Tag: Google

CS4FN Advent 2023 – Day 24: Santa’s Sleigh – track its progress through the skies

We are nearly coming to the end of our CS4FN Christmas Computing Advent Calendar with one more post to come tomorrow. If you’ve missed any you can catch up by scrolling to the end and click on the Christmas Tree in the panel for the complete list so far.

Today’s advent calendar window shows Father Christmas’ sleigh with a sack full of presents ready for delivery. Today’s theme is about the many different online ways that you can now ‘track’ his movements around the world. You may be able to see (cloud permitting) his sleigh ‘in person’ as it flies over. In reality it’s International Space Station (ISS) whizzing past – but other interpretations are available 🙂

Visit this page https://www.astroviewer.net/iss/en/observation.php and type in your city to see when and where you might spot the ISS. On Christmas Day 2025 the ISS will pass over the South of England from around 6.17am to 6.22am, reaching its highest point at around 6.19am, so you’ll have to get up early!

You can track Father Christmas as he dashes through the sky, delivering presents. Image drawn and digitised by Jo Brodie.

1. NORAD Santa tracker

https://www.noradsanta.org/en/ for games
https://www.noradsanta.org/en/map (you can also track him on NORAD’s apps too)

Vintage photo image by Alexa from Pixabay

In 1955, so the story goes, an American department store published a newspaper advert with a phone number for children to call so that they could speak to Father Christmas. Unfortunately a misprint meant that the wrong number was given and instead people found they were talking to the US military’s Air Defense Command (now called North America Air Defense Command or NORAD).

Realising the mistake, but also spotting a great public relations opportunity, the team capitalised on this and began to make an annual event of it.

NORAD uses radar and geosynchronous* satellites to monitor Father Christmas. The satellites are able to detect infrared (heat) radiation and apparently Rudolph’s red nose gives quite a strong signal. This data is then shared with everyone via their website, though they don’t know in advance what route he’ll take.

If you’re visiting the website hover over the different bits of the picture as there are linked activities and extra information too.

*geo = Earth, synchronous = matching / following (like when you sync devices), the satellite follows the Earth’s orbit and is always above the same spot, so effectively (from the Earth’s point of view) the satellite appears not to move (it is moving but it follows the Earth’s rotation).

2. FlightRadar24 Santa tracker

https://www.flightradar24.com/R3DN053/335a9682

Father Christmas in flight image by Maria Guerrero from Pixabay

FlightRadar24 is a great website for telling you the answer to “what was that aircraft that’s just flown by?” It tracks the flight of aircraft all over the globe in real time, using a signal transmitted by the aircraft’s beacon (called a transponder) which announces where it is. Father Christmas’ sleigh has its own transponder too which is transmitting its location to receivers around the world.

An aircraft, or Santa’s sleigh, gets information about where it is from a GPS satellite (very similar to using a maps app on a smartphone and it telling you where you are and whether you should go left or right) and it then transmits this location info, along with other data, through its transponder.

There are thousands of receivers here on Earth, many of them in people’s homes and gardens (you can even apply to host a receiver antenna, or build your own with a Raspberry Pi) and whenever Santa’s sleigh passes over one of these ‘ground stations’ its signal is picked up and collected by FlightRadar24. The receivers are in different places so they are receiving the same signal at slightly different times and this information can be used to work out (by triangulation) how fast the sleigh is moving and in what direction.

Apparently Santa has been “able to extend the reach of his transponder by using the reindeer antlers as additional antenna” so the tracking should be fairly accurate.

3. Google Santa tracker

https://santatracker.google.com/

Google’s Santa Tracker has lots of games to play while you wait for Santa and his sleigh to take flight, including Code Boogie where you can try and program some dancing elves. You move little blocks (a bit like Scratch) to copy the dance moves and, if you get it right, it will show you the underlying JavaScript code.

Dave Holmes, a developer who works at Google and who works on the Santa Tracker project says “Santa Tracker launched in 2004, and has been an important project at Google ever since. While there’s a small core team dedicated to Santa, up to 20 or so Googlers volunteer to help make it happen every year, and it’s become a true community effort. It’s also a way for our developers to try things and see what Google products can do … I like to say that everything I’ve learned at Google, I learned from Santa.”

Google has also added some ‘Easter eggs‘ to its search page – try typing in Christmas or where is Santa to https://www.google.com/. You can also colour in some images online at their Christmas-themed Art Coloring Book, from Google’s Arts and Culture.

Further reading

The Googlers who help track Santa each Christmas (22 December 2021) Google Blog

4. Early internet Santa-themed humour

Image by Jo Brodie for CS4FN.

Back in the early 1990s email was very new but right from the start people used it to send each other amusing things. One of them was a rather literal consideration of the physics of a sleigh that is laden with gifts and a traditionally overweight Santa, led by a team of reindeer moving at unlikely speeds (after all Father Christmas has to get around the entire world to deliver presents, in just one day). The author (unknown) began –

“No known species of reindeer can fly. BUT there are 300,000 species of living organisms yet to be classified, and while most of these are insects and germs, this does not COMPLETELY rule out flying reindeer which only Santa has ever seen.”

