A very unusual galaxy field in SDSS

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Date: 21 Jul 2007 06:35:32
From: ukastronomy
Subject: A very unusual galaxy field in SDSS

I came across this very curiously shaped object and I was wondering
what the experts on this group made of it.

http://www.martin-nicholson.info/dart/dart3.htm

Date: 31 Jul 2007 03:46:13
From: ukastronomy
Subject: Re: A very unusual galaxy field in SDSS

On Jul 28, 11:36 pm, AstroApp <Astro-...@not-receiving-email.com >
wrote:
> On Sat, 21 Jul 2007 06:35:32 -0700, ukastronomy
>
> <martin_piers_nichol...@yahoo.co.uk> wrote:
> >I came across this very curiously shaped object and I was wondering
> >what the experts on this group made of it.
>
> >http://www.martin-nicholson.info/dart/dart3.htm
>
> Intriguing. I was so impressed with your website, Martin, that I just
> added it to my 'select' choice of amateur astronomy websites, under
> the category of General Topics (the last item added right before the
> section on Imaging and Photography.) Your website is a remarkable
> collection of valuable projects, and I salute you!
>
> http://home.earthlink.net/~8-h-haggis/astrolinks.htm
>
> AstroApp
>
> P. S. For what it's worth, I *totally* agree with Greg C's take on the
> issue of the decimal, versus 'standard', units of RA. And I was so
> struck by the excellence of his reasoning that I just wrote up a
> commentary on it.
>
> The ONLY usefulness of the decimal value of RA to an amateur would be,
> it seems to me, in entering data into the controller of my telescope.
> But, not every GOTO scope's programming allows use of RA in decimal
> values; nor does the input interface of every star chart program.
> But, they all accept h,m,s units. Obviously the audience being
> addressed by the scientists who run SDSS is a professional one who
> have their 'connection' to the sky exclusively by means of computers.
> That's understandable. But, note that NED still gives RA in h,m,s
> too. Why not? Indeed, by doing this, the information is universally
> usable without conversion.
>
> Srw

Thank you for the kind words about my website.
http://www.martin-nicholson.info/index.htm

Date: 28 Jul 2007 22:36:18
From: AstroApp
Subject: Re: A very unusual galaxy field in SDSS

On Sat, 21 Jul 2007 06:35:32 -0700, ukastronomy
<martin_piers_nicholson@yahoo.co.uk > wrote:

>I came across this very curiously shaped object and I was wondering
>what the experts on this group made of it.
>
>http://www.martin-nicholson.info/dart/dart3.htm

Intriguing. I was so impressed with your website, Martin, that I just
added it to my 'select' choice of amateur astronomy websites, under
the category of General Topics (the last item added right before the
section on Imaging and Photography.) Your website is a remarkable
collection of valuable projects, and I salute you!

http://home.earthlink.net/~8-h-haggis/astrolinks.htm

AstroApp

P. S. For what it's worth, I *totally* agree with Greg C's take on the
issue of the decimal, versus 'standard', units of RA. And I was so
struck by the excellence of his reasoning that I just wrote up a
commentary on it.

The ONLY usefulness of the decimal value of RA to an amateur would be,
it seems to me, in entering data into the controller of my telescope.
But, not every GOTO scope's programming allows use of RA in decimal
values; nor does the input interface of every star chart program.
But, they all accept h,m,s units. Obviously the audience being
addressed by the scientists who run SDSS is a professional one who
have their 'connection' to the sky exclusively by means of computers.
That's understandable. But, note that NED still gives RA in h,m,s
too. Why not? Indeed, by doing this, the information is universally
usable without conversion.

Srw

Date: 22 Jul 2007 17:46:05
From:
Subject: Re: A very unusual galaxy field in SDSS

> I see decimal degrees being used in astronomy more and more often, thank
> goodness. We can't get rid of the h:m:s/d:m:s convention soon enough,
> IMO. It's only useful for unautomated amateurs, and marginally so even
> there.

Nonsense! How the heck would anybody find ANYTHING if we did away with
traditional right ascension? Can you name one star atlas that shows
right ascension in degrees?!? (And I couldn't care less what
professional astronomers use - this is sci.astro.amateur.)

Date: 23 Jul 2007 02:45:03
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Sun, 22 Jul 2007 17:46:05 -0700, allisonki@IGNmail.com wrote:

>Nonsense! How the heck would anybody find ANYTHING if we did away with
>traditional right ascension? Can you name one star atlas that shows
>right ascension in degrees?!? (And I couldn't care less what
>professional astronomers use - this is sci.astro.amateur.)

Greg is complaining about an online (professional) resource that expects
the RA to be given in degrees. So in fact, such things do exist. I don't
usually find things from atlases, I find them on the computer. And in
many cases, if you are entering coordinates in the computer, degrees are
the easiest (or at least, decimal hours).

