Celestial navigation (quiz) - Page 2 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > Skills and Seamanship > Seamanship & Navigation
 Not a Member? 

Seamanship & Navigation Forum devoted to seamanship and navigation topics, including paper and electronic charting tools.


Reply
 
LinkBack Thread Tools
  #11  
Old 02-04-2010
AdamLein's Avatar
Senior Member
 
Join Date: Nov 2007
Location: SF Bay area
Posts: 1,862
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 8
AdamLein will become famous soon enough
Quote:
Originally Posted by Boasun View Post
You wouldn't by chance be referring to the Diurnal circle...Which is the path of a celestial body during its daily apparent revolution around the earth.
The sun's diurnal circle would be a subset of this set of all possible points. What would you get if you took the globe and drew the diurnal circle for every day of the year? ... for every year, ever?
__________________
s/v Essorant
1972 Catalina 27
Reply With Quote Quick reply to this message Share with Facebook
  #12  
Old 02-04-2010
Senior Member
 
Join Date: Jun 2006
Posts: 5,004
Thanks: 5
Thanked 18 Times in 18 Posts
Rep Power: 11
wind_magic has a spectacular aura about wind_magic has a spectacular aura about wind_magic has a spectacular aura about
Quote:
Originally Posted by AdamLein View Post
The sun's diurnal circle would be a subset of this set of all possible points. What would you get if you took the globe and drew the diurnal circle for every day of the year? ... for every year, ever?
AdamLein, are you referring to the celestial sphere ?
__________________
What are you pretending not to know ?

Please support my
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #13  
Old 02-04-2010
Senior Member
 
Join Date: Jun 2006
Posts: 5,004
Thanks: 5
Thanked 18 Times in 18 Posts
Rep Power: 11
wind_magic has a spectacular aura about wind_magic has a spectacular aura about wind_magic has a spectacular aura about
My turn ..

Without a sextant, what simple method can you use to find your latitude in the northern hemisphere ?
__________________
What are you pretending not to know ?

Please support my
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #14  
Old 02-04-2010
erps's Avatar
the pointy end is the bow
 
Join Date: Aug 2006
Location: La Conner, Washington
Posts: 6,216
Thanks: 2
Thanked 26 Times in 26 Posts
Rep Power: 10
erps will become famous soon enough erps will become famous soon enough
measure the angle of Polaris above the northern horizon?
__________________
Ray
S.V. Nikko
1983 Fraser 41
La Conner, WA


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Boating for over 25 years, some of them successfully.
Reply With Quote Quick reply to this message Share with Facebook
  #15  
Old 02-04-2010
Senior Member
 
Join Date: Jun 2006
Posts: 5,004
Thanks: 5
Thanked 18 Times in 18 Posts
Rep Power: 11
wind_magic has a spectacular aura about wind_magic has a spectacular aura about wind_magic has a spectacular aura about
Quote:
Originally Posted by erps View Post
measure the angle of Polaris above the northern horizon?
Correct.
__________________
What are you pretending not to know ?

Please support my
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #16  
Old 02-04-2010
Senior Member
 
Join Date: Jun 2006
Posts: 5,004
Thanks: 5
Thanked 18 Times in 18 Posts
Rep Power: 11
wind_magic has a spectacular aura about wind_magic has a spectacular aura about wind_magic has a spectacular aura about
Here is a two point question ...

If you draw a line through the center of the earth to the center of the Sun, when will someone in Boston be nearest to that line ?
__________________
What are you pretending not to know ?

Please support my
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by wind_magic; 02-04-2010 at 06:21 PM. Reason: sp
Reply With Quote Quick reply to this message Share with Facebook
  #17  
Old 02-04-2010
CalebD's Avatar
Tartan 27' owner
 
Join Date: Jan 2008
Location: NYC
Posts: 4,616
Thanks: 4
Thanked 93 Times in 85 Posts
Rep Power: 7
CalebD will become famous soon enough
This link was useful for the first 2 questions: Journey North: Mystery Class
When viewed from a North Pole orientation:
Earth orbits the sun in a CCW direction.
Earth also rotates or spins in a CCW direction so the sun appears to rotate the earth in a CW fashion since it is relatively standing still compared to the earths rotation on its axis.
The moon is a trickier beast and appears to rotate around the earth in a CW direction which is due entirely to the earths rotation again. The moon is actually orbiting the earth in a CCW direction.

The next question: "What would you get if you took the globe and drew the diurnal circle for every day of the year? ... for every year, ever?" smells like a trick question to me since it includes every year, ever.
If I were to assume the last 1000 or 10,000 years the suns path across the sky would form a doughnut or taurus shape. There is some conjecture that the earth took on its current axis and rotation from collisions with an asteroid in the not so measurable past.
You guys are too fast for me.
Summer in Bahston.
__________________
"The cure for anything is salt water~ sweat, tears, or the sea." ~Isak Denesen

Everybody has one:

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #18  
Old 02-04-2010
erps's Avatar
the pointy end is the bow
 
Join Date: Aug 2006
Location: La Conner, Washington
Posts: 6,216
Thanks: 2
Thanked 26 Times in 26 Posts
Rep Power: 10
erps will become famous soon enough erps will become famous soon enough
Quote:
Originally Posted by wind_magic View Post
Here is a two point question ...

If you draw a line through the center of the earth to the center of the Sun, when will someone in Boston be nearest to that line ?
I'm thinking twice a year, at local area noon on the longest day in summer and around midnight on the shortest day of the year, but I'm shooting from the hip. (longest and shortest day for the northern hemisphere)
__________________
Ray
S.V. Nikko
1983 Fraser 41
La Conner, WA


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Boating for over 25 years, some of them successfully.
Reply With Quote Quick reply to this message Share with Facebook
  #19  
Old 02-04-2010
Senior Member
 
Join Date: Jun 2006
Posts: 5,004
Thanks: 5
Thanked 18 Times in 18 Posts
Rep Power: 11
wind_magic has a spectacular aura about wind_magic has a spectacular aura about wind_magic has a spectacular aura about
Quote:
Originally Posted by erps View Post
I'm thinking twice a year, at local area noon on the longest day in summer and around midnight on the shortest day of the year, but I'm shooting from the hip. (longest and shortest day for the northern hemisphere)
That's correct, and it was a trick question because most people would just guess noon on Midsummer's day and would not think of midnight on Midwinter's night. Very good.

That's why you can see so many southern stars at Midwinter's.
__________________
What are you pretending not to know ?

Please support my
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #20  
Old 02-05-2010
Senior Member
 
Join Date: Jun 2006
Posts: 5,004
Thanks: 5
Thanked 18 Times in 18 Posts
Rep Power: 11
wind_magic has a spectacular aura about wind_magic has a spectacular aura about wind_magic has a spectacular aura about
During the winter in the northern hemisphere, what is the name of the small tight cluster of stars that moves along north and west of Orion ?
__________________
What are you pretending not to know ?

Please support my
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Basic Celestial Concepts Jim Sexton Seamanship Articles 0 06-28-2004 09:00 PM
Working With the Stars—Celestial Navigation Jim Sexton Seamanship Articles 0 05-06-2003 09:00 PM
Working With the Stars—Celestial Navigation Jim Sexton Her Sailnet Articles 0 05-06-2003 09:00 PM
Navigation Basics Jim Sexton Learning to Sail Articles 0 01-04-2002 08:00 PM
Navigation Basics Jim Sexton Her Sailnet Articles 0 01-04-2002 08:00 PM


All times are GMT -4. The time now is 01:02 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.