## Telling eggs apart

Last evening after I took out boiled eggs from my electric kettle, I tested a solution to a problem I once got from Anoop, an ex-colleague and a good friend.

How can we tell raw eggs and hard-boiled eggs apart?

One solution I knew from childhood experiments involves spinning the given egg, then momentarily stopping it with hand while it is spinning and then releasing it immediately. If the egg starts spinning again, it is a raw egg. If it doesn't, it is a hard-boiled one. This can be explained with Newton's first law of motion. One might even see it as a demonstration of Newton's third law of motion.

Anoop, a friend of mine, told me about another solution which I believe is simpler and uses the same principle as the one behind the solution I mentioned above. Can you guess this simpler solution?

Do you know other ways of finding out whether an egg is boiled or not without breaking it?

#### v sayikiran said:

Boiled egg will float in water whereas raw egg will sink.

#### Susam Pal said:

Sayi,

That's not true. Boiled eggs sink in water as well.

#### Prashanth M said:

Just shake the eggs!!

#### Susam Pal said:

Prashanth,

Could you please clarify your comment? How are we supposed to know if an egg is boiled or raw after shaking it?

#### shaswat said:

HI susam

I agree with Prashanth.If you shake a raw egg, a sound of yolk hitting the shell would come which is not in the case of boiled egg.

Shaswat

#### Susam Pal said:

Shaswat,

I didn't find this to be true. There was no sound of yolk hitting the shell when I shook a raw egg. In fact, I couldn't find any noticeable difference between a raw egg and a hard-boiled egg while shaking them.