Eric Casagrande (24 Nov 2005)
"The Shortened Days"


Hi John & All:
 
Just a quick comment on Neil's post from yesterday, where he said the following --
 
"Consider this.  If however the Lord causes the earth to rotate faster on its axis (shorter days), this same event causes the earth to drop into "a lower orbit around the sun" (ie. closer to the sun), at some distance closer to the sun the sun would be seven times brighter than it is right now. "
 
This is not true, as I will show below. Note: A "rotational period" is the length of its day.
 
Earth is about 93 million miles from the sun, and has a rotational period of 24 hours (1 day).
 
Venus is about 67 million miles from the sun, and has a rotational period of 247 days.
 
Mercury is about 36 million miles from the sun, and has a rotational period of 59 days.
 
There is no relationship between the rotational speed of a planet, and its distance from the sun. In other words, it doesn't move closer because it spins faster. As evidenced above, both Mercury and Venus are significantly closer to the sun than Earth, and yet have an exceedingly slower rotational period. Using the logic of rotational speed determines distance, then both Mercury and Venus should be outside the orbit of Earth -- but they are not.
 
But let's move further outward from the sun ....
 
Mars is about 143 million miles from the sun, with a rotational period of about 24.5 hours
 
Jupiter is about 489 million miles from the sun, with a rotational period of about 9.8 hours.
 
Saturn is about 891 million miles from the sun, with a rotational period of about 10.3 hours.
 
Uranus is about 1.8 billion miles from the sun, with a rotational period of about 17.2 hours.
 
Neptune is about 2.8 billion miles from the sun, with a rotational period of about 16.11 hours.
 
Even tiny Pluto, at 3.7 billion miles from the sun, has a rotational period of about 6.4 days, which is almost 10-times faster than Mercury, despite being 100-times further from the sun.
 
Again, using the logic of rotational speed determining distance, then Jupiter, Saturn, Uranus and Neptune should all be closer to the sun than Earth -- but again, they are not.
 
Also as a note of interest, Neil stated --
 
" ... at some distance closer to the sun the sun would be seven times brighter than it is right now. This would cause fierce heat on the earth ... "
 
As a matter of fact, if the Earth were to move closer to the sun, this would be obviously true. But we need to calculate how close to the sun the Earth would have to be for the sun to appear seven-times brighter. So how do we do it? Very simple -- the brightness or dimness of a given light source, is directly porportional to the square of its distance.
 
For example: If the Earth were twice as far from the sun as it currently is, then the sun would be 4-times darker (2 squared). If the Earth were to move twice as close to the sun from its current position, then the suns light would be 4-times brighter (again ... 2 squared).
 
For the suns brightness to change by a factor of 7-times, as a result of the Earth moving closer to it, then the Earth would have to move 2.65-times closer than it is currently situated ( 2.65 x 2.65 = 7.02 ). This would put Earth slightly closer to the sun than Mercury -- the same Mercury whose surface temperature ranges from 662 - 800 degrees farenheit, which is hot enough to melt lead and tin. The Earths oceans would quickly boil and evaporate, its atmosphere would disappear, and every living organism would be dead within a matter of minutes (if even that long).
 
See ya in the air,
 
Eric