# Geometry of an Egg

1. Aug 26, 2014

### Ontophile

Is the bottom half of an egg a hemisphere?

2. Aug 26, 2014

Do eggs have a top half and a bottom half? If so which is which? What sort of eggs are you referring to?

3. Aug 26, 2014

### Ontophile

I'm sorry. I thought it was rather intuitive which half of an egg is the top and which is the bottom. Whenever an egg is drawn or otherwise depicted, it is almost always oriented the same way, and so I'm having trouble believing that there is any real confusion here. Besides, my question immediately suggests which half I'm talking about, since only one half is even possibly a candidate for being a hemisphere. Furthermore, most English speakers are referring to a chicken egg whenever the type of egg that they're talking about isn't specified. The rigor you seem to require is superfluous. Your confusion isn't real, it's forced or performed, just for the sake of being difficult. No matter; someone reasonable will come along soon and answer my question.

4. Aug 26, 2014

### jbriggs444

No. It is not. It has bumps.

5. Aug 26, 2014

### AlephZero

Really? Look at the pictures on http://en.wikipedia.org/wiki/Bird_egg.

The natural orientation for an egg is in stable equilibrium on its side, not standing on one whichever end you think is the bottom.

But let's not restart the Big-Endian and Little-Endian disputes in http://en.wikipedia.org/wiki/Lilliput_and_Blefuscu.

6. Aug 26, 2014

It was correct of me to ask for clarification. When I read your question I imagined that you were doing some sort of project and different types of eggs popped into my mind, birds eggs, insect eggs, human eggs, fish eggs etc.

7. Aug 27, 2014

### tleave2000

The following link has a pretty nice summary. It suggests the answer is YES.

http://www.mi.sanu.ac.rs/vismath/rojas/index.html

However according to this picture from wiki, neither end of an ovoid is usually a full hemisphere. I don't know if these geometric versions of an egg shape really correspond to a birds egg.

http://en.wikipedia.org/wiki/File:Owal_by_Zureks.svg

Also did you know that if you spin a hard boiled egg fairly fast on its side on a flat surface, it will sit up on its fat end? I guess that's to minimise its angular momentum, but it never ceases to amaze me.