The point is, the best units to use depend on the application, and in
the professional world I think the most common units for RA and
declination will ultimately be degrees.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 23 Jul 2007 01:47:03
From: Sam Wormley
Subject: Re: A very unusual galaxy field in SDSS

allisonki@IGNmail.com wrote:
>> I see decimal degrees being used in astronomy more and more often, thank
>> goodness. We can't get rid of the h:m:s/d:m:s convention soon enough,
>> IMO. It's only useful for unautomated amateurs, and marginally so even
>> there.
>
> Nonsense! How the heck would anybody find ANYTHING if we did away with
> traditional right ascension? Can you name one star atlas that shows
> right ascension in degrees?!? (And I couldn't care less what
> professional astronomers use - this is sci.astro.amateur.)
>

It doesn't matter... I teach my astronomy student to use both hours
and degrees of RA. One should be just as comfortable with hh:mm:ss.sss,
ddd:mm:ss.sss or ddd.dddddd the latter being most convenient in
calculation.

Date: 22 Jul 2007 05:40:09
From: oriel36
Subject: Re: A very unusual galaxy field in SDSS

On Jul 22, 2:07 am, Chris L Peterson <c...@alumni.caltech.edu > wrote:

> I'm a units pragmatist. I don't care about tradition, I use what works
> best for the given problem. RA in hours makes sense if you are doing a
> calculation in your head to figure out if some particular object is
> visible. But it is a poor choice for almost any instrumental
> application... which these days describes most cases.

> Chris L Peterson
> Cloudbait Observatoryhttp://www.cloudbait.com

The Wikipedia article has the most inventive solution for meshing 23
hours 56 minutes 04 seconds with 24 hour of terrestrial longitudes -

"Greenwich Sidereal time is the hour angle of the vernal equinox at
the prime meridian at Greenwich, England; local values differ
according to longitude. When one moves eastward 15=B0 in longitude,
sidereal time is larger by one hour (note that it wraps around at 24
hours)."

http://en.wikipedia.org/wiki/Sidereal_time

That was certainly the handiwork of a physicist for even the
astrologers are not that silly.

Although I cannot account for why people positively refuse to adopt
the only correct correlation between clocks,terrestrial longitudes and
the axial cycle all wrapped up in 24 hours/360 degrees,both your
points of view as representing observational astrologers or the
mathematical numbskulls are now extremely funny for all sorts of
reasons.

Unfortunately there is work to be done and if doing that work is
periodically highlighting how dumb this entire froup is then so be
it.

Date: 22 Jul 2007 02:44:21
From: oriel36
Subject: Re: A very unusual galaxy field in SDSS

You hardly realise that you are a freak yourself by way of technical
argument,the only one that counts.The poor physicist has absolutely no
idea that the astrological framework of Flamsteed is based on trying
to fit four annual orbital circuits of the Earth into a system based
on 3 years of 365 days and 1 year of 366 days.

A genuine person would ask you how come a star constantly returns in
23 hours 56 minutes 04 seconds of a 24 hour day regardless of how many
days occupy a specific year (365/366) and you have your Ra/Dec system
right there in all its hideous glory.

I am enjoying the spectacle of an astrologer chastising a physicist
but ultimately it is for real astronomers to appreciate how the
natural noon cycles are unequal and how brilliant men worked this
observation into a system which keep clocks in sync with the axial
cycle at precisely 24 hours/360 degrees -

http://www.xs4all.nl/~adcs/Huygens/06/kort-E.html

Major explanations are not changed by dour people like you or the
caltech numbskull and say what you will, about me that is all that
matters.

