Learn more about Russian war crimes in Ukraine.

What are web push notifications?

You probably know what mobile push notifications are. On your phone, there’s a notification center, which shows things like “Remember to practice French today!” (sent by Duolingo to your Duolingo app instance), or “Could you review the Goat & Boot pub?” (sent Google to your Google Maps app instance). Your app instances can ask you for permission to receive these push notifications. If you authorize it, your phone will display notifications which the app developers send to that app instance.

The same technology exists for browsers! Websites can ask you for permission to receive push notifications. If you authorize it, your browser will display notifications which the website owner sends to your browser.

There are two APIs: the Push API and the Notification API. The Push API enables data to be sent from website operators to your browser. The Notification API lets web apps on your browser to display system-level notifications, outside of any webpage viewport. In mobile push notifications, these two separate pieces of functionality are confused and mixed together.

The mobile OS operators operate central push notification gateways. Apple has one called APNs, and Google has one called FCM. These gateways are central internet services which mobile app instances can subscribe to and app developers can publish to.

What can computers do? What are the limits of mathematics? And just how busy can a busy beaver be? This year, I’m writing Busy Beavers, a unique interactive book on computability theory. You and I will take a practical and modern approach to answering these questions — or at least learning why some questions are unanswerable!

It’s only $19, and you can get 50% off if you find the discount code ... Not quite. Hackers use the console!

After months of secret toil, I and Andrew Carr released Everyday Data Science, a unique interactive online course! You’ll make the perfect glass of lemonade using Thompson sampling. You’ll lose weight with differential equations. And you might just qualify for the Olympics with a bit of statistics!

It’s $29, but you can get 50% off if you find the discount code ... Not quite. Hackers use the console!

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