ATOM

Operated near Geneva by CERN (The European Laboratory for Particle Physics) the accelerator is more than four miles long and one the largest machines even built. It produces temperatures as high as 7,000 trillion degrees Celsius.

The subatomic particles make 43,000 times each second, the circuit of Super Proton Synchrotron.

The magnets guide a stream of protons around the beam line at nearly the speed of light (300,000 km per second = 186,82 miles per second) before they collide with a beam of antiprotons whirling in the opposite direction. The impacts are so violent –like volleys of cannonballs smashing into matter, creating subatomic particles that fly wildly in all directions. Most of this particles are short –lived, some last only a trillionth of a trillionth of a second before vanishing.

It a world where matter and energy are interchangeable, where empty space is not really empty and where gravity is overwhelmed by stronger forces that bind together matter.

Your every breath holds a trillion trillion atoms. Protons, carrying a positive electric charge and electrically neutral particles called neutrons cluster within the atom’s central region or nucleus –one hundred-thousandth the diameter of the atom. Whirling around the nucleus is a third subatomic particle, the electron, which caries a negative charge. Some particles exist so briefly that they are not real but virtual.

Paradoxically, exploring the smallest things in the universe requires the largest machines on earth.

In 1808 the chemist John Dalton argued that for each chemical element there is a corresponding atom and that all else is made from combinations of those atoms. Pierre Curie indicated that atoms had a internal structure. J.J. Thomson, which identified electrons, charged prticles much smaller than the hydrogen atom. The uncuttable was cut; there was a subatomic world.  

Max Plank’s assumption in 1900: Energy was not exchanged in a continuous flow but individual packets, or quanta; energy moved not like a river but like raindrops. In 1905 Albert Einstein was developing what would become his special relative theory equating energy and mass.

Niels Bohr proposed that electrons behaved in quantum fashion. They remained in fixed orbits and moved from one orbit to another –in quantum leaps – when the emitted or absorbed energy.

Enrico Fermi, who studied electrons and gases before building the first fission reactor that led to atomic bomb and nuclear power.

Werner Heisenberg formulated the uncertainty principle: It is impossible to measure simultaneously both the precise momentum and position of a subatomic particle.

Paul Dirac’s mathematics predicted antimatter. Carl Anderson confirmed this idea in 1932, with his discovery of a positive electron or positron, a particle just like an electron but with positive rather than a negative charge. When matter and antimatter meet, they annihilate each other in a burst of radiation. For every type pf particle there must also be an antiparticle. This quirk of nature has led physicists to speculate about encounters between the universe and an anti-universe.   

To hit an atom’s with a charged particle is something like playing pool in the dark on a table as big as Texas. The cue ball, a proton with positive charge, is shot at nearly the speed of light. Fortunately, the player can fire many cue balls at the same time. At least one of the objects balls, the nuclei, will be hit by a proton. Score is done by observing what other subatomic particles are created out of the energy transformed into matter by the force of the collision.

We now know that electrons do not orbit the nucleus in a two dimensional plane as planets orbit about the sun. Orbit is a term left over from what has become and outdated view of atoms.

How can an elephant closely inspect an ant except by destroying it?  If the parts of atoms seem always elusive, their behavior is statistically predictable to high degree of accuracy and sufficient for detailed scientific study.

Carbon 12 is of particular interest, for its atomic weight has been established as the basis for the weights of all other atoms.

Two miles long and as straight as the laser beam used align it; the accelerator hurls electrons at 99.99 % the speed of light. However, collisions in an electron accelerator are easier to analyze.

Almost every home has a primitive accelerator: the television picture tube. Inside it electricity heats a metal filament, boiling off negatively charged electrons and accelerating them through a positively charged wire grid. A magnet then steers them at the phosphorus –coated TV screen, which glows from the collisions.

One way to boost energy is to fire two beams of particles in opposite directions around a ring, so that they slam together. We are repeating one of the miracles of the universe- transforming energy into matter.

The atoms of all the elements then known were described as combinations of protons, neutrons and electrons-held to be the fundamental building blocks of matter.

At the center of each atom, in this view, was a nucleus of neutral neutrons and positive protons, the number of protons identifying the element. The lightest was the hydrogen, with one proton. The heaviest naturally occurring element, uranium, had 97 protons.

For each proton in the nucleus, there was negative charged electron, gyrating around the atom’s core at a distance 50,000 times the diameter of the nucleus. If a hydrogen atom’s nucleus were the size of a tennis ball, its electron would be two miles away.        

Antimatter poses a mystery: If particles vanish when they meet their opposites and if every particle can have an antiparticle, why is the world made only of matter? Where has all the antimatter gone? During the first split second after the big bang, there was a small excess of matter over antimatter. Particles and antiparticles collided, annihilating each other and leaving behind only radiation and surplus matter. This residual particle make up almost everything in the universe today: stars, galaxies, the sun system, the Milky Way, the earth, the moon and us.

Ernest O. Lawrence Constantly uncovered new particles. By the early 1960 dozens were known. Three smaller building blocks were discovered by Murray & Zweig at the CERN, named quarks. Now the protons and neutrons- could be explained as combinations of quarks, bonded together according to their color.

A proton consist of two up quarks with positive charge of two –thirds each and one down quark with negative charge of one third; together they yield a single positive charge. In the same way, one up and two down quarks combine to form a neutral neutron. Quarks apparently exist only in trios or in quarks/antiquarks pairs.

“Remember energy is matter and matter is energy” Nearly all the several hundred known subatomic particles are made of quarks, bound together by what physicist calla the strong nuclear force. The exceptions are called leptons.  The best lepton (slight) is the electron, first identified in 1897. Muons, discovered in 1937, have about 200 times as much mass of the cosmic radiation that constantly bombards earth. The other leptons are neutrinos –little neutral ones-

Several million neutrinos, traveling at the speed of light, are flying through your body al this instant. Nothing stops them.

The W and Z particles carry the weak force, one of three forces governing the behavior of atoms, breaking down each neutron in the nucleus of a radioactive atom into a proton, an electron and an antineutrino. Other gauge particles, called photons, impart the electromagnetic force (responsible for keeping electrons in orbit around the nucleus), about 100,000 time more powerful than the weak force. Most powerful of all –a hundred times than the electromagnetic force – is the strong force.

Besides these three forces, the other known force at work in the universe is the gravity. It is by far weakest –the strong force is some 1 followed by 38 zeros times more powerful. A still undetected particle, the graviton, may be the carrier of gravity, which has no meaningful role inside atoms. Without gravity, however, there would be no universe, since it binds together stars & galaxies, holds the earth in orbit, and keeps our feet planted on the ground.

Maxwell discovered that electricity and magnetism are two aspects of the same force. Today some physicists believe that the universe’s four forces are but manifestations of a single and deeper force.

None of these theories yet embrace the universal fourth force, gravity. But they do predict that protons decay into other particles, because the strong force that binds a proton together and the weak force that causes radioactive decay may spring from the same basic interaction. But if proof is found that protons decay, it will mean that the matter is inherently unstable – nothing lasts forever.

Besides predicting proton decay, grand unified theories attempt to trace the history of the universe back to its creation in the big bang some 15 thousand millions years ago. Since then the cosmos has been constantly expanding. Today the visible universe is growing every second by a volume equal to that of the Milky Way galaxy.