Given Earth rotates, can I travel by going straight up and waiting?

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If Earth turns at (say) 1000 kilometres per hour at London’s latitude, why not, when you want to travel, just go straight up and wait for your destination to rotate around until it is beneath you?

Herman D’Hondt
Sydney, Australia

Let’s start by considering the following question: why don’t you face a 1000 km/h wind when standing still in London? The original question overlooks the fact that Earth’s atmosphere rotates along with the planet. If it didn’t, you would indeed have to face such winds. At the equator, the wind would be even stronger, a supersonic 1600 km/h. So if you hover above London, the air will carry you along at 1000 km/h and you will go nowhere.

You could, of course, go straight up until you are out of the atmosphere – say 100 km up – and hover there. In that case, assuming your destination is at the same latitude as you, your suggestion would work.

To hover at 100 km, large amounts of propellants are needed. First you need fuel to get that high. Richard Branson and Jeff Bezos can tell you how much fuel their “spaceships” use to get there and fall back. Then you would need even more fuel to hover there while waiting for your destination, and more fuel again to accomplish a soft landing there.

Branson’s SpaceShipTwo flights cost upwards of $450,000 per seat. While Bezos hasn’t revealed the cost of a flight on Blue Origin, the deposit alone is $150,000.

Believe me: airlines charge much less than that for a flight!

Rachael Padman
Newmarket, Suffolk, UK

The question appears to assume that it is easy to hover above a rotating planet. However, Earth drags its atmosphere along with it, so the would-be traveller is faced with a 1000 km/h sidewind, and the only way we know to counter that is in a commercial airliner.

The proposed travel path is more or less exactly what happens if you fly west along a line of constant latitude, since airliners can almost (but not quite) keep pace with Earth at 51° north.

Of course, this means that to get to, say, Vancouver from London, you need to spend a lot of time waiting while the North Atlantic and Canada rotate beneath you. That will take around 8 hours. You will observe that it is much the same solar time there as when you left the UK. To get to Kyiv, it might be easier to simply fly east.

If the assumption is that you somehow wait out the journey above the atmosphere, then it is hard to see how to do this. There is no stable orbit where a satellite is stationary directly above London, so maintaining its position would require continuous thrust – and, as such, the burning of fuel.

If you are prepared to allow the “hover position” to move in latitude, maybe you could sit at one of the Earth-Sun Lagrange points, L1 or L2, but those are 1.5 million km from Earth and the travel time to and from there, not to mention the energetic requirements, would more than outweigh any potential advantages.

Hillary Shaw
Newport, Shropshire, UK

For the same reason that on a train doing 72 km/h, or 20 metres per second, with the restaurant car 40 metres behind you, you can’t just jump up for 2 seconds and get there. You have the same momentum as the train does.

Imagine the chaos if you could, hurtling back down the train at 72 km/h. Similarly, imagine the chaos on Earth if airborne things didn’t have a (similar) angular momentum to the rotating Earth below. Birds, if there were any, would shoot east at 1000 km/h as soon as they took off. But the air and sea’s surge eastwards would mean there could be no life, bird or otherwise. We’d have 1000 km/h hurricanes and 1000 km/h tidal waves sweeping across land (at European latitudes).

Air masses move east when heading away from the equator, into regions of slower rotation, and west if they are moving towards the equator. This is the Coriolis effect, which has a major influence on our weather. But it would be very inefficient for humans to travel this way. To get from London to Warsaw by the Coriolis effect, you’d need to fly north to the Arctic and then south again, getting your timing right so you land in Poland.

It’s probably easier just to go via Germany.

Bryn Glover
Kirkby Malzeard, Yorkshire, UK

This idea for easier travel sounds good, but for one small glitch.

If the Earth is travelling at 1000 km/h, then so is the questioner, standing on it. So in order to “go straight up”, they will need to slow their velocity to a relative zero.

The best way to do this is to get in a jet plane and power themselves backwards – which, by coincidence, is exactly how people do it already.

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