On Jul 22, 7:21 am, Greg Crinklaw <theskyhoundyour...@yahoo.com >
wrote:
> Chris L Peterson wrote:
> > On Sat, 21 Jul 2007 17:37:20 -0600, Greg Crinklaw
> > <theskyhoundyour...@yahoo.com> wrote:
>
> >> In fact I wasn't complaining about the use a decimals. I was complaining
> >> about the improper use of units. The unit of Right Ascension is hours.
> >> Period.
>
> > That is simply untrue. RA corresponds to longitude, and any units are
> > acceptable (as long as it is clear which units are being used). For a
> > long time, hours have been the most common units, of course, but that
> > seems to be changing, since there's little reason to use hours in
> > today's astronomical environment. You may prefer hours, but you'd better
> > get used to seeing degrees. (Many astronomical applications give you an
> > option of selecting your RA units, including simple degrees.)
>
> Standards are important. They provide an agreed upon method for
> communicating information. Just because no group of physicists ever got
> together and decreed that the unit of RA is hours doesn't mean it is not
> the accepted standard. To ignore that standard is simply arrogant and
> those who do are doing a disservice to the community--a community they
> apparently don't have enough respect for to even bother adhering to its
> standards! No other science would be treated this way--like astronomical
> standards are quaint and old fashioned and unimportant. That's as
> arrogant as it is ignorant.
>
> The ugly narrow culture of physics worships at the god of memorization
> and considers scientific curiosity something "amateuristic" -- something
> that needs to be flogged out of students so they will know their place
> in the rigid class structure. Physics is the one discipline of modern
> science that is still largely devoid of women in any real science
> capacity. Why? Because it worships all the wrong things. Because it
> sold its soul to Big Science and government money when it started
> creating bombs that could kill millions.
>
> Unfortunately I fear that it is dragging astronomy down with it. When I
> see RA stated in degrees, not only is it a nuisance and a insult, it
> reminds me of how astronomy is ever changing under the influence of its
> big ugly brother, and not for the better.
>
> --
> Greg Crinklaw
> Astronomical Software Developer
> Cloudcroft, New Mexico, USA (33N, 106W, 2700m)
>
> SkyTools: http://www.skyhound.com/cs.html
> Observing:http://www.skyhound.com/sh/skyhound.html
> Comets: http://comets.skyhound.com
>
> To reply take out your eye

Date: 21 Jul 2007 23:16:49
From: Sam Wormley
Subject: Re: A very unusual galaxy field in SDSS

ukastronomy wrote:
> I came across this very curiously shaped object and I was wondering
> what the experts on this group made of it.
>
> http://www.martin-nicholson.info/dart/dart3.htm
>

IR images look a bit different than we are used to. For example look
at this weird galaxy.
http://antwrp.gsfc.nasa.gov/apod/ap070721.html

Date: 21 Jul 2007 09:47:55
From: oriel36
Subject: Re: A very unusual galaxy field in SDSS

On Jul 21, 4:47 pm, Greg Crinklaw <theskyhoundyour...@yahoo.com >
wrote:
> Chris L Peterson wrote:
> > On Sat, 21 Jul 2007 09:08:54 -0600, Greg Crinklaw
> > <theskyhoundyour...@yahoo.com> wrote:
>
> >> Rant on: few things make my blood boil more than a bunch of physicists
> >> who come along and think they can dabble in astronomy while ignoring and
> >> thus disrespecting astronomical conventions. (The RA on the SDSS page
> >> is in degrees).
>
> > I see decimal degrees being used in astronomy more and more often, thank
> > goodness. We can't get rid of the h:m:s/d:m:s convention soon enough,
> > IMO. It's only useful for unautomated amateurs, and marginally so even
> > there. For everybody else, it's just a PITA.
>
> Baloney. It only becomes a PITA when people don't use it. You are one
> of those damned physicists who dabble in astronomy and think astronomy
> is a lesser "science" aren't you? Admit it.
>
> --
> Greg Crinklaw
> Astronomical Software Developer
> Cloudcroft, New Mexico, USA (33N, 106W, 2700m)
>
> SkyTools: http://www.skyhound.com/cs.html
> Observing:http://www.skyhound.com/sh/skyhound.html
> Comets: http://comets.skyhound.com
>
> To reply take out your eye

Greg

It is time for you to take up stamp collecting,birdwatching or some
other genuine endeavor for astronomy is not your strongest point but
to be fair to you,I have yet to see anyone else with a little buried
talent from astronomy and especially as far as the motions of the
Earth are concerned.

Take it from me,the person who has more influence on matters
astronomical than anyone else that although the conditions for real
astronomy may take years or even decades,it will eventually bypass the
concepts of the sour and dismal mathematicians,astrological
photographers and other riff raff who now call themselves
'astronomers'.

Remember now,the daily cycle has been observed to be unequal since
antiquity so go teach your peers this basic fact before you even
consider mentioning Ra/Dec again -

http://en.wikipedia.org/wiki/Image:Tiempo_sid%C3%A9reo.en.png

If you can't then there are great sites promoting birdwatching where
you can excel without doing any harm and your magnification equipment
will not go to waste.I will even help guide you there -

http://www.birdwatching.com/

Take the physicists with you and you can discuss how birds manage to
fly .

