Just to get something out of the way first.

If there is any one aspect of being a parent we have been avidly preparing for for years, it's how to explain the concept of Santa Claus to our child. So that you won't be left out, here are some popular children's questions about the Claus and the answers.

~How can Santa visit everywhere in the world in one night?

Santa's sleigh contains an Improbability Drive. When in use, it is simultaneously everywhere in the entire universe at once due to a quirk of quantum physics theory that states that there is a very small chance of a subatomic particle being very far from the nucleus of an atom. All you have to do is create a field of infinite improbability and off you go. Fun fact: an unexpected mis-ignition of the Improbability Drive and its reality-warping effects turned the sleigh's engine into eight reindeer, and Santa liked them so much he never bothered to attempt to turn them back. They remain a living part of Santa's sleigh.

~How can Santa carry so many presents in one tiny sleigh?

Santa is a longtime ally of the Doctor, and has access to Time Lord technology including mastery of hammerspace. The sleigh is actually huge on the inside, and contains not only storage space for all the world's presents, but also living quarters for up to 30 passengers, stables for the reindeer, a 3-D printing lab for last-minute gifts due to sudden changes to naughty/nice status, a den with a fireplace, and a small home theatre.

~How can Santa fit down the chimney and what does he do when there isn't one?

Santa has access to Floo Powder, so he's not so much coming down your chimney as using it for a magical portal. Because of the nature of Floo Powder, Santa can also emerge from heating vents, gas valves, and since there's a connection between the teleportational ether and ionized gas, from plasma TVs. He tries not to do that one too much as some people find it a little creepy.

~How does Santa know if I've been good?

When a child turns five years old, parents are given access to a special Web site (Previously it was a mail-in form) where they can enter information regarding your behavior since last Christmas. We do it like we do taxes every year. Don't worry, children are graded on a curve and if for some reason a parent doesn't fill out the questionnaire, Santa errs on the side of presents.

Speaking of taxes, the Web site allows parents to opt out of Santa delivery so that Santa can spend more time, money and energy on people who can't afford or otherwise won't receive presents. That's why sometimes you catch your parents filling stockings. They're participating in the opt-out program to help the less fortunate. Parents get a tax credit for doing this, a provision set up by President Richard Nixon in gratitude after Santa Claus single-handedly stopped an invasion by S.P.I.D.E.R. in the late 1960s.

~How does Santa make all the presents?

Santa's elves are actually the last surviving members of the Middle Earth elves, and they bring both magic and craftsmanship to toy making in addition to Santa's own skills and genius. Many of the world's best gadgets, gizmos and playthings have actually been developed by Santa and the elves, and they are licensed through various companies to fund Christmas and promote innovation in the realm of whimsy. Santa Claus, Inc. is the largest patent-holder in the world.

Why does Santa live at the North Pole?

The North Pole is not under any particular country's territorial claims, and thus serves as the perfect neutral ground for Santa to conduct his operations free from war, economic shifts and other political factors. This holds true for his base on the Moon as well, though that site is still in the development phase as a back-up base should global warming render the Arctic too unstable.

~Why don't I always get the present I ask for?

Mrs. Claus is an accomplished scryer, which she learned directly from studies with Dr. John Dee. Her job at the North Pole is checking a small distance into the future to see whether or not the present you ask for causes any kind of trouble, and sends her recommendation on to her husband. This is why most kids don't get the pony or flamethrower that they ask for.

~Is Santa real?

Santa, like all gods, demigods, myths and extra-normal beings, operates on the Gaiman principle. They are defined by the perception of humans to their existence. In short, he is as real as the belief in him is real. At various times in history he has been either a fully corporeal entity capable of magic and wonder in our reality, at others he has merely been a small voice inside our heads urging us to generosity and love in the cold of winter. He has been a saint, a shaman, a god, a cultural icon and a corporate mascot. He is more or less all of these things at once.

You'll never find an element in the periodic table called "hope," or "love," or "charity." Yet those things are as real as hydrogen despite not being measured by any way known to science, and so is Santa Claus.