Two Islands
 

There are two mythical islands out in the Pacific ocean, on the same meridian. The north island is 30 degrees north of the equator, and the south island is 30 degrees south of the equator. Both islands are the exact same size and both are 20 feet above sea level. Both are unique because the wind never blows and no clouds are ever seen from either island.

Our RC club wants to build a flying field on one of these islands and we want to maximize the daylight flying time available over the next 100 years.

Which island should we choose?

RE: Two Islands
 

Ok, since I'm bored anyway, I'll bite. And I'm not googling anything, just answering off the cuff.;)

If I'm not mistaken, which I probably am, the tilt of the Earth's axis would cause slighty more daylight time on the Northern island. Of course, in the next 100 years, the Earth could flop on a new axis again, so who knows?

RE: Two Islands
 

I don't think that Google has the answer, but you should be able to find information on Google that may lead to a answer.

Possible answers:

North Island
South Island
Both exactly the same.

RE: Two Islands
 

I googled a NASA page and came up with the Southern Hemisphere having a slight advantage right now.
Our orbit is elliptical and the Earth is tilted with the Southern hemisphere nearest to the Sun at the time when we are nearest to the Sun. There are other meterologic reasons why the South might get less cloud cover, too.
The Earth has a wobble on its' axis and the tilt might be either advancing or retarding which could be why HP qualified his question with a 100 year limit.

Now I await the "trick" answer........:D

RE: Two Islands
 

I too await the correct answere. He took the meteroligical differences out with his hypothetical question. So I guess it comes down to which hemisphere gets longer daylight hours for more days of the year. I can't find anything that says otherwise, so I'm sticking with the Northern hemisphere getting slightly more daylight because of the tilt.;)

RE: Two Islands
 

You both get full credit for the attempt. Take the tilt of the axis, and throw in the elliptical orbit and you are almost there. Knowing when the Perihelion occurs is the missing information. Currently the Earth reaches Perihelion (closest part of the Earths orbit around the sun) on January 3. Kepler's 2nd law says that the swept area in a given time is always equal regardless of the distance from the body that is being orbited.

So in the winter time in the northern hemisphere, the Earth is closest to the sun and going the fastest in it's orbit, thus it spends less time shining on the south island.

There is a bit of variation in all the orbital mechanics over time as surmised, but on a very long time scale - Tens of thousands of years. The tilt of the Earth wobbles, and precession changes where it points. Measurement of this may mean the Pyramids in Egypt are much older than a few thousand years old, since they were aligned to the stars when constructed.

Even the Earth's elliptical orbit precesses due to the gravity of the large gas giants in the solar system.

For a really interesting summary of these and other things see the following:

http://en.wikipedia.org/wiki/Milankovitch_cycles

RE: Two Islands
 

Well, Highplains, your island ain't in Kansas. You built your field, but some idiot blabbed about it and someone figured out there was an island in the Pacific without a golf course on it. Not long after that the RCers were run off. NOW, does it matter?

Grin,

Bedford

RE: Two Islands
 

100 year lease[8D]

While I knew that Kepler's 2nd law would favor the North Island, I was really surprised at the extent of the difference in terms of time (4.66 days/year)

RE: Two Islands
 

I was surprised to see that much difference too. As close to the equator as your islands are the Sun will rise pretty high year round.

I should have remembered the part about the acceleration and deceleration during orbit. I've seen a large working model somewhere that included that feature.

RE: Two Islands
 

Ok, I've got one:

What is the difference in the straight line and relativistic (curved space) measurement of the distance from the Earth to the Sun.

IE. Earth to sun (straight line)-Earth to sun (relativistic) =?

Calculators and google not allowed!!! If someone gets it I'll tell them.

Hint: Mass causes space to bend (according to relativity).

RE: Two Islands
 

You should build the field on the island you live on or you'll waste all your daylight travelling to the other island and back.

Dave

RE: Two Islands
 

Interesting post, HighPlains!

I have learned something; I would have responded both exactly the same.

Did you consider solar eclipses for that century?

RE: Two Islands
 

It sure is easy to tell that it's the middle of winter.

Don't you folks have an airplane to build or something? :D

RE: Two Islands
 

Look for an island on the Equator and be done with it.

Charles

RE: Two Islands
 

This is such an easy question to answer. Use the Southern Island because it's the closest to the greatest country in the world, namely Australia. Too easy.

Wedge
Wedgetails rule the skies

RE: Two Islands
 

.
An old friend said that when he was stationed on Adak in the Aleutians, they'd build models all winter long, waiting for summer.
But... they had a big party that day and no one flew.

RE: Two Islands
 

There is no difference. Curved space looks straight from within the system.

RE: Two Islands
 

Didn't ask what does the distance appear to be, I asked what it was.

RE: Two Islands
 

Which ever island is chosen it needs to have a conveyor runway so we can practice takeoffs.. haha

RE: Two Islands
 

When the weather keeps one indoors, do something!

RE: Two Islands
 

I think you need another SFG on that float plane.

RE: Two Islands
 

More is better, I always say. :)
.
Actually, adding depth to the floats to get the nose of the floats out of the water.
And despite the name, Labrador Retrievers don't! :)

RE: Two Islands
 

It's not the weather that keeps me inside. It's the dirty big mozzies! I put chicken wire across the windows and it keeps them from getting inside, but I have now run out of chicken wire. There is no way I'm going out side to the car to get more wire netting.
Wedge

According to the US Naval Observatory, you have about 40 additional hours of daylight on the north island.

THREAD NECROPHILIA!

OK, it was fun back then but time to get back to discussing model airplanes again..... closed.