I'm not sure if this happens to you but I always hard (or soft) boil a bunch of eggs for the next few days, I'll put them back in the carton, making a mental note that the hard boiled eggs are on the right side. A day later I come back to the fridge and I can't remember if it was the right or the left side of the carton that was hard boiled. So this is what I found works.
Step 1: Materials
Materials required are as follows:
I know, lots of materials.
Notice, they don’t have to be hard boiled or unboiled, you'll figure it out as you test them. (in case you've eaten all your hard boiled eggs)
Step 2: The Test
For this, you only need to test one egg at a time, though to show you the difference I took two eggs (one boiled and one fresh).
Spin the egg and observe how it spins. Watch video for a better understanding the following explanation:
First egg: As you see, the egg didn't really want to spin, it wobbled and was very slow to spin, this means that there is a lot of liquid inside the egg (It's not boiled). The liquid is breaking up the Centrifugal force. The harder you try to spin this egg, the less it wants to spin.
Second egg: As you can see with this egg, it spun really well, to the point that it was very hard to keep it in shot. This means there is much less (if any) liquid left in the egg (It's boiled)!
A soft boiled egg will have similar properties to the hard boiled egg.
Hopefully this saves you from, what do they say, having egg on your face!