David Eagleman: Your Time-Bending Brain

David Eagleman: So this is an area of interest to me and my lab’s been studying this for a while, is why time is rubbery and can speed up or slow down.  And it turns out, when I looked into the literature on this, the experiment had never been done about why time seems to move in slow motion when you’re in a life threatening situation.  But I talked to so many people and I’d experienced it myself that I wanted to study that.  So I found a way to study it by dropping people from 150 foot tall tower and measuring their time perception on the way down.  And that, plus several other experiments we did in my lab, led me to understand that people don't actually see time in slow motion during an event.  Instead, it’s a completely retrospective assessment.

In other words, when you’re in a life threatening situation, your brain writes down memory much more densely, and then retrospectively, when you look at that, you have so many details that you don't normally have that it seems as though it must have lasted a very long time.

That's the only interpretation your brain can make.  So time, your assessment of how long something took, has a lot to do with how much energy your brain has to burn during the event and how much footage you have of the event.

Directed / Produced by Jonathan Fowler and Elizabeth Rodd

 

Neuroscientist David Eagleman explains how your brain perceives time (retrospectively).

​There are two kinds of failure – but only one is honorable

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Scientists study tattooed corpses, find pigment in lymph nodes

It turns out, that tattoo ink can travel throughout your body and settle in lymph nodes.

17th August 1973: An American tattoo artist working on a client's shoulder. (Photo by F. Roy Kemp/BIPs/Getty Images)
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In the slightly macabre experiment to find out where tattoo ink travels to in the body, French and German researchers recently used synchrotron X-ray fluorescence in four "inked" human cadavers — as well as one without. The results of their 2017 study? Some of the tattoo ink apparently settled in lymph nodes.


Image from the study.

As the authors explain in the study — they hail from Ludwig Maximilian University of Munich, the European Synchrotron Radiation Facility, and the German Federal Institute for Risk Assessment — it would have been unethical to test this on live animals since those creatures would not be able to give permission to be tattooed.

Because of the prevalence of tattoos these days, the researchers wanted to find out if the ink could be harmful in some way.

"The increasing prevalence of tattoos provoked safety concerns with respect to particle distribution and effects inside the human body," they write.

It works like this: Since lymph nodes filter lymph, which is the fluid that carries white blood cells throughout the body in an effort to fight infections that are encountered, that is where some of the ink particles collect.

Image by authors of the study.

Titanium dioxide appears to be the thing that travels. It's a white tattoo ink pigment that's mixed with other colors all the time to control shades.

The study's authors will keep working on this in the meantime.

“In future experiments we will also look into the pigment and heavy metal burden of other, more distant internal organs and tissues in order to track any possible bio-distribution of tattoo ink ingredients throughout the body. The outcome of these investigations not only will be helpful in the assessment of the health risks associated with tattooing but also in the judgment of other exposures such as, e.g., the entrance of TiO2 nanoparticles present in cosmetics at the site of damaged skin."

Why are so many objects in space shaped like discs?

It's one of the most consistent patterns in the unviverse. What causes it?

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  • Spinning discs are everywhere – just look at our solar system, the rings of Saturn, and all the spiral galaxies in the universe.
  • Spinning discs are the result of two things: The force of gravity and a phenomenon in physics called the conservation of angular momentum.
  • Gravity brings matter together; the closer the matter gets, the more it accelerates – much like an ice skater who spins faster and faster the closer their arms get to their body. Then, this spinning cloud collapses due to up and down and diagonal collisions that cancel each other out until the only motion they have in common is the spin – and voila: A flat disc.