So, you have been mulling over the answer to this one all weekend. What is the Mpemba effect and how will it make me richer?

First, the effect:

Named after Erasto Mpemba, a Tanzanian student who posted the question in 1968 to a visiting professor to his school (Professor Denis Osborne).

‘Why Sir, does hot water freeze faster than cold water? If you take two similar containers with equal volumes of water, heat one so that it is boiling and leave the other one at room temperature but put both of them in the freezer at the same time the hotter one always freezes first. But why?’

The professor was speechless and couldn’t answer the question. He went back to his lab to try the experiment (Erasto had been carrying out the same experiment for five years) and found that it was true. The hotter liquid froze the fastest.

The professor couldn’t answer the question, but published his findings, hoping that somebody would be able to. But he is still waiting – nobody, it seems can explain this phenomena.

How will it make me richer? Well, the Royal Society of Chemistry are inviting people to explain the effect. If you can convince the rOyal Society of Chemistry they will award you £1000. So put your thinking caps on and get in touch!

(For more info click here)