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Why does Earth's tilt produce summers and winters?



 
 
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  #1  
Old November 2nd 06, 08:06 AM posted to alt.sci.physics,sci.astro,sci.physics,soc.culture.indian
AlexZ
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Posts: 1
Default Why does Earth's tilt produce summers and winters?

One explanation I have never understood is that we have Summers and
Winters because Earth is tilted.

On a hot Summer day, I cannot cool myself by "tilting" my body in any
direction. My body still gets the heat that falls on it, no matter the
tilt. Otherwise people would have discovered this trick long ago and we
wouldn't need fans or air-conditioning.

So...if you understand why tilt at an angle works for Earth, please do
explain in simple English.
  #2  
Old November 2nd 06, 09:42 AM posted to alt.sci.physics,sci.astro,sci.physics,soc.culture.indian
Sorcerer[_4_]
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Posts: 326
Default Why does Earth's tilt produce summers and winters?


"AlexZ" wrote in message
...
| One explanation I have never understood is that we have Summers and
| Winters because Earth is tilted.
|
| On a hot Summer day, I cannot cool myself by "tilting" my body in any
| direction. My body still gets the heat that falls on it, no matter the
| tilt. Otherwise people would have discovered this trick long ago and we
| wouldn't need fans or air-conditioning.
|
| So...if you understand why tilt at an angle works for Earth, please do
| explain in simple English.

Actually, you can... but not in India where the sun is overhead.
Stand upright at the North Pole (on floating ice) and sun's rays
hit every part of your body that faces the sun.
Lay flat on your back at the North Pole, feet toward the sun,
and you are in the shadow of your feet. You can do that twice
a day in India, once at dawn and once at dusk when shadows are
long. They are always long at the poles, and because the Earth
is tilted the sun never rises on Dec 22nd at the North Pole, and
never sets at the South Pole. It scoots around the horizon.
The real "new year" starts with the sun just peeping above the
horizon on 23rd Dec and so early Northern man had a party
to celebrate the sun being reborn, bringing green things into
their homes and eating the food they'd been carefully hoarding.
It still goes on today, but the Catholic Church got the calendar
mixed up and the celebrations are a tad late. It's even more
screwed up in China, where there was little contact with the West.
This was an early calendar to measure time:
http://www.sacredsites.com/europe/en...enge_aeril.jpg
The ancients were not stupid. It takes organization, management, skill,
mathematics and a good reason to haul heavy rocks 100 miles and arrange
them in a circle. Note the length of shadows around 10 am to noon in
Britain.
I can tell that is the time the picture was taken from the shadows,
on Jun 21st the sun rises over the heel stone, which is the big rock next
to the road at the top of the picture.
Androcles.



  #3  
Old November 2nd 06, 12:33 PM posted to alt.sci.physics,sci.astro,sci.physics,soc.culture.indian
Ben Newsam[_1_]
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Posts: 70
Default Why does Earth's tilt produce summers and winters?

On Thu, 02 Nov 2006 07:06:24 GMT, AlexZ wrote:

One explanation I have never understood is that we have Summers and
Winters because Earth is tilted.

On a hot Summer day, I cannot cool myself by "tilting" my body in any
direction. My body still gets the heat that falls on it, no matter the
tilt. Otherwise people would have discovered this trick long ago and we
wouldn't need fans or air-conditioning.

So...if you understand why tilt at an angle works for Earth, please do
explain in simple English.


One half of the globe is always pointed towards the sun, so you are
right that tilting it cannot change the amount of "heat falling on
it". Now imagine the globe spinning so that every part of the globe
goes in and out of the light to produce day and night. Next, tilt (in
your mind, or use an orange and a lamp if you want) the top of the
globe away from the light. You will notice that the "top", ie the
point around which the globe is spinning, never gets any light at all,
whereas the "bottom" is in the light all the time. In Earth terms,
that means the North Pole is in total darkness (winter) and the South
Pole has summer. Between those extremes, the "season" varies from
summer to winter depending on where "you" are on the globe at the
time. If you then (without altering the tilt) move the globe (or
orange) to the other side of the lamp, you will see that it is the
North Pole that is in the light (summer) and the South Pole has
winter. The real Earth does the same in travelling round the sun once
per year, and so the seasons change.
  #4  
Old November 2nd 06, 01:13 PM posted to alt.sci.physics,sci.astro,sci.physics,soc.culture.indian
Richard Tobin
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Posts: 230
Default Why does Earth's tilt produce summers and winters?

In article , AlexZ Newsgroup wrote:

On a hot Summer day, I cannot cool myself by "tilting" my body in any
direction. My body still gets the heat that falls on it, no matter the
tilt.


It's late spring in Australia.

-- Richard
--
"Consideration shall be given to the need for as many as 32 characters
in some alphabets" - X3.4, 1963.
  #5  
Old November 2nd 06, 01:56 PM posted to alt.sci.physics,sci.astro,sci.physics
Sam Wormley
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Posts: 836
Default Why does Earth's tilt produce summers and winters?

AlexZ wrote:
One explanation I have never understood is that we have Summers and
Winters because Earth is tilted.

On a hot Summer day, I cannot cool myself by "tilting" my body in any
direction. My body still gets the heat that falls on it, no matter the
tilt. Otherwise people would have discovered this trick long ago and we
wouldn't need fans or air-conditioning.

