Astronomers Create 8 Million Baby Universes Inside A Computer

(THIS ARTICLE IS COURTESY OF LIVE SCIENCE)

 

Astronomers Create 8 Million Baby Universes Inside a Computer and Watch Them Grow. Here’s What They Learned.

helix nebula

(Image: © Shutterstock)

A team of astrophysicists has just spawned 8 million unique universes inside a supercomputer and let them evolve from just tots to old geezers. Their goal? To nail down the role that an invisible substance called dark matter played in our universe’s life since the Big Bang and what it means for our fate.

After discovering that our universe is mostly composed of dark matter in the late 1960s, scientists have speculated on its role in the formation of galaxies and their ability to give birth to new stars over time.

According to the Big Bang theory, not long after the universe was born, an invisible and elusive substance physicists have dubbed dark matter began to clump together by the force of gravity into massive clouds called dark matter haloes. As the haloes grew in size, they attracted the sparse hydrogen gas permeating the universe to come together and form the stars and galaxies we see today. In this theory, dark matter acts as the backbone of galaxies, dictating how they form, merge and evolve over time.

Related: The 11 Biggest Unanswered Questions About Dark Matter

To better understand how dark matter shaped this history of the universe, Peter Behroozi, an assistant professor of astronomy at the University of Arizona, and his team created his own universes using the school’s supercomputer. The computer’s 2,000 processors worked without pause over a span of three weeks to simulate more than 8 million unique universes. Each universe individually obeyed a unique set of rules to help researchers understand the relationship between dark matter and the evolution of galaxies.

“On the computer, we can create many different universes and compare them to the actual one, and that lets us infer which rules lead to the one we see,” Behroozi said in a statement.

While previous simulations have focused on modeling single galaxies or generating mock universes with limited parameters, the UniverseMachine is the first of its scope. The program continuously created millions of universes, each containing 12 million galaxies, and each allowed to evolve over nearly the entire history of the real universe from 400 million years after the Big Bang to the present day.

“The big question is, ‘How do galaxies form?’” said study researcher Risa Wechsler, a professor of physics and astrophysics at Stanford University. “The really cool thing about this study is that we can use all the data we have about galaxy evolution —  the numbers of galaxies, how many stars they have and how they form those stars — and put that together into a comprehensive picture of the last 13 billion years of the universe.”

Related: From the Big Bang to Present: Snapshots of Our Universe Through Time

Creating a replica of our universe, or even of a galaxy, would require an inexplicable amount of computing power. So Behroozi and his colleagues narrowed their focus to two key properties of galaxies: their combined mass of stars and the rate at which they give birth to new ones.

“Simulating a single galaxy requires 10 to the 48th computing operations,” Behroozi explained, referring to an octillion operation, or a 1 followed by 48 zeros. “All computers on Earth combined could not do this in a hundred years. So to just simulate a single galaxy, let alone 12 million, we had to do this differently.”

As the computer program spawns new universes, it makes a guess on how a galaxy’s rate of star formation is related to its age, its past interactions with other galaxies and the amount of dark matter in its halo. It then compares each universe with real observations, fine-tuning the physical parameters with every iteration to better match reality. The end result is a universe nearly identical to our own.

According to Wechsler, their results showed that the rate at which galaxies give birth to stars is tightly connected to the mass of their dark matter haloes. Galaxies with dark matter halo masses most similar to our own Milky Way had the highest star-formation rates. She explained that star formation is stifled in more massive galaxies by an abundance of blackholes

Their observations also challenged long-held beliefs that dark matter stifled star formation in the early universe.

“As we go back earlier and earlier in the universe, we would expect the dark matter to be denser, and therefore the gas to be getting hotter and hotter. This is bad for star formation, so we had thought that many galaxies in the early universe should have stopped forming stars a long time ago,” Behroozi said. “But we found the opposite: Galaxies of a given size were more likely to form stars at a higher rate, contrary to the expectation.”

Now, the team plans to expand the Universe Machine to test more ways dark matter might affect the properties of galaxies, including how their shapes evolve, the mass of their black holes and how often their stars go supernova.

