The doorbell that never stops watching
A smart doorbell has a camera. It films all day and sends every second of video to a computer far away.
One evening the home internet stops. The doorbell cannot send anything. A visitor arrives and nobody is told.
Could the doorbell be smarter? Could it decide for itself what to send? This is the idea of edge computing.
Key words
| Word | What it means | Example |
|---|---|---|
| Storage medium | A device or service that keeps data. | A phone memory card or a hard disk |
| Terabyte (TB) | A unit of storage. One TB is 1,000 GB. | A big laptop disk |
| Quantum computer | A new kind of computer that uses the rules of very, very tiny things. | A research machine |
| Qubit | The unit of a quantum computer. It can hold a mix of 0 and 1. | A quantum bit |
| Encryption | Scrambling (mixing up) data so only the right person can read it. | A secret code on your messages |
| Internet of Things | Everyday objects with sensors that connect to the internet. | A smart heating system |
| Sensor | A part that measures something, such as heat or movement. | A temperature sensor |
| Edge computing | Working on data close to where it is made, not far away. | A doorbell that decides what to send |
| Latency | The delay before data arrives. | A video call with a long delay |
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Quick check: the doorbell
Have a go
Quick check: the doorbell
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
We need more and more storage
Every photo, film, message and game save uses storage. A storage medium is any device or service that keeps data.
Demand goes up every year. Phone cameras make bigger photos. Films are in higher quality. Companies keep records for many years. AI needs huge piles of data.
More storage means more machines in data centres (buildings full of computers), more electricity and more cost.
Worked example: how big is a TB?
| Unit | Size | Roughly holds |
|---|---|---|
| Kilobyte (KB) | 1,000 bytes | A short text message |
| Megabyte (MB) | 1,000 KB | One phone photo, about 4 MB |
| Gigabyte (GB) | 1,000 MB | A film, about 3 GB |
| Terabyte (TB) | 1,000 GB | About 250,000 photos |
| A 64 GB phone | 64 x 1,000 = 64,000 MB (64 times 1,000) | 64,000 divided by 4 = 16,000 photos |
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Try it: how many photos fit?
photo_mb = 4
phone_gb = 64
phone_mb = phone_gb * 1000
print(phone_mb // photo_mb)
# Change phone_gb to 128 and run it again.
# Change photo_mb to 8. What happens?
Quantum computers
A normal computer uses bits. A bit is 0 or 1.
A quantum computer uses qubits. A qubit can be a mix of 0 and 1 at the same time. For some special problems this lets the machine try many answers together.
Quantum computers are still new, big and expensive. They will not replace your laptop.
Quantum computers: gains and worries
| Possible gain | Possible worry |
|---|---|
| Test new medicines on a computer before making them | They are very expensive, so only a few groups have them |
| Plan the best routes for thousands of vans | A strong one might break some of today's encryption |
| Faster searches in huge sets of data | Most must be kept very, very cold, which uses a lot of energy |
The cells students fill in are left blank in this preview.