Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Immutable firmament?
    From: Gary LaPook
    Date: 2010 Dec 05, 23:54 -0800

    I'm a Scorpio and Scorpios don't believe in astrology.
    
    gl
    
    
    On 12/5/2010 10:42 PM, Frank Reed wrote:
    >
    > Gary, you wrote:
    > "But even the ancients noticed that the sun had changed its position
    > in relationship to the stars at the time of the solstices and equinoxes."
    >
    > Yes, Gary, but precession is a PURE ROTATION of the coordinate system.
    > The point here is that it does not change the "immutability" of the
    > firmament. For comparison, obviously when the stars change their
    > altitudes and azimuths all during the night, we can still treat them
    > as if they are fixed on a celestial sphere. Sirius climbs from 10 to
    > 20 to 30 degrees, while Rigel rises from 30 to 37 to 40 degrees in the
    > same period of time. The coordinates are changing, but the relative
    > relationships of the stars on the "immutable firmament" of the
    > celestial sphere does not change. Apart from refraction, the angles
    > between the stars do not change during this daily rotation of the
    > coordinates. While precession is drastically slower, it is exactly the
    > same sort of thing. Over the course of 26,000 years, the celestial
    > sphere rotates around the axis passing through the north and south
    > ecliptic poles. And just like the daily rotation, this does not
    > require us to drop the idea of an immutable celestial sphere. And sure
    > enough, Hipparchus and Ptolemy did NOT abandon the celestial sphere
    > even though Hipparchus had discovered precession.
    >
    > The "mutability" of the celestial sphere only comes about when we
    > recognize that the stars are other individual celestial objects each
    > with its own specific motion. And again, if you want to see evidence
    > of this, look at the angular distance between Arcturus and Spica over
    > the past couple of hundred years. Arcturus is a fast-moving star. It
    > certainly isn't tied down to any "immutable" sphere of quintessence!
    >
    > Gary, you wrote:
    > "I have always chuckled at astrology that assigns statuses to people
    > born while the sun is in a particular constellation. The problem with
    > this is that the dates given for the sun being in the birth
    > constellation are incorrect and the sun is actually one and a half
    > constellations removed from the stated constellation for those dates
    > due to precession of the equinoxes over the time period since the
    > astrologers set up their reckoning."
    >
    > I've got to warn you, Gary, that this isn't true AT ALL. Do you really
    > suppose that astrologers would somehow have missed the news out of
    > Greece 21 centuries ago informing the world of the existence of the
    > precession of the equinoxes?? Professional or "real" astrologers are,
    > in fact, well aware of this. The problem for people who know just
    > enough astronomy to mock astrologers is that they don't understand
    > what the zodiacal signs are (there are, by the way, plenty of
    > excellent reasons to doubt astrology, but this is not one of them).
    > The signs of the zodiac are indeed named after the constellations, but
    > they are not the same as the constellations. The signs, from a
    > mathematical perspective, can be considered nothing more than an
    > extension of the sexagesimal system of degrees, minutes, and seconds.
    > They are simply thirty-degree divisions of the circle. So, for
    > example, I can express a position in a circle as 3s, 10d, 15', 59"
    > where "3s" means "third sign". Depending on whether the numbering
    > starts with zero or one, this "3s" would be equivalent to either 90 or
    > 60 degrees. When applied to the ecliptic, these thirty-degree bands of
    > ecliptic longitude are given names (corresponding to the
    > constellations lined up with them thousands of years ago). So the
    > first thirty-degree band is called Aries, the second Taurus, and so
    > on. Thus the position of a planet could be given in quick shorthand as
    > "Aries 12" or "Taurus 28" which, in modern terminology, would mean
    > that the ecliptic longitude of that planet is 12 degrees or 58 degrees
    > respectively. Is that easier? Is it perhaps easier to remember "Taurus
    > 28"?? I would say that it depends on what you're used to. It rather
    > reminds me of "Klondike 5-1234" being replaced by "555-1234" (see the
    > PS if that is an unfamiliar reference for anyone following along).
    >
    > Now you might think that only superstitious astrologers would use such
    > a weird system as attaching verbal labels to bands of ecliptic
    > longitude or using names that do not reflect the current sky, but it's
    > not so. As late as the early 19th century, professional astronomers
    > still used the "S.D.M.S." (sign, degree, minute, second) system for
    > listing ecliptic longitudes. I am attaching a page from the Nautical
    > Almanac from 1820. And note that this is not back in the dark ages.
    > This is over a century after Isaac Newton, decades after the discovery
    > of the planet Uranus (known as the "Georgian" in Britain back then),
    > and it's after the Enlightenment and the birth of real modern science.
    > Nonetheless, they used the zodiac signs to specify the positions of
    > the planets. In the attached almanac page, the geocentric longitude
    > (meaning geocentric longitude in ecliptic coordinates) for Mercury on
    > April 1, 1820 is listed under S.D.M. as 0.27.27. For us today, that's
    > just 27d 27' ecliptic longitude. Meanwhile, at the bottom, the
    > longitude of the Georgian is 8.28.48 which would be, as a modern
    > angle, 268d 48' (268=8*30+28).
    >
    > And lest you still think you might mock astrologers for using such an
    > old-fashioned, nearly two-hundred-years obsolete, system for naming
    > positions along the ecliptic, bear in mind that a clever enough
    > astrologer can turn the tables on you and point out that celestial
    > navigators do EXACTLY the same thing in one special case, a vestige of
    > that common usage from 200 years ago. The "GHA of Aries", so important
    > in navigation, does not refer to the constellation Aries at all. It's
    > almost as if celestial navigators are "too stupid to realize that
    > precession exists" (so a debating astrologer might say). But no, this
    > is just the old system for labeling the ecliptic. It's called Aries
    > because that's the name for the first band of thirty degrees, the zero
    > point of ecliptic longitude, starting from the point where the
    > ecliptic crosses the celestial equator north-bound.
    >
    > By the way, there are some very intelligent people who post here who
    > take a serious interest in astrology and do not consider it nonsense.
    >
    > ...Not me.
    >
    > -FER
    > PS: I said above that the change in the system for labeling points on
    > the ecliptic "reminds me of Klondike 5-1234 being replaced by
    > 555-1234". For those, especially outside the US, who are scratching
    > their heads, this was the old system for listing phone number in the
    > United States (and some other countries). A number in a local exchange
    > has a three-digit exchange number followed by four digits for the
    > specific number. Those local exchanges used to be known by letters
    > which were then given mnemonic names like "Klondike". Until the early
    > 1960s (so I have read), most phone numbers were listed with this mixed
    > alphanumeric system and you can still here "Klondike" numbers in old
    > movies and tv shows. More here:
    > http://en.wikipedia.org/wiki/Telephone_number.
    >
    >
    > ----------------------------------------------------------------
    > NavList message boards and member settings: www.fer3.com/NavList
    > Members may optionally receive posts by email.
    > To cancel email delivery, send a message to NoMail[at]fer3.com
    > ----------------------------------------------------------------
    >
    
    
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site