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Many book lovers still prefer the traditional paper book option over an ebook. They value the tactile feel of a bound paper book. Paper books are, as a rule, very well designed, smell good, and they carry with them a more human touch.

A paper book provides a more intense psychological sensation of possession. You possess the book as an almost totemic object. In an ebook you only use the book. But beyond the romantic halo, there is a practical reason (and scientific) why it is inadvisable to read ebooks before going to sleep (at least some types of ebooks).

Backlight and melanin

High levels of screen brightness on an electronic device can contribute to eye strain, a condition characterized by tired, itchy, and burning eyes.

In Xataka Science

Reading a book is not the same as listening to an audiobook: commitment, understanding and presence of the narrator

Also there are potential considerations for those who read e-books on light-emitting e-readers at night (although some e-readers do not use light-emitting screens). Exposure to artificial light from light-emitting e-readers may interfere with users' ability to sleep and ultimately generate adverse health effects.

A 2014 study published in the magazine PNAS Thus, it suggests that reading an ebook before going to bed decreases the production of melatonin, a hormone that prepares the body to sleep. E-books had also affected the reader's alertness the next day.

In Xataka Science

Reading radically transforms our brain

Reading is unnatural because the natural state of the human brain, as well as that of most primates, tends to be distracted. However, reading a book requires intense concentration for a long period of time. Doing it on paper is as unnatural as doing it on an ebook, but it seems more convenient to do it (at least for now) on paper.

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The news

If you are going to read a book before going to sleep, it better not be an ebook.

was originally published in

Xataka Science

by
Sergio Parra

.

He Ursus maritimus tyrannus It measured 1.83 meters and had an average mass of more than a ton (1200 – 1500 kg), making it almost three times heavier than an adult male brown bear.

This fossil subspecies evolved from an isolated population of Arctic brown bears in the late Pleistocene and It was the largest carnivorous land mammal of all time.

Since the oldest fossil is 100,000 years old, it is estimated that they evolved between 100,000 and 250,000 years ago, from a population of Arctic brown bears, probably isolated by glaciation.

Evolution

The contemporary descendant of this enormous creature is the largest bear today, the Polar Bear: The adult male has a mass of 400 – 600 kg and measures up to 2.6 meters in length from nose to tail.

The species lives in latitudes 65 – 85º N, making it the northernmost bear.

Also in the terrestrial mammal with a more extensive habitat: Adult polar bears in Hudson Bay, Canada, have vast territories of up to 350,000 square kilometers, approximately the size of Germany.

In Xataka Science

Global animal populations have declined by an average of two-thirds in less than half a century.

Under the fur is the skin, which is black to better attract solar radiation and thus increase body heat. Ordinary light reflects on the fur, normally generating the false sensation of whiteness. Nevertheless, At certain times and places it can appear yellowish or even light brown.

By the way, The most nutritious bear milk is also that of the polar bear: contains up to 48.4 % fat and is vital for bear cubs, which must survive in a frigid environment.

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The news

This was the largest bear of all time and had a mass of more than a ton

was originally published in

Xataka Science

by
Sergio Parra

.

A team of researchers has studied brain aging measuring the volume of the cortical mantle and hippocampal regions of the brain provided with MRI scanners of more than 2000 participants.

These areas of the brain are prone to shrink over time, as a natural part of aging. The brains of the participants were scanned up to three times over a period of 11 years, thus being a large-scale longitudinal test, one of the largest of its kind.

Brain shrinkage

The researchers compared the rate of reduction in these areas in people who had obtained higher education before age 30 and those who did not. Participants were between 29 and 91 years old.

What they concluded is that higher education is modestly related to larger brains.

In Xataka Science

How the secret language of neurons was discovered and the first person who could hear it

While the rate of brain change was similar in participants with and without higher education, the researchers found that those with higher education had slightly larger cortical volume in some regions, but even in these regions, the rate of change was not related to education.

In conclusion, the human brain shrinks. Even in healthy individuals, those who do not suffer from any neurodegenerative disease, or those who have higher education, this gradual reduction in size is recorded from the age of 25 and the process accelerates after the age of 50. This atrophy is mainly localized. in the frontal lobe and the hippocampus, the area where memories are fixed, so that it has direct consequences on faculties such as our ability to reason, mental speed or episodic memory.

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The news

No, having higher education does not influence how the brain ages

was originally published in

Xataka Science

by
Sergio Parra

.

With the first evidence of fire use or tool making, the Wonderwerk Cave in South Africa hIt has been confirmed as the oldest human-populated cave in the world, according to a new investigation published in Quaternary Science Reviews, led by a team of geologists and archaeologists from the Hebrew University of Jerusalem (HU) and the University of Toronto.

axes and fire

The study establishes the change from Oldowan tools (mainly sharpened slabs and cutting tools) to the first hand axes more than 1 million years ago, and the deliberate use of fire by our prehistoric ancestors 1 million years ago, in a layer deep in the cave.

Additionally, Wonderwerk contained a full range of fire remains: burnt bones, sediments and tools, as well as the presence of ashes.

As explained by the main author, Professor Ron Shaar from the HU Institute of Earth Sciences:

In Xataka Science

The largest "Stone Forest" in the world is located on the oldest island in the world

We can now say with confidence that our human ancestors were making simple stone tools inside Wonderwerk Cave 1.8 million years ago. Wonderwerk is unique among ancient Oldowan sites, a type of tool first found 2.6 million years ago in East Africa, precisely because it is a cave and not an open-air occurrence.

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The news

It is confirmed that this is the oldest human-populated grotto in the world and is in South Africa

was originally published in

Xataka Science

by
Sergio Parra

.