Today in Science

[LaurieHolden]

If there's an exisitng 'science thread', let me know. I scrolled through, nothing jumped out.

This article is the sort that captures my sometimes vivid imagination, and makes me wonder what others might think about the connections between the natural and cultural world. I wonder about such subjects as sound waves. e.g. why dogs sense earthquakes? One possible way dogs are detecting earthquakes is by sensing “P waves” – otherwise known as, “compressional waves.” It’s a seismic body wave that travels out from the quake’s source.

Another is where light is faster than sound. (In fact, light is faster than just about anything in the known universe.) It’s why we see lightning before we hear thunder.


Scientists create the loudest possible sound
Using SLAC's Linac Coherent Light Source (LCLS) X-ray laser, the researchers blasted tiny jets of water to create incredible sound pressures above 270 decibels.

https://newatlas.com/loudest-possible-sound/59746/

Microphones and hydrophones (underwater microphones) record volcanic sounds. These instruments can record sounds audible to human ears as well as infrasound data—sound waves with a frequency so low that people can’t hear them.
Krakatoa in 1883, was the loudest sound in recorded history. But, powerful as Krakatoa was, it was far from the most powerful volcano in history. Why do you think the eruption of the Yellowstone Supervolcano—much more explosive than Krakatoa—didn’t make more noise?
It probably did. The key words in the first statement is recorded history. People weren’t measuring barometric pressure 2.2 million years ago, when Yellowstone went boom.
In 1883, meteorologists in Europe, Asia, and Australia used barometers to track the blips in air pressure associated with the eruption at Krakatoa.
The Krakatoa explosion registered 172 decibels at 100 miles from the source. This is so astonishingly loud, that it’s inching up against the limits of what we mean by “sound.”
https://www.discovermagazine.com/environment/the-loudest-sound-ever-heard
To put that in context, if you were operating a jackhammer you’d be subject to about 100 decibels. The human threshold for pain is near 130 decibels, and if you had the misfortune of standing next to a jet engine, you’d experience a 150 decibel sound. (A 10 decibel increase is perceived by people as sounding roughly twice as loud.)
Oddly enough, in air, a sound can't get any higher than about 194 decibels and in water it's around 270. This is because sound is an example of something where the measurements break down at either end of the scale.

I asked the question on the main sub re the loudest crowd they'd heard at the MCG.
The MCG people have recorded the sound before, I just can't find the publisged article.

https://www.guinnessworldrecords.com/world-records/loudest-crowd-roar-at-a-sports-stadium#:~:text=29%20September%202014%20The%20loudest%20crowd%20roar%20at,with%208%20seconds%20remaining%20in%20the%20first%20quarter.

[think positive]

Best ever the Collingwood chant against geefrickenlong in the prelim!

I have new proper hearing aides, I’m shocked by how loud somethings are.

[LaurieHolden]

Date: January 9, 2023
Source: University of Eastern Finland
Summary: Fewer cases of melanoma were observed among regular users of vitamin D supplements than among non-users, a new study finds. People taking vitamin D supplements regularly also had a considerably lower risk of skin cancer, according to estimates by experienced dermatologists. The study included nearly 500 people with an increased risk of skin cancer.

https://www.sciencedaily.com/releases/2023/01/230109112555.htm#

[stui magpie]

https://www.theage.com.au/lifestyle/health-and-wellness/if-you-change-anything-about-your-diet-this-year-change-this-20230110-p5cbha.html

[LaurieHolden]

^ Dr.Karl agrees!

Eat your way into happiness
https://open.spotify.com/episode/3MuPH4LM5oSlfzXuN4Ssfd?si=ccc232209a6b47fc

How's your regime going Stui?

[stui magpie]

Going well thanks Laurie, currently stable at 89kg.

I still eat carbs, just not often. Nothing like chips with a steak or fish, but it's just sensible eating. Avoid sugar and starchy carbs, eat plenty of fresh protein and veges and good fats from olives, eggs and avocados.

[What'sinaname]

The 5 brightest planets aligned December 2022 and California is experiencing heavy rainfall, the heaviest since 2004, when five planets last aligned.

[LaurieHolden]

Timeline: The Most Important Science Headlines of 2022

https://www.visualcapitalist.com/science-headlines-of-2022/