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Nasa investigating 'anomaly' in Earth's magnetic field – Metro.co.uk

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Nasa is investigating a ‘dent’ in Earth’s magnetic field that occurs over the southern Atlantic ocean.

Known as the ‘South Atlantic Anomaly’ (SAA), it’s a region of weakness in the magnetic field that stretches from Africa to South America.

Data suggests this area has lost a considerable amount of strength over the last fifty years, which could expose the planet’s surface to harmful radiation.

The magnetic field repels and traps solar radiation, but this dent in protection is causing it to get closer and closer to the surface. The consequences are severe: computers on board ships and aircraft could be affected and technical difficulties could extend to satellites orbiting above.

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Nasa says that over the last five years a second area of low intensity inside the region has formed, which researchers say could indicate the anomaly will split into two different cells.

The space agency is trying to understand the SAA better so it can predict what changes may be coming in order to better protect its satellites.

A second cell within the SAA has been growing since 2015 (Picture: NASA)

‘The South Atlantic Anomaly arises from two features of Earth’s core: The tilt of its magnetic axis, and the flow of molten metals within its outer core,’ the space agency explained.

‘Earth is a bit like a bar magnet, with north and south poles that represent opposing magnetic polarities and invisible magnetic field lines encircling the planet between them. But unlike a bar magnet, the core magnetic field is not perfectly aligned through the globe, nor is it perfectly stable.

‘That’s because the field originates from Earth’s outer core: molten, iron-rich and in vigorous motion 1800 miles below the surface. These churning metals act like a massive generator, called the geodynamo, creating electric currents that produce the magnetic field.

‘As the core motion changes over time, due to complex geodynamic conditions within the core and at the boundary with the solid mantle up above, the magnetic field fluctuates in space and time too. These dynamical processes in the core ripple outward to the magnetic field surrounding the planet, generating the SAA and other features in the near-Earth environment – including the tilt and drift of the magnetic poles, which are moving over time.’

Nasa monitoring evolving dent in Earth's magnetic field (Picture: NASA)

Earth’s magnetic field could be about to flip (Picture: NASA)

One scientific theory is that the divergence and weakening of the SAA could indicate the magnetic field is about to reverse polarity.

This is a shift that happens over centuries and has occurred many times in the past – roughly every 250,000 years.

‘Even though the SAA is slow-moving, it is going through some change in morphology, so it’s also important that we keep observing it by having continued missions,’ said  Terry Sabaka, a geophysicist at Nasa’s Goddard Space Flight Center in Greenbelt, Maryland.

‘Because that’s what helps us make models and predictions.’

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This modular home workout setup fits in your closet, no more excuses to not exercise! – Yanko Design

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Few industries have changed due to the COVID-19 pandemic like the fitness industry has changed. Acclimating to the increasingly strange times, home gym designers have taken to the drawing boards by storm. Working out at home is possible, yes. Fun? Depends. Comfortable? Hard to say. What’s definite is that the team at G-Wall turned the everchanging state of 2020 into the well-knit, conceptual core of their sleek, modular home gym design. Recently, the designers behind the G-Wall Home Fitness System were presented with 2020’s K-Design Award.

Instead of answering the unanswerable (really, who can say what’s up next for 2020), the team behind G-Wall designed their home gym specifically so that it could be stored behind a closet or armoire cabinet’s door. That way the time that you would have spent making room for your home fitness system, instead is spent actually putting it to use. G-Wall’s Home Fitness System has several standout features: variable modules, user-adjustability, and compatibility, to name a few. Each user decides on which modules they want to comprise the larger system. This means that despite the amount of space in your home, G-Wall’s design makes it possible to incorporate a home gym anywhere. The different modules that users can decide on range from cardiovascular equipment, to free weights and even heavy training. The gear that comes with each module is stored in cabinets or racks that easily hang behind doors or however the user deems appropriate for their personal space.

Once quarantine started, many of us twiddled our thumbs while figuring out how to stay healthy and active within the confines of our respective homes. Fitness and health remained a top priority for many global citizens. It was never a question of compromise or adjustment when it came to working out during quarantine. Rather, designers and gym-goers took to the drawing boards to concoct their own solutions. That’s all to say that while the fitness industry has indeed changed with 2020’s unpredictable timeline, some of the most innovative new designs have been devised. Such deliberate and convenient designs like G-Wall prove that as unanswerable as some questions may be, as uncertain as the time may feel, design’s practical and adaptive nature is one thing on which we can always depend.

Designers: Tan Xuwen, Zhang Hu, Huang Shumei, Tong Bomin, Gao Lin x Guangdong Piano Customized Furniture Co., Ltd.









