Earth rotation and long flights

1. Dec 22, 2007

pixel01

I have this question related to the rotation of the earth:

Lets say I am in London and I have to fly to New Zealand (non-stop). I can fly to the east and also to the west to get to the destination. If the distances of the two directions are equal, so which route should I choose?

2. Dec 22, 2007

Hootenanny

Staff Emeritus
Well, the earth rotates counterclockwise looking down from the north pole, which is equivalent to an east to west rotation. It would be quickest to fly against the rotation and therefore you should fly eastwards.

3. Dec 22, 2007

Staff: Mentor

Well the reason it is quickest isn't exactly because of the rotation, it's the winds. The jet stream goes west to east at 100-200mph, which makes a big difference flying across the US. For London to New Zeland, the winds are probably kinda complex since you are crossing the equator.

4. Dec 22, 2007

pixel01

So it is only the winds that may change the plane's speed, isn't it

5. Dec 22, 2007

ghost02

Also the altitude and what that wind has in it. [eg. Rain, snow, fog etc.]

6. Dec 22, 2007

LURCH

Pretty much. The atmosphere is rotating with the Earth, so while you're in the atmosphere, wind direction has all the influence over your trip, because rotation of the ground and rotation o fthe air nearly match. If you were going via sub-orbital hop, Earth's rotation would have a lot more importance, though still less than you might think (because the ground from which you launched would be travelling at the rotational speed for that lattitude).

7. Dec 22, 2007

ghost02

What would happen if we went above the atmosphere? Sorry, I just have to ask!

8. Dec 23, 2007

LURCH

If your destination is at the same latitude, not much. You leave the ground travelling eastward at the same speed as the ground froom whch you launched (rotational velocity). Your target, being at the same latitude, has the same rotational velocity. You turn East or West, you get there in the same amount of time. But, if you're at 45N, and going further north, then you leave the ground already travelling East faster than your target, so by turning East you get there faster than if you turned West. OTOH, if you go South, your target is travelling East faster than you are, so you turn West to get there more quickly.

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