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Space Physics:
Miscellaneous

A Common Shape?

I have observed that there seems to be one constant structure in the Universe. It is a central mass with a spiral shape and objects orbiting around it. I have noticed this shape in atoms, moons orbiting planets, galaxies, and other systems with orbiting masses. Why is this structure found so many places in the Universe?

Circular (or near circular) motions are a mathematical consequence of the fact that the two widespread forces in the Universe (gravity and electromagnetism) both get smaller with the square of the distance between the two objects. Disks appear due to conservation of angular momentum. There is no real evidence that elliptical and irregular galaxies are evolving (much less "striving") towards spirals. And the motion of electrons about the nucleus is certainly 3-D, not disk or spiral shaped. Geometry and the mathematics of the universe are closely tied together, and this has been known and studied for quite some time. Spirals are only one manifestation of this.

Dr. Eric Christian
(July 2001)


Quasars, Black Holes, and the Evolution of the Universe

I am confused. If the Universe is 10 to 20 billion years old, and black holes are the end of a star cycle taking maybe 10 billion years, how is it possible for quasars, which need, or are a form of, black hole, to be 14 billion light years from Earth. Wouldn't the quasar's rays still be traveling to Earth's atmosphere?

Let's say the farthest quasar from Earth was formed at the exact same time its host black hole was created, and that the black hole's former star self was formed a second after the Big Bang. If the star took 10 billion years to become a black hole, wouldn't that mean that the farthest quasars are only 10 billion light years away? This, I realize, is not possible, since I understand it took at least 1 billion years after the Big Bang for the first stars to form. And it would take a star the size of our Sun 10 billion years from creation to become a black hole. How is it possible? Is my understanding wrong?

The assumption that you've got wrong is that it takes 10 billion years for a star to become a black hole. Only extremely massive stars explode in supernova and become black holes. Our Sun will end up as a white dwarf, and stars more massive than the Sun can end up as neutron stars. Only stars with mass more than 10 times our Sun's will become black holes, and these stars burn brighter and die sooner. Their lifetime is only a few hundred million years, not 10 billion. Also, quasars and giant black holes at the center of galaxies may form from stellar and gas collisions, and may not require that the stars that started them go through their entire life cycles.

Dr. Eric Christian

Black Holes and the Speed of Light

From what I understand, if something could travel at the speed of light, it's mass would reach an enormous size, and it would appear to be nothing (since as things approach the speed of light they become thiner and thiner until they appear to be nothing). This is similar to the description of a black hole, something with an enormous mass that we are unable to see. Is there any connection between these? That is, black holes could be objects or planets that have reached the speed of light. This would explain their huge mass and the fact that we cannot see them.

They are not really related. If an object is moving at close to the speed of light, it will appear to have a very high density (more mass and thinner), but it will not be a black hole. It will appear normal to something moving along at the same speed. A black hole has enough rest mass (mass in the reference frame where it is at rest) that light cannot escape it.

Two different things.

Dr. Eric Christian