我的最新狀態(微型blog)

   

2008年11月20日

Four philosophical questions to make your brain hurt

Four philosophical questions to make your brain hurt

Jean-Paul Sartre (right)
Gauloise. Check. Expansive hand gestures. Check. Get that philosopher look

David Bain
It's World Philosophy Day - an opportunity to contemplate one's very existence and whether computer monitors really exist, says David Bain.

People expect different things of philosophers. Some expect us to be sages. When these people meet me, my heart sinks, since I know theirs is about to. Others expect us to have a steady supply of aphorisms up our sleeves, such as that love is never having to say you're sorry (something no partner of mine has ever been persuaded of).

They too are disappointed when they meet me, especially when I say that the glass so beloved by optimists and pessimists is both half full and half empty.

Others expect of us not sagacity, but madness, or at least outlandish beliefs. And here, it must be said, some philosophers really have delivered. Thales believed that everything is made of water, for example, while Pythagoras avoided eating beans because he believed they have souls.

Andre Glucksmann, Bernard-Henri Levy
Eccentric hair: The mark of a modern-day French philosopher

As Princeton philosopher David Lewis once said: "When philosophers follow where argument leads, too often they are led to doctrines indistinguishable from sheer lunacy."

But beware. this is the same David Lewis who believed that, for each of the ways things might have been but are not, there is a world at which they are that way, eg a world at which your counterpart is spending today with the world's greatest sex god or goddess.

And, reassuring though it can be to think that at least that counterpart is having fun, even those impressed with Lewis's towering intellect have often found these other worlds of his hard to swallow.

Not all philosophers pin such striking colours to the mast, but there is a good reason why people associate the subject with surprising views. Philosophy involves standing back and thinking - intensely and rigorously - about aspects of our lives that are at once ordinary and fundamental.

And when the surface is scratched, what you find below is extraordinary - or, rather, extraordinarily difficult to make good, clear sense of. Lying in wait are arguments that lead to, if not sheer lunacy, then bullets we're loathe to bite.

So, with World Philosophy Day upon us, here are some pesky arguments to apply your minds to:

1. SHOULD WE KILL HEALTHY PEOPLE FOR THEIR ORGANS?

Suppose Bill is a healthy man without family or loved ones. Would it be ok painlessly to kill him if his organs would save five people, one of whom needs a heart, another a kidney, and so on? If not, why not?

Consider another case: you and six others are kidnapped, and the kidnapper somehow persuades you that if you shoot dead one of the other hostages, he will set the remaining five free, whereas if you do not, he will shoot all six. (Either way, he'll release you.)

If in this case you should kill one to save five, why not in the previous, organs case? If in this case too you have qualms, consider yet another: you're in the cab of a runaway tram and see five people tied to the track ahead. You have the option of sending the tram on to the track forking off to the left, on which only one person is tied. Surely you should send the tram left, killing one to save five.

But then why not kill Bill?

2. ARE YOU THE SAME PERSON WHO STARTED READING THIS ARTICLE?

Consider a photo of someone you think is you eight years ago. What makes that person you? You might say he she was composed of the same cells as you now. But most of your cells are replaced every seven years. You might instead say you're an organism, a particular human being, and that organisms can survive cell replacement - this oak being the same tree as the sapling I planted last year.

But are you really an entire human being? If surgeons swapped George Bush's brain for yours, surely the Bush look-alike, recovering from the operation in the White House, would be you. Hence it is tempting to say that you are a human brain, not a human being.

But why the brain and not the spleen? Presumably because the brain supports your mental states, eg your hopes, fears, beliefs, values, and memories. But then it looks like it's actually those mental states that count, not the brain supporting them. So the view is that even if the surgeons didn't implant your brain in Bush's skull, but merely scanned it, wiped it, and then imprinted its states on to Bush's pre-wiped brain, the Bush look-alike recovering in the White House would again be you.

But the view faces a problem: what if surgeons imprinted your mental states on two pre-wiped brains: George Bush's and Gordon Brown's? Would you be in the White House or in Downing Street? There's nothing on which to base a sensible choice. Yet one person cannot be in two places at once.

In the end, then, no attempt to make sense of your continued existence over time works. You are not the person who started reading this article.

3. IS THAT REALLY A COMPUTER SCREEN IN FRONT OF YOU?

What reason do you have to believe there's a computer screen in front of you? Presumably that you see it, or seem to. But our senses occasionally mislead us. A straight stick half-submerged in water sometimes look bent; two equally long lines sometimes look different lengths.

Muller-Lyer illusion
Are things always as they seem? The Muller-Lyer illusion indicates not

But this, you might reply, doesn't show that the senses cannot provide good reasons for beliefs about the world. By analogy, even an imperfect barometer can give you good reason to believe it's about to rain.

Before relying on the barometer, after all, you might independently check it by going outside to see whether it tends to rain when the barometer indicates that it will. You establish that the barometer is right 99% of the time. After that, surely, it's readings can be good reasons to believe it will rain.

