Discussion in 'Community Discussion' started by Gloor, Apr 19, 2007.

1. ### Gloor macrumors 6502a

Joined:
Apr 19, 2007
#1
Hi,

I remember reading here about different posts describing Spring (starts/ends) etc. and I would like to ask you one thing. I recently had this argument with my gf. I believe that The Equator is not the closest to the Sun because of the tilt ot the Earth (26.5degree i believe) so for me its technically impossible that the Equator would be the closest one to the Sun as the tilt changes (not really, but the Earth is staying in that position so you kinda get different tilt in winter than in summer) and therefore this must change the closest position to the Sun accordingly. I believe its simple math but I might be wrong. Can somebody explain to me if I am right or if it is my gf? Also detail information would be very nice. Thanks

Joined:
Dec 27, 2006
3. ### yellow Moderator emeritus

Joined:
Oct 21, 2003
Location:
Portland, OR
#3
I thought the equator just got the most consistant sunlight, and had nothing to do with being closest to the sun.
The seasons are based on the tilt of the earth.
And isn't Mt. Everest the closest point to the sun?

EDIT: Ah, Wikipedia to the resuce.

4. ### BigPrince macrumors 68020

Joined:
Dec 27, 2006
#4
Not sure if it helps though.

"The equator is one of the five main circles of latitude that are based on the relationship between the Earth's axis of rotation and the plane of the Earth's orbit around the sun. It is the only line of latitude which is also a great circle. The imaginary circle obtained when the Earth's equator is projected onto the heavens is called the celestial equator.

The Sun, in its seasonal movement through the sky, passes directly over the equator twice each year, on the March and September equinoxes. At the equator, the rays of the sun are perpendicular to the surface of the earth on these dates."

is semi related.

5. ### MongoTheGeek macrumors 68040

Joined:
Sep 13, 2003
Location:
Its not so much where you are as when you are.
#5
The point on the earth closest to the sun is on the equator during the vernal and autumnal equinoxes. Other wise its somewhere between in the tropics. The northern tropics in june, july, august, september; southern in november, december, january, february.

6. ### JNB macrumors 604

Joined:
Oct 7, 2004
Location:
In a Hell predominately of my own making
#6
And at the June and December solstices, the sun is directly overhead the Tropics of Cancer and Capricorn before beginning it's relative movement in the other direction.

7. ### obeygiant macrumors 68040

Joined:
Jan 14, 2002
Location:
totally cool
#7
Also semi related.

NASA

8. ### Queso macrumors G4

Joined:
Mar 4, 2006
#8
It's not just the shorter days that make it colder in Winter though. Because where you are is at a shallower angle in relation to the Sun, the sunlight has to go through more of the atmosphere before hitting the Earth. So by the time it reaches the ground it's lost more of it's energy to surrounding air particles.

Difficult to explain without a picture. I'll see whether I can find one.

EDIT: Can't find one, so quickly knocked this one up (sorry it's a bit crap). The outer circle is the top of the atmosphere and the inner one represents the Earth's surface. The pole through the circles is the axis of the Earth at 23˚, and the line that crosses that represents a line of latitude, basically the path your location takes as the Earth spins.
The lines coming from the side represent beams of light from the Sun. When the light is coming from the left, it's midday in the Summer, and you should be able to see that the distance the upper and lower beams have to travel to cross the atmosphere gap between the two circles is less than the distance they have to travel when the beams are coming from the right, representing midday in Winter. You will probably have worked out by now that the effect gets more pronounced as you go further north and is pretty negligible down in the Tropics.

Yeah, told you it was crap, but I hope you get the idea

9. ### Gloor thread starter macrumors 6502a

Joined:
Apr 19, 2007
#9
So I was right then? The closest point to the Sun changes throughout the year and the Equator is the closest in autumn and spring only, right?

10. ### Queso macrumors G4

Joined:
Mar 4, 2006
#10
Right. On the day of each equinox to be precise

11. ### the vj macrumors 6502a

Joined:
Nov 23, 2006
#11
I though the Ecuador is at a constant distant from the sun and the poles are the ones that got closer or farther.

I live in Venezuela, pretty close, and we have about the same weather and same seasons.

What I always have in the back of my mind regarding that is how sublime is the change of weather and temperature because of that. It makes me think that if earth were just 5 kilometers or so close to the sun everything would be warmer here on earth.

12. ### JNB macrumors 604

Joined:
Oct 7, 2004
Location:
In a Hell predominately of my own making
#12
The seasonal changes between the Tropics are not as distinct as those outside of them. There's less variation as the Earth precesses around its axis at the Equator as compared to the poles.