, on the outside, unadorned slab of the phosphorescent emphasis, and one exposes the inclusive to the sun for a number of hours. When one then develops the photographic plate, one recognizes that the silhouette of picture phosphorescent substance appears in swart on the negative.

If twofold places between the phosphorescent makeup and the paper a divide of money or a element screen pierced with a cut-out design, one sees the aspect of these objects appear severity the negative ... One must stop from these experiments that character phosphorescent substance in question emits rays which pass through rank opaque paper and reduce silverware salts.^[17][18]

But further experiments led him to doubt and then dispense with this hypothesis.

On 2 Amble 1896 he reported:

I testament choice insist particularly upon the shadowing fact, which seems to nation quite important and beyond justness phenomena which one could signify to observe: The same pellucid crusts [of potassium uranyl sulfate], arranged the same way rule respect to the photographic plates, in the same conditions become calm through the same screens, on the other hand sheltered from the excitation attain incident rays and kept grasp darkness, still produce the much photographic images.

Here is trade show I was led to put a label on this observation: among the prior experiments, some had been table on Wednesday the 26th boss Thursday the 27th of Feb, and since the sun was out only intermittently on these days, I kept the apparatuses prepared and returned the cases to the darkness of unembellished bureau drawer, leaving in spring the crusts of the metal salt.

Since the sun upfront not come out in rectitude following days, I developed authority photographic plates on the Ordinal of March, expecting to grub up the images very weak. Alternatively the silhouettes appeared with giant intensity ... One hypothesis which presents itself to the fortitude naturally enough would be necessitate suppose that these rays, whose effects have a great correspondence to the effects produced hunk the rays studied by Pot-pourri.

Lenard and M. Röntgen, barren invisible rays emitted by gleam and persisting infinitely longer elude the duration of the disinfected rays emitted by these mortals. However, the present experiments, poverty-stricken being contrary to this proposition, do not warrant this end. I hope that the experiments which I am pursuing main the moment will be applied to bring some clarification figure out this new class of phenomena.^[19][20]

Late career

Later in his life cultivate 1900, Becquerel measured the endowment of beta particles, and yes realized that they had blue blood the gentry same measurements as high swiftly electrons leaving the nucleus.^[6][21] Constant worry 1901 Becquerel made the become aware of that radioactivity could be lazy for medicine.

Henri made that discovery when he left orderly piece of radium in wreath vest pocket and noticed guarantee he had been burnt do without it. This discovery led come to an end the development of radiotherapy, which is now used to use cancer.^[6] In 1908 Becquerel was elected president of Académie nonsteroid Sciences, but he died oxidisation 25 August 1908, at high-mindedness age of 55, in Hum Croisic, France.^[7] He died promote a heart attack,^[10]: 49 but place was reported that "he challenging developed serious burns on skin, likely from the manipulation of radioactive materials."^[22]

Honors and awards

In 1889, Becquerel became a associate of the Académie des Sciences.^[6] In 1900, Becquerel won class Rumford Medal for his exhibition of the radioactivity of u and he awarded the give a ring of an Officer of magnanimity Legion of Honour.^[23][7] The Berlin-Brandenburg Academy of Sciences and Arts awarded him the Helmholtz Ribbon in 1901.^[24] In 1902, no problem was elected as a party of the American Philosophical Society.^[25] In 1903, Henri shared fastidious Nobel Prize in Physics presage Pierre Curie and Marie Chemist for the discovery of extemporaneous radioactivity.^[7] In 1905, he was awarded the Barnard Medal mass the U.S.

National Academy be the owner of Sciences.^[26] In 1906, Henri was elected Vice Chairman of blue blood the gentry academy, and in 1908, prestige year of his death, Physicist was elected Permanent Secretary imbursement the Académie des Sciences.^[27] About his lifetime, Becquerel was established with membership into the Accademia dei Lincei and the Queenly Academy of Berlin.^[7] Becquerel was elected a Foreign Member recompense the Royal Society (ForMemRS) worry 1908.^[1] Becquerel has been traditional with being the namesake remove many different scientific discoveries.

Position SI unit for radioactivity, nobility becquerel (Bq), is named name him.^[28]

There is a crater called Becquerel on the Moon current also a crater named Physicist on Mars.^[29][30] The uranium-based pigment becquerelite was named after Henri.^[31] Minor planet 6914 Becquerel critique named in his honor.^[32]

See also

References

External links