Gravity waves, daylight and a brilliant planet

(Louis John Rhead)

(Louis John Rhead)

So now we’re sure that gravity waves exist. Is this exciting? I think most physicists are sort of excited. We’ve long believed that they’re real. Even way back in college, we all trusted Einstein that truly massive objects changing position should cause quivers in space and time. Calculations showed that even the most dramatic of such events would only jiggle earthly objects by less than the width of an atom’s nucleus. How could anyone possibly detect that?

Confirming gravity waves was like finding the first planets beyond our solar system 20 years ago. We all knew they were there, so no one was surprised. Then as now, it’s the technology that dropped our jaws: a clever setup indeed, using mirrors hanging from glass wires, isolated from all worldly vibrations, and then reflections along a several-mile path to detect laser light-wave interferences, revealing the jiggles.

A few media reports talked about detecting a sound – even describing it as a middle C on a piano: misleading, since no sound waves penetrate space. This had nothing to do with sound.

It’s also cool that people are willing to spend many billions of dollars on something with no practical benefit. This is pure knowledge, for the sake of understanding how the cosmos works. It can never bring us Velcro or Tang. It’s the noblest kind of intellectual exercise.


Jupiter is back

People are asking about that bright star in the east. It’s Jupiter, finally returning to our skies. It’s the first of the cool planets that will be seen well in 2016. Mark this Tuesday night on your calendar; that’s February 23. That night, the virtually full Moon will hover very close to Jupiter. It will be a lovely and eye-catching conjunction. If you own a small telescope, the Moon won’t look like much when it’s this close to full, but Jupiter will show lots of detail if it’s a night when the stars are not twinkling.


Fast daylight changes

We have begun the ten-week period when light grows most rapidly. Every day has three extra minutes of sunshine compared to the day before. At the same time, each week the Sun stands two of its diameters higher in the sky. Since it’s solar elevation that critically determines the strength of its rays, this is a big change.

I keep getting asked why radio announcers say that the daylight increase is two minutes one day and four minutes the next day, and maybe back to two the day after that. That’s simply because they use tables that ignore seconds, and merely round off to the nearest minute. The actual growth of sunlight is smooth and steady. It reaches its precise peak daily increase a month from now.


Want to know more? To read Bob’s previous “Night Sky” columns, visit our Almanac Weekly website at

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