Can someone who knows Astronomy help me? Please!?

[patrick t. cakes]

I have a short essay to write on this topic, and I have no clue where to begin.
I'm taking an online (1 credit) course in astronomy and its over my head.

I'm a history major damit! Can any on walk me through this?

(a) Suppose that the tilt of the earth were double what it actually is. Which of the following would be affected: The dates of the equinoxes; the declination of the sun at the equinoxes; the declination of the Sun at the solstices. Explain!

(b) What observations could an observer at the Earth's equator make to determine the declination of the Sun?

[wtmusic]

1. Google and personal industry are your friends. nt

[patrick t. cakes]

2. cliche DU posts don't help

[MineralMan]

4. I believe the poster was telling you to do your own work.

For someone to answer your questions adequately, that person would have to write the equivalent of your paper.

[patrick t. cakes]

5. i just asked for help, not for someone to do the work

big difference

[Whoa_Nelly]

3. Maybe these links will help?

http://wiki.answers.com/Q/What_would_happen_to_Earth's_climate_if_the_tilt_of_its_axis_became_less_than_23.5

http://docs.google.com/viewer?a=v&q=cache:6v57GnYrskQJ:www.math.nus.edu.sg/aslaksen/gem-projects/hm/hw1-0506-1-32.pdf+observations+at+the+Earth's+equator+determine+the+declination+of+the+Sun&hl=en&gl=us&pid=bl&srcid=ADGEEShDnx_NTN-ueYpv5D8wca0kWjgy3X-ofMlA6www8FutmgjGTCoK3TmP3p9fsI8UZUVDSTNub4IU9PIExBijiKK89JLQTEFKMpGOb9kocbHABaK7PJWBx4SX7aLHfTRZBnkjrzzW&sig=AHIEtbRtjCqyKuc_syG45VY93TH70rcSVQ

[patrick t. cakes]

7. thanks alot! I'll look at these.

every little bit helps.

[TupperHappy]

6. This might help for the first question.

Suppose that the tilt of the earth were double what it actually is. Which of the following would be affected: The dates of the equinoxes; the declination of the sun at the equinoxes; the declination of the Sun at the solstices. Explain!

Dates of the equinoxes would not be affected. Changing the tilt won't affect which day the equinoxes and solstices occur.

Declination as the equinoxes will not be affected. The equinoxes occur when the equator is aligned with the plane of the orbit of the earth.

Declination at the solstices would be affected. They would be double what they are now. Solstices occur when the earth is titled at the greatest extent in the orbit.

[patrick t. cakes]

10. Thanks for the help. This leads me in a better direction

I appreciate it.

[bananas]

8. Apples and oranges

Pretend the orange is the sun, and the apple is the earth.
Tilt the apple a little, then tilt it a lot, see what happens as it moves around the orange.

[patrick t. cakes]

9. our time zones would change for one thing

[AlecBGreen]

17. time zones should be unaffected

they are a product of longitude. 360 degrees divided by 24 hours in a day = 15 degrees longitude per hour.

the length of day and night at any given longitude WOULD be affected

[patrick t. cakes]

18. Ahhh. Yes I see

And the poles would have shorter days and nights?

[AlecBGreen]

21. I think the daylength would not be affected

I will discuss the north pole but the south would be affected the same, inversely.

In a single year the geographic north pole experiences a single, long continuous day, a single long night, and an extended sunrise & sunset in between. This would remain unaffected by a doubling of the tilt. However I think with a doubled tilt, the sun & moon and all the objects along the ecliptic (planets, constellations of the zodiac) would rise much higher, up to 47 degrees above the horizon. This is strictly based on quick visualization exercise and not backed up with my astronomy program (starry night).

[Silent3]

29. Average length of day would not be affected...

...but the degree of seasonal change in hours of daylight would be increased, and more of the earth would seasonally experience winter days of total darkness and summer days when the sun never sets.

If the tilt of the axis were reduced to zero, the length of the day would be nearly constant all year long, at all latitudes (with some slight variation in daylight duration over the course of the year remaining due to the eccentricity of the Earth's orbit).

[Uben]

11. Sounds like swivelling drink holders would ne needed!

I'd invest in the house levelling business!













/sarcasm

[patrick t. cakes]

12. and velcro

:D

[Uben]

13. Damn, I knew I was missing something!

Good catch! And wheel chocks!

[patrick t. cakes]

14. I might put this stuff in my essay

see where it gets me.

[Uben]

15. Probably on a stool in a corner with a pointed cap!

See if my initials are still on the stool, will ya?

[patrick t. cakes]

16. I know that cap well. Cheers

[bettyellen]

19. the declination of the sun on solstice is related to our current tilt, so more tilt

would mean greater declination

[Orsino]

20. a) The latitudes of the tropics would double...

...the latitudes of the Arctic and Antarctic Circles would be twice as far from the poles, and the solstice declinations of the sun would double as well. Declination at either equinox is by definition zero (sun directly over the equator), and so would not change. I guess that last is a sort of trick question.

b) This seems a remarkably dumb phrasing. Declination is the angle of the sun above the horizon, and the question probably is best served by using that measurement taken at noon. What observations could you make of the declination? Well, one could observe the fucking declination, for a start.

[pokerfan]

22. and the tropics (Cancer & Capricorn) would extend further from the equator

The OP could probably get some bonus points by taking a map of the Earth and redrawing the new lines.

This seems a remarkably dumb phrasing. Declination is the angle of the sun above the horizon, and the question probably is best served by using that measurement taken at noon.

I believe it's the appropriate word. Altitude is the angle of the sun above the horizon. Declination is the angle (north/south) of the celestial equator. To determine the declination, you would need to start by measuring the altitude of the sun at its highest point, i.e. noon.

[Orsino]

23. That kind of misses my point.

The phrasing of question b amounts to a tautology. One observes the declination by observing the declination.

[pokerfan]

25. No it doesn't

Declination is the angle of the sun above the horizon

No, it really doesn't.

The phrasing of question b amounts to a tautology.

No, it really isn't.

http://en.wikipedia.org/wiki/Declination
http://en.wikipedia.org/wiki/Altitude_%28astronomy%29#Altitude

[Orsino]

27. What would you say is the answer to question b, then? n/t

[Orsino]

24. The funny part: tropics overlapping the Arctic and Antarctic Circles.

The tropics would be at 47 degrees north and south, with the Arctic and Antarctic Circles at 43 degrees each.

[petronius]

26. Declination in this context is the latitude where the sun passes directly overhead

at solar noon, or the angle above the celestial equator. 'Altitude' is more common for the angle above the horizon, I think...

[Silent3]

28. Declination is the relative to the celestial equator, not the horizon.

Maximum declination, attained at the solstices, is equal to the tilt of the axis of the earth. Declination reaches 0 at the equinoxes, where the ecliptic and the celestial equator intersect.