Date: 21 Jul 2007 09:26:04
From: oriel36
Subject: Re: A very unusual galaxy field in SDSS

On Jul 21, 4:08 pm, Greg Crinklaw <theskyhoundyour...@yahoo.com >
wrote:
> ukastronomy wrote:
> > I came across this very curiously shaped object and I was wondering
> > what the experts on this group made of it.
>
> Here's the NED page:
>
> http://tinyurl.com/yur8ss
>
> When it comes to galaxies NED is the place to look them up rather than
> SIMBAD.
>
> Rant on: few things make my blood boil more than a bunch of physicists
> who come along and think they can dabble in astronomy while ignoring and
> thus disrespecting astronomical conventions. (The RA on the SDSS page
> is in degrees).
>
> --
> Greg Crinklaw
> Astronomical Software Developer
> Cloudcroft, New Mexico, USA (33N, 106W, 2700m)
>
> SkyTools: http://www.skyhound.com/cs.html
> Observing:http://www.skyhound.com/sh/skyhound.html
> Comets: http://comets.skyhound.com
>
> To reply take out your eye

Both of you or rather all of you are dabbling in an astrological
framework created by Flamsteed but too dumb to know it or if you do
know it are too dumb to do anything about it -

"Equatorial mounts could then be accurately pointed at objects with
known right ascension and declination by the use of setting circles.
The first star catalog to use right ascension and declination was John
Flamsteed's Historia Coelestis Britannica (1712, 1725)."

http://en.wikipedia.org/wiki/Right_ascension

Dear oh dear,all these outwardly polished reputations and not one of
them able to do their job correctly.Apart from brilliant technical
advancements this era is intutively dead,no civilisation has existed
with such a poor intutive grasp of its heritage and especially its
astronomical heritage.Not much I can do about it but boy do you guys
look poor.

Its not the physicists who know no better,it is astrologers with the
Ra/Dec constellational framewoirk that is objectionable.

Date: 21 Jul 2007 09:08:54
From: Greg Crinklaw
Subject: Re: A very unusual galaxy field in SDSS

ukastronomy wrote:
> I came across this very curiously shaped object and I was wondering
> what the experts on this group made of it.

Here's the NED page:

http://tinyurl.com/yur8ss

When it comes to galaxies NED is the place to look them up rather than
SIMBAD.

Rant on: few things make my blood boil more than a bunch of physicists
who come along and think they can dabble in astronomy while ignoring and
thus disrespecting astronomical conventions. (The RA on the SDSS page
is in degrees).

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://comets.skyhound.com

To reply take out your eye

Date: 24 Jul 2007 01:04:28
From: Pig Enc
Subject: Re: A very unusual galaxy field in SDSS

Greg Crinklaw wrote:

> ukastronomy wrote:
> > I came across this very curiously shaped object and I was wondering
> > what the experts on this group made of it.
>
> Here's the NED page:
>
> http://tinyurl.com/yur8ss
>
> When it comes to galaxies NED is the place to look them up rather than
> SIMBAD.
>
> Rant on: few things make my blood boil more than a bunch of physicists
> who come along and think they can dabble in astronomy while ignoring and
> thus disrespecting astronomical conventions. (The RA on the SDSS page
> is in degrees).
>
> --
> Greg Crinklaw
> Astronomical Software Developer
> Cloudcroft, New Mexico, USA (33N, 106W, 2700m)
>
> SkyTools: http://www.skyhound.com/cs.html
> Observing: http://www.skyhound.com/sh/skyhound.html
> Comets: http://comets.skyhound.com
>
> To reply take out your eye

No I will leave my eye in, thank you!

Technology changes. Conventions change. The only "issue"
(besides your mental health) is "work".

Sometimes you talk as if you didnt know the difference between
a light bulb and a cow pie.

Good luck.

Date: 25 Jul 2007 13:50:06
From: Greg Crinklaw
Subject: Re: A very unusual galaxy field in SDSS

Pig Enc wrote:
> Sometimes you talk as if you didnt know the difference between
> a light bulb and a cow pie.

Sometimes you sound like the same childish troll over and over... No,
wait, all the time. Get a life! Or at least get some help for your
problem.

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://comets.skyhound.com

To reply take out your eye

Date: 21 Jul 2007 15:41:26
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Sat, 21 Jul 2007 09:08:54 -0600, Greg Crinklaw
<theskyhoundyoureye@yahoo.com > wrote:

>Rant on: few things make my blood boil more than a bunch of physicists
>who come along and think they can dabble in astronomy while ignoring and
>thus disrespecting astronomical conventions. (The RA on the SDSS page
>is in degrees).

I see decimal degrees being used in astronomy more and more often, thank
goodness. We can't get rid of the h:m:s/d:m:s convention soon enough,
IMO. It's only useful for unautomated amateurs, and marginally so even
there. For everybody else, it's just a PITA.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 21 Jul 2007 09:47:39
From: Greg Crinklaw
Subject: Re: A very unusual galaxy field in SDSS

Chris L Peterson wrote:
> On Sat, 21 Jul 2007 09:08:54 -0600, Greg Crinklaw
> <theskyhoundyoureye@yahoo.com> wrote:
>
>> Rant on: few things make my blood boil more than a bunch of physicists
>> who come along and think they can dabble in astronomy while ignoring and
>> thus disrespecting astronomical conventions. (The RA on the SDSS page
>> is in degrees).
>
> I see decimal degrees being used in astronomy more and more often, thank
> goodness. We can't get rid of the h:m:s/d:m:s convention soon enough,
> IMO. It's only useful for unautomated amateurs, and marginally so even
> there. For everybody else, it's just a PITA.

