A Matter of Some Gravity
Posted On March 8, 1998
A Matter of Some Gravity
There are forces in the universe which affect all of our lives. Through the centuries madmen and scientists have tried to recognize and label these forces. The difference between madman and scientist is whether the theories of the individuals are accepted or rejected.
A fundamental premise of the scientific method is that no theory is ever proven true, but if it is unable to be disproven, its validity is generally accepted. Current conventional scientific wisdom says that the universe is curved in time and space. Much of this theory rests on the work of Albert Einstein, especially his theory of relativity (E=MC2). The bending of space and time would be most likely to occur in the vicinity of a massive amount of gravity. A black hole is conjectured to be one of these gravity sinks. In the process of its evolution a star would eventually be acted upon by a contraction of matter, which causes an increase in the gravitational pull at the center of the star. Eventually the matter becomes so contracted that it becomes a single point or singularity. This singularity is so dense that light ( which appears to be one of the only constants in the universe) is unable to escape and so a black hole can be detected as only an absence of anything detectable. The proof of black holes has been that we cannot detect them, however in 1973 Stephen W. Hawking discovered that quantum effects will cause black holes to emit particles, as this happens the black hole will evaporate, leaving none of the original mass, maybe. In such a situation particles are packed so densely together that fundamental movement is arrested on the quantum and molecular level. Time stops. A less than perfect analogy is that of water going through a funnel. At some point the width of the funnel becomes so narrow that the water stops. But instead of going still the water would keep swirling because the force of gravity is still acting upon it from below. At this point the water above the narrowest point of the funnel is pulled into the swirling motion and the curvature of space and time occurs. The swirling causes a stronger gravitational pull which draws in more water which increases the pull drawing in more water etc. etc. etc. Relativity points out that time moves more quickly when acted upon by outside gravity. The closer you are to the source of the gravity, the slower time moves. On a miniscule level this means that the higher your altitude on earth the faster time moves for you since the center of earths gravity is presumed to be somewhere in the center of the earth. If time is arrested inside a black hole how does a particle have time to escape?
A problem arises with paradox. If time is stopped at the center of a black hole, then further collapse is impossible because the collapse occurs in time. This could mean that extending outward form the center of a black hole time would gradually stop leaving a solid body of stopped particles. The singularity no longer exists, the black hole is now an extending solid which changes the entire set of equations which define a black hole. Another problem is that if time is observed to have stopped within the black hole from the outside, what is observed both inside and outside from the black hole? Einstein discovered that space-time is curved by the presence of matter. The famous analogy is a rubber sheet stretched tight with balls of various weights and sizes placed upon it. The larger a body, the larger the curvature of space. The larger the curvature of space, the more other bodies are affected by that curvature. If eneough weight is placed upon the sheet all bodies will fall to the center and movement stops. Time is measured by the movement of matter/energy. If the movement stops, time stops. At the present time the universe is in a state of movement (expansion), debate rages at whether that movement will continue indefinately (infinite) , stop at an outer limit (static), or reach an outer limit and then contract back to a stopping point (clockwork).
Black holes are presumed by some to be regions of such intense gravity that everything (most easily thought of as information by scientists such as Stephen Hawking and Roger Penrose) captured by a black hole is irretrievable. Both scientists agree that a black hole continues to contract until the point of evaporation. It is at his point that they disagree. Penrose believes that at the moment of evaporation information is regained by the universe and phase space volumes increase. Hawking believes that the information is lost which, violates the theories of conservation of matter and energy. His argument is that the beginning and end of the universe ( and hence time) cannot be the same. Through a single small irregularity at the beginning of time, multiple irregularities grew. Therefore we are travelling from a orderly universe to a sloppy one. Another imperfect analogy would be a clean house (the universe) before a party (time), each guest ( irregularity ) creates a small mess, but like good guests, they clean up after themselves. Each partygoer however forgets to wash the glass they are drinking from and at the end of the night despite each person cleaning their mess, the house is filled with glasses of various liquids. Some of the glasses are still full (young stars), some of the glasses are empty (black holes) , most are in a state somewhere in between (stars between formation and collapse). Hawking seems to
be saying that the state of the house never really changed because the glasses and liquid were already there so there are no limits to the universe, things just change position, Penrose on the other hand seems to feel that because the glasses are no longer in the cupboard or the liquid in the bottle a new state has been created which demands that at some point the glasses be washed and put away and the bottles refilled.
What keeps black holes from forming from every bit of matter in the universe? Stars and galaxies radiate heat which causes thermal pressure which acts as a temporary balancing point against gravity. The reason it is temporary is because heat has a tendency to radiate outward (almost as if it is drawn to cold) thus the material which provides the fuel which provides the heat is sent outward in tight little packets of energy called quantum. Quantum actully fill the space between the states of matter and energy, exhibiting properties of both. Thus as the quantum is carried away, the actual matter begins to shrink. If it is no more than two times the mass of our sun, the shrinkage will be stopped on the atomic level by the motion of electrons or neutrons and a neutron star or white dwarf star is formed. For larger mass objects this force is overcome and eventually (according to Hawking ) a black hole forms which keeps mass, energy, and quantum from proceeding outward to the edge of infinity. This is a black hole. Eventually the black hole swallows everything around it including itself leaving behind less than was put into it. Black holes a a massive solid emptyness where time stops but change continues and laws of conservation do not apply. Is it any wonder they also lie at the center of so much debate?