:: Neither Newton nor anybody else claimed that Venus turn once in 23
:: hours.
: oriel36 <
kellehe...@gmail.com>
: Fascinating !
:
http://books.google.ie/books?id=gB2-Hqdx_LUC&pg=PA579&dq=newton+moon+=
: rotates&hl=en&ei=SQJ5TJP1FYTKswadoL2yDQ&sa=X&oi=book_result&ct=re=
: sult&resnum=4&ved=0CDkQ6AEwAw#v=onepage&q&f=false
Indeed it is. For several reasons. Eg, first, it illuminates the
cognitive deficits of crackpottery, which seems to treat improved findings
as a Bad Thing.
Second, Newton died before even the fact that venus had an atmosphere
was known, let alone before radar and other measures could meaningfully
measure anything beneath it. And there's nothing in newtonian mechanics
that would allow him to determine what the rotation rate *should* be.
The other numbers he quotes are from observatons. Is newtonian mechanics
to blame if somebody published bogus observatons of venus before anything
substantial was known about it? No. Or rather, not to any reasonable
person.
Of course, it *is* incorrect that *nobody* ever claimed such a rotation
rate. I've seen two references to people in the 1700s and earlier that
did so. And it's a safe bet that their observations were just as
solid as the observations of the Martian canals.
However, it remains correct that nobody ever claimed such a rotation rate
was made necessary by newtonian mechanics.
So. The crackpot would insist that people mis-estimating a rotation rate
before they even knew that planet had an almost-blank atmosphere somehow
invalidates studies after the atmosphere was known of, and radar used
to penetrate it. And that Newton using an estimate made by somebody
most likely in good faith but bad data, somehow taints F=dp/dt and all
it implies. Any doubts what ori will do?
If you wonder, just note that ori deleted the physical proof that
the moon is, in fact, rotating just as the earth is (if a bit slower).
SOMEhow, that part of the post managed to sail over his head.
Here it is again:
::: oriel36 <
kellehe...@gmail.com>
::: A spinning round object has a maximum equatorial speed and zero
::: polar speed (Earth for example) while the moon does not spin as it
::: orbits the Earth
::
thr...@sheol.org (Wayne Throop)
:: There are physical consequences to the equatorial speed of a rotating
:: object. And the moon shows the same kind of physical consequences
:: that the earth has due to it's equatorial speed (though smaller
:: consequences because the speed is lower). Slight oblateness to the
:: spheroid, the most obvious. So the claim that the earth has an
:: equatorial speed and the moon doesn't is inconsistent, since both
:: exhibit the effects of centrifugal force (if you're over 35 or went
:: to a private school; if you're under 35 or went to a public school,
:: you say "centripetal acceleration", or possibly "centrifugal
:: pseudoforce").
Again, any doubts what ori's going to do with this fairly direct
observation of the results of the moon's rotation?
And how about libration, which is a direct observation of an equatorial
speed of the moon wrt an observer on earth, fastest at full moon every
month, more or less. Moon doesn't rotate? Just look at it with timelapse
photography; it rotates back and forth and up and down and everything.
http://en.wikipedia.org/wiki/File:Lunar_libration_with_phase_Oct_2007.gif
It's why we can see more than half of its surface. If it didn't
rotate back and forth wrt the earth, we couldn't. Of course, unlike
libration, it rotates *smoothly* wrt any inertial frame, irregularly
wrt to most anything else including earth. But ori would rather build
his ... assertions on shifting sand, rather than admit that the odious
Newton was onto something. I suppose one must be reassured that at
least he doesn't go about claiming that planets actually reverse their
direction of orbit, and Copernicus was pernicious.
Or... does he? Hard to tell, since he's so coy about precisely which parts
of what one sees through the devils-tube-with-lenses he rejects.