Once upon a time when the Earth was young it spun so fast that a day lasted only around 5 hours.
Earth’s rotation is actually being slowed down by the gravity of the Moon, which extracts energy from the Earth’s spin and uses it to move a little further away (yes the Moon is also moving away from us – at some point it’ll be the most famous breakup in history).
Over the last 100 years the Earth’s spin has slowed down by around 0.0014s which I know sounds very small, but the universe works on much longer timescales than we can even comprehend. At that rate, in around 250 million years each day will be 25 hours long. Aka, one more hour in bed.
Crazily however in 2020 it seemed the Earth stopped slowing down and appeared to be speeding up.
Some research suggests it could have happened because of the melting glaciers and consequential redistribution of that weight from the poles into the oceans.
[Read more here]
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To a billionth of a second...
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Measuring time is important for all kinds of things so humans have sought to measure it throughout history. Both sundials and water clocks can be dated back to the ancient Egyptians. Over the past few centuries, we've enjoyed mechanical clocks that use springs or pendulums to keep the time.
But what if you want to measure time really, really precisely?
The 20th-century brought us quartz crystal oscillators. These crystals vibrate at a specific rate (many many times) per second when electricity is applied to them. Like the swinging pendulum in a grandfather clock, the crystals vibrate consistently, just on a smaller timescale. Nowadays even your average wristwatch is powered by one of these crystals.
But for really accurate time-keeping we also need to know that it's consistent over time.
Say hello to atomic clocks - these use quartz crystal oscillators but also introduce additional atoms to increase their stability. The additional atoms essentially act as sensors measuring when the vibration frequency is and isn’t as expected. By looking at how the atoms behave we can tell by how much the quartz is “off-frequency” and correct for it.
The tiny changes in the length of the day mentioned in the previous article have a significant impact on technology (smartphones, satellites, computers etc). They all rely on quartz oscillators that accurately measure time but don’t take into account the Earth’s changing rotation speed, which could render them completely useless. For example, if the clocks in GPS satellites are out of sync by even one-millionth of a second, the system could not locate you to better than 700m.
Check out the link below to learn about NASA's Deep Space Atomic Clock launched in 2019, the most stable atomic clock ever flown in space, that's up to 50x more stable than clocks in GPS satellites.
[Read more here]
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Beaver the Builder. Can he build it? Yes he can. Beavers are known for their building of dams, but it might surprise you to know they don’t actually live in them.
Beavers use the dams to deepen the water. In this deeper water they create a ‘Lodge’, which they use to live and store food in. They do this in order to protect themselves from predators such as Wolves or Bears.
The cool part about this is the secret underwater entrance they use to gain access to their homemade lodge as seen in the picture below.
In the UK, Beavers dams can be up to 100m in length, while across the pond the largest ever discovered in Alberta Canada reached a massive 850m long! That's longer than the height of the Shard (London) and the Empire State Building (New York) combined.
[Read more here]
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- Scientist behind coronavirus vaccine says next target is cancer.
- Indian E-Scooter Factory to Make an electric vehicle every 2 Seconds.
- Volkswagen Group wants six new European battery factories by 2030.
- Texas lawmaker files bill to raise minimum teacher salary to $70,000.
- El Salvador is certified as malaria-free by World Health Organisation.
- Any Oklahoman can now get the Covid-19 vaccine, thanks to several Native tribes.
- Researchers discover breakthrough solid-state electric vehicle battery manufacturing technique.
- California desert to get America's first 3D-printed neighbourhood.
- London pub rebuilt brick by brick after illegal bulldozing. |
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Mind Bender Answer:
Dinosaurs are actually most closely related to birds. They evolved from a group of meat-eating dinosaurs called theropods. That's the same group that Tyrannosaurus rex belonged to, although birds evolved from small theropods, not huge ones like T. rex.
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Thanks
Thank you for reading today's Digital Caffeine.
If you learned something interesting share it with someone who'd find it cool!
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Have a great day, see you on Friday!
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