But then goes on to point out that such a gift-delivery system would be working far beyond normal levels and would probably end in disaster, suggesting that –

“In short, they will burst into flame almost instantaneously, exposing the reindeer behind them, and create deafening sonic booms in their wake. The entire reindeer team will be vaporized within 4.26 thousandths of a second. Santa, meanwhile, will be subjected to centrifugal forces 17,500.06 times greater than gravity. A 250-pound Santa (which seems ludicrously slim) would be pinned to the back of his sleigh by 4,315,015 pounds of force.”

Fortunately Father Christmas has his own magic, meaning that we don’t need to worry too much about him disobeying the laws of physics. But he and his reindeer really deserve those cookies, milk and carrots!

You can read the full post here: The Physics of Santa and His Reindeer Snopes.com

The creation of this post was funded by UKRI, through grant EP/K040251/2 held by Professor Ursula Martin, and forms part of a broader project on the development and impact of computing.

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EPSRC supports this blog through research grant EP/W033615/1.

Marissa Mayer: Lemons Linking 41 Shades of Blue – A/B Testing

A bunch of lemons turned blue
Lemons image by Richard John from Pixabay – colour changed to blue

Google, one of the most powerful companies in the world, is famous for being founded by Larry Page and Sergey Brin, but a key person, the 20th person employed, was engineer, programmer and believer in detail, Marissa Mayer. Her attention to detail made a gigantic difference to Google’s success. She was involved in most of their successful products, from the search engine to Gmail to Adwords and if she wasn’t convinced about a new feature or change, then it didn’t happen. When a designer suggested a new shade of blue for the links of ads, for example, she had to be persuaded. But how could she be sure she did make the right decisions? She used a centuries old idea from medicine, first used to help cure scurvy in sailors, and applied it to software design: the randomized controlled trial.

Randomized controlled trials revolutionized medicine. They could revolutionize many other aspects of our lives too, from education to prison reform, if they were used more. Computer Scientists realized that, and more trials are now used on software than medicines. It’s part of the Big Data revolution and is the way to avoid relying on hunches, instead relying on scientific method to find out what the right answer really is.

But what if …?

The problem with the way we do most things is “what-if”. We make decisions, but never know what would have happened if we took the other choice. If things go well we pat ourselves on the back and tell ourselves we are right. But things might have gone even better had we only made the other decision. We will never know. However good or bad it seems, there is no way of knowing actually if our decision was the right one, if all we do is make it. We then delude ourselves, and so keep doing bad things, over and over. That’s why illness was treated by getting leeches to suck blood for centuries!

Controlled trials overcome this. The big idea boils down to making sure you do both alternatives! Not only do you make the change, you also leave things alone too! That sounds impossible, but it’s simple. Split your population (patients, users, prisoners, students, …) into two groups at random. Apply the change to one group, but leave the other group alone. Then at the end of a suitable period, long enough so you can see any difference, compare the results. You see not only the result of making the change, but also what would have happened if you didn’t. Only then, with hard data about the consequences of both possibilities, do you take the decision.

The first medical trial like this involved sailors who were ill with scurvy – a disease that killed more wartime sailors than enemy action in the 18th century. Scottish Navy surgeon James Lind waited until his ship had been at sea long enough for many sailors to get scurvy. He then split a dozen into 6 pairs: one group had oranges and lemons on top of the normal food, and the others were given different alternatives like cider or vinegar instead. Within a week, the two eating fruit were virtually recovered. More to the point, there was no difference in any of the others apart from an improvement in the pair given cider. Eating fruit was clearly the right decision to cure scurvy. All new drugs are now tested in trials like this to find out if they really do make patients better or not. Because you know what happens to those not given the new treatment, you know any improvement wouldn’t have happened any way.

So how do computer scientists use this sort of trial? The way Marissa Mayer’s team did it is a classic example. One of Google’s designers was suggesting they use a slightly different shade of blue for the links on ads in Google’s mail program. Rather than take his word that it was an improvement, they ran a trial. They created a version of the program that had multiple colours possible for the links, each a different shade of blue. They then split all the users of the program into groups and gave each a different shade of blue for their links, tracking the results. One particular shade led to more clicks on the ads than any other. That was the shade Marissa chose (and it wasn’t the shade the designer had suggested!)

Software trials like this are called A/B Testing. They have become the mainstay of hi-tech companies wanting an edge. It actually leads to a new way of developing software. Rather than get a perfect product at the outset you get something basic that works well enough quickly. Then you set to work running trials on lots of small details, making what are called ‘marginal gains’, as soon as possible. One small detail may not make a big difference, but when you pile them up, each known to be a definite improvement because of the trial, then very quickly your software improves. Trials can give better results than intelligent design!

Does it make a difference? Well the one decision about that shade of blue of Marissa’s team supposedly made Google $200 million a year, as a result of more people clicking on ads. Google now run tens of thousand of trails like this each year. Add the benefits of lots and lots of small improvements and you get one of the most powerful companies on the planet.

Little Gains in Life

The idea of developing software through marginal gains is actually based on the process used by nature: evolution by natural selection. Each species of animal seems perfectly designed for its environment, not because they were designed, but because only the fittest individuals survive to have babies. Any small improvement in a baby that gives it a better ability to survive means the genes responsible for that improvement are passed on. Over many generations the marginal gains add up to give creatures perfectly adapted to their environment.

Paul Curzon, Queen Mary University of London

Related Magazine …

EPSRC supports this blog through research grant EP/W033615/1.