What are they? Where do they come from? Bob’s BLACK HOLES. What are they? Where do they come from? Hello. Today, I want to talk to you about Black Holes. What are they and where do they come from?

How do we know they are there? Albert Einstein first predicted black holes in 1916 with his general theory of relativity. The term "black hole" was coined in 1967 by American astronomer John Wheeler, and the first one was discovered in 1971. That is 55 years before we knew he was right… A black hole is essentially a star that has collapsed in on itself and forms a hole from which nothing can escape… BUT…how do they get there?

HOT STUFF! So let’s look at how a star can burn off all its energy and become a black hole. So lets look at how a star forms, how it burns off its energy and becomes a black hole. (HERE YOU CAN POINT AT THE DIAGRAM) Stars form from nebulas, their great mass means that the gravity inside these giant fireballs is very powerful…making the inside of these stars into massive nuclear reactors. The bigger ones, as they burn up expand and cool. But these stars do not go out with a whimper…they go out with a BANG.. A SUPERNOVA is a massive last explosion of the collapsing star. Once they have collapsed they can either become a dense neutron star OR THEY COLLAPSE INTO THE SUPER DENSE, INESCAPABLE BLACK HOLE… Only stars with very large masses can become black holes. Our Sun, for example, is not massive enough to become a black hole. Four billion years from now when the Sun runs out of the available nuclear fuel in its core, our Sun will die a quiet death. ...

FUSION PROCESSES: Fusion is the process that powers our sun and the stars…   ALL of suns life is WAR between pressure and gravity… The pressure is the release of energy outwards…while gravity is pulling to collapse on itself…ITS LIKE A HUGE FIGHT BETWEEN TWO MIGHTY ARMS… Uncontrollable arm of pressure from right…and left arm of gravity stops it EVENTUALLY the Left arm runs out of energy and you are going to get hit…A BIG LEFT HOOK…POW… A black hole is like a bruise in space, after the punch up between gravity and nuclear pressure…

Gravity wins every time Eventually… GRAVITY WINS.

But seriously… BUT SERIOUSLY HERE ARE THE FACTS:   How a massive star fuses its energy…FOR A WHILE IT IS IN EQUILIBRIUM OR BALANCE…the fusion pushes outwards gravity pulls inwards. Hydrogen into helium…this releases loads of energy…heat and light…this is what heats and lights our world…

DEEP INSIDE AT THE ATOMIC LEVEL… FIRST UNDER THIS IMMENSE FORCE, PAIRS OF HYDROGEN ATOMS ARE FUSED TOGETHER TO PRODUCE ONE HELIUM ATOM, AND RELEASE A BURST OF HEAT AND LIGHT… THEN after this it fuses the Helium into Carbon + Oxygen (each time it fuses new element.) CARBON FUSES INTO MORE OXYGEN, NEON, SODIUM + MAGNESIUM. NEON FUSES INTO MORE OXYGEN AND MAGNESIUM OXYGEN THEN FUSES INTO SILICON; SULPHUR AND PHOSPHOROUS. SILICON FUSES INTO IRON + NICKEL THIS LEAVES A SOLID CORE OF IRON + NICKEL… … SO EACH TIME AN ELEMENT IS PRODUCED THE ENORMOUS PRESSURES WITHIN THE STAR CRUSH IT INTO SOMETHING NEW when it pases 100 million degrees , the star gets its diploma…no seriously though…100 million degrees..that is the heat from 10 milllion fresh cups of tea… no seriously though …its very hot…  NOTE ON RED DWARF STARS: red dwarf stars live longer…helium and hydrogen mix, no heavy elements in core that slow fusion down…   AS iron builds up in the core, there remains less available matter for fusion, so pressure of energy release decreases. So the force of gravity forces the star to collapse. …IT BURNS UNTIL THERE IS NO ENERGY LEFT…THE STAR LOSES ITS FIGHT AGAINST GRAVITY…

A BLACK HOLE IS FORMED! The star collapses to an almost infinitely small pinpoint. . The star's outer layers may blast away into space, or they may fall into the black hole to make it heavier. TO GIVE YOU AN IDEA OF HOW MUCH THEY SHRINK…IF THE EARTH BECAME A BLACK HOLE IT WOULD BE THE SIZE OF A GOLF BALL.

SO WHAT IS THE EFFECT? AT THE CENTRE OF ALL GALAXIES IT IS NOW THOUGHT THERE IS A MASSIVE BLACK HOLE…AND ITS HUNGRY…AT THE CENTRE OF OUR OWN MILKY WAY IS A SUPER MASSIVE BLACK HOLE…DRINKING ALL THE MILK! THIS MASSIVE GRAVITY SUCKS EVERYTHING IN AND CRUSHES IT ALL INTO ITSELF…THIS CENTRAL POINT, THIS GALACTIC GARBAGE MASHER IS CALLED THE SINGULARITY…AND ONCE YOU PASS THE RIM…CALLED THE EVENT HORIZON…YOU ARE LOST…

BUT, BOB, WHY ARE THEY BLACK? THEY ARE BLACK SIMPLY BECAUSE THEY EXERT SO MUCH GRAVITY THAT EVEN LIGHT CANNOT ESCAPE… Light becomes heavy…its amazing… Talk about diagram…EXPLAIN THAT THE BOAT STUCK AT EVENT HORIZON IS FROZEN IN TIME…FREEZE… THEY DON’T JUST EAT LIGHT BULBS FOLKS…

HUNGRY! EXPLAIN… SO REMEMBER IF YOU SEE A BLACK HOLE; RUN THE OTHER WAY… BECAUSE ONCE YOU GET SUCKED IN …THERE IS NO ESCAPE…

Oops! WELL THAT’S BLACK HOLES…THANK YOU…