In 2018, UK tabloid newspaper The Sun ran a very disturbing story.

"The Earth's magnetic poles could be about to flip, sparking chaos and making large parts of the planet uninhabitable, it has emerged," the paper reported.

And while it is true that Earth's magnetic field has reversed in the past - multiple times, in fact - and that doing so today would very likely cause some serious problems, not least to navigation equipment, new modelling suggests it's not going to happen any time soon.

And that's genuinely reassuring. Research shows that the magnetic north and south poles historically flip about every 300,000 years, but that the last time it happened was 780,000 years ago. Technically, therefore, the next one is long overdue.

According to the British Geological Survey, however, the periodicity of the changes is much more apparent than real. At some stages in the Earth's history millions of years have passed between reversals.

Blue Origin, owned by Amazon CEO Jeff Bezos, launched a New Shepard suborbital capsule from West Texas on Sunday, boosting a suite of microgravity experiments and an instrumented dummy astronaut known as Mannequin Skywalker to the edge of space in the company's eighth test flight.

Perched atop a reusable booster powered by a single hydrogen-fueled BE-3 engine, the New Shepard spacecraft blasted off from the company's Van Horn, Texas, test facility at 1:06 p.m. EDT (GMT-4) and smoothly climbed away, generating 110,000 pounds of thrust and trailing a brilliant jet of flame.

Designed to carry up to six "space tourists" to altitudes above 62 miles, the widely recognized threshold of space, the unmanned New Shepard capsule separated from its booster, as planned, at an altitude of about 47 miles, before soaring on its own to a height of 351,000 feet, or 66.5 miles.

Worse than the 1906 earthquake. Worse than eight Hurricane Katrinas. Worse than every wildfire in California history, combined. The world's first trillion-dollar natural disaster.

A wintertime megaflood in California could turn out to be the worst natural disaster in U.S. history by far, and we are making it much more likely, according to an alarming study published this week in Nature Climate Change.

The odds are good that such a flood will happen in the next 40 years, the study says. By the end of the century, it's a near certainty. (And then another one hits, and another - three such storms are possible by 2100). By juicing the atmosphere, extreme West Coast rainstorms will happen at five times their historical rate, if humanity continues on roughly a business-as-usual path, the new research predicts.

The study's lead author, Daniel Swain, a climate scientist at the University of California, Los Angeles, and a lifelong Californian, says the best way to understand what we're doing to California's weather is to think of earthquakes.

The Earth will experience a number of (relatively) close calls in one day, as NASA reports that an alarming total of five asteroids will hurtle towards - but happily not quite at - our planet.

The Center for Near Earth Object Studies at NASA's Jet Propulsion Laboratory in California publishes a comprehensive list of space rocks that are worth keeping an eye on, just to prepare yourself for any potential armageddons or extinction-level collisions. These rocks can range in size from a few meters in length to asteroids more akin to skyscrapers.

The series of space rock flybys begins at 10:29 UTC Sunday as asteroid 2013 US3, travelling at a respectable 7.69 km/s (27,646 kph) with a diameter of between 160-360 meters whizzes past us. For comparison, the Eiffel Tower measures 324 meters from ground to tip.

On March 24, 1993, in the midst of a photographic search for near-Earth objects at the fabled Palomar Observatory, Drs. Carolyn and Eugene Shoemaker and Dr. David Levy acquired an image in the vicinity of planet Jupiter using surplus film. This image surprised the observers when they first examined it. Expecting to find yet another small asteroid trail, they instead found an elongate object comprising several large clumps all strung out in a chain thousands of kilometers long in the night sky, each with its own cometary tail. Its orbital position proved to be quite close to Jupiter, and it did not take long to determine that it was in fact orbiting that giant planet and would come very close to the cloud tops the following year.The discovery of this strange comet was both serendipitous and completely unexpected, and the rest of the world was startled when the image was released three days later. No object like it had ever been seen before. It would be named P/Shoemaker-Levy 9 after its discoverers (SL-9 for short). We had observed comets break apart during close encounters with the Sun into irregular clumps, but the linear geometry of this object indicated that it had passed very close to Jupiter in July 1992 and been ripped apart by tidal forces, something we had not observed or even predicted before. The original comet may have been captured by Jupiter as far back as 1929 or so. More surprises were to come.

The acceleration of human progress and knowledge about health has reached a breakneck pace, and it appears as though there are two distinct camps emerging: people who believe natural health is the answer to a long and healthy life, and those who would rather side with modern medicine.