So...if you understand why tilt at an angle works for Earth, please do
explain in simple English.



Try using solar panels instead of your body!


  #6  
Old November 2nd 06, 02:07 PM posted to alt.sci.physics,sci.astro,sci.physics,soc.culture.indian
[email protected]
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Posts: 1
Default Why does Earth's tilt produce summers and winters?


Ben Newsam wrote:
On Thu, 02 Nov 2006 07:06:24 GMT, AlexZ wrote:


One half of the globe is always pointed towards the sun, so you are
right that tilting it cannot change the amount of "heat falling on
it". Now imagine the globe spinning so that every part of the globe
goes in and out of the light to produce day and night. Next, tilt (in
your mind, or use an orange and a lamp if you want) the top of the
globe away from the light. You will notice that the "top", ie the
point around which the globe is spinning, never gets any light at all,
whereas the "bottom" is in the light all the time. In Earth terms,
that means the North Pole is in total darkness (winter) and the South
Pole has summer. Between those extremes, the "season" varies from
summer to winter depending on where "you" are on the globe at the
time. If you then (without altering the tilt) move the globe (or
orange) to the other side of the lamp, you will see that it is the
North Pole that is in the light (summer) and the South Pole has
winter. The real Earth does the same in travelling round the sun once
per year, and so the seasons change.


I need a clarification as well. Is the moon's gravity a major facotr in
the earth's tilt? In the absence of the moon will the tilt be
different? Can some one clarify? Thanks

  #7  
Old November 2nd 06, 02:07 PM posted to alt.sci.physics,sci.astro,sci.physics,soc.culture.indian
N:dlzc D:aol T:com \(dlzc\)
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Posts: 155
Default Why does Earth's tilt produce summers and winters?

Dear Alexz:

"AlexZ" wrote in message
...
One explanation I have never understood is that we
have Summers and Winters because Earth is tilted.

On a hot Summer day, I cannot cool myself by
"tilting" my body in any direction.


You can get yourself cool*er*, by keeping the shadow of your head
where your feet are. If you were to lay out flat, the Sun would
make you warmer still.

My body still gets the heat that falls on it, no
matter the tilt. Otherwise people would have
discovered this trick long ago and we wouldn't
need fans or air-conditioning.


You have two effects:
1) The area doesn't change, but the incident light does change
with angle. More tilt, and any particular area gets less
delivered power.

Your "body" analogy ignores that if one small area is tilted
away, another is tilted towards.

2) During a full day, any particular latitude (how far N / S
from the equator you are) will have a different length of day or
length of night, depending on how the Earth's axis is oriented
with respect to the Sun.

http://www.physicalgeography.net/fundamentals/6i.html
http://www.uwm.edu/~kahl/CoVis/Seasons/

David A. Smith


  #8  
Old November 2nd 06, 02:11 PM posted to alt.sci.physics,sci.astro,sci.physics,soc.culture.indian
N:dlzc D:aol T:com \(dlzc\)
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Posts: 155
Default Why does Earth's tilt produce summers and winters?

Dear tripurantaka:

wrote in message
oups.com...
....
I need a clarification as well. Is the moon's gravity a
major facotr in the earth's tilt? In the absence of the
moon will the tilt be different?


http://www.astronomycafe.net/qadir/q106.html

David A. Smith


  #9  
Old November 2nd 06, 02:27 PM posted to alt.sci.physics,sci.astro,sci.physics
Sam Wormley
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Posts: 836
Default Why does Earth's tilt produce summers and winters?

N:dlzc D:aol T:com (dlzc) wrote:
Dear tripurantaka:

wrote in message
oups.com...
...
I need a clarification as well. Is the moon's gravity a
major facotr in the earth's tilt? In the absence of the
moon will the tilt be different?


http://www.astronomycafe.net/qadir/q106.html

David A. Smith



http://www.astronomycafe.net/qadir/q106.html is pretty out of data
as is says...

"Without the Moon, there might not be any seasons, or the seasons
might be very different ones. It is believed that the Moon is an
interloper from a more distant spot in the solar system which was
captured by the Earth billions of years ago. This capture would
have caused the rotation axis of the Earth to be seriously shifted
to where it is now. The Earth may have started off with a rotation
axis pointing almost perpendicular to the plane of the solar
system, rather than canted at 23.5 degrees as it is now. Without
this tilt, the rays from the Sun would always strike the Earth's
surface at a fixed angle every day of the year. At the Earth's
equator, the Sun's rays would always be perpendicular to the ground
all year long. At a latitude of 45 degrees, they would strike the
ground at 45 degrees every day, and at the North and South Poles,
the Sun would never make it above the horizon".

The scientific evidence strongly suggests that the moon was formed
as the result of a major collision with the young earth. The impact
certainly also contributed to the degree of tilt in the earth's axis
of rotation.




  #10  
Old November 2nd 06, 03:05 PM posted to alt.sci.physics,sci.astro,sci.physics
dlzc
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Posts: 1,426
Default Why does Earth's tilt produce summers and winters?

Dear Sam Wormley:

Sam Wormley wrote:
....
The scientific evidence strongly suggests that the
moon was formed as the result of a major collision
with the young earth. The impact certainly also
contributed to the degree of tilt in the earth's axis
of rotation.


Thanks, Sam. I guess I've got to a little better quality control on my
links.

David A. Smith

 




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