How did we measure the fastest speed there is? | The History of the Speed of Light Part I
Dr. Becky
@drbeckyAbout
Your friendly neighbourhood astrophysicist. I'm Dr Becky Smethurst, an astrophysicist at the University of Oxford. I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! I have also written a few books. My latest, "A Brief History of Black Holes", is available in hardback, e-book and audio (which I narrated myself!) My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars. Channel art by Megan Smethurst: https://www.instagram.com/megansmethurst_gdesign/
Latest Posts
No results found. Try different keywords.
Video Description
The speed of light is 299,792,458 meters per second. That's an incredibly fast speed. But how did we even figure that out in the first place? And how do we even know it that accurately? Part 2 - Why can’t anything go faster than the speed of light? https://youtu.be/jRLNVvsxfFo My phases of the Moon necklace is from Eclectic Eccentricity, who have a great selection of space-themed jewellery: https://eclecticeccentricity.co.uk/products/roam-moon-phase-necklace?_pos=1&_sid=cd742dc82&_ss=r ------- More details on measuring the speed of light (or really, the length of a meter!) with your microwave: https://physicamechanica.wordpress.com/2013/12/04/speed-of-light-in-a-microwave/ Here are links to the papers mentioned: Rømer (1667) - https://gallica.bnf.fr/ark:/12148/bpt6k77856x.image.f39.langEN# Huygens (1677) - https://gallica.bnf.fr/ark:/12148/bpt6k77856x.image.f37.langEN Newton (1704) - https://gallica.bnf.fr/ark:/12148/bpt6k3362k.image.f235.vignettesnaviguer Bradley (1729) - https://royalsocietypublishing.org/doi/pdf/10.1098/rstl.1727.0064 Fizeau (1849) - https://onlinelibrary.wiley.com/doi/abs/10.1002/andp.18501550113 Weber & Kohlrausch (1856) - https://onlinelibrary.wiley.com/doi/epdf/10.1002/andp.18561750903 Maxwell (1864) - https://upload.wikimedia.org/wikipedia/commons/1/19/A_Dynamical_Theory_of_the_Electromagnetic_Field.pdf Essen (1950) - https://www.jstor.org/stable/pdf/98433.pdf?refreqid=excelsior%3A117b745e1aa593a54098a1332f856030 Evenson et al. (1972) - https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.29.1346 ---- 📚 "Space: 10 Things You Should Know": http://bit.ly/SpaceDrBecky 📚 US & Canada version: "Space at the speed of light" (same book, different title): https://www.penguinrandomhouse.com/books/635406/space-at-the-speed-of-light-by-dr-becky-smethurst/ 📚 German translation "Das kleine Buch vom großen Knall" : https://www.dtv.de/buch/becky-smethurst-das-kleine-buch-vom-grossen-knall-28254/ --- 🔭 Royal Astronomical Society podcast that I’m co-hosting 😱 🥳- podfollow.com/supermassive --- 🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video! --- 📹 Dr. Becky also presents videos on Sixty Symbols: https://www.youtube.com/user/sixtysymbolsand Deep Sky Videos: https://www.youtube.com/user/DeepSkyVideos --- 👩🏽💻 Dr Becky Smethurst is an astrophysicist researching galaxies and supermassive black holes at Christ Church at the University of Oxford. http://drbecky.uk.com https://rebeccasmethurst.co.uk
Upgrade Your Everyday
AI-recommended products based on this video

Amazon Echo Show 8 (newest model), With Spatial Audio, Smart Home Hub, and Alexa, Charcoal

Apple AirPods 4 Wireless Earbuds, Bluetooth Headphones, with Active Noise Cancellation, Adaptive Audio, Transparency Mode, Personalized Spatial Audio, USB-C Charging Case, Wireless Charging, H2 Chip

Wireless Earbuds, Bluetooth 5.4 Headphones, True Wireless Stereo Earphones with IPX7 Waterproof, Noise Cancelling Mic, Fast Charging and Comfort Fit Ear Buds for Sports/Workouts - Black

Apple AirPods 4 Wireless Earbuds, Bluetooth Headphones, Personalized Spatial Audio, Sweat and Water Resistant, USB-C Charging Case, H2 Chip, Up to 30 Hours of Battery Life, Effortless Setup for iPhone

Apple AirPods Pro 2 Wireless Earbuds, Active Noise Cancellation, Hearing Aid Feature, Bluetooth Headphones, Transparency, Personalized Spatial Audio, High-Fidelity Sound, H2 Chip, USB-C Charging

Smart Watch for Men/Women, 1.95" AMOLED Fitness Tracker Watches with Bluetooth Calls/Flashlight/100+ Sport Modes Heart Rate/Sleep Monitor Ultra Lightweight Ultrathin Design