Baloney. It only becomes a PITA when people don't use it. You are one
of those damned physicists who dabble in astronomy and think astronomy
is a lesser "science" aren't you? Admit it.

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://comets.skyhound.com

To reply take out your eye

Date: 21 Jul 2007 22:13:25
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Sat, 21 Jul 2007 09:47:39 -0600, Greg Crinklaw
<theskyhoundyoureye@yahoo.com > wrote:

>Baloney. It only becomes a PITA when people don't use it. You are one
>of those damned physicists who dabble in astronomy and think astronomy
>is a lesser "science" aren't you? Admit it.

I'm an astrophysicist. Where does that place me?

Seriously, as a programmer, I don't see how you can not see h:m:s and
sexagesimal notation as anything other than a pain. The system is
useless for any sort of calculations, so you always have to be doing
conversions. Every online catalog and astronomy app handles things a
little differently, so providing coordinates is never straightforward.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 22 Jul 2007 00:55:46
From: Davoud
Subject: Re: A very unusual galaxy field in SDSS

Greg Crinklaw wrote (concerning the expression of RA as hh:mm:ss) -

> >Baloney. It only becomes a PITA when people don't use it. You are one
> >of those damned physicists who dabble in astronomy and think astronomy
> >is a lesser "science" aren't you? Admit it.

Chris L Peterson:
> I'm an astrophysicist. Where does that place me?

Heh, heh, heh. You don't want to know. In favor of a decimal
day/month/year, among other places? If your species had seven digits I
suspect you would argue that only base-7 makes sense. The same
elevation that does great things for your astronomical seeing is
starving your brain of oxygen.

> Seriously, as a programmer, I don't see how you can not see h:m:s and
> sexagesimal notation as anything other than a pain. The system is
> useless for any sort of calculations, so you always have to be doing
> conversions.

Nowadays we have computers to take care of those matters. Even Windoze
can do that, no? I feel no pain.

> Every online catalog and astronomy app handles things a
> little differently, so providing coordinates is never straightforward.

Hmmm. Between Mac OS, Unix, and Windoze I have maybe six
planetarium/telescope control programs on this machine. All six can
send my little 'scope pointing to a given star + or - a couple of arc
minutes -- close enuf to the center of an eyepiece or chip as makes no
difference. Straightforward? I don't know from straightforward, but
somebody's doing somethin' right because the various apps on three OS's
agree with considerable precision on where the star is.

Davoud

--
usenet *at* davidillig dawt com

Date: 22 Jul 2007 01:07:54
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Sun, 22 Jul 2007 00:55:46 GMT, Davoud <star@sky.net > wrote:

>Heh, heh, heh. You don't want to know. In favor of a decimal
>day/month/year, among other places? If your species had seven digits I
>suspect you would argue that only base-7 makes sense. The same
>elevation that does great things for your astronomical seeing is
>starving your brain of oxygen.

I'm a units pragmatist. I don't care about tradition, I use what works
best for the given problem. RA in hours makes sense if you are doing a
calculation in your head to figure out if some particular object is
visible. But it is a poor choice for almost any instrumental
application... which these days describes most cases.

>> Seriously, as a programmer, I don't see how you can not see h:m:s and
>> sexagesimal notation as anything other than a pain. The system is
>> useless for any sort of calculations, so you always have to be doing
>> conversions.
>
>Nowadays we have computers to take care of those matters. Even Windoze
>can do that, no? I feel no pain.

You would if you were programming, and had to deal with a wide range of
possible numeric formats. And you would if you ever went out to online
databases, and realized that they all handle coordinates slightly
differently.

>> Every online catalog and astronomy app handles things a
>> little differently, so providing coordinates is never straightforward.
>
>Hmmm. Between Mac OS, Unix, and Windoze I have maybe six
>planetarium/telescope control programs on this machine. All six can
>send my little 'scope pointing to a given star + or - a couple of arc
>minutes -- close enuf to the center of an eyepiece or chip as makes no
>difference. Straightforward? I don't know from straightforward, but
>somebody's doing somethin' right because the various apps on three OS's
>agree with considerable precision on where the star is.

