So, wait a minute. If the sun and the moon are the same distance apart, and the same size then solar eclipses should result in a catastrophic collision. Right?
For someone that's as active as you on these forums, trolling and mocking the idea of Flat Earth, you'd think you would have at least read the Flat Earth Information Repository:
It is said the diameter of the moon is about 2,160 miles,
and that of the earth about 8,000. It is also stated that
the moon’s motion round the earth works out at about thirty-
seven miles per minute, while in its journey round the sun
the earth travels along at about 1,080 miles per minute. Now
supposing the shadow cast by the earth on the moon is equal
to half its (the earth’s) diameter—4,000 miles is an outside
estimate, as the shadow would tend to converge. And if
these figures, given by astronomers of the earth’s and moon’s
motion are correct, readers will see it is impossible for an
eclipse to last in the moon for more than seven minutes,
although eclipses have been known to last for over
four hours, so that this shows the eclipse.- cannot possibly be caused by
the shadow of the earth’s rotation.
Y'know, iWitness, it might be a good idea to do a sanity check on calculations you post in support of an argument you make. Are you qualified to do so? (Sorry; couldn't resist...
)
Even assuming all the other info in that quote is correct, I get just shy of 50 minutes for the
total phase of an eclipse (presuming the 4000 mi refers to only the Earth's Umbra, which it sounds like from the description).
(4000 mi - 2160 mi) / (37 mi/min) = (1840 mi) / (37 mi / min) = 49.7 min
But where did that 4,000 miles come from, anyway? The quoted text says it's half the Earth's diameter, an "outside estimate", which sounds like code for "wild-ass guess".
It's easy enough to calculate.
Sun: 864,000 mi diameter, 93 million miles distant from earth
Earth: 8,000 mi diameter
Moon: 2,160 mi diameter, 240,000 mi distant from earth.
The Umbra is a cone extending beyond earth defined by lines that are tangent to both the Sun and earth.
So you have a long, skinny cone that is
860 864 kmi (thousand miles) wide at one end, and is 8 kmi wide at a point 93 Mmi (million miles) away. The total length of this cone is the 93 Mmi plus the additional part beyond the Earth (Earth's Umbra).
Total length = 93 Mmi + x. x is, of course, the length of the Umbra itself
Since the 'x' part of the cone is exactly the same shape as the whole thing, then it's proportional length to the whole thing is:
(93 Mmi + x) / (864 kmi) = x / (8 kmi)
Solving for x (here's why you shouldn't have slept through Algebra even though it was Bo
oooooring!):
744 Mmi / 856 = x (the kmi units divide out)
So
x = 0.87 Mmi
So the Earth's Umbra is 0.87 million miles, or 870,000 miles long. The Moon's orbit is about 240,000 miles in radius, so the width of the Umbra at that distance is:
(1 - (240 / 870))(8,000 mi) = (1 - 0.28)(8,000 mi) (rounded to two places)
= (0.72)(8,000 mi)
= 5,760 miles
Significantly larger than the 4,000-mi WAG.
Corrected length for totality:
(5,760 mi - 2,160 mi) / (37 mi/min) = (3,600 mi) / (37 mi / min)
= 97 min (rounded down)
The partial phases will add the time it takes for the moon's diameter to traverse into and out of the Umbra; at least (2,160 mi) / (37 mi/min) = 58 min on each side. We're up to more than 3.5 hours now, before even considering the penumbral phases.
The Earth's Penumbra is outside the Umbra, so the entire eclipse will be longer than the umbral phases alone. Determining the width of the Penumbra is left as an exercise for the reader. Why should I have all the fun?
Math FTW!
BTW, in last night's eclipse, totality lasted just under an hour (it didn't pass through the center of the Umbra), and the whole umbral eclipse totaled right at 3h 20m. Right in line with the calcs above.
Can you see why we mock many of the FE ideas here? Any argument that comes along that purports to disprove the mainstream is too often simply accepted without question. Lunar Eclipses can only last 7 min. This easily disproves "RET"! The Shuttle has to accelerate at 5 mi/sec/sec; they can't possibly be real!
This also illustrates the value of Peer Review. Similar mistakes are sometimes made in mainstream science, but those are usually found before publication when the paper is reviewed by a competent audience.
[Edit] Oops... said 860 instead of 864 in description; calcs OK