Posts Tagged ‘spatiu’

Michael M. Woolfson – Time, Space, Stars and Man: The Story of the Big Bang – cateva citate

Wednesday, November 10th, 2010

Michael M. Woolfson - Time, Space, Stars and Man“The factors that govern the rate of any particular nuclear reaction are the temperature and the densities of the reacting isotopes. The temperature at the centre of the Sun is about 15 million K and this enables nuclear reactions to take place that convert hydrogen into helium. However, at that temperature, it is a very ineffective process.
This statement may seem surprising — surely the Sun is a stupendous generator of energy! Well, it is in the sense that large total amounts of energy are generated but in terms of the power generation per unit mass it is not very impressive. The mass of the Sun is 2 × 1030 kilograms and its power production is about 4 × 1026 watts giving 2 × 10−4 watts per kilogram. By comparison, an average person of mass 70 kilograms generates and emits about 95 watts of heat radiation by chemical processes going on within his body, giving about 1.4 watts per kilogram, some 7,000 times greater than the solar value! It is indeed fortunate that the Sun is such an inefficient producer of energy. If it produced energy per 276 unit mass at the rate of a mammal, it would long ago have exhausted its fuel.”

“Perhaps the only objective measure of success in an evolutionary sense is survivability and on that basis, the cockroach and the shark come out well. They have been around for a long time — about 400 million years. It is also claimed that if man ever created a nuclear hell-on-Earth the best, and perhaps only, survivors on land would be cockroaches. They would carry forward the banner of future evolution, perhaps culminating in a few hundred million years in another kind of intelligent creature, perhaps one that knew how to survive with its intelligence.”

“Karl Marx stated in Das Kapital that “capitalism contained the seeds of its own destruction”, but what he claimed applied to capitalism probably applies in a wider sense. For example, many of the world’s most beautiful places have attracted tourists, whose physical needs have been met by building concrete and glass hotels which by their very nature detract from the beauty that led to their construction.
Perhaps mankind has evolved with too large a brain — which will become the agency of its own destruction. Mankind, as a species, could have existed indefinitely with bows and arrows, windmills and the Black Death, but it may not be able to survive very long with nuclear weapons, coal-fired power stations and antibiotics.”

Una geniala

Saturday, October 30th, 2010

Eu am venit cu ideea, altii s-o puna in practica, apoi imi vreau milionul de dolari!

Pale Blue Dot – Carl Sagan, cateva citate

Monday, February 15th, 2010
The Pale Blue Dot

Punctul acela alb, acolo suntem noi cu totii

“Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was,  lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, ever king and peasant, every young couple in love, every moth and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there—on a mote of dust suspended in a sunbeam.”

“You might imagine an uncharitable extraterrestrial observer looking down on our species over all that time—with us excitedly chattering, “The Universe is created for us! We’re at the center! Everything pays homage to us!”—and concluding that our pretensions are amusing, our aspirations pathetic, that this must be the planet of the idiots.”

“In some respects, science has far surpassed religion in delivering awe. How is it that hardly any major religion has looked at science and concluded, “This is better than we thought! The Universe is much bigger than our prophets said, grander, more subtle, more elegant. God must be even greater than we dreamed”? Instead they say, “No, no, no! My god is a little god, and I want him to stay that way.” A religion, old or new, that stressed the magnificence of the Universe as revealed by modern science might be able to draw forth reserves of reverence and awe hardly tapped by the conventional faiths. Sooner or later, such a religion will emerge.”

“Voyager cost each American less than a penny a year from launch to Neptune encounter.”

“In all Romance languages, such as French, Spanish, and Italian, the connection is still more obvious, because they 4 derive from ancient Latin, in which the days of the week were named (in order, beginning with Sunday) after the Sun, the Moon, Mars, Mercury, Jupiter, Venus, and Saturn. (The Sun’s day became the Lord’s day.)”
(N.A. Luni – Luna, Marti – Marte, Miercuri – Mercur, Joi – Jovian/Jupiter, Vineri – Venus, Sambata – Saturn, Duminica – (ziua lui) Dumnezeu.)

“In five billion years, all humans will have become extinct or evolved into other beings, none of our artifacts will have survived on Earth, the continents will have become unrecognizably altered or destroyed, and the evolution of the Sun will have burned the Earth to a crisp or reduced it to a whirl of atoms. Far from home, untouched by these remote events, the Voyager s, bearing the memories of a world that is no more, will fly on.”

“I’m struck again by the irony that spaceflight—conceived in tile cauldron of nationalist rivalries and hatreds—brings with it a stunning transnational vision. You spend even a little time contemplating the Earth from orbit and the most deeply engrained nationalisms begin to erode. They seem the squabbles of mites on a plum.”