If you need to specify an object by coordinates alone, you'll find that
the situation isn't so simple. You are mostly identifying an object by
some designation, or even point-and-click, so you aren't even worrying
about units. I don't care what gets sent between the control program and
the telescope, but I do care that the user interface is easy to use.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 23 Jul 2007 04:11:26
From: Davoud
Subject: Re: A very unusual galaxy field in SDSS

Chris L Peterson:
> >> Seriously, as a programmer, I don't see how you can not see h:m:s and
> >> sexagesimal notation as anything other than a pain. The system is
> >> useless for any sort of calculations, so you always have to be doing
> >> conversions.

Davoud:
> >Nowadays we have computers to take care of those matters. Even Windoze
> >can do that, no? I feel no pain.

Chris L Peterson:
> You would if you were programming, and had to deal with a wide range of
> possible numeric formats. And you would if you ever went out to online
> databases, and realized that they all handle coordinates slightly
> differently.

I appreciate the work that programmers perform to make great software
such as TheSky &c. I really do. But I can't concern myself too much
with the details of their work so long as they produce software that
works for me.

Davoud:
> >Hmmm. Between Mac OS, Unix, and Windoze I have maybe six
> >planetarium/telescope control programs on this machine. All six can
> >send my little 'scope pointing to a given star + or - a couple of arc
> >minutes -- close enuf to the center of an eyepiece or chip as makes no
> >difference. Straightforward? I don't know from straightforward, but
> >somebody's doing somethin' right because the various apps on three OS's
> >agree with considerable precision on where the star is.

Chris L Peterson:
> If you need to specify an object by coordinates alone, you'll find that
> the situation isn't so simple. You are mostly identifying an object by
> some designation, or even point-and-click, so you aren't even worrying
> about units. I don't care what gets sent between the control program and
> the telescope, but I do care that the user interface is easy to use.

Typing the coordinates of a star still sends my little 'scope to it.
And point & click isn't easy!? This is sci.astro. /amateur/ . I have
never before heard an amateur (or a professional, for that matter)
complain about the RA coordinate system. I just had a look at GSC 2.2.
A star at RA 10h 25m 20.14s and Dec 6° 43m 14.1s is designated as
"GSC22 1025201+064314". I can go to those coordinates, manually or with
goto, and find the star. Was the GSC drawn up by a bunch of ignorant
amateurs, or by a bunch of ignorant professional astronomers who didn't
know know any better than to identify a star by the problematical RA
coordinate system?

For me the bottom line is that in the 25 years I've been using
telescopes, beginning with the manual RA circle on my Q (which I still
use) I have always started the evening by calibrating on a known star
and moving on from there. With manual settings I repeat the calibration
as I move around the sky. This hasn't failed me yet.

You don't discuss matters, however. You make pronouncements /ex/
/cathedra/ and that's the end of it. What's true for you is true for
everyone, and there is no need for discussion, so I have no idea why
I'm barking at the moon. Must be because it's overcast. Anyway, please
don't lose any sleep over all those ignorant astronomers who are
directing their telescopes to RA 10h 25m 20.14s and Dec 6° 43m 14.1s
tonight.

Davoud

--
usenet *at* davidillig dawt com

Date: 23 Jul 2007 04:27:44
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Mon, 23 Jul 2007 04:11:26 GMT, Davoud <star@sky.net > wrote:

>You don't discuss matters, however. You make pronouncements /ex/
>/cathedra/ and that's the end of it. What's true for you is true for
>everyone, and there is no need for discussion, so I have no idea why
>I'm barking at the moon. Must be because it's overcast. Anyway, please
>don't lose any sleep over all those ignorant astronomers who are
>directing their telescopes to RA 10h 25m 20.14s and Dec 6� 43m 14.1s
>tonight.

You entirely miss the point. Entirely. The point is nothing more than
that the choice of units depends on application. You should use what you
find works best. The concept of RA is unchanged regardless of units.

When working with RA, I find myself most frequently preferring degrees
to hours, so I'm happy when apps and web-based catalogs support those
units (and it seems to be an increasing trend to do so).

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 21 Jul 2007 17:37:20
From: Greg Crinklaw
Subject: Re: A very unusual galaxy field in SDSS

Chris L Peterson wrote:
> On Sat, 21 Jul 2007 09:47:39 -0600, Greg Crinklaw
> <theskyhoundyoureye@yahoo.com> wrote:
>
>> Baloney. It only becomes a PITA when people don't use it. You are one
>> of those damned physicists who dabble in astronomy and think astronomy
>> is a lesser "science" aren't you? Admit it.
>
> I'm an astrophysicist. Where does that place me?
>
> Seriously, as a programmer, I don't see how you can not see h:m:s and
> sexagesimal notation as anything other than a pain. The system is
> useless for any sort of calculations, so you always have to be doing
> conversions. Every online catalog and astronomy app handles things a
> little differently, so providing coordinates is never straightforward.

