March 2006 - Utah-Astronomy - mailman.xmission.com

Non-shadow sundial
by Chuck Hards 22 Mar '06

22 Mar '06

Kurt, are you familiar with polarization-type sundials? They work even on overcast days, since the diffused sunlight scattered through the cloud deck retains it's polarization orientation. Of course, instead of looking down at a shadow, you'd be looking up through a tube, through crossed polarizing filters, and then noting the relative angle between the two at the setting of either greatest extinction, or greatest transmission, depending on how that particular sundial was set-up. I've read that the Vikings used crystals with polarizing properties to estimate solar altitudes and azimuths when at sea, on overcast days. I'm at work now and can't do the instant research, but I'm sure there is more on this on the Web somewhere. > From: Canopus56 <canopus56(a)yahoo.com> > I'll probably walk over to the Gallivan Center at > around _12:30pm_ to watch the Gallivan sundial tick > off local equinox. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Some spring equinox notes for Utah science teachers
by Canopus56 22 Mar '06

22 Mar '06

The following are some notes on tomorrow's spring equinox that may be of use to Utah educators. The spring equinox is tomorrow, 3/20/2006 at 18:26 UTC (11:26 MDT). The NASA/JPL Horizons Ephemeris << http://ssd.jpl.nasa.gov/?ephemerides >> for my topocentric observing point (o.p.) ( 111Â°53'27.6''W, 40Â°45'23.0''N ), shows Sun crossing 0 deg ecliptic longitude between 18:25 and 18:26 UT: Date/Time Az/Alt Eclip Long Lat Local solar time 2006-Mar-20 18:25 154.2263 46.2549 359.9995381 -0.0018950 10 49 00.7171 2006-Mar-20 18:26 154.5682 46.3370 000.0002209 -0.0018920 10 50 00.7313 Local transit of the Sun (our topocentric equinox) occurs later at 19:34-19:35 UT (12:34-12:35 pm MDT): Date/Time Az/Alt Eclip Long Lat Local solar time 2006-Mar-20 19:34 179.6279 49.2600 0.0466343 -0.0016771 11 59 01.7169 2006-Mar-20 19:35 180.0111 49.2608 0.0473167 -0.0016739 12 00 01.7312 2006-Mar-20 19:36t 180.3942 49.2604 0.0479991 -0.0016706 12 01 01.7456 At this point, that this observing point's latitude (~ 41N degs) is equal to 90 degrees (zenith) minus the altitude of the Sun, e.g. - 41 degs = 90 degs - 49 degs Due to the effect of precession, from this SLC topocentric o.p., the Sun does not cross the celestial coordinate spring equinox until 20:22-20:23 UT (1:22-1:23pm): Date/Time RA/Dec Alt/Az 2006-Mar-20 20:22 23 59 59.85 -00 00 07.1 197.6971 47.8966 2006-Mar-20 20:23 00 00 00.00 -00 00 06.1 198.0597 47.8387 These angles can be demonstrated to students using a protractor with a string and hanging weight (like a bolt or nut) run through the center hole - at the 19:34-19:35 UT (12:34-12:35 pm MDT) time mark. The protractor is held so that the string hangs through the 90 degree mark. Then stick a pencil perpendicular to the protractor into the center hole. A fuzzy shadow will be cast by the Sun. To reduce the chance of eye injury, advise students to not sight along the protractor at the Sun. Measure angles indirectly using the pencil's shadow. An accurately aligned north-south building edge (check with a compass) can also be used. Use the protractor to make a large graduated quarter circle on a piece of paper. Using the protractor with plumb bob, tape the graduated circle to the north-south side of the building. Hold a pencil perpendicular to the building and take a shadow measurement. Degree of accuracy for such methods is ~ 1.0 - 3.0 degrees. - Canopus56 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: [Utah-astronomy] Re: Re: What do you think?
by Michael Carnes 20 Mar '06

20 Mar '06

>...the abacus? Boots up quickly, too. >fingers? Multipurpose.

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Re: Re: What do you think?
by Chuck Hards 20 Mar '06

20 Mar '06

...the abacus? fingers? > From: Michael Carnes <MichaelCarnes(a)earthlink.net> > > OSI, Kaypro? > On Mar 16, 2006, at 9:58 PM, Chuck Hards wrote: > > > Anybody else remember Imsai? Cromemco? __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: Re: Some spring equinox notes for Utah science teachers
by Chuck Hards 20 Mar '06

20 Mar '06

Yeah, good luck with that today, Kurt. Take your umbrella. (Wouldn't it be 12:28pm local time?) > From: Canopus56 <canopus56(a)yahoo.com> > I'll probably walk over to the Gallivan Center at > around _12:30pm_ to watch the Gallivan sundial tick > off local equinox. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Blackstar (?)
by Patrick Wiggins 16 Mar '06

16 Mar '06

An interesting read that Bill Biesele sent me. I _want_ to believe... :-) Patrick Two-Stage-to-Orbit 'Blackstar' System Shelved at Groom Lake? http://www.aviationnow.com/avnow/news/channel_awst_story.jsp?id=news/030606…

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Happy "somewhat belated" National Pi Day
by Dale Hooper 14 Mar '06

14 Mar '06

Pi is very important to astronomy and its also somewhat a celebration of Albert Einstein's Birthday so: Happy National Pi Day!!!! www.piday.org http://en.wikipedia.org/wiki/Pi_day I celebrated by having a Hostess apple pie at 3:14pm today - but I guess a lot of people actually celebrated it at 1:59pm (i.e. 3/14 1:59pm). We are also celebrating with cherry, pumpkin and apple pies tonight. Clear skies, Dale.

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http://stardustathome.ssl.berkeley.edu/
by Wade Starks 14 Mar '06

14 Mar '06

Anyone interested in participating in find stardust particles may preregister at this site. They are hosting a stardust at home site which will allow volunteers from the general public to view individual aerogel cells for evidence of the particles, using a web based "microscope". Go to this site to find out more about the program. Wade http://stardustathome.ssl.berkeley.edu/ ------------------------------------------------------------------------------ NOTICE: This email message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. ------------------------------------------------------------------------------

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Comet Pojmanski Movie
by Edward Lunt 13 Mar '06

13 Mar '06

-Hi All; This link is to a site that has a short "movie" of Comet Pojmanski. The movie can be viewed by scrolling down past the two still images. Note the movement of the Comet relative to the stars is sideways. This explains the "bar" shaped core in my close-up. It is indeed the result of the sideward movement relative to the stars. Have fun watching. The link is: http://home.att.net/~dpersyk/new.htm Enjoy; Ed Lunt __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: [Utah-astronomy] What do you think?
by Michael Carnes 13 Mar '06

13 Mar '06

Works for me. Gotta say that's pretty cool. Can't see any houses, though. -----Original Message----- >From: Patrick Wiggins <paw(a)wirelessbeehive.com> >Sent: Mar 13, 2006 2:35 PM >To: Utah Astronomy <utah-astronomy(a)mailman.xmission.com> >Subject: Re: [Utah-astronomy] What do you think? > >Joe Bauman wrote: > >> I can't get it to connect. -- Joe > >Anyone else having this problem? > >The URL is http://www.google.com/mars/ . > >Patrick > >_______________________________________________ >Utah-Astronomy mailing list >Utah-Astronomy(a)mailman.xmission.com >http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy >Visit the Photo Gallery: http://www.utahastronomy.com

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