Smart Watch for Men Women (Answer/Make Call), 1.96" HD Smartwatch Fitness Activity Tracker, 110+ Sports IP68 Waterproof, Heart Rate/Sleep Monitor/Pedometer/Calories, Fitness Watch for Android iOS
![Apple Watch Series 10 [GPS 46mm case] Smartwatch with Rose Gold Aluminium Case with Light Blush Sport Band - M/L. Fitness Tracker, ECG App, Always-On Retina Display, Water Resistant](https://m.media-amazon.com/images/I/61nNNMI1cFL._AC_UL960_FMwebp_QL65_.jpg)
Apple Watch Series 10 [GPS 46mm case] Smartwatch with Rose Gold Aluminium Case with Light Blush Sport Band - M/L. Fitness Tracker, ECG App, Always-On Retina Display, Water Resistant
![Apple Watch Series 10 [GPS 42mm case] Smartwatch with Jet Black Aluminium Case with Black Sport Band - S/M. Fitness Tracker, ECG App, Always-On Retina Display, Water Resistant](https://m.media-amazon.com/images/I/6105jZyXyPL._AC_UL960_FMwebp_QL65_.jpg)
Apple Watch Series 10 [GPS 42mm case] Smartwatch with Jet Black Aluminium Case with Black Sport Band - S/M. Fitness Tracker, ECG App, Always-On Retina Display, Water Resistant

NOCO Boost GB40: 1000A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack, Portable Jump Box, Power Bank & Jumper Cables - for 6.0L Gas and 3.0L Diesel Engines

UGREEN Nexode Power Bank 20000mAh 130W Portable Charger 72Wh PD Fast Charging 3-Port USB C Battery Pack with TFT Smart Display for MacBook/iPad/iPhone 16/Samsung S24 and More

ANKER 737 Power Bank, 24,000mAh 3-Port Laptop Portable Charger with 140W Fast Charging, Smart Display, for Outdoor Work, Compatible with iPhone 16/15/14 Series, Vision Pro, Samsung, MacBook, and More

VOLTME Portable Charger, Slim 10000mAh 5V/3A Power Bank, USB C in&Out High-Speed Charging Battery Pack, Travel Essentials Dual Output Compatible with iPhone 16 15 14 13 12 Samsung Google iPad etc

Apple AirPods 4 Wireless Earbuds, Bluetooth Headphones, with Active Noise Cancellation, Adaptive Audio, Transparency Mode, Personalized Spatial Audio, USB-C Charging Case, Wireless Charging, H2 Chip

Apple AirPods 4 Wireless Earbuds, Bluetooth Headphones, Personalized Spatial Audio, Sweat and Water Resistant, USB-C Charging Case, H2 Chip, Up to 30 Hours of Battery Life, Effortless Setup for iPhone

Apple AirPods Pro 2 Wireless Earbuds, Active Noise Cancellation, Hearing Aid Feature, Bluetooth Headphones, Transparency, Personalized Spatial Audio, High-Fidelity Sound, H2 Chip, USB-C Charging

Bose QuietComfort Bluetooth Headphones, Wireless Headphones with Active Over Ear Noise Cancelling and Mic, Deep Bass, Up to 24 Hours of Playtime, White Smoke

Barnyard Designs Indoor Herb Garden Planter Set with Tray, Metal Windowsill Plant Pots with Drainage for Outdoor or Indoor Plants, Set/3 (Black)

Eye Contact Web Camera for Desktop Computer – 1080P USB Camera with Microphone & Stand, Center Cam for Laptop or Desktop, Manual Focus, Plug & Play for macOS & Windows(Black)
![PEHAEL 3+3Pack for iPhone 17 Pro Max Privacy Screen Protector with Camera Lens Protector Full Coverage Anti-Spy Tempered Glass Film 9H Hardness Easy Installation Bubble Free [6.9 inch]](https://m.media-amazon.com/images/I/61PnVkv6KKL._AC_UL960_FMwebp_QL65_.jpg)
PEHAEL 3+3Pack for iPhone 17 Pro Max Privacy Screen Protector with Camera Lens Protector Full Coverage Anti-Spy Tempered Glass Film 9H Hardness Easy Installation Bubble Free [6.9 inch]
![Ailun 3 Pack Screen Protector for iPhone 16 Pro Max [6.9 inch] + 3 Pack Camera Lens Protector with Installation Frame,Sensor Protection,Dynamic Island Compatible,Case Friendly Tempered Glass Film](https://m.media-amazon.com/images/I/815keamN-BL._AC_UL960_FMwebp_QL65_.jpg)
Ailun 3 Pack Screen Protector for iPhone 16 Pro Max [6.9 inch] + 3 Pack Camera Lens Protector with Installation Frame,Sensor Protection,Dynamic Island Compatible,Case Friendly Tempered Glass Film