As a programmer I know that all calculations are done in radians and
internally everything is actually done in binary arithmetic.

That does not mean that I would choose to use radians for my coordinates
any more than I would use binary numbers.

In fact I wasn't complaining about the use a decimals. I was complaining
about the improper use of units. The unit of Right Ascension is hours.
Period. It is not degrees. In order to enter the RA given on the DSS
web site into NED I had to enter it into my calculator and divide it by
15. That's completely unnecessary as the standard unit is hours, not
degrees.

In my opinion any person or group of persons who arrogantly enter
another discipline and ignores it's standards is being arrogant and
disrespectful.

Why use hours? Because this system was derived over many decades by
people who actually watched the sky; people who had a connection to it
beyond equations and computer models. In short, astronomers. Human
beings, not computers. You mention the sexagesimal system; it is also
useful for human beings. As an example:

I give you the Declinations for two stars that have the same RA:

(1) 32.265083
(2) 32.251611

Haw far apart are these stars in arc seconds? Will they appear as a
double star? A wide pair? Close pair? Will they both fit within a 1'
field of view?

Now I give you these same numbers in units designed for people rather
than computers:

(1) +32d15'54.3"
(2) +32d15'05.8"

The answer to the questions should now be obvious without any computer
or even a calculator. Those of us who have a proper education in
astronomy, and didn't just walk in thinking they could pick up a little
here and there (because astronomy is not a real science worth teaching)
understand this.

Likewise, Right Ascension in hours is useful to the astronomer (if not
the physicist who can't even name a single constellation) because it
relates to time.

The role of the computer is not to dehumanize us be forcing us to use
binary arithmetic or radians. The role of a computer is to do its
calculations however it needs to, yet relate the input/output to humans
in those ways that humans can best relate to. They are computers after
all, and simple unit conversions are something they excel at. Any
programmer who forces his/her users to adhere to the needs of the
computer without bothering to provide an interface that is best for
humans is lazy.

Physicists are arrogant. I know, I have an advanced degree in physics.
Unfortunately they won't let me give it back. ;-) Physicists believe
that all they need is their memorized equations and math skills; armed
with these all other sciences must kneel at their feet. This may work
in the subatomic world where no one has ever seen the particles
involved, but it is in fact a handicap in the real world of science.
The real world is fraught with specialized problems that must be fully
understood in order to do the best science. Uncertainties in
observations is chief among them. Standard error analysis is a limited
tool in the real world; an empirical understanding of what really goes
into the measurements is much more useful. Without the astronomers of
the world astrophysicists would long ago have convinced themselves that
their pet theories were reality based on little more than wishful
thinking and a heavy dose of arrogance.

They used to tell this story at Illinois (Urbana-Champaign): the
"astrophysics" who were comprised of both physicists and traditional
astronomers were sitting around a table discussing the future of their 1
meter telescope, which at the time was in the midwest of the US. With
great contempt for one of the astronomers present a famous
astrophysicist went on a tirade and exclaimed, "Why don't you study
something important with that telescope like the Magellanic clouds!".

I'll say it again, waltzing into a field with a long history and rich
traditions and blatantly ignoring them is arrogant and disrespectful,
and those who do so while looking down their noses at others may just
find themselves the butt of a joke...

Ok, I'm done ranting now. :-)

Greg

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://comets.skyhound.com

To reply take out your eye

Date: 22 Jul 2007 00:51:01
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Sat, 21 Jul 2007 17:37:20 -0600, Greg Crinklaw
<theskyhoundyoureye@yahoo.com > wrote:

>In fact I wasn't complaining about the use a decimals. I was complaining
>about the improper use of units. The unit of Right Ascension is hours.
> Period.

That is simply untrue. RA corresponds to longitude, and any units are
acceptable (as long as it is clear which units are being used). For a
long time, hours have been the most common units, of course, but that
seems to be changing, since there's little reason to use hours in
today's astronomical environment. You may prefer hours, but you'd better
get used to seeing degrees. (Many astronomical applications give you an
option of selecting your RA units, including simple degrees.)

>The answer to the questions should now be obvious without any computer
>or even a calculator...

