Yes, to think of a universe with a definite beginning in time begs the question: “but what came before? ” It places an implicit demand that something greater and bigger exist that is both external to and greater than the universe. For, if the universe had an exact beginning, it implies that there was nothing material before it, since everything material that exists now is part and parcel of the universe. Hence, since it exists now, the universe must have arisen from nothingness. But what or who could give rise to such an entity from nothing?
Different religions and philosophers would answer differently – some would say God, some would say any transcendent being that is not encompassed by the limits of the universe – yet it all boils down to positing the existence of something omnipotent and transcendent. DQ2 – The evidence for black holes at the center of galaxies is strong. However, it is very difficult to prove absolutely that they exist because the black holes do not emit light. We can only infer their existence from their powerful gravitational influences on surrounding matter. How compelling do you find the evidence?
Do you think astronomers have proved the case for black holes beyond a reasonable doubt? Even though theories and evidence may point to the existence of black holes, they do not present an entirely convincing argument. For one thing, the cause of “powerful gravitational influences on surrounding matter” may not necessarily be black holes. They can actually be caused by dark matter in the universe. On the other hand, however, though black holes may not emit visible light, theories predict that they in fact emit other types of electromagnetic waves with very short wavelengths, such as x-rays and gamma rays.
The cause of this emission is due to the high gravitational force at the event horizon of the black hole. As interstellar matter is sucked by the black hole, the very high gravitational force accelerates the matters, causing it to heat up to extremely high temperatures, thus emitting gamma rays and x-rays. Still, even with this evidence, it is still too early to say whether black holes exist or not. DQ3 – The end of time. Just as there was a “big bang”, astronomers say, there will be a “big crunch”.
Some people speculate that the universe will experience a re-birth and eventually a new big bang. Do you believe on this? Discuss some ideas on how this may happen. For “big crunch” to happen, there needs to be a critical mass of dark matter in the universe. This means that at a certain point, the gravitational force exerted by dark matter in the universe must be enough to pull the other matter in the universe together. As they come closer and closer together, gravitational force increases, accelerating the rate of contraction.
Eventually, the gravitational force will be so high that all the matter in the universe will collapse into a single point. Evidence is inconclusive, since the actual nature of dark matter is yet unknown. Hence, it is hard to say whether I believe it or not. DQ4 – Suppose the universe will keep expanding forever, as much observation suggests. How would you satisfy your energy needs as time goes on? How would you grow food? If the universe will expand forever, then there will come a point when it will spread itself too thin, cool down, and die.
Since the total energy in the universe cannot increase and must remain constant, when the universe keeps on expanding, all these energy will be diffused until too little will remain at any localized point to be useful. One alternative is to harvest energy sources in the universe and concentrate it in a single location in order to maximize its potential. One probable source could be dark energy, which is uncharacterized as yet. Food will have to be obtained through alternative means, considering that we can no longer rely on the energy from the sun by the time the universe has expanded so much,Sample Essay of Custom-Writing