January 25, 2007 by mr_flood.

The evidence just keeps coming:

There’s a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years – exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star’s core.

Robert Ehrlich of George Mason University in Fairfax, Virginia, modelled the effect of temperature fluctuations in the sun’s interior. According to the standard view, the temperature of the sun’s core is held constant by the opposing pressures of gravity and nuclear fusion. However, Ehrlich believed that slight variations should be possible.

He took as his starting point the work of Attila Grandpierre of the Konkoly Observatory of the Hungarian Academy of Sciences. In 2005, Grandpierre and a collaborator, Gábor Ágoston, calculated that magnetic fields in the sun’s core could produce small instabilities in the solar plasma. These instabilities would induce localised oscillations in temperature.

Ehrlich’s model shows that whilst most of these oscillations cancel each other out, some reinforce one another and become long-lived temperature variations. The favoured frequencies allow the sun’s core temperature to oscillate around its average temperature of 13.6 million kelvin in cycles lasting either 100,000 or 41,000 years. Ehrlich says that random interactions within the sun’s magnetic field could flip the fluctuations from one cycle length to the other.

These two timescales are instantly recognisable to anyone familiar with Earth’s ice ages: for the past million years, ice ages have occurred roughly every 100,000 years. Before that, they occurred roughly every 41,000 years.

Most scientists believe that the ice ages are the result of subtle changes in Earth’s orbit, known as the Milankovitch cycles. One such cycle describes the way Earth’s orbit gradually changes shape from a circle to a slight ellipse and back again roughly every 100,000 years. The theory says this alters the amount of solar radiation that Earth receives, triggering the ice ages. However, a persistent problem with this theory has been its inability to explain why the ice ages changed frequency a million years ago.

Via Junk Science

Posted in Climate | 1 Comment »

January 25, 2007 by mr_flood.

Arnold Kling from the Cato Institute gives us the lowdown on the new plan.

Since the President’s plan was leaked, I have seen three complaints from the left.

1. The tax break benefits the rich more than the poor.
2. The tax break encourages people to leave employer-provided health plans and instead get health insurance on their own.
3. The proposals encourage catastrophic health insurance rather than insulation.

If this is what the plan aims for then I’m all for it. I’ve long believed that insulating people from having to pay directly for their insurance does nothing but drive up costs and eliminate market forces from having any impact on the system. And that’s what employer provided health care does.

Via Instapundit

Posted in Current Events | 1 Comment »