“For me, the most exciting thing is that we now have a model where we can start to ask all of these questions in a framework that works,” Wechsler said. “We have a model that is inexpensive enough computationally, that we can essentially calculate an entire universe in about a second. Then we can afford to do that millions of times and explore all of the parameter space.”

The research group published their results in the September issue of the journal Monthly Notices of the Royal Astronomical Society.

Originally published on Live Science.

What Is the Universe Made of?

(THIS ARTICLE IS COURTESY OF LIVE SCIENCE)

 

What Is the Universe Made of?

Image of galaxy cluster Abell 2744 shows dark matter locations

In this image of galaxy cluster Abell 2744, a blue overlay shows the location of dark matter, which makes up about 75% of the cluster’s mass.
(Image: © NASA/ESA/ESO/CXC, and D. Coe (STScI)/J. Merten (Heidelberg/Bologna))

The universe is filled with billions of galaxies and trillions of stars, along with nearly uncountable numbers of planets, moons, asteroids, comets and clouds of dust and gas – all swirling in the vastness of space.

But if we zoom in, what are the building blocks of these celestial bodies, and where did they come from?

Hydrogen is the most common element found in the universe, followed by helium; together, they make up nearly all ordinary matter. But this accounts for only a tiny slice of the universe — about 5%. All the rest is made of stuff that can’t be seen and can only be detected indirectly. [From Big Bang to Present: Snapshots of Our Universe Through Time]

Mostly hydrogen

It all started with a Big Bang, about 13.8 billion years ago, when ultra-hot and densely packed matter suddenly and rapidly expanded in all directions at once. Milliseconds later, the newborn universe was a heaving mass of neutrons, protons, electrons, photons and other subatomic particles, roiling at about 100 billion degrees Kelvin, according to NASA.

Every bit of matter that makes up all the known elements in the periodic table — and every object in the universe, from black holes to massive stars to specks of space dust — was created during the Big Bang, said Neta Bahcall, a professor of astronomy in the Department of Astrophysical Sciences at Princeton University in New Jersey.

“We don’t even know the laws of physics that would have existed in such a hot, dense environment,” Bahcall told Live Science.

About 100 seconds after the Big Bang, the temperature dropped to a still-seething 1 billion degrees Kelvin. By roughly 380,000 years later, the universe had cooled enough for protons and neutrons to come together and form lithium, helium and the hydrogen isotope deuterium, while free electrons were trapped to form neutral atoms.

Because there were so many protons zipping around in the early universe, hydrogen — the lightest element, with just one proton and one neutron — became the most abundant element, making up nearly 95% percent of the universe’s atoms. Close to 5% of the universe’s atoms are helium, according to NASA. Then, about 200 million years after the Big Bang, the first stars formed and produced the rest of the elements, which make up a fraction of the remaining 1% of all ordinary matter in the universe.

Unseen particles

Something else was created during the Big Bang: dark matter. “But we can’t say what form it took, because we haven’t detected those particles,” Bahcall told Live Science.

Dark matter can’t be observed directly — yet — but its fingerprints are preserved in the universe’s first light, or the cosmic microwave background radiation (CMB), as tiny fluctuations in radiation, Bahcall said. Scientists first proposed the existence of dark matter in the 1930’s, theorizing that dark matter’s unseen pull must be what held together fast-moving galaxy clusters. Decades later, in the 1970’s, American astronomer Vera Rubin found more indirect evidence of dark matter in the faster-than-expected rotation rates of stars.

Based on Rubin’s findings, astrophysicists calculated that dark matter — even though it couldn’t be seen or measured — must make up a significant portion of the universe. But about 20 years ago, scientists discovered that the universe held something even stranger than dark matter; dark energy, which is thought to be significantly more abundant than either matter or dark matter. [Gallery: Dark Matter Throughout the Universe]

Hubble Space Telescope Image

Captured in 2014 by the Hubble Space Telescope, this picture of the evolving universe is among Hubble’s most colorful deep-space images.

(Image credit: NASA/ESA)

An irresistible force

The discovery of dark energy came about because scientists wondered if there was enough dark matter in the universe to cause expansion to sputter out or reverse direction, causing the universe to collapse inward on itself.

