Comments on: The pressure of living on a spinning planet

By: Phil

Phil — Tue, 10 Jan 2012 18:51:37 +0000

Everything on and in a plane moves or does not move as one entity. If you are moving faster or slower than I am. The distance between us must change. Since the distance between us does not change your claim of different speeds has zero evidence.

By: Igor Kornilov

Igor Kornilov — Thu, 29 Sep 2011 16:05:36 +0000

#59 You may imagine earth as a disk, being the upper surface the north hemisphere and the other face the southern hemisphere. Then you can see why storms rotate oposite in each hemisphere.

By: Srikar

Srikar — Thu, 29 Sep 2011 15:40:21 +0000

I still can’t visualise the Cariolis in my mind. With the picture in my mind, I still tend to think storms rotate counter-clockwise even in the Southern Hemisphere

By: Igor Kornilov

Igor Kornilov — Thu, 29 Sep 2011 15:21:35 +0000

#57 The main reason to operate landings and take-offs in spinning objects as close to the equator as possible is that less energy per useful kg of load is needed. This implies more useful load for the same rocket or less rocket for the same load. Baikonur is a very bad place and the reason why russian rockets are more powerful than french ones. Guyana is so closed to the equator that a firework rocket can go to the orbit. Also you can see how moon landings tend to be in the equator.

PS : I misread Phil about Coriolis. He was saying the same that I always say but shorter and more to the point. In fact he said something that many people does not accept that is “the angular speed of the object increases to maintain its linear speed”.

By: Nigel Depledge

Nigel Depledge — Thu, 29 Sep 2011 12:41:52 +0000

@ Joseph G (56) -
Good point. Maybe that reason is more compelling than the extra velocity you get, but I stil think that the extra velocity is more significant than the difference in gravitational force.

By: Joseph G

Joseph G — Wed, 28 Sep 2011 18:21:19 +0000

@49 Nigel Depledge: Well, yes, but the difference is less than 1%, whereas the main advantage of an equatorial launch site is that your rocket is already moving at 1700 km/h relative to the centre of the Earth even before it leaves the launch pad.

I always thought that one main concern was a greater choice of orbital inclinations. A launch site on the equator, for instance, can launch directly into an orbit of any inclination. A launch site at, say, 46 degrees latitude, on the other hand, can’t launch directly into an orbit that’s inclined by less then 46 degrees to the equator. You can change your orbit once you’re up there, of course, but it takes fuel.
Incidentally, the Baikonur Cosmodrome is at 46 degrees latitude, which is the stated reason for the ISS’s orbital inclination of 51 degrees. Cape Canaveral is at about 28.5 degrees, but a greater orbital inclination is necessary so that the Soyuz missions can be flown.

By: Nigel Depledge

Nigel Depledge — Wed, 28 Sep 2011 14:11:43 +0000

On the plus side, you can console yourselves with the knowledge that England is basking in sunshine this week.

By: Chris M

Chris M — Wed, 28 Sep 2011 13:25:45 +0000

A comma is a nice way to describe it. I live under that thing, which looks more like a rain turd coiling itself right on top of my home state, delivering bleak, miserable rain for nearly five days now.

By: john

john — Wed, 28 Sep 2011 13:22:44 +0000

@Liath You can get a quick estimate of the height from conservation of energy, potential+kinetic =constant. So the transported being would drop to zero velocity at mgh = (mgR + mv^2/2), or R+v^2/(2g) [R=the Earth's radius] They’d reach a height of v^2/(2g). with v=1700kph and g~12740kphph I get approximately 11.3 km into the air.
This would be slightly reduced by air resistance (the reduction from the non-spherical shape of the Earth is less than .05km). It might be an interesting exercise to see how hot something (or someone) would get from heating due to friction.
Wait, g is one earth diameter per hour squared? Why did I not know this?

By: Lee Bishop

Lee Bishop — Wed, 28 Sep 2011 12:36:53 +0000

I have been struggling to understanding the coriolis effect for so long. Thank you!!