At the end of the day, both methods have their benefits and drawbacks, and have been instrumental in increasing human lifespan even at a time when chronic diseases are out-of-control.

But now, mainstream medicine is entering into unchartered territory, and it could change the future of our species for good. Whether or not it ends up being a positive development, however, remains to be seen.

For environmentalists of a certain vintage, the words "acid" and "lakes" can stir strangely fond memories. Back in the 1970s and 80s, acid rain from coal-fired power stations was turning lakes across the northern hemisphere into vinegar. Scientists identified the problem, activists campaigned, governments listened. Today, in the West at least, acid rain is largely a thing of the past.

But acid lakes are not. Even while many are still recovering from being deluged with acid rain, they face a resumed assault - this time from carbon dioxide. High concentrations of the gas in the atmosphere means more is dissolving in the world's lakes and rivers. Goodbye sulphuric acid, hello carbonic acid.

The new acid invasion shouldn't come as a surprise. For over a decade, marine biologists have been on alert for the effects of acidifying oceans as rising amounts of atmospheric CO₂ dissolve into them. But until now, the parallel acidification of rivers and lakes has largely escaped attention. That changed in January with the publication of the first research to pinpoint freshwater lakes accumulating CO₂ from the air, and growing more acidic as a result. "The rate of acidification is really quite fast - three times faster than in the world's oceans," says Linda Weiss of the Ruhr University Bochum in Germany, who led the study (Current Biology, vol 28, p 327).

That is obviously a cause for concern. Ocean acidification - sometimes known as "the other CO₂ problem" - is expected to have severe effects on marine ecosystems. About a third of all the CO₂ released into the atmosphere dissolves in seawater and turns into carbonic acid. Since the industrial revolution, the pH of the ocean surface has fallen from 8.16 to 8.05, a 30 per cent increase in the concentration of hydrogen ions. This isn't a concern yet, but if it continues it will eventually cause some corals and shells to dissolve.

From Inception to the anime classic Paprika, science-fiction is filled with devices that let people manipulate dreams. Though researchers have started work on machines that can read your mind and translate thoughts into text, the realm of sleep has remained relatively unexplored...until now.

Scientists at MIT are working on the third generation of a device called Dormio, which is already being described as "workable system for dream control."

Surprisingly, Dormio isn't concerned with REM sleep, the deep stage of sleep where most dreams occur-instead, it's focused on the hypnagogic state, the area between waking and dreaming.

In hypnagogia, people can experience vivid 'microdreams' and even auditory and visual hallucinations, along with strong bursts of creativity.

During hypnagogia, a person can still speak and hear people talking to them, but their thinking begins to change.

If Joey was Chloe's age when he was twice as old as Zoe was, how many times older will Zoe be when Chloe is twice as old as Joey is now?

Or try this one for size. Two farmers inherit a square field containing a crop planted in a circle. Without knowing the exact size of the field or crop, or the crop's position within the field, how can they draw a single line to divide both the crop and field equally?

You've either fallen into a cold sweat or you're sharpening your pencil (if you can't wait for the answer, you can check the bottom of this page). Either way, although both problems count as "maths" - or "math" if you insist - they are clearly very different. One is arithmetic, which deals with the properties of whole numbers: 1, 2, 3 and so on as far as you can count. It cares about how many separate things there are, but not what they look like or how they behave. The other is geometry, a discipline built on ideas of continuity: of lines, shapes and other objects that can be measured, and the spatial relationships between them.

Mathematicians have long sought to build bridges between these two ancient subjects, and construct something like a "grand unified theory" of their discipline. Just recently, one brilliant young researcher might have brought them decisively closer. His radical new geometrical insights might not only unite mathematics, but also help solve one of the deepest number problems of them all: the riddle of the primes. With the biggest prizes in mathematics, the Fields medals, to be awarded this August, he is beginning to look like a shoo-in.

Scientists have developed a prototype for an app that's been designed for cannabis users so that they can determine whether or not they're actually high. The app tests memory, attention and reaction -- traits that are often impaired by cannabis use.

The app, called "Am I Stoned", has been created by researchers from the University of Chicago to assess the effects of cannabis on cognitive ability.

Co-authors Elisa Pabon, a doctoral student, and Harriet de Wit, professor in the department of psychiatry and behavioural neuroscience, presented the app yesterday at the Emerging Biology conference in California.

The app, which has been supported by the National Institute on Drug Abuse Grant, provides users with a series of tasks to test the impact of cannabis use on memory, reaction time and attention span.