Lo and behold, when a team of researchers investigated this in the late 1990s, they found that not only was the universe not collapsing in on itself, it was expanding outward at an ever faster rate. The group determined that an unknown force — dubbed dark energy — was pushing against the universe in the apparent void of space and accelerating its momentum; the scientists’ findings earned physicists Adam Riess, Brian Schmidt and Saul Perlmutter the Nobel Prize in Physics in 2011.

Models of the force required to explain the universe’s accelerating expansion rate suggest that dark energy must make up between 70% and 75% of the universe. Dark matter, meanwhile, accounts for about 20% to 25%, while so-called ordinary matter — the stuff we can actually see — is estimated to make up less than 5% of the universe, Bahcall said.

Considering that dark energy makes up about three-quarters of the universe, understanding it is arguably the biggest challenge facing scientists today, astrophysicist Mario Livio, then with the Space Telescope Science Institute at Johns Hopkins University in Baltimore, Maryland, told Live Science sister site Space.com in 2018.

“While dark energy has not played a huge role in the evolution of the universe in the past, it will play the dominant role in the evolution in the future,” Livio said. “The fate of the universe depends on the nature of dark energy.”

Originally published on Live Science.

Antarctica breakthrough: Scientists discover NEW species ‘like nothing seen before’

(THIS ARTICLE IS COURTESY OF THE UK EXPRESS NEWS)

 

Antarctica breakthrough: Scientists discover NEW species ‘like nothing seen before’

ANTARCTICA scientists discovered a new species of fish after heading deep below the frozen continent, a documentary revealed.

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Antarctica is of great interest to scientists as it is a totally unspoiled landscape where they can study the history of the Earth and the effects of climate change. Thousands of scientists reside there, drilling below the ice to get a better idea of the icy continent’s past. However, one group took things a step further.

Expedition Antarctica embarked on a journey through the surrounding waters of Antarctica to uncover some of the most bizarre marine life known to man.

They documented their journey, which saw them pull out a number of strange fish from the depths of the ocean.

Andrew Stewart, a leading scientist in the excavation was left stunned by some of the species.

He said last month: “This is why I came to Antarctica, to see things like this.

Antarctica scientists found a new species

Antarctica scientists found a new species (Image: YOUTUBE)

The expedition headed around the continent

The expedition headed around the continent (Image: YOUTUBE)

This is why I came to Antarctica

Andrew Stewart

“We now have whole families of fish found nowhere else in the world, except the Southern Ocean and these are fascinating animals.

“These are the ice fish, temperatures above five degrees are too hot for them.”

However, the narrator of the show went on to reveal how one discovery stood out from the rest.

He said: “The sea holds a dizzying variety of fish to baffle and thrill marine biologists.

“Nature even saw fit to make about 115 species of snailfish.

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The team then pulled fish up from the depths of the ocean

The team then pulled fish up from the depths of the ocean (Image: YOUTUBE)

“Then, along comes the type of discovery that blows biologists out of the water.

“Most scientists hope to find something truly new, but only a few actually accomplish it.

“Andrew has discovered another new species, making him the first human to lay eyes on this creature, that has evolved over millions of years.”

Dr Stewart held the creature up to the camera.

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A number of strange creatures emerged

A number of strange creatures emerged (Image: YOUTUBE)

There was one fish more bizarre than the rest

There was one fish more bizarre than the rest (Image: YOUTUBE)

The team plan to scour the rest of the ocean

The team plan to scour the rest of the ocean (Image: YOUTUBE)

Antarctica: Scientists discover when continent froze over

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He then exclaimed: “I have to look at such features as the shape of the teeth, the jaws, the shape of the gill rakers, as well as counts of the vertebrae [to determine what it is].

“Now I have no idea what species this is.

“The colour pattern on the fins is like nothing I’ve ever seen before.”

Scientists also discovered a four-million-year-old piece of wood that has helped researchers to map out Antarctica’s past.

Territorial claims in Antarctica

Territorial claims in Antarctica (Image: DX)

Our Galaxy’s Supermassive Black Hole Has Emitted a Mysteriously Bright Flare

(THIS ARTICLE IS COURTESY OF SCIENCE ALERT)

 

Our Galaxy’s Supermassive Black Hole Has Emitted a Mysteriously Bright Flare

MICHELLE STARR
12 AUG 2019

The supermassive black hole at the heart of the Milky Way, Sagittarius A*, is relatively quiet. It’s not an active nucleus, spewing light and heat into the space around it; most of the time, the black hole’s activity is low key, with minimal fluctuations in its brightness.

