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标题: Stephen Hawking: Why you might want to give A Brief History Of Time another go [打印本页]

作者: 名本 时间: 2018-3-17 22:18
标题: Stephen Hawking: Why you might want to give A Brief History Of Time another go
本帖最后由名本于 2018-3-17 22:20 编辑

Stephen Hawking: Why you might want to give A Brief History Of Time another go

By Michael Collett
Updated Thu at 10:59am

PHOTO: If Stephen Hawking's book is still too difficult for you, don't feel like you're the only one. (Reuters: Toby Melville)
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It's on your bookshelf. It looks well-worn. But it's never been read.
Stephen Hawking's A Brief History Of Time was an immediate sensation upon its release in 1988, and sold more than 10 million copies.
But while it was written in non-technical language — and contained only one mathematical formula, E = mc2 — the mind-blowing and potentially headache-inducing topics of black holes and big bangs seemingly proved too much for some readers.
If you're thinking of giving it another go following the famed physicist's death at the age of 76, but you're daunted by the thought, you're not alone:

External Link: Paul Bernal tweet: "Across the world, tens of thousands of unread copies of A Brief History of Time will be being taken off the shelves, dusted down, and still not read."

But here's why it might be worth it.

This book is about more than just explaining physics

A Brief History Of Time will give you a primer on the nature of time, the strange behaviour of particles, and lots more. But ultimately, it's about existence itself.

"This is also a book about God … or perhaps about the absence of God," Carl Sagan wrote in the foreword.

Specifically, Professor Hawking was attempting to answer the famous question posed by Einstein: how much choice did God have in constructing the universe?
As Mr Sagan puts it, A Brief History Of Time ultimately suggests the universe might have "no edge in space, no beginning or end in time, and nothing for a creator to do".

It was written with non-scientists like you in mind

PHOTO: A Brief History Of Time made a star of Stephen Hawking. (Flickr: Wil C Fry)

The book's editor, Peter Guzzardi, said his job was basically to pepper Professor Hawking with questions until he actually understood what the author was talking about.

"We were just trying to create a book that was scientifically accurate without being impenetrable to the general reader, someone like me," he wrote in The Guardian.

However, if the book is still too difficult for you, don't feel like you're the only one.

"Of every 100 people who bought A Brief History of Time, three finished it," wrote Time's book critic Paul Gray in 2001.

He was basing that approximation on a formula called the Fully Read Index, which measures how easy a book is to read and how dumb the author makes readers feel.
If you're one of those 97 people, you'll be glad to know an even more concise version of A Brief History of Time was released in 2005: A Briefer History of Time.

If you read it, you'll have an idea of what black holes are all about
This was Professor Hawking's area of expertise. He showed that they must contain "a singularity of infinite density and space-time curvature", and he showed that they aren't completely black — theoretically, they can emit tiny amounts of radiation.
But in A Brief History Of Time, he took it back to the basics, giving this neat explanation for the phenomenon:

"According to the theory of relativity, nothing can travel faster than light. Thus if light cannot escape, neither can anything else; everything is dragged back by the gravitational field. So one has a set of events, a region of space-time, from which it is not possible to escape to reach a distant observer.
"This region is what we now call a black hole. Its boundary is called the event horizon."

Anything or anyone who fell past the event horizon, Professor Hawking explained, would soon reach a point of "infinite density and the end of time" — bad news for hypothetical astronauts.
Professor Hawking described the search for black holes as "a bit like looking for a black cat in a coal cellar", given that by definition they don't emit light. But explained how it can be done.

You'll also understand (a bit better, at least) the origin and fate of the universe

Five things we learned

Here are just a few of the mind-blowing discoveries Stephen Hawking made throughout his stellar career.

This might seem ambitious, but Professor Hawking was uniquely qualified to try — along with mathematician Roger Penrose, he demonstrated in 1970 that the universe started as a singularity. (However, Professor Hawking later tweaked his big bang theory, saying that there actually was no singularity at the beginning of the universe because "it can disappear once quantum effects are taken into account".)
In A Brief History Of Time, Professor Hawking explained why the universe must have had a beginning in time, due to the discovery that the universe was expanding.
And as for the ultimate fate of the universe, Professor Hawking had this to say:

"The present evidence … suggests that the universe will probably expand forever, but all we can really be sure of is that even if the universe is going to recollapse, it won't do so for at least another 10,000 million years, since it has already been expanding for at least that long.
"This should not unduly worry us: by that time, unless we have colonised beyond the solar system, mankind will long since have died out, extinguished along with our Sun!"

Finally, you'll understand the quest to find a complete unified theory that describes everything in the universe
Put simply, this is the attempt to reconcile the general theory of relativity (which deals with phenomena on a large scale, for instance planets) and quantum mechanics (which deals with phenomena on an extremely small scale, for instance atoms).

"We do not yet have such a theory, and we may still be a long way from having one, but we do already know many of the properties that it must have," Professor Hawking wrote.

However, at the end of his book, Professor Hawking said:

"Even if there is only one possible unified theory, it is just a set of rules and equations."

He put forward some of the questions that might remain:

"What is it that breathes fire into the equations and makes a universe for them to describe? The usual approach of science of constructing a mathematical model cannot answer the questions of why there should be a universe for the model to describe.
Why does the universe go to all the bother of existing? Is the unified theory so compelling that it brings about its own existence? Or does it need a creator, and, if so, does he have any other effect on the universe? And who created him?"

So, don't expect to know everything after reading A Brief History Of Time.

VIDEO: Stephen Hawking reflects on his greatest achievement (ABC News)

作者: 名本 时间: 2018-3-17 22:19
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Topics: science-and-technology, human-interest, physics, england, united-kingdom
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