The Hard Boiled Egg Sprinkler Mystery

By Anupum Pant


Cracking an egg to check if it is boiled or not is not a very intelligent way. While many know that spinning an egg can be used to determine whether an egg is a boiled one or not, I’m amazed by the sheer number of people who aren’t still aware of this trick.

Just in case you are one of those who don’t know this, it works like this –  try spinning an egg on a smooth surface. If it spins well and stands up vertically, it is a boiled egg. If it doesn’t spin properly, you can say that it isn’t cooked….as simple as that.

Tip: There’s a way to check if your eggs have gone bad without risking opening it up to take in the nasty stench. [Here]

Boiled Egg Sprinkler Experiment

Now that I’m sure you know about the boiled egg spinning trick I can tell you about this simple experiment you can do at home. Besides dealing with an angry mom, it carries no other risks.

Here’s what you do – Get some milk and pour it on the kitchen counter. Now, boil an egg if you don’t have a boiled one already. Make sure it is hard-boiled by doing the spinning test. Next, spin it on the milk puddle you created on the counter. Nasty mess ensues…

Yes, there sure is a mess afterwards. But something amazing happens when the egg spins on the milk puddle. When it spins, the egg first stands up and then the milk starts rising on the surface of the egg till it reaches the equator and then the milk gets sprinkled at the equator in a very beautiful manner. It’s like a skirt of milk. Different sprinkling effects can be obtained with different spinning speeds.

Until now, no one knew why this happened. The rotating egg would suck up milk like magic and create a fountain of milk. The exact physics part of it wasn’t known until some researchers at Brigham Young University decided to figure out why this happens. I, on the other hand didn’t even know this sprinkling thing could be done. Nice to know.

Turns out, there’s nothing peculiar about milk and eggs that creates this effect. The same thing can be done with an 8-ball or any other ball for that matter. On the other side, it works with other liquids too. For instance, if you use a liquid with a higher viscosity (glycerine and water mix), the rotating ball could create not just sprinkles, but whole sheets of liquid getting flicked off at the equator. Some times if the fluid is viscous enough and the ball is spinning fast enough, sheets spanning several feet can be seen getting flicked off the equator of the spinning balls! It’s like a motor.

Here is an amazing hi-speed video of this happening in the laboratory and the elegant physics behind has been explained too. Watch it here:

After having watched the explanation, I can say one thing for sure: There’d be no sprinkling if this was done on Superfluid Helium because superfluid helium would have no viscosity and it wouldn’t rotate with the ball!

The Natural Segmented Sleep

By Anupum Pant


The light bulb changed everything. Before it came, when the only practical sources of artificial light were candles & lamps, people did not often use candles to stay awake at night. These sources of artificial light costed a lot more per lumen hour. They were not always used. They were used only when artificial light was totally necessary. Normally, as the sun went down, people preferred sleeping. As bulbs came, they transformed the way we slept. Or, so argued the historian A. Roger Ekirch.

In his detailed published anthropological work – At Day’s Close: Night in Times Past – he mentions that the eight-hour single block of sleep is a recent change in our sleeping schedule. For many many years more than we’ve slept for eight hours in the night, our ancestors had practised a very different kind of sleep schedule which became the natural way of sleeping for humans. It was a segmented sleep.

The schedule went like this…

When the sun went down, there was more or less no artificial source of light. Due to this, our ancestors could do nothing useful. Bored with inactivity, they slept. Then somewhere in the mid-night, they woke up. For an hour or so, they remained awake and went back to sleep again till the morning.

The time for which these people remained awake, was probably the most relaxing and most calm time of their lives. Due to increased levels of pituitary hormone prolactin, people felt a lot at peace during this hour. During this time, people liked involving themselves in some kind of activity. Some preferred reading, others wrote. Some smoked, others visited their friends. And so on… The point is, people found themselves replenished during this time. It was apparently blissful.

This pattern of sleep became a natural way for us humans. Turns out, the eight-hour block of sleep is not the way we always used to sleep!

This sleep pattern has been observed to come back to today’s humans when they were completely deprived of any artificial light. This can be seen in the famous experiments of a psychiatrist, Thomas Wehr.


That waking hour of bliss – a fact of life before the industrial revolution came – was probably a period which I feel, needs to come back to cure the modern world’s rising anxiety, stress, depression, alcoholism and drug abuse.

Some scientists believe that if you give your bodies a chance, they’d go back to a segmented sleep pattern. This is also bolstered by Wehr’s experiments. While others prescribe you sleeping pills if you tell them you wake up at night for an hour or so.

Just for the record, I’m writing this at 2:30 AM. I just woke up, and I’m off to sleep again.

[Read more] [Mastering Biphasic sleep] A detailed blogpost on the experience by Jayson Feltner…