h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Right, I've got me egg in me bottle, now I want to get it back out again... So, the bottle's upside down, the egg is in the neck, I'm blowing and I'm blowing and I all i'm doing is lifting the egg... So I'm sucking instead, and now I'm sucking eggs and I'm at risk of choking myself... So, right, shall I just remove the bottle from my gob and smash it or what?

Blow hard into the bottle to increase the amount of air and therefore raise the air pressure. As the egg falls into the neck of the bottle, the pressure of the air behind it should force it out.

surely though if you are blowing into the same neck as the egg is trying to come out, you're going to reach a point where you're blowing directly against the egg, therefore pushing it back into the bottle?

Tilt the bottle slightly to the side so you're blowing past the egg. When you stop blowing, straighten the bottle up so the egg falls back into the neck.

Honestly, it does work. It just needs practice maybe

I just dont understand how, at the point that the egg seals the neck you can blow past it to get the necessary higher pressure of air behind it to push it through the neck...

OK, one day you can show me... Until then I'm going to be extremely cynical of this one...

However, I'm being somewhat remiss, as I did enjoy the article all bar the egg removal bit was great. And funny

Well, you could always try it

I'm got my egg-sucking class till easter, I'll sign up for the bottle-blowing next summer

You need to blow hard across the cross sectional plane of the opening.

It's actually wrong to say that by blowing, the pressure inside the bottle increases. It's actually in inverse.

According to Bernoulli's principle, an increase in velocity leads to a decrese in pressure. By blowing across the opening, the increased air speed lowers the air pressure, forcing the egg out due to the pressure difference. The pressure inside the bottle doesn't actually change.

It's the same reason those yellow lines exist on train platforms. Air gets pulled along at the speed of the train when it passes a platform, lowering its pressure. This pressure difference between the train and the platform results in a pulling force towards the train if someone is stood past the line. This is why we should never take those lines for granted!