A Little Mind-Bender About Perception …

I’ve been thinking a lot about this reader question today. It’s completely mind-blowing to think that even our immediate, present experience is not actually present or immediate. There is a delay to everything, and we are never truly experiencing now.

Let’s take that mind-bender to another level!

  1. Extend each of your index fingers. Close your eyes.
  2. Slowly and carefully attempt to touch your nose and your ankle at the same time. This obviously works better if you’re sitting down.
  3. After a few tries, you should be able to feel each finger touching at the same time.
  4. Even better, find a friend and have them do the previous steps to you, to make the sensory experience completely independent.

Most of us, if we have any coordination at all, should be able to touch our ankle and nose simultaneously, so that it feels like a single moment.

But hold up a sec! The signal from your ankle had to travel maybe twenty times as far to get to your brain. Depending on the exact type of nerve cell stimulated by that touch, the message can take a noticeable fraction of a second to reach the brain from your foot (the nerve type that responds to touch transmits in the range of 30-70 m/s, although dull pain and warm/cold are about ten times slower).

So did they happen at the same time? Did you actually touch your nose and ankle simultaneously and your brain reassembled the asynchronous signals? Or did you touch your ankle and nose at slightly different moments, so that the sensory info would arrive at the same time?

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I genuinely do not know the answer to this. Is there an answer? What do you all think?

Did you know there are lakes within the oceans? The photo above shows a rippled lake, lapping against a sandy shore, surrounded by salty deposits and eroded coral formations. What might NOT be readily apparent is that this lake is underwater. Off of the coast of the Yucatán peninsula, in the Gulf of Mexico, there exist a number of undersea brine lakes. Way back in the Jurassic, the Gulf of Mexico was a shallow, mineral-rich sea. For a time, it was cut off from the ocean and dried up, leaving loads of salt deposits behind. Many years later, as the ocean reformed and the geography continued to evolve, we were left with the Gulf that we see today. Some of those salt deposits remained buried, a valuable commodity to be later mined by us humans. One particular salt dome along the Gulf, Avery Island, is the tasty origin of Louisiana’s famous Tabasco sauce! But much of that salt remains buried deep under ocean sediments. When it is exposed, super-salty brines are formed, far saltier than seawater. And just like the deadly brinicles that send starfish scurrying for their lives beneath the Antarctic ice, these super-concentrated salty pools are denser and heavier than the seawater around them. So they “sink”, forming lakes within the ocean devoid of all but microbial life, slowly lapping salty waves onto the ocean shore around them. Check out more at Ocean Explorer.
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Did you know there are lakes within the oceans?

The photo above shows a rippled lake, lapping against a sandy shore, surrounded by salty deposits and eroded coral formations. What might NOT be readily apparent is that this lake is underwater.

Off of the coast of the Yucatán peninsula, in the Gulf of Mexico, there exist a number of undersea brine lakes. Way back in the Jurassic, the Gulf of Mexico was a shallow, mineral-rich sea. For a time, it was cut off from the ocean and dried up, leaving loads of salt deposits behind. Many years later, as the ocean reformed and the geography continued to evolve, we were left with the Gulf that we see today.

Some of those salt deposits remained buried, a valuable commodity to be later mined by us humans. One particular salt dome along the Gulf, Avery Island, is the tasty origin of Louisiana’s famous Tabasco sauce!

But much of that salt remains buried deep under ocean sediments. When it is exposed, super-salty brines are formed, far saltier than seawater. And just like the deadly brinicles that send starfish scurrying for their lives beneath the Antarctic ice, these super-concentrated salty pools are denser and heavier than the seawater around them. So they “sink”, forming lakes within the ocean devoid of all but microbial life, slowly lapping salty waves onto the ocean shore around them.

Check out more at Ocean Explorer.

Why Listening Is So Much More Than Hearing

The fascinating neurological differences between listening and hearing, how our bodies automatically filter the surprising or important from the background, and what our modern digital age may mean for our listening abilities. Fascinating stuff from the NY Times:

This is because hearing has evolved as our alarm system — it operates out of line of sight and works even while you are asleep. And because there is no place in the universe that is totally silent, your auditory system has evolved a complex and automatic “volume control,” fine-tuned by development and experience, to keep most sounds off your cognitive radar unless they might be of use as a signal that something dangerous or wonderful is somewhere within the kilometer or so that your ears can detect.

This is where attention kicks in.

Take a moment and listen to your surroundings. Coworkers talking, machines whirring, air conditioning humming, printer printing, dogs barking … you can voluntarily pick out any number of sounds when you focus on that input.

The real mindbender is that your brain is always listening to those noises, but it doesn’t trigger you to consciously hear unless it is startling or out of the ordinary. Chew on that for a while … the idea that we are always listening but rarely hearing is pretty freakin’ cool.

The Largest Ever 3D Map of the Universe

Fly through the latest release of the Sloan Digital Sky Survey, with images of 200 million galaxies. The spectra and motion collected in this ongoing project, which released this latest data this week, are like a lens into the early days of our universe.

Don’t feel small, feel special! That we can know so much about something so immense … that is truly amazing. 

(via The Atlantic)

Source: The Atlantic

Super Stunning Scientific Slinky Slow-Mo Strikes Me Slack-Jawed 

Watch as an extended slinky is released and captured in super slow-motion. You’ll have to see it to believe me, but the bottom of the slinky remains completely stationary in air, the force of gravity balanced by the upward tension, until the wave travels all the way to the bottom.

It’s almost like levitation, thanks to the principles of physics. For another look at this by the same folks (featuring some sports principles), here’s another slow-mo slinky video.

(by 1veritasium)

Source: youtube.com