Know It All

He's got an answer for everything, week 1

1) Which country has the most powerful armed forces?
The USA has the most powerful military. Of the .47 trillion (about £1 trillion) annual global military expenditure, a little under half (1bn) is spent by the USA. By comparison, the EU as a whole spends 2bn (France and the UK spend about bn each) and China spends £59bn. That's not to say that in a free-for-all, the USA would have it all their own way: the USA has 1.38m troops, compared to China's standing army of 2.25m. Russia's 28,381 tanks would make short work of America's 7,821 due to sheer weight of numbers. America dominates the sea and sky though. Of course, numbers don't decide who wins wars - Vietnam being the obvious example and the Millennium Challenge 2002 (MC02) being the most interesting. MC02 was a wargame pitching the USA (Blue) against an unnamed Middle Eastern country (Red). Lt Gen Paul Van Riper led the Red team, using motorcycle couriers instead of electronic communication (to avoid detection) and small boats (to avoid detection, with some also being used for suicide attacks). This proved hugely effective. The Americans threw a hissy fit, insisted they got their 'sunken' ships back, and that they started again, changing the rules of engagement. Van Riper resigned because the new version was essentially scripted to ensure his defeat. Recent history shows they don't learn from their wargames, but hopefully people will eventually learn from the 1983 Matthew Broderick film WarGames: "A strange game. The only winning move is not to play. How about a nice game of chess?"


2) How do nuclear bombs work? Why are they so potent? Strategically, what is the best country to occupy should there be a nuclear war?
An atom bomb has neutrons fired at plutonium or uranium isotopes. This causes the heavy nuclei to break apart into lighter nuclei. This sets other neutrons firing at other heavy nuclei, which sets even more neutrons firing into even more heavy nuclei. This massive chain reaction converts the matter into a huge release of energy. That's nuclear fission in a nutshell.
The more powerful hydrogen bombs use a combination of fission and fusion. A fission bomb begins the process, compressing the light nuclei of deuterium or tritium. Deuterium and tritium are hydrogen isotopes - hydrogen atoms with extra neutrons in each nuclei. This compression (fusion) releases huge amounts of energy. It also fires off additional neutrons, which set off fission reactions with the uranium bomb casing. The combination of fission and fusion means that hydrogen bombs release more energy than an atom bomb of similar weight.
Fission and fusion release about a million times more energy than comparable chemical reactions, hence their immense potency. If it's time to head for the hills, your best bet is the southen hemisphere, because the nuclear powers are the USA, Russia, UK, France, China, India, Pakistan, North Korea and Israel. Even if you survive the unimaginable destruction of a nuclear war, you'll have the radioactive fallout and a nuclear winter to deal with. Australia would seem like an obvious choice, but it's likely to be hit hardest by a nuclear winter. A small Pacific island gives you the best chance of survival - especially if you've watched lots of Ray Mears' TV programmes, or seen an episode or two of Lost. Head for the southernmost of Vanuatu's islands, coincidentally named Anatom.


3) Is there a chance we'll ever be able to smoke in English pubs again? Are there any loopholes in the law etc?
War, nuclear bombs and lung cancer? You're a cheery lot this week. No, the smoking ban is here to stay. It exists to protect members of the public and bar staff. You can still smoke in nursing homes, prisons, designated smoking rooms in hotels and oil rigs, phone boxes that are open to the elements, and bus shelters that are less than 50% covered. They're no substitute for a pub though; if you ever find a pint of beer in a phone box you really shouldn't drink it. The closest you'll get to replicating a pub is buying a few bottles and inviting your smoking mates round to your house. If you make a regular occurrence of it, you could all get into home-brewing too – you will have to grow a beard and smoke a pipe though. I’d stick to pubs if I were you.


4) Why do glow-in-the-dark objects glow in the dark?
Phosphorescence is what people typically mean when they talk about glowing in the dark. GS phosphor is most often used to achieve this; it gives off a greeny-yellow glow. It's zinc sulphide mixed with 5 parts per million of a copper activator. As with all phosphors, it stores natural light, then slowly releases it. If you kept a glow-in-the-dark item in pitch darkness for a long time, it would eventually stop glowing. Simply shining a light on it would 'recharge' it. Despite its name, the chemical element phosphorous isn't a phosphor. Phosphorous can be chemiluminescent, rather than phosphorescent. This means it emits light as part of a chemical reaction, rather than by storing light and releasing it. Glowsticks are chemiluminescent: when phenyl oxalate and a fluorescent dye are mixed with hydrogen peroxide, they glow. Until the mid-1920s, watch dials were painted with a mix of glue, water and radium powder. The radium was radioluminescent - it glowed because it was radioactive. The chemists in the factories were safely behind lead screens, wore masks and used tongs. Many of the 4,000 people employed to paint the watches got sick, or even died of radiation poisoning, because they were encouraged to lick the brushes to keep the points small. For fun, they also painted their teeth and nails with radium. When they all began to get sick, the factory owners tried to claim the workers had syphilis. Five workers eventually sued, and settled for ,000 each. Thankfully, modern glow-in-the-dark items don't use radium.

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