Tag Archives: Time

What is time? The mysterious essence of the fourth dimension | New Scientist

The true nature of time continues to elude us. But whether it is a fundamental part of the cosmos or an illusion made in our minds has profound implications for our understanding of the universe

Physics 15 June 2022, By Richard Webb

Skizzomat

WE ARE BORN; we live; at some point, we die. The notion that our existence is limited by time is fundamental to human experience.

We can’t fight it – and truth be told, we don’t know what we are fighting against. Time is a universal whose nature we all – and physicists especially – fail to grasp. But why is time so problematic?

“If we had a really good answer to that question,” says Astrid Eichhorn, a theoretical physicist at the University of Southern Denmark in Odense, “then it wouldn’t be so problematic.”

On a certain level, time is simple: it is what stops everything happening at once. That might seem flippant, but it is at least something people can agree on. “The causal order of things is really what time is all about,” says Eichhorn.

Viewed this way, the existence of time can be interpreted as a necessary precondition for the sort of universe where things lead to other things, among them intelligent life that can ask questions, such as “what is time?”.

Beyond that, time’s essence is mysterious. For instance, why can things only influence other things in one direction in time, but in multiple directions in the three dimensions of space.

Most physical theories, from Isaac Newton’s laws of motion to quantum mechanics, skirt such questions. In these theories, time is an “independent variable” against which other things change, but which can’t be changed by anything else. In that sense, time exists outside physics, like the beat of a metronome outside the universe to which everything inside it plays out.

Source: What is time? The mysterious essence of the fourth dimension | New Scientist

Why We Forget Things, According to Neuroscience | Time

By Corinne Purtill, April 28, 2022 7:00 AM EDT

Studies on the brains of zebrafish, like the one shown here, are helping scientists better understand memory, and the power of forgetting.
Illustration by TIME (Source image: Zhuowei Du)

A baby zebrafish is just half the size of a pea. A recent look inside its transparent brain, however, offers clues to the far bigger mystery of how we remember—and how we forget.

In an experiment that yielded insights into memory and the brain, a team of researchers at the University of Southern California taught the tiny creature to associate a bright light with a flash of heat, a temperature change the fish responded to by trying to swim away.

Using a custom-designed microscope, the team then captured images of the animals’ brains in the moments before and after they learned to associate the light and the heat. It’s the first known look at how a living vertebrate’s brain restructures itself as the animal forms a memory.

Editor’s Note: Read more, see link below for original item…

Source: Why We Forget Things, According to Neuroscience | Time

TIME: Is There Life on Mars? A New Study Offers Tantalizing Clues

By Jeffrey Kluger, January 20, 2022 11:54 AM EST

This low-angle self-portrait of NASA’s Curiosity Mars rover shows the vehicle at the site from which it reached down to drill into a rock target.
JPL/NASA

Mars is both a wonderful and a terrible place to go looking for life. On the one hand, the planet is a wasteland, where wintertime temperatures plunge to -153º C (-225º F), and the atmosphere—such as it is—is just 1% the density of Earth’s and composed principally of carbon dioxide.

On the other hand, the Red Planet wasn’t always such a wreck. For the first billion or so years of its 4.5 billion year life span, it was awash in oceans and seas and protected by a thick blanket of air. Eventually, however, its magnetic field shut down, allowing the solar wind to claw away the atmosphere and the water to vanish into space.

But that first billion years offered Mars plenty of time to cook up at least microbial life, some of which may have died and left chemical traces on the surface—or even have retreated underground to continue thriving in deep, warm aquifers.

Now, a new study, announced by NASA and published on Jan. 18 in the Proceedings of the National Academy of Sciences, suggests that some of those lingering surface markers of ancient life may have been found—lying in plain sight, in fact.

Source: https://time.com/6140688/life-on-mars-clues/

Will There Be Libraries in 25 Years?  | Time

By Brewster Kahle, October 22, 2021 1:21 PM EDT
Kahle, Founder and Digital Librarian of the Internet Archive. Member, National Academy of Engineering, American Academy of Arts and Sciences, and the Internet Hall of Fame
Getty Images

When I started the Internet Archive 25 years ago, I focused our non-profit library on digital collections: preserving web pages, archiving television news, and digitizing books. The Internet Archive was seen as innovative and unusual.

Now all libraries are increasingly electronic, and necessarily so. To fight disinformation, to serve readers during the pandemic, and to be relevant to 21st-century learners, libraries must become digital.

But just as the Web increased people’s access to information exponentially, an opposite trend has evolved. Global media corporations—emboldened by the expansive copyright laws they helped craft and the emerging technology that reaches right into our reading devices—are exerting absolute control over digital information.

These two conflicting forces—towards unfettered availability and completely walled access to information—have defined the last 25 years of the Internet. How we handle this ongoing clash will define our civic discourse in the next 25 years.

If we fail to forge the right path, publishers’ business models could eliminate one of the great tools for democratizing society: our independent libraries.

Source: Will There Be Libraries in 25 Years?  | Time