8 April 2007
Christianity isn’t some kind of club designed to exclude nonbelievers from heaven, or, worse, to segregate people on earth according to their beliefs. The teachings of Jesus are about universal love and forgiveness. Jesus was well aware of tribal rivalries and the hostilities that have historically separated man from man. What he preached is that only when each side commits to laying down of arms – to declaring peace unilaterally if necessary – only then will we approach an end to senseless and mutually destructive conflicts.
– Josh Mitteldorf
7 April 2007
It was an April morning: fresh and clear
6 April 2007
Einstein pioneered the use of the ‘thought experiment’ as a way to help formulate physical theory. Just thinking about a situation in which physics physics predicts paradoxical results may highlight troubles with the theory, or even suggest ways to modify the theory to avoid paradox.
One of the great challenges before physicists today is the problem of combining two great – but incompatible – theoretical monuments of the twentieth century: quantum mechanics and the Einstein’s theory of gravity (=General Relativity). Loosely speaking, the problem is that quantum mechanics says that certain quantities can only take on discrete values. For example, an atom’s energy cannot change smoothly as it releases energy to its environment, but it must make ‘quantum leaps’ of a specific size. But General Relativity is a theory about geometry – the very fabric of space and time itself. In a quantum theory of gravity, it may well be that objects are constantly disappearing in one place, reappearing a little ways off.
Recently, Lucien Hardy of the Perimeter Institute has published an article describing ways to exploit the paradoxes inherent in quantum gravity in order to construct a ‘computer’ with fantastic powers: it would not be limited by our ordinary ideas of cause and effect. It might exhibit powers we could describe as ‘telepathy’.
Thinking about such a device is a good way to constrain our ideas about what kinds of quantum gravity theories are plausible. Or, just maybe, it’s a way to expand our ideas about what kinds of phenomena are permitted by physical law.
5 April 2007
Jews around the world celebrate Passover at family dinners this week. My favorite moment in the Passover Seder comes after the Red Sea parts, allowing the Jews to pass in safety. Moses raises his staff once more, and the wall of water rushes back down to drown the pursuing Egyptian army. The Jews are dancing in jubilation, when an angel comes down to chasten them for this inappropriate sentiment: it was necessary and just that the Egyptians should die in this way, but we must not celebrate the defeat of our enemies, because the suffering of another should always be an occasion for our sadness.
Today, I looked for this passage in Exodus, and I must report that it is not to be found. In fact, the opposite message is underscored with no mitigating text:
The God of the Old Testament
rules with terror and vindictiveness. The inspiration in this story is
that we are a more compassionate world than the one that gave rise to the
Old Testament. Some time in the last 5,000 years, we have learned to
reach for a nobler humanity. I still don’t know whether my favorite
story can be attributed to an ancient Talmudic scholar or to a New Age
Reconstructionist, but perhaps the important thing is that humanity has
4 April 2007
Social welfare is good for business. A new international comparison shows that even companies that lobby for lower taxes vote with their feet, and invest in countries with higher taxes and better social services.
“Most economists have always argued that globalisation leads to a ‘race-to-the-bottom’ as countries compete to cut tax rates in the hope of attracting multinational investment and the jobs that come with it. The traditional theory is that this then leads to a shrinking of tax revenues and undermines the welfare state.
“But our evidence shows that...when investing abroad, firms find countries with higher taxes attractive because they associate them with a happy, stable workforce...
“Perceptions about the host country’s economic and social environment are key to the choice of location for many multinationals. It seems that investment decisions depend on the combination of taxation and the provision of public goods and services that host countries can offer because of taxation. So an ‘unfavourable’ tax differential may lead to more and not less investment flowing into a country.”
3 April 2007
Last week, I wrote about Kurt Godel, who shocked the mathematics community 75 years ago, proving that there are statements in mathematics that can never be proven either true or false. This changed the way mathematicians thought about their work – how could they know, as they worked on a problem, whether the problem just seemed difficult or whether, perhaps it was literally impossible? Werner Heisenberg did something similar for physics: he demonstrated that there was a limit to the predictive power of physics, and that the past could never determine the future, even for someone who had unlimited computing power and a perfect knowledge of the past.
Today’s physicists still work toward a Theory of Everything. Even if they know that it won’t give them a perfect predictive power, it will represent an exhaustive knowledge of ‘the way things work’. Many physicists think that such an endeavor is possible. Some think the goal is imminent.
But I hold with those who prefer to think physics is inexhaustible – the more we probe, the more fundamentally new and basic processes we will discover. The way the world works may be infinitely complex.
2 April 2007
“April comes like an idiot, babbling and strewing flowers.”