The speaker discusses the everyday applications of quantum physics in our lives, emphasizing that it's more than just the strange aspects often highlighted. They list five technologies that rely on quantum physics:
1. **Computers**: The basic element of a computer, the transistor, relies on quantum physics. Transistors are tiny switches that can be miniaturized and switched billions of times per second. The rules of semiconductors, which are the basic electronic components of computers, are dictated by quantum physics.
2. **Screens and Cameras**: Both the screen you're watching this on and the camera used to record it rely on the quantum physics of semiconductors. LEDs (light-emitting diodes), which are used in screens, and sensors in digital cameras, are semiconductor devices.
3. **Lasers**: Lasers use quantum physics in the process of stimulated emission, where electrons are promoted to a higher energy state in one atom and transferred to another atom. This process results in the emission of light.
4. **Fiber Optic Cables**: Fiber optic cables use laser beams to transmit data, which relies on quantum physics.
5. **GPS**: GPS technology relies on incredibly accurate clocks on GPS satellites, which are based on the quantum physics of cesium atoms.
The speaker concludes by stating that the entire modern world could be argued to exist because of our understanding of quantum physics. They also mention the upcoming development of quantum technologies like quantum information, quantum computing, quantum metrology, and quantum simulation.
1. Quantum physics is a fundamental part of our everyday lives, even though it may seem abstract or strange.
2. The modern world, including computers, wouldn't exist without our understanding of quantum physics.
3. The basic element of a computer, the transistor, uses the special electronic properties of silicon, a semiconductor.
4. The rules of semiconductors, which are essential for transistors, are dictated by quantum physics.
5. Electronics in a semiconductor can only be in certain energy states, which can be used to create on-off switches.
6. To create a transistor, we engineer materials by adding extra elements like phosphorus or boron to create materials with different energy levels.
7. By combining these materials, we can make a junction where electrons don't flow until a voltage is applied, creating an on-off switch.
8. The energy levels in different materials are dictated by the laws of quantum physics.
9. Without this understanding, we wouldn't have been able to invent the transistor.
10. The screen and camera used to watch this video both rely on the quantum physics of semiconductors.
11. Most screens today are backlit by LEDs, which are semiconductor devices.
12. LEDs have been gradually getting better over time, with a lot of engineering effort going into making them brighter and whiter.
13. The sensor in a digital camera is made up of tiny little pixels called photo detectors or photo diodes.
14. When these detectors receive light, they create a current of electrons through our manipulation of the energy levels in semiconductors.
15. The reason why these cameras have kept getting better with more megapixels and higher sensitivities is our increasing ability to engineer the quantum physics of these semiconductors.
16. In a laser, voltage is applied to specific mixtures of elements to excite the electrons, which then give off light.
17. The process that lasers use is called stimulated emission, where an electron is promoted to a higher energy state in one atom, transferred to another atom, and then knocked down with a correctly tuned theme of light, releasing more light.
18. To make a laser beam work, elements with very similar energy levels are needed, which requires our understanding of quantum physics.
19. Laser beams are used every day, for example, to transmit this video through a fiber optic cable.
20. GPS technology relies on incredibly accurate clocks on GPS satellites.
21. The satellites continuously broadcast their time, and a phone takes these signals to work out where it is on earth.
22. The ticking of these atomic clocks depends on the frequency of a transition between two particular energy states in a cesium atom.
23. The frequency of these clocks depends on the laws of nature, and all of the clocks are exactly in time and are accurate to one second in 1.4 million years.
24. There are loads of other technologies that we use in the world today based on the laws of quantum physics.
25. Because these days we do pretty much everything on computers, you could argue that the entire modern world exists because of our understanding of quantum physics.