Most of the time. Recently, astronomers caught it going absolutely bananas, suddenly growing 75 times brighter before subsiding back to normal levels. That’s the brightest we’ve ever seen Sgr A* in near-infrared wavelengths.

“I was pretty surprised at first and then very excited,” astronomer Tuan Do of the University of California Los Angeles told ScienceAlert.

“The black hole was so bright I at first mistook it for the star S0-2, because I had never seen Sgr A* that bright. Over the next few frames, though, it was clear the source was variable and had to be the black hole. I knew almost right away there was probably something interesting going on with the black hole.”

But what? That’s what astronomers are on a mission to find out. Their findings so far are currently in press with The Astrophysical Journal Letters.

Do and his team took observations of the galactic center galaxy

using the WM Keck Observatory in Hawaii over four nights earlier this year. The strange brightening was observed on May 13, and the team managed to capture it in a time lapse, two hours condensed down to a few seconds.

Tuan Do@quantumpenguin

Here’s a timelapse of images over 2.5 hr from May from @keckobservatory of the supermassive black hole Sgr A*. The black hole is always variable, but this was the brightest we’ve seen in the infrared so far. It was probably even brighter before we started observing that night!

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That brightly glowing dot right at the beginning of the video is the dust and gas swirling around Sgr A*. Black holes themselves don’t emit any radiationthat can be detected by our current instruments, but the stuff nearby doeswhen the black hole’s gravitational forces generate immense friction, in turn producing radiation.

When we view that radiation with a telescope using the infrared range, it translates as brightness. Normally, the brightness of Sgr A* flickers a bit like a candle, varying from minutes to hours. But when the surroundings of a black hole flare that brightly, it’s a sign something may have gotten close enough to be grabbed by its gravity.

The first frame – taken right at the beginning of the observation – is the brightest, which means Sgr A* could have been even brighter before they started observing, Do said. But no one was aware that anything was drawing close enough to be swallowed by the black hole.

The team is busily gathering data to try and narrow it down, but there are two immediate possibilities. One is G2, an object thought to be a gas cloud that approached within 36 light-hours of Sgr A* in 2014. If it was a gas cloud, this proximity should have torn it to shreds, and parts of it devoured by the black hole – yet nothing happened.

The flyby was later called a “cosmic fizzle“, but the researchers believe the black hole’s May fireworks show may have been a delayed reaction.

sgr a s02(Do et al., arXiv, 2019)

But – have a look at the timelapse again. See that bright dot at around 11 o’clock from the black hole? That’s S0-2, a star on a long, looping, 16-year elliptical orbit around Sgr A*. Last year, it made its closest approach, coming within 17 light-hours of the black hole.

“One of the possibilities,” Do told ScienceAlert, “is that the star S0-2, when it passed close to the black hole last year, changed the way gas flows into the black hole, and so more gas is falling on it, leading it to become more variable.”

The only way to find out is having more data. They are currently being collected, across a larger range of wavelengths. More observations will take place over the coming weeks with the ground-based Keck Observatory before the galactic centre is no longer visible at night from Earth.

But many other telescopes – including Spitzer, Chandra, Swift and ALMA – were observing the galactic centre over the last few months, too. Their data could reveal different aspects of the physics of the change in brightness, and help us understand what Sgr A* is up to.

“I’m eagerly awaiting their results,” Do said.

The paper has been accepted into The Astrophysical Journal Letters, and is available on arXiv.

Astronomers Uncover Dozens of Previously Unknown Ancient and Massive Galaxies

(THIS ARTICLE IS COURTESY OF ASTRONOMY TODAY)

 

Astronomers Uncover Dozens of Previously Unknown Ancient and Massive Galaxies

For decades, astronomers have been trying to see as far as they can into the deep Universe. By observing the cosmos as it was shortly after the Big Bang, astrophysicists and cosmologists hope to learn all they can about the early formation of the Universe and its subsequent evolution. Thanks to instruments like the Hubble Space Telescope, astronomers have been able to see parts of the Universe that were previously inaccessible.

