A new fund is offering a prize of £10 million to anyone who comes up with a solution to one of six shortlisted problems that face humanity. The selected challenge is being chosen by the public.

The challenge is called the Longitude Prize, named after the groundbreaking contest that lasted over 200 years to find a scientific solution to the problem of maritime navigation.

What was the first Longitude Prize?

For hundreds of years sailors had no way of accurately knowing where they were and thousands of lives were lost as a result. The British scientific establishment offered a prize to anyone who could come up with a way of determining longitude within a certain degree of accuracy.

The prize was eventually won by a common Yorkshireman, John Harrison, who devoted his life to solving the problem, facing huge opposition from the establishment of the time. The result was a new type of clock, and the way we developed it was by thinking in a completely novel way.

The story of the Longitude Prize is fascinating, and elegantly told in a book that I read recently by Dava Sobel. It caught the imagination of the world at the time, fostering thousands of entries, most of which were bogus.

The new Longitude Prize aims to emulate the success of the first. But initially there is the need to choose the nature of the challenge. The committee put together and tasked with this by the charity Nesta came up with a shortlist. Last night viewers of BBC television's Horizon science program could see a presentation of these. From then on the public was invited to vote.

What are the six shortlisted problems?

1. Water: an increasingly scarce resource. How can we ensure that the planet's population has enough access to fresh water? 97% of the surface water of the planet is saline and undrinkable. The challenge is to come up with a cheap, low energy and effective means of making it potable.

2. Food: how do we ensure that every member of the growing world population has sufficient, nutritious food that is supplied sustainably? Will it come from a new type of genetically modified organism? From new fertilisers?

3. Fossil free flight: aircraft emissions contribute hugely to global warming. Could a new type of energy storage or energy source be developed to transport goods and people through the air with no harm to the environment?

4. Paralysis: in the UK alone one person becomes paralysed every eight hours. Would new types of mechanical bodysuits or biochips enable them to move again?
5. Dementia: by 2050 it estimated that 13 5 million people around the world will suffer from this terrible affliction and require much personal care. Would it be possible to develop automated systems that could support them and enable them to remain at home for longer?

6. Antibiotics: immunity to these life-saving drugs which we take the granted is spreading. Common infections could once more become untreatable. This final challenge is to create a cost-effective, easy-to-use test for bacterial infections to allow the administering of the right antibiotics at the right time.

To have to choose between these six compelling and seemingly intractable problems presents a dilemma requiring the wisdom of Solomon. I have reached my own conclusion, and voted, and I will share with you not my conclusion but the questions I asked myself to arrive at it - but I'm sure you can think of your own:

• Which of these challenges are more fundamental than others and so deserve priority, in that unless they are solved, the others become more academic?
• Do any of them already appear to be relatively near to a technical solution?
• Which, if solved, would have immense spin-offs in other areas?
• Which are more likely to be solved at a very high level by well-financed teams, and which might be more accessible to less well-resourced individuals?

You can visit the website and find out more yourself, and you can vote up until 7.10 p.m. on 25 June.