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A Physicist Has Come Up With Math That Makes 'Paradox-Free' Time Travel Plausible – ScienceAlert

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No one has yet managed to travel through time – at least to our knowledge – but the question of whether or not such a feat would be theoretically possible continues to fascinate scientists.

As movies such as The Terminator, Donnie Darko, Back to the Future and many others show, moving around in time creates a lot of problems for the fundamental rules of the Universe: if you go back in time and stop your parents from meeting, for instance, how can you possibly exist in order to go back in time in the first place?

It’s a monumental head-scratcher known as the ‘grandfather paradox’, but now a physics student Germain Tobar, from the University of Queensland in Australia, says he has worked out how to “square the numbers” to make time travel viable without the paradoxes.

“Classical dynamics says if you know the state of a system at a particular time, this can tell us the entire history of the system,” says Tobar.

“However, Einstein’s theory of general relativity predicts the existence of time loops or time travel – where an event can be both in the past and future of itself – theoretically turning the study of dynamics on its head.”

What the calculations show is that space-time can potentially adapt itself to avoid paradoxes.

To use a topical example, imagine a time traveller journeying into the past to stop a disease from spreading – if the mission was successful, the time traveller would have no disease to go back in time to defeat.

Tobar’s work suggests that the disease would still escape some other way, through a different route or by a different method, removing the paradox. Whatever the time traveller did, the disease wouldn’t be stopped.

Tobar’s work isn’t easy for non-mathematicians to dig into, but it looks at the influence of deterministic processes (without any randomness) on an arbitrary number of regions in the space-time continuum, and demonstrates how both closed timelike curves (as predicted by Einstein) can fit in with the rules of free will and classical physics.

“The maths checks out – and the results are the stuff of science fiction,” says physicist Fabio Costa from the University of Queensland, who supervised the research.

Fabio Costa (left) and Germain Tobar (right). (Ho Vu)

The new research smooths out the problem with another hypothesis, that time travel is possible but that time travellers would be restricted in what they did, to stop them creating a paradox. In this model, time travellers have the freedom to do whatever they want, but paradoxes are not possible.

While the numbers might work out, actually bending space and time to get into the past remains elusive – the time machines that scientists have devised so far are so high-concept that for they currently only exist as calculations on a page.

We might get there one day – Stephen Hawking certainly thought it was possible – and if we do then this new research suggests we would be free to do whatever we wanted to the world in the past: it would readjust itself accordingly.

“Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency,” says Costa. “The range of mathematical processes we discovered show that time travel with free will is logically possible in our universe without any paradox.”

The research has been published in Classical and Quantum Gravity.

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The Great Conjunction of 2020: Jupiter and Saturn sky show this fall – Minnesota Public Radio News

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There’s a spectacular sky show in the southern sky this fall.

It’s called the Great Conjunction. Saturn and Jupiter are bright in the southern sky on clear evenings. The waxing moon adds to the show tonight hanging to the lower left of Saturn.

Southern sky for the evening of Sept. 25, 2020

Courtesy NASA/JPL-Caltech

Earthsky.org elaborates:

On September 23, 24, 25 and 26, 2020, look for the moon in the evening sky, and it’ll guide you to Jupiter and Saturn, our solar system’s two biggest gas giant planets. Given clear skies, you can’t miss these bright worlds. The moon is the second-brightest celestial object, after the sun. And Jupiter is exceptionally bright, too, outshining all the stars (but just a hair less bright than dazzling Mars; more about Mars below). As for Saturn, it’s as bright as the brightest stars. Plus Jupiter and Saturn are noticeable now for their nearness to each other. They’re headed for a great conjunction before 2020 ends.

The Great Conjunction of December 2020

Jupiter and Saturn are 7.5 degrees apart in the southern sky now. They will draw closer this fall and will be just 0.1 degrees apart on the winter solstice on December 21.

Astro Bob writes for the Duluth News Tribune about how the two planets draw closer until conjunction on December 21.

More distant Saturn orbits at 21,675 mph (9.7 km/sec) and takes 29 years to circle the sun. Because Jupiter is both closer to the Earth and travels faster it overtakes Saturn about once every 20 years, an event called a great conjunction.

Because the orbits of Jupiter and Saturn are tilted slightly with respect to Earth’s orbit, 1.3° and 2.5° respectively, when they do line up the distance between them varies, making every conjunction different. If they were in exactly the same plane Jupiter would always pass directly in front of Saturn, but that’s extremely rare.

Enjoy the amazing sky show on clear evenings this fall.

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