Off to London.
Strange quirk of the train journey down.
Obviously when you're on the train and belting along at a ton, you have no sensation of actually moving.
Again obviously, the train tilts (at quite an angle) as it goes around curves and bends in the track.
Just south of Rugby, the track curves and the train tilts as it passes some bodies of water.
Due to the train's tilt (and not feeling like you're moving) the bodies of water don't look horizontal, but rather curve up towards the sky.
Like that film Inception