Marcelo Gleiser

We named our science and culture commentary 13.7: Cosmos & Culture when it launched nearly nine years ago.

At the time, the universe was believed to be 13.7 billion years old. But according to data released from the Planck satellite since, it took a bit longer: 13.8 billion years from the Big Bang to this blog.

Here's how it (the commentary, not the Big Bang) came to be:

There is a paradox with living as a human nowadays.

A 2014 article from the United Nations states that about 54 percent of the human population lives in urban areas (more by now), a proportion that is projected to increase to 66 percent by 2050. By 2045, the report says, more than six billion people will crowd cities.

Marcelo Gleiser is a theoretical physicist and writer — and a professor of natural philosophy, physics and astronomy at Dartmouth College. He is the director of the Institute for Cross-Disciplinary Engagement at Dartmouth, co-founder of 13.7 and an active promoter of science to the general public.

"Hauntingly beautiful." "Terrifying and seductive." "A bit too crazy for me."

These are some viewer reactions after watching Alex Garland's Annihilation, a fantasy sci-fi drama that leaves you in a weird state for days.

Is humanity doomed? Are we one of the last generations of homo sapiens — soon to be supplanted by engineered cyberbeings, with a distant semblance to their creators (us)?

Who has no regrets about things done in the past? Wouldn't it be nice if, somehow, we could go back to tweak a couple of bad decisions?

This sounds (and as we will see, is, to a certain extent) like science fiction.

As the fox told the prince in Antoine de Saint-Exupéry's wonderful fable The Little Prince: "What is essential is invisible to the eye."

If the fox had not been talking about love, she could have been referring to the elementary particles of matter, the building blocks of everything that exists. The poetry here is in knowing that the world is made of tiny, invisible bits of stuff that carry, in them, the story of creation itself.

On Tuesday, Elon Musk's SpaceX successfully launched its most ambitious rocket to date, the Falcon Heavy.

This is a transformative spacecraft, a behemoth that essentially straps three Falcon 9 rocket cores together. At 224-feet tall, it's smaller than NASA's giant Saturn V (363 feet) — but it is the largest privately built spacecraft to date. The Falcon Heavy is capable of lifting 70 tons of payload to low-Earth orbit and almost 30 tons to a geostationary transfer orbit.

If Victorians were offended by Charles Darwin's claim that we descended from monkeys, imagine their surprise if they heard that our first ancestor was much more primitive than that, a mere single-celled creature, our microbial Eve.

I'm old enough to have grown up in a household with a single rotary telephone.

I imagine that most children would not know what to do with one today. Conversely, my grandparents, if I could bring them back to life, would have had no idea of what to do with a smartphone.

Technology changes the way we live — and it also changes us.

Last week, the PBS series Nova presented an episode on black holes, these most mysterious and mind-boggling physical objects.

To close the door on 2017, the strangest year I can remember, there's nothing more appropriate than the revelation in December from the U.S. government that it, indeed, had an office dedicated to the investigation of UFO-related phenomena.

It's enough to make X-Files and conspiracy-theory fans rejoice.

Two years ago yesterday, Dec. 12, nearly 200 countries came to a consensus that greenhouse emissions — mostly caused by the burning of fossil fuels — had to be drastically cut if we were to halt the planetary-changing consequences of a choking atmosphere.

Trial and error, experimentation, the understanding that some questions have complex answers or no answers at all, the notion that failure teaches, the acceptance that mistakes can actually guide you in the right direction, persistence in the face of difficulty: These are some of the everyday components of scientific research, accumulated wisdom that can serve us well in many walks of life — from how to face challenges as individuals to running corporations.

For this post-Thanksgiving week, I'd like to suggest a remarkable video produced over two decades by NASA scientists.

Satellites monitored populations of plant life on land and oceans, mapping variations of green regions of vegetation and snow cover on the North and South Poles. As seasons pass, we witness a rhythmic dance between white and green, as if the planet itself were breathing.

