Four things to do before you die

1 ― Mix the world's weirdest cocktail
Now you stir it, now you can't

It has to be one of the most mind-bending experiences you can legally enjoy in your kitchen: manufacture your own dilatant liquid ― one whose viscosity increases as soon as you try to stir it, or do pretty much anything else with it.

The easiest way to make it is a simple mix of about 300 grams of cornflour (cornstarch) and 250 millilitres of water. The mixture ripples like water, but instantly solidifies if you dip your finger or a spoon into it. Go slowly and you can put your finger in, but just try pulling it out in a hurry. You can roll the stuff into a ball in your hands, but stop rolling and it just runs through your fingers. Hit it with a hammer and it can even shatter.

Coolest of all, broken-off pieces liquefy and pool together, just like the shape-shifting T-1000 robot in the film Terminator 2. Well, almost. But then the T-1000 couldn't thicken sauces for you.

2 ― Visit Tuvalu
Enjoy it before it sinks

As sea levels rise, this clutch of South Pacific islands is poised to become the first nation to disappear beneath the waves ― possibly as early as 2050. Currently located halfway between Brisbane and Honolulu, soon Tuvalu may exist only in cyberspace as the prized internet domain ".tv".

Tuvalu's smallest islands are disappearing fast. Already you've missed the chance to visit the coconut groves of Te Pukasavilivili. Tuvalu's paradise world of coral lagoons, swaying palms and international sex phone lines is doomed because not one speck of land is more than 4 metres above sea level and spring tides regularly take 3 metres of that. Almost every tropical cyclone could bring down the curtain.

So why not board the weekly flight from Fiji to the capital Funafuti while you can? As you travel from one of Tuvalu's four guest houses in its single taxi to its lone bar, speculate on who will own the rights to the .tv domain and the tuna-fishing rights in its vast territorial waters, after the last of its 11,000 Polynesian inhabitants has left. Go now, before it dies.

3 ― Win a fortune the mathematical way
Who wants to be a millionaire?

If you're time-rich and cash-poor, then have a go at winning one of the many maths prizes up for grabs. If you're a hotshot mathematician, set your sights on one of seven $1 million prizes offered by the Clay Mathematics Institute in Cambridge, Massachusetts.

To win, you have to prove one of seven conjectures that have given mathematicians sleepless nights for decades. They include the Yang-Mills mass-gap hypothesis, which asserts that if a particle has mass, there is a lower limit to what the mass actually is.

Or you could try hunting for giant prime numbers. Prime numbers, such as 11 or 13, are divisible only by themselves and 1. If you find the first prime with 10 million, 100 million or a billion digits, a US campaign group called the Electronic Frontier Foundation will award you a prize of between $100,000 and $250,000. Your home computer could do all the work. Aproject at www.mersenne.org offers free software that sifts sets of numbers for primes, although if you hit the jackpot, you'd have to share the bounty with the organisers. Failing that, there are maths prizes starting from $10 at www.mathpuzzle.com.

Or maybe you should just get out more.

4 ― Find happiness
What does it look like?

Why do some people manage to skip through life shrugging off disappointments and setbacks like discarded clothing, while others struggle to survive the daily grind?

The secret partly lies in our genes. These account for around half of the variation in happiness between different people. What's more, good-looking people tend to be more contented, if not downright happy. Granted, there's not a lot you can do about your genes. But don't despair, there's plenty else you can do.

Being sociable, helping other people and having lots of friends all help. And getting married boosts happiness for a couple of years at least.

Then there's money. It certainly won't do any harm, but beware: wealth is a short-term fillip. We quickly adapt our expectations to new-found riches and end up always wanting that little bit more. Envy on the other hand is a sure-fire route to misery.

One last tip: consider moving to Denmark. It's the only industrialised nation where people are happier than they were 30 years ago. Why? The Danes are keeping the answer very close to their chest.

Selected extracts from '100 Things to Do Before You Die (plus a few to do afterwards)', from NewScientist and Profile Books.