But professionals always use computers and calculators. And in that work
flow environment, simple degrees is the best choice. And that's why
things are shifting in that direction.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 22 Jul 2007 00:21:01
From: Greg Crinklaw
Subject: Re: A very unusual galaxy field in SDSS

Chris L Peterson wrote:
> On Sat, 21 Jul 2007 17:37:20 -0600, Greg Crinklaw
> <theskyhoundyoureye@yahoo.com> wrote:
>
>> In fact I wasn't complaining about the use a decimals. I was complaining
>> about the improper use of units. The unit of Right Ascension is hours.
>> Period.
>
> That is simply untrue. RA corresponds to longitude, and any units are
> acceptable (as long as it is clear which units are being used). For a
> long time, hours have been the most common units, of course, but that
> seems to be changing, since there's little reason to use hours in
> today's astronomical environment. You may prefer hours, but you'd better
> get used to seeing degrees. (Many astronomical applications give you an
> option of selecting your RA units, including simple degrees.)

Standards are important. They provide an agreed upon method for
communicating information. Just because no group of physicists ever got
together and decreed that the unit of RA is hours doesn't mean it is not
the accepted standard. To ignore that standard is simply arrogant and
those who do are doing a disservice to the community--a community they
apparently don't have enough respect for to even bother adhering to its
standards! No other science would be treated this way--like astronomical
standards are quaint and old fashioned and unimportant. That's as
arrogant as it is ignorant.

The ugly narrow culture of physics worships at the god of memorization
and considers scientific curiosity something "amateuristic" -- something
that needs to be flogged out of students so they will know their place
in the rigid class structure. Physics is the one discipline of modern
science that is still largely devoid of women in any real science
capacity. Why? Because it worships all the wrong things. Because it
sold its soul to Big Science and government money when it started
creating bombs that could kill millions.

Unfortunately I fear that it is dragging astronomy down with it. When I
see RA stated in degrees, not only is it a nuisance and a insult, it
reminds me of how astronomy is ever changing under the influence of its
big ugly brother, and not for the better.

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://comets.skyhound.com

To reply take out your eye

Date: 22 Jul 2007 14:21:54
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Sun, 22 Jul 2007 00:21:01 -0600, Greg Crinklaw
<theskyhoundyoureye@yahoo.com > wrote:

>Standards are important...

And standards change. Few of the units we use in science today were the
ones commonly used by scientists a couple of hundred years ago. And as
the methods used for working with certain quantities change, the most
commonly used units may change as well.

In any case, this really doesn't have much to do with standards. There
are, in fact, very few rigid standards when it comes to units. Most
people are quite comfortable choosing their units based on need: seconds
may be the "standard" for time, but we have no problem using minutes or
years when it's more appropriate. Meters are the "standard", but we
switch between that and astronomical units, light years, or parsecs as
seems best.

No, this isn't about standards, it's about common convention... and that
can change even easier than standards. (And this change isn't coming
from physicists, but from astronomers.)

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 22 Jul 2007 08:34:36
From: Greg Crinklaw
Subject: Re: A very unusual galaxy field in SDSS

Chris L Peterson wrote:
> No, this isn't about standards, it's about common convention... and that
> can change even easier than standards. (And this change isn't coming
> from physicists, but from astronomers.)

Call it a convention, fine. The fact is that it is a convention and I
should not have had to use my calculator just because some physicist
(and I know all about the SDSS, I live next door --it's the physicists)
decided to use units he was more familiar with rather than bother with
the convention use by those quaint astronomers.

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://comets.skyhound.com

To reply take out your eye

Date: 22 Jul 2007 14:56:00
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Sun, 22 Jul 2007 08:34:36 -0600, Greg Crinklaw
<theskyhoundyoureye@yahoo.com > wrote:

>Call it a convention, fine. The fact is that it is a convention and I
>should not have had to use my calculator just because some physicist
>(and I know all about the SDSS, I live next door --it's the physicists)
>decided to use units he was more familiar with rather than bother with
>the convention use by those quaint astronomers.

Well, astronomers who are not also physicists are, indeed, rather quaint
<g >.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 21 Jul 2007 20:10:56
From: Greg Crinklaw
Subject: Re: A very unusual galaxy field in SDSS

Date: 21 Jul 2007 08:03:08
From: Ben
Subject: Re: A very unusual galaxy field in SDSS

Lots of deformation on both wings. I'd call it a merger.

Ben

Date: 21 Jul 2007 15:09:02
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS

On Sat, 21 Jul 2007 08:03:08 -0700, Ben <bet71743@netzero.com > wrote:

>Lots of deformation on both wings. I'd call it a merger.

It certainly could be. I still suspect a barred spiral, though. I'm not
at all certain there is any deformation, just an appearance of it
because there is so little signal. I think there may be a lot of
structure that isn't visible because it's just too dim. If you take a
galaxy like M51 (not barred, of course) and adjust the contrast so that
all the dim structure goes away, the resulting image looks similarly
distorted. The brightest parts of a galaxy aren't necessarily highly
symmetrical.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Date: 21 Jul 2007 14:20:08
From: Chris L Peterson
Subject: Re: A very unusual galaxy field in SDSS