Why do you feel hollow lower stomach while getting down in a ghat road or down the bridge by a four-wheler?

Question

When we travel by car or a bus down the ghat road or a slope bridge, we have a feeling of stomach being pulled down or a hollow effect for a moment? There must be a science behind it. Please try to answer my question or clarify this point!

Answer 1

It's causes by vertical acceleration or deceleration when you go through a dip or over a hill. You effectively weigh more or less, respectively, for the moment. The most noticeable sensation is the downward or upward shifting of your innards, which feels funny and can cause nausea. Astronauts must habituate themselves to this feeling on the "vomit comet" - an airplane used for momentary free fall.

Answer 2

Your stomach is only loosely connected to other stuff inside. Things tend to want to keep going in a straight line (Newton's First Law), so when your body starts to change direction, your stomach will briefly keep going in a straight line until the internal connections pull it along with the rest of you.