LOOK ON THIS PAGE UNDER QUIZZES FOR A
SET OF SAMPLE QUESTIONS FOR THURSDAYS QUIZ
We have an ancient comet in our midst with a period of 4200 years. It was one of the dirty snowballs that condensed when the solar system was first formed 4.5 billion year ago.
Even more ancient objects are the photons of light form the primordial fireball which formed some 12 billion years ago.
Ours is a universe of light in which photons outnumber us particles of matter by a billion to one. For every particle of matter there are a billion photons moving through our curved universe. There are stars, like our sun, that are producing light, but their output is minuscule compared to the original photons.
Primordial light appeared in two great flashes as matter and anti-matter self-annihilated. Both kinds of matter were converted into energy and light. The first flash was associated with protons and anti-protons destroying each other some .0001 seconds after the onset of expansion. The second great flash occurred 100 seconds later when electron and positrons annihilated each other.
The amount of matter and anti-matter were nearly but not perfectly equal. If it had been exactly equal, then nothing would have been left over except light. Because there was a slight excess by one part in a billion of matter over anti-matter, some matter remained after the annihilation. This is one of the great mysteries of existence: why was there matter left over after particles experiences annihilation.
The universe has continued expanding after that radiation was formed; as seen by us it is now moving away from us at nearly the speed of light. As a consequence it is experiencing an enormous relativistic Doppler effect by a factor of z = 1500. This is the largest red shift that we have measured. It has changed the temperature of the primordial radiation from 4500K to 2.7K
Curved space can act like a giant lens. If space is positively curved, it is the same a convergent, double-convex, lens. If space is negatively curved, it acts as a divergent, double concave lens. A window pane acts as flat space.
Curved space causes tides on the earth. The friction between the earth and those tides cause the earth to slow down and loose .002 seconds per century. A consequence of that slowing is that the moon moves away from the earth at the rate of 4 cm/century.
The moons recession is due to the conservation of angular momentum:
mvr = constant. The total angular momentum of the earth-moon system is
mvr(moon) + mvr(earth) = constant.
When the velocity of rotation of the earth decreases, something else must increase to keep the sum the same. That is accomplished by increasing the radius of the moons orbit around the earth.
The moon will continue to spiral outward until the rotation of the earth and the revolution of the moon both equal 47 days. At that time the moon will be 550,000 from the earth, and too small in the sky to cover over the sun at the time of an eclipse. NO MORE ECLIPSES!
Conservation of angular momentum also caused the solar system to develop in to a sun with planets in one plane. Initially the solar system was a ball of gas. The comet cloud probably condensed out of the gas well before the planets were formed. As it collapsed in size, it spun faster and faster due to the conservation of angular momentum and the gas became distended in its equator, eventually resulting in the planets. Other similar situations are the rings of Saturn and a spiral galaxy.