But even the venerable Hubble is incapable of seeing all that was taking place during the early Universe. However, using the combined power of some of the newest astronomical observatories from around the world, a team of international astronomers led by Tokyo University’s Institute of Astronomy observed 39 previously-undiscovered ancient galaxies, a find that could have major implications for astronomy and cosmology.

The team behind the discovery included members from Tokyo University’s Institute of Astronomy, the French National Center for Scientific Research (CNRS), the Anhui Normal University in China, the University of Ludwig-Maximilians in Munich, the National Astronomical Observatories of China, and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan. Their research appeared in the Aug. 7th issue of Nature.

Artist impression of galaxies detected by ALMA as they appear in the very early, very distant universe. Credit: NRAO/AUI/NSF; S. Dagnello

Spotting the “Invisible”

To put it simply, the earliest possible galaxies in the Universe have remained invisible until now because their light is very faint and occurs at long wavelengths that are undetectable by Hubble. The team therefore turned to the Atacama Large Millimeter/submillimeter Array(ALMA), whose telescopes are optimized for viewing this kind of light.

The discovery that resulted was not only unprecedented, but the discovery of this many galaxies of this type defies current cosmological models. As Tao Wang, a researcher from the AISAA and a co-author on the study, explained:

“This is the first time that such a large population of massive galaxies was confirmed during the first 2 billion years of the 13.7-billion-year life of the universe. These were previously invisible to us. This finding contravenes current models for that period of cosmic evolution and will help to add some details, which have been missing until now.”

These galaxies, though they were the largest in existence at the time, were still very difficult to spot. Much of the reason has to do with the extent to which their light has been stretched by the expansion of the Universe. In everyday astronomy, this phenomena is known as redshift, where the expansion of space (the Hubble Constant) causes the wavelength of light to become elongated, shifting it towards the red end of the spectrum.

This allows astronomers to not only tell how distant an object is, but what that object looked like in the past. But when looking to the very earliest epoch of the Universe (over 13 billion years ago) the immense distance stretches the wavelength of visible light to the point where it is no longer in the domain of visible light and becomes infrared.

NASA’s Spitzer Space Telescope captured this stunning infrared image of the center of the Milky Way Galaxy, where the black hole Sagitarrius A resides. Credit: NASA/JPL-Caltech

Another reason these galaxies are difficult to spot is that larger galaxies tend to be shrouded in dust, especially when they are still in the early parts of their formation. This tends to obscure them more than their smaller galactic counterparts. For these reasons, there was some suspicion that these galaxies were not as old as the team suggested. As Wang indicated:

“It was tough to convince our peers these galaxies were as old as we suspected them to be. Our initial suspicions about their existence came from the Spitzer Space Telescope’s infrared data. But ALMA has sharp eyes and revealed details at submillimeter wavelengths, the best wavelength to peer through dust present in the early universe. Even so, it took further data from the imaginatively named Very Large Telescope in Chile to really prove we were seeing ancient massive galaxies where none had been seen before.”

What Does This Mean for Astronomy?

Since the discovery of these galaxies defies our current cosmological models, the team’s findings naturally have some significant implications for astronomers. As Kotaro Kohno, a professor with the Institute of Astronomy and a co-author on the study, explained:

“The more massive a galaxy, the more massive the supermassive black hole at its heart. So the study of these galaxies and their evolution will tell us more about the evolution of supermassive black holes, too,” added Kohno. “Massive galaxies are also intimately connected with the distribution of invisible dark matter. This plays a role in shaping the structure and distribution of galaxies. Theoretical researchers will need to update their theories now.”

Ancient galaxies from the study are visible to ALMA (right) but not to Hubble (left). Credit: Wang (et al.) 2019

Another interesting find was the ways in which these 39 ancient galaxies differ from our own. For starters, these galaxies had a higher density of stars than the Milky Way does today; which means that if our galaxy were similar, stargazers would be seeing something very different when they looked up at the night sky.

“For one thing, the night sky would appear far more majestic. The greater density of stars means there would be many more stars close by appearing larger and brighter,” said Wang. “But conversely, the large amount of dust means farther-away stars would be far less visible, so the background to these bright close stars might be a vast dark void.”