As Europe was being torn apart in the early 17th century by conflicts between Catholics and Protestants — that would lead to the devastating Thirty Years War in 1618 — the German astronomer Johannes Kepler wrote:

"When the storm rages and the shipwreck of the state threatens, we can do nothing more worthy than to sink the anchor of our peaceful studies into the ground of eternity."

Some 130 million years ago, when dinosaurs roamed Earth, two dead stars in a far-away galaxy collided violently, after spiraling around each other for millions of years.

The dead stars were neutron stars, exotic objects the size of Mount Everest and with the mass of the sun. Being this small and dense, the gravitational force is fierce. Someone once compared the pull of gravity near the surface of a neutron star to having all the population of Paris tied to your feet.

As a Brazilian-born scientist, it pains me to witness the devastating cuts — and proposal of future additional reductions — to the country's science funding.

The cut of 44 percent in March brought the 2017 budget for Brazil's Ministry of Science, Technology, Innovation and Communications the lowest level in 12 years. Additional cuts of about 16 percent have been proposed for the 2018 budget.

If it's true that a picture is worth a thousand words, what NASA's Cassini mission has left for us is indeed a treasure.

Launched in 1997, the mission terminated dramatically last week with the probe's final plunge into Saturn's upper atmosphere.

America seems to be a magnet for devastating hurricanes these days.

This year, Harvey came out strong with its horrific toll on parts of Texas and Louisiana. Now Irma, downgraded slightly Friday morning to a Category 4 storm from its most recent days as a Category 5, has left destruction in its wake as it plows through the Caribbean and Cuba — and is on path to hit Florida Sunday morning.

Hurricane Harvey is a devastating reminder of how helpless we are when facing nature's human-dwarfing powers.

We dig holes and barricades, build dams and create ingenious systems of canals and levees. We try to pull the brakes on natural forces, or at least tame them. These measures protect us, and we surely would be worse off without them. We have come a long way since our cave dwellings.

This has been quite a space week for Americans.

After Monday's stunning solar eclipse, Wednesday night PBS will air its two-hour documentary film about the two Voyager missions, launched 40 years ago. The Farthest: Voyager In Space, celebrates a technological and intellectual achievement rarely matched in history. Two small, nuclear-powered spacecraft have traveled farther than any other man-made machine and have forever changed our views of the solar system — and our place in it.

"Nature loves to hide."

This is how, more than 25 centuries back, the pre-Socratic Greek philosopher Heraclitus of Ephesus expressed the sense of mystery we all feel when we start pondering how the world works.

There seem to be hidden mechanisms, secret pacts between the things that make the world the world, from the smallest building blocks of matter to the neurons in our brains to the way the whole universe is stretching out in its inexorable expansion.

I entered the packed cafeteria with tray in hand, searching for the right food to eat.

Around me, hundreds of people of all ages spoke excitedly in dozens of different languages, commenting on each other's ideas, asking questions, and thinking of the next steps in their research programs.

Lunchtime at the United Nations?

On Aug. 21, a narrow, 70-mile wide swath of the United States from Oregon to South Carolina will be the stage for one of the most (if not the most) spectacular celestial events, a total eclipse of the sun.

Space.com has put together a nice informational guide, including a video and a map explaining where to go, what to expect, and how to watch it safely. This is the first total solar eclipse in America in almost 40 years. The next one in the U.S. will be on April 8, 2024.

The history of science — in particular the physical sciences, like physics and astronomy — can be told as the incremental realization that there is large-scale coherence in the universe.

By large-scale coherence, I mean that some of the same physical laws hold at scales as diverse as the atom and the galaxy, and even the universe as a whole. In a sense, the universe speaks one language and scientists act as the interpreters, translating this language in terms that humans can understand and relate to.

Let's face it: Vegetarians are a strict minority of the U.S. population.

The numbers seem to be increasing, though data from various surveys vary widely.

Sometimes, I veer off my beloved scientific topics to explore another of my passions — human endurance.

Today we address the composition of the universe, in the final essay of our trilogy on cosmic questions.

As the great German astronomer Johannes Kepler once wrote in the early 17th century: "When the storm rages and the shipwreck of the state threatens, we can do nothing more worthy than to sink the anchor of our peaceful studies into the ground of eternity."

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