Long Eye Relief Eyepieces

If you wear eyeglasses for near or far-sightedness, you won’t need them to look through a telescope. You just need to slightly tweak the focuser of your scope to compensate for your eyes. But if you wear eyeglasses for astigmatism, a condition which often afflicts older observers, then you may need to keep your glasses at the telescope. This makes it hard to get your eye close enough to the eyepiece to take in the whole field of view unless you choose an eyepiece specially designed with long eye relief.

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Your Guide to the Transit of Venus

On June 5-6 you get your last chance to see one of the rarest of astronomical events, the Transit of Venus, during which the black disk of Venus passes across the glowing disk of the Sun.  This transit has happened just seven times since the invention of the telescope more than 400 years ago.  The last transit was in 2004.   There won’t be another until December 2117.  Here’s how and where to see next month’s transit for yourself…

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The Big Bang Theory

You learned how Vesto Slipher discovered nearby galaxies flying apart at high speed. You learned how Edwin Hubble and Milton Humason found the speed at which galaxies recede is directly related to their distance. And you heard the story of the Georges Lemaitre, the modest priest and mathematician who used Einstein’s general theory of relativity to predict Hubble’s measurements and suggest our universe itself is expanding.

But the idea of an expanding universe led to another shocking idea: that our universe was once smaller, perhaps at one time as small as a “primordial atom”, as Lemaitre called it, that exploded in a gigantic “Big Bang” some 13.7 billion years ago. This expansion caused the matter in the universe to cool and condense into the atoms, stars, and galaxies we see today.

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