Since this is the first time that a galactic population of this kind has been discovered, astronomers are looking forward to what else they might find. As it stands, even ALMA is not sophisticated enough to investigate the chemical compositions and stellar populations of these galaxies. However, next-generation observatories will have the resolution for astrnomers to conduct these studies.

These include the James Webb Space Telescope, which is currently slated for launch in 2021. Ground-based observatories like the ESO’s Extremely Large Telescope (ELT), the Thirty Meter Telescope (TMT) and the Giant Magellan Telescope (GMT) are also likely to play a vital role.

It’s an exciting time for astronomers and cosmologists. Ever so slowly, they are peeling back another layer of the Universe to see what secrets lurk beneath!

Further Reading: University of Tokyo

Space travel breakthrough: could cover 3.6 Million miles per day passes test

(THIS ARTICLE IS COURTESY OF THE UK EXPRESS)

Space travel breakthrough: Spacecraft which cover 3.6 Million miles per day passes test

A SPACESHIP which is so fast it could travel 3.6 million miles per day has been successfully tested in Earth’s orbit.

LightSail 2: Planetary Society demonstrates solar sail spacecraft

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The Lightsail 2 craft is an experiment to prove the practical application of a controlled ‘solar sail’, which has the ability to far outstrip traditional rocket engines. The revolutionary mission was launched on June 25 and developed by ‘The Planetary Society’, based in the US. The voyage became the first ever to demonstrate solar sailing and used energy from the Sun to orbit Earth.

The tiny 10x10x30cm spacecraft was powered with propelled sunlight bouncing off its mirrored sails.

The exploration used thin plastic sheets to gather the momentum from the Sun.

Most notably the spacecraft was able to manoeuvre without the need for fuel or engines.

science

The Lightsail 2 was successful in its orbit around Earth (Image: AP)

science

The voyage became the first ever to demonstrate solar sailing (Image: The Planetary Society)

Bruce Betts LightSail program manager and Planetary Society chief scientist hailed the groundbreaking mission.

Mr Betts said: “We’re thrilled to announce mission success for LightSail 2.

“Our criteria was to demonstrate controlled solar sailing in a CubeSat by changing the spacecraft’s orbit using only the light pressure of the Sun, something that’s never been done before.

READ MORE: Sun explosion: Terrifying moment Sun shockwave sends particles flying

Science

The exploitation used thin plastic sheets to gather the momentum from the Sun (Image: GETTY)

“I’m enormously proud of this team. It’s been a long road and we did it.”

Leading scientist and Planetary Society CEO Bill Nye said the mission was a “game-changer” for further space exploration.

He said: ”For The Planetary Society, this moment has been decades in the making.

“Carl Sagan talked about solar sailing when I was in his class in 1977. But the idea goes back at least to 1607, when Johannes Kepler noticed that comet tails must be created by energy from the Sun.

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Lightsail: An artist impression of the space craft in orbit

Lightsail: An artist impression of the space craft in orbit (Image: PA)

Lightsail: The designs were released on the launch of the spacecraft

Lightsail: The designs were released on the launch of the spacecraft (Image: PA)

“The LightSail 2 mission is a game-changer for spaceflight and advancing space exploration.”

The LightSail 2 is a crowdfunded mission and involved donations from 50,000 people from across the world.

Jennifer Vaughn Planetary Society CEO said the mission can be a “paradigm shift” to get more people involved in space missions.

Ms Vaughn said: “LightSail 2 proves the power of public support.

Lightsail: The Planetary Society tweeted out the last information emitted from the spacecraft

Lightsail: The Planetary Society tweeted out the last information emitted from the spacecraft (Image: TWITTER•@exploreplanets)

“This moment could mark a paradigm shift that opens up space exploration to more players.

“It amazes me that 50,000 people came together to fly a solar sail.

“Imagine if that number became 500,000 or 5 million. It’s a thrilling concept.”

In a statement on the Planetary Society Twitter account, the team wrote: “LightSail2 is now the highest performing solar sail to date and it’s 100% crowdfunded by our members and backers!”

History of solar sailing

• The idea for solar sailing dates back to the 17th century
• NASA came up with the plan for a solar sail to Halley’s comet in the 1970s
• Russia teamed up with the Planetary Society for a doomed solar test for Cosmos 