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The theory is that dark matter is made up of particles that can’t interact with the electromagnetic force, and thus can’t be revealed with light. But they do interact gravitationally–in fact, it’s the gravitational pull of dark matter that stops galaxies from flying apart as they rotate. Astronomers think there is five times as much dark matter in the universe as there is ordinary matter, even though we can’t see it. Since both the dark and the visible forms of matter are affected by gravity, they tend to cluster together.

If we can’t see dark matter, how is it detected? By looking at the distorting effect that dark matter has on the light emitted by nearby galaxies.
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We’re having something unusual for people who live near the ocean: a heat wave. Surprisingly, Whitley (who grew up in Texas without air conditioning) is having a harder time bearing it that I am.

As the thermometer creeps up into the 80s and 90s, I get a inkling of what the future may be like for many of us here on Earth.

When we lived in New York, where it can get so cold, everyone tried to travel to the Caribbean in the winter in order to get some sun. We did it one year and found it a bore. We also went to Florida one winter, but discovered that it gets COLD down there too.
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