Perhaps so, but the analogy fails. For you cannot independently check your senses. You cannot jump outside of the experiences they provide to check they're generally reliable. So your senses give you no reason at all to believe that there is a computer screen in front of you."

4. DID YOU REALLY CHOOSE TO READ THIS ARTICLE?

Suppose that Fred existed shortly after the Big Bang. He had unlimited intelligence and memory, and knew all the scientific laws governing the universe and all the properties of every particle that then existed. Thus equipped, billions of years ago, he could have worked out that, eventually, planet Earth would come to exist, that you would too, and that right now you would be reading this article.

After all, even back then he could have worked out all the facts about the location and state of every particle that now exists.

And once those facts are fixed, so is the fact that you are now reading this article. No one's denying you chose to read this. But your choice had causes (certain events in your brain, for example), which in turn had causes, and so on right back to the Big Bang. So your reading this was predictable by Fred long before you existed. Once you came along, it was already far too late for you to do anything about it.

Now, of course, Fred didn't really exist, so he didn't really predict your every move. But the point is: he could have. You might object that modern physics tells us that there is a certain amount of fundamental randomness in the universe, and that this would have upset Fred's predictions. But is this reassuring? Notice that, in ordinary life, it is precisely when people act unpredictably that we sometimes question whether they have acted freely and responsibly. So freewill begins to look incompatible both with causal determination and with randomness. None of us, then, ever do anything freely and responsibly."

IN CONCLUSION

Let me be clear: the point is absolutely not that you or I must bite these bullets. Some philosophers have a taste for bullets; but few would accept all the conclusions above and many would accept none. But the point, when you reject a conclusion, is to diagnose where the argument for it goes wrong.

Doing this in philosophy goes hand-in-hand with the constructive side of our subject, with providing sane, rigorous, and illuminating accounts of central aspects of our existence: freewill, morality, justice, beauty, consciousness, knowledge, truth, meaning, and so on.

Rarely does this allow us to put everything back where we found it. There are some surprises, some bullets that have to be bitten; sometimes it's a matter simply of deciding which. But even when our commonsense conceptions survive more or less intact, understanding is deepened. As TS Eliot once wrote:

"…the end of our exploring,

Will be to arrive where we started,

And know the place for the first time."

David Bain is a lecturer in philosophy at the University of Glasgow

2008年11月19日

分享 How dangerous are networking sites?

How dangerous are networking sites?

By Anna Jones
BBC News

A court in the US is preparing to hear the case of a woman accused of using MySpace to bully a 13-year-girl who later committed suicide

MySpace page (file image)
MySpace users create their own profiles online
The case has prompted new concerns over the potential dangers of online social networking sites.

Websites like Facebook, Bebo, Twitter and others have come to be seen as an essential part of life for millions of people.

They enable users to share their lives with friends around the world, and get in touch with people with similar interests.

And, perhaps more importantly, they give people an engaging way of wasting time and socialising without the inconvenience of leaving their computers.

With 120 million active users on Facebook alone, there is certainly a wide social networking world to discover.

But for all those people for whom networking sites are a harmless time-waster, there are, as in all parts of society, some who use it for more malicious purposes.

For 13-year-old Missouri girl Megan Meier, the bullying she received through MySpace, which she believed was coming from a boy in the neighbourhood, appears to have driven her to take her own life.

In fact, while Megan thought she was being abused by 16-year-old Josh Evans, she was actually talking to Lori Drew, the 49-year-old mother of one of her former friends who, it is alleged, had set up a fake profile to taunt Megan.

Ms Drew is now standing trial on computer fraud charges.

Nothing private

Marsali S Hancock, president of the US-based Internet Keep Safe Coalition, says that "by far the biggest danger of social networking sites is that a child will connect with someone that could be potentially harmful".

Marsali S Hancock, President of Internet Keep Safe Coalition
Parents need to recognise the impact of what their child is experiencing online
Marsali S Hancock
Ms Hancock said that if there was anything to learn from the tragic Missouri case, "it's that parents need to be involved and need to follow guidelines".

She believes their children should not be using such sites at all, but also encourages parents to keep up to date with technology, so they know what their children are doing online.

The coalition has worked with MySpace to produce a series of short online films showing children and their parents how to use social networking sites safely.

"Helping parents know how to recognise digital safety is a struggle," says Ms Hancock. "Parents need to recognise the impact of what their child is experiencing online".

'Hate-mongers'

Although they are particularly vulnerable, it is not just children who face dangers on networking sites and it is not just playground bullies who exploit the freedoms they offer.

"MySpace, Facebook and YouTube are the 'killer apps' of the internet today, and they're used by millions," said Christopher Wolf, chair of the International Network Against Cyber Hate (INACH).

"But the virus of hate certainly has infected those technologies."

For every site that we can report and get taken down there is at least one other site to replace it and often many others
Christopher Wolf
Speaking at the Global Summit on Internet Hate Speech in Washington, Mr Wolf warned that the "internet toolbox that is available to hate-mongers has had a number of new items added to it over the last several years".

He said that with the rapid development of the internet, "every aspect of the internet is being used by extremists of every ilk to repackage old hatreds and to recruit new haters".

"On YouTube, for example, there are thousands of hate videos that are uploaded with messages of racism, anti-Semitism, homophobia and intolerance towards minorities."

Wolf acknowledges that such material is prohibited by the terms of most networking sites but says the amount is overwhelming.

"For every site that we can report and get taken down there is at least one other site to replace it and often many others," he said.

Online reputation

Social networking sites have certainly grabbed media attention, particularly when they go wrong for the users.

Virgin Atlantic plane (file image)
Virgin objected to comments about customers made online by staff
In October 2008, Virgin Atlantic sacked 13 members of its cabin crew for bringing the company into disrepute after they posted derogatory comments about customers on Facebook.

And an Israeli soldier was dismissed over an image he posted online, at a time of concern about possible security risks.

Technology experts continually warn that personal details posted online - date of birth, mother's name, pet's names - can be used by fraudsters for identity, and then financial, theft.

But perhaps most worryingly, Ms Hancock says many users do not realise that they add to a permanent "online reputation" every time they post a comment, a picture or a link online.

This could affect them for life. If an employee or university searches for two otherwise identical applicants online, for example, "the one with the best online reputation will get the opportunity".

For all the concerns, social networking sites remain popular, fun and, for the majority of careful users, safe.

But experts warns that as each site takes steps to protect its users and remain within the law, there is always someone ready to take advantage of any lapses in judgement.

No-one, and especially children, "should ever have the impression that what they do online is private", says Ms Hancock.

2008年11月17日

統一場論-msn對話

表哥:
愛因斯坦的統一場論
你知道量子力學是機率論對ㄅ
表哥:
測不准原理有沒有聽過
表哥:
薛丁格的貓
一平:
我是高職生
表哥:
薛丁格的貓的故事講給你聽
表哥:
有一個盒子
表哥:
把一隻貓裝進去
表哥:
從外面看不見裡面
表哥:
然後
表哥:
一段時間後
表哥:
這段期間盒子沒打開過
表哥:
開始討論
表哥:
裡面的貓是死的還是活的
表哥:
機會是一半一半
表哥:
所以你說他活的
表哥:
也對
表哥:
說他是死的
表哥:
也對
表哥:
但是一但你去測量他
表哥:
也就是打開那個核子去看
表哥:
你就可以看到其中一種狀況
表哥:
不是死就是活
表哥:
但是這時你已經破壞了盒子內的原始狀態
表哥:
因為你去測量他了
一平:
ohoh
表哥:
主要就是不可準確測量的觀念拉
表哥:
所以都適用機率來討論
表哥:
這樣的情況機率有多少...那樣有多少
表哥:
可是愛因斯坦就粉不喜歡這個東西
表哥:
他覺得宇宙應該要是因果論的
表哥:
就像以前牛頓力學
表哥:
我給你一個確定的方程式
表哥:
我就能準確預測一切
表哥:
有怎樣的因
表哥:
有怎樣的果
表哥:
可是機率論就不是這樣
表哥:
統一場論是愛因斯坦想把量子力學搞成因果論所做出來的產物
表哥:
不過大家一般來說愛因淤坦的統一場論是一偏精緻的數學論文
表哥:
但是他的物理應該不正確
表哥:
不果後來還有發展其他的場論
表哥:
量子場論
一平:
愛因斯坦想把重力場和電場磁場統一起來,用一個理論含括進去
一平:
我爸說的
表哥:
跟我剛說的是
表哥:
其實是再做同一件事
表哥:
如果他成功了...基本上你霸剛說的也會實現
表哥:
但是他會去做統一場論
表哥:
主要還是度濫機率論
表哥:
他有依據明言
表哥:
我不相信上第會跟我們玩直骰子的遊戲
表哥:
你應該看過或聽過
一平:
物理學討論的東西,從旁人來看很屌
一平:
科學家的想法是希望簡單化
表哥:
其實我們自己來看
表哥:
也覺得那些東西粉屌
表哥:
對阿
表哥:
目的是這樣阿
表哥:
所以有一堆數學是
表哥:
如果你數學購強
表哥:
你覺得
表哥:
一個定理適用一條數學是來看比較清楚
表哥:
還適用一大段文字敘述比較容易理解
一平:
數學式啊
表哥:
所以嚕
一平:
我們資料庫老師也是這樣說的
表哥:
最後變成一堆數學是
表哥:
但是為了推廣
表哥:
就是把一條數學定理
表哥:
推廣到全宇宙都適用
表哥:
就會付出代價
一平:
不過我們老師老是用一堆名詞
一平:
金木水火土的
表哥:
那是啥玩意
一平:
pp上有
一平:
還有天地人
一平:
心理法
一平:
還有太極拳
表哥:
埃埃...這些東西要我來跟你靠北
表哥:
我也可以靠北出一堆道理
一平:
越簡單就越接近真理
表哥:
不過要等面對面
表哥:
這種事情用msn講只會越獎越模糊
一平:
哈哈

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