Get those clouds out of the way!
The internet often offers us only a cloudy sort of reality. The information that
it brings us is often information that we want to believe, but upon second thought
have to relate to with a healthy dose of scepticism. That being the case, this
month's tie-in holds at least a fleeting similarity to the web. It was on this
day, in 1613, that, from a modern reading of his notebooks we can determine that
Galileo probably viewed the planet Neptune. We can, however, only write "probably".
Speculation has it that while observing Jupiter and it's moons he noticed an additional
object that he assumed was a star.
Galileo continued to observe Jupiter, and he noted that the additional object
moved slightly with respect to another, nearby, star. Soon therafter, however,
it moved out of his field of vision. Had Galileo been able to continue tracking
the object, he probably would have realized that it was a planet, but the previous
nights had been cloudy, and he wasn't able to view Jupiter as precisely as he
would have needed. It was because of this that Neptune remained "undiscovered"
for quite a while ... until 1843 (or 1846, according to your source). Interestingly,
when it was "discovered" it wasn't through spotting it out there in
the sky, but first through mathematical predictions - calculations based on changes
in the orbit of Uranus.
We know today that Neptune completes an orbit around the sun in 164 years and
280 days. And that means that if those clouds hadn't blocked Galileo's view Neptune
would have completed a full orbit since it's discovery long ago (it would even
be on its third). Instead, we're still waiting (rather soon) for the completion
of the first.
Go to: Dr. Hierarchy and Mr. Associative