Antoine Laurent Lavoisier (1743- 1794) was a brilliant French scientist who is regarded as the founder of modern chemistry.
He was elected to the French Royal Academy of Sciences at just 25 for an essay on street lighting. A year later, he worked on the first geological map of France.
Lavoisier earned his living for a long while as a ‘tax farmer,’ which meant he worked for a private company collecting taxes.
In 1771 he married 14-year old Marie Paulze, who later became his illustrator and collaborator in the laboratory.
Lavoisier was the first person to realize that air is essentially a mixture of two gases: oxygen and nitrogen.
Lavoisier discovered that water is a compound of hydrogen and oxygen.
Lavoisier showed that the popular phlogiston theory of burning was wrong and that burning involves oxygen instead. The frontiers of science
A Lavoisier showed that old theories about burning were wrong and that oxygen is essential in order for burning to take place.
Lavoisier gave the first working list of chemical elements in his famous book Elementary Treatise of Chemistry (1789), which was illustrated by his wife Marie.
From 1776 Lavoisier headed research at the Royal Arsenal in Paris, developing gunpowder manufacture.
Lavoisier ran schemes for public education, fair taxation, old-age insurance and other welfare schemes. But his good deeds did not save him. When Lavoisier had a wall built round Paris to reduce smuggling, revolutionary leader Marat accused him of imprisoning Paris’s air. His past as a tax farmer was remembered and Lavoisier was guillotined in 1794. Lavoisier had a wall built round Paris to reduce smuggling; revolutionary leader Marat accused him of imprisoning Paris’s air. His past as a tax farmer was remembered and Lavoisier was guillotined in 1794.
Galileo Galilei (1564-1642) was a great Italian mathematician and astronomer.
Galileo was born in Pisa on 15 February 1564, in the same year as William Shakespeare.
The pendulum clock was invented by Galileo after watching a swinging lamp in Pisa Cathedral in 1583.
Galileo’s experiments with balls rolling down slopes laid the basis for our understanding of how gravity affects acceleration (speeding up).
Learning of the telescope’s invention, Galileo made his own to look at the Moon, Venus and Jupiter.
Galileo described his observations of space in a book called The Starry Messenger, published in 1613.
Through his telescope Galileo saw that Jupiter has four moons (see Jupiter’s Galilean moons). He also saw that Venus has phases (as our Moon does).
Jupiter’s moon and Venus’s phases were the first visible evidence of Copernicus’ theory that the Earth moves round the Sun. Galileo also believed this.
Galileo was declared a heretic in 1616 by the Catholic Church, for his support of Copernican theory. Later, threatened with torture, Galileo was forced to deny that the Earth orbits the Sun. Legend has it he muttered `eppur si muove’ (`yet it does move’) afterwards
Quarks are one of the three tiniest basic, or elementary, particles from which every substance is made.
Quarks are too small for their size to be measured, but their mass can. The biggest quark, called a top quark, is as heavy as an atom of gold. The smallest, called an up quark, is 35,000 times lighter.
There are six kinds, or flavors, of quark: up (u), down (d), bottom (b), top (t), strange (s) and charm (c).
Down, bottom and strange quarks carry one-third of the negative charge of electrons; up, top and charm ones carry two-thirds of the positive charge of protons.
Quarks never exist separately but in combination with one or two other quarks. Combinations of two or three quarks are called hadrons.
Three-quark hadrons are called baryons and include protons and neutrons. Rare two-quark hadrons are mesons.
A proton is made from two up quarks (two lots of +2/3 of a charge) and one down quark (-1/3) and has a positive charge of 1.
A neutron is made from two down quarks (two lots of –1/3 of a charge) and an up quark (+2/3). The charges cancel each other out, giving a neutron no charge.
The theory of quarks was first proposed by Murray Gell-Mann and Georg Zweig in 1964.
Quarks are named after a famous passage in James Joyce’s hook Ulysses: ‘Three quarks for Muster Mark!’
There are three kinds of spacecraft – artificial satellites, unmanned probes and manned spacecraft.
Spacecraft have double hulls (outer coverings) to protect against other space objects that crash into them.
Manned spacecraft must also protect the crew from heat and other dangerous effects of launch and landing.
Spacecraft windows have filters to protect astronauts from the Sun’s dangerous ultraviolet rays.
Supposed alien spacecraft are sometimes called flying saucers. Modern science-fiction portrays them as more like this.
Radiators on the outside of the spacecraft lose heat, to stop the crew’s body temperatures overheating the craft.
Manned spacecraft have life-support systems that provide oxygen to breathe, usually mixed with nitrogen (as in ordinary air). Charcoal filters out smells.
The carbon dioxide that crews breathe out is absorbed by pellets of lithium hydroxide.
Spacecraft toilets have to get rid of waste in low gravity conditions. Astronauts have to sit on a device which sucks away the waste. Solid waste is dried and dumped in space, but the water is saved.
To wash, astronauts have a waterproof shower which sprays them with jets of water from all sides and also sucks away all the waste water, most astronauts sleep floating in the air. The weightlessness of space means that held in place by a few straps.
The US space shuttle, the first reusable spacecraft, has made manned space flights out into Earth’s orbit and back almost a matter of routine.
Steam trains get their power by burning coal in a firebox. This heats up water in a boiler, making steam. The steam drives a piston to and fro and the piston turns the wheels via connecting rods and cranks.
It takes about three hours for the crew to get up enough steam to get a locomotive moving.
Coal and water are often stored in a wagon called a tender, towed behind the locomotive.
A tender holds 10 tons of coal and 30,000 liters of water.
Loco classes are described by their wheel layout.
A 4-6-2 has four small leading ‘bogie’ wheels, six big driving wheels and two small trailing wheels. The small bogie wheels carry much of the weight.
The greatest Victorian loco designer was James Nasmyth.
In the American Civil War (1861-65) the loco The General was recaptured by Confederates after an epic chase in another loco.
The Flying Scotsman was a famous loco designed by Sir Nigel Gresley (1876-1941). It pulled trains non-stop the 630 km from London to Edinhurgli in less than six hours.
The first loco to hit 100 mph (160 km/h) was in the City of Truro in 1895.