Thursday, June 19, 2008

Moon

From Yahoo:


As the full moon rises this Wednesday evening, June 18, many people will be tricked into thinking it's unusually large

The moon illusion, as it's known, is a trick in our minds that makes the moon seem bigger when it's near the horizon. The effect is most pronounced at full moon. Many people swear it's real, suggesting that perhaps Earth's atmosphere magnifies the moon.

But it really is all in our minds. The moon is not bigger at the horizon than when overhead.

The illusion will be particularly noticeable at this "solstice moon," coming just two days before summer starts in the Northern Hemisphere. The reason, according to NASA, lies in lunar mechanics: The sun and full moon are like kids on a see-saw; when one is high, the other is low. This week's high solstice sun gives us a low, horizon-hugging moon and a strong, long-lasting version of the illusion.

If it's any consolation, space station astronauts report the same effect.

Here's how it works: Your mind believes things on the horizon are farther away than things overhead, because you are used to seeing clouds just a few miles above, but the clouds on the horizon can indeed be hundreds of miles away. So if we think something (such as the moon) is farther away, and it's not, then it seems larger.

If you remain doubtful, test the idea yourself. Go out at moonrise with a small object, perhaps a pencil eraser. Hold it at arm's length as the moon rises and compare the sizes of the moon and the eraser, then repeat the experiment an hour or two later when the moon is high in the sky. A rolled up tube of paper works well, too.

Moonrise times vary by location. On Wednesday, it will come up at these local times at these locations, according to NASA: New York City, 8:58 p.m.; Miami, 8:35 p.m.; Seattle, 9:51 p.m.

The moon rises about 50 minutes earlier Tuesday night, when the effect will also be noticeable because the moon will be nearly full. Oh, and that raises another fallacy: There's no such thing as a full moon.


It finally cleared up enough for me to see it.

This was taken with my crappy phone at about 12:30 et and does not do any justice at all to what I saw. It still looked really big. There was this strange blue aura thing surrounding it, and surrounding that was a "rainbow". Pretty darned cool.

8 comments:

fifi said...

what a lovely moon! I will watch the moonrise tonight:it is very clear, but today is the wintersolstice here.

Perahps I should perform a ritual for the new year and the light returning .

Unknown said...

It was quite lovely in reality. In that dumb picture it might as well be a halogen streetlight.

That's a streetlight in the lower left.

fifi said...

it is very hard to take a good photograph of the moon, and I often try it armed with a tripod and a good camera.

I quite like the fuzzy quality of that one, and you did remind me to go look. Normally I'm onto these things but it has been nasty weather and has cleared.

DJ MotorCityMonk said...

I love when the moon is extra large and low on the horizon...it's a "jumbo moon".

Anonymous said...

Helloooooooo?

Unknown said...

Yes, I know it's been a bit boring around here. I'm working on it.

Regulus said...

"Blue Moon / You saw me standing alone / Without a dream in my heart /
Without a love of my own ..."


Hope you're feeling better. Update your blog.

Unknown said...

Regulus: Yes, Blue Moon was playing in my headphones. I was very annoyed that it was a shitty night anf I couldn't really see it.