Nucear reactions page

 

 

 

 

April 18th

 

In 1972 Bangladesh joined the Commonwealth of Nations. After gaining its independence (on the 26th of March 1971) from Pakistan, Bangladesh joined India and Pakistan as a member of the Commonwealth of Nations on this day in 1972.

In 1955 Albert Einstein died at the age of 76. The German born theoretical physicist was the father of general relativity and the ...of the worlds most famous equation E=MC2. His discoveries revolutionised the world of “modern physics” (Relativity and Quantum Mechanics). In 1916 Einstein published his ‘General theory of Relativity’ which described gravity as a property of space and time (spacetime) and he proposed that the properties of gravity, space and even time were relative (dependent on) the speed of motion of the observer of object in question. One of the most controversial ideas of this theory is that time actually slows down the closer you get to the speed of light, a theory now proven many times and is a pivotal part of satellite navigational technology. He also received the Nobel Prize in 1921 for his work on the ‘Photoelectric Effect’ which helped to establish Quantum Physics. The ‘Photoelectric Effect’ regards the transfer of energy from a light beam onto a metal surface which becomes heat. The theory suggested that with enough time, however strong the beam of light, enough energy should be transmitted to the metal to liberate one of its electrons from one of the atoms. In practice physicists found that this worked on some metals and not others and that an electron would eject with more energy dependant on the colour of the beam rather than the intensity. This perplexed physicists until 1905 when Einstein applied a previous theory by Max Planck. Plank had suggested that light beams (and all Electromagnetic radiation) were not a continuous flow of energy, as previously thought, but actually packets (quanta) of energy (like the way information is sent across the internet). When Einstein applied this theory he was able to explain why it didn’t matter the length of time that the light beam shone on the metal but it the individual photons (energy packets) had enough energy within them to cause an electron to escape. It even explained why the colour affected the energy the electrons ejected by was effected by colour rather than intensity. His most famous work was the idea that the mass of an object could be converted to energy or energy into matter. E = MC2 suggests that the amount of (potential) energy is equal to the mass of matter multiplied by the speed of light squared. This is used in nuclear weapons but also explain how the sun is able to produce so much power. Every time a hydrogen atom becomes a helium atom in the plasma of the sun, a little bit of mass is ‘lost’ and converted into energy. Einstein left an amazing legacy when he died on this day in 1955 and his contributions changed physics and our lives forever.

Technology and Invention

 

On This Day...

Biology                  Chemistry                 Physics                  Maths                          History                    Geography              General Knowledge                  World Cultures                Music                  Art                Film and Entertainment                   Technology & Invention

Loading
Biology
Chemistry
Physics
Maths
History
Geography
General Knowledge
World Cultures
Music
Art
Film and Entertainment
On This Day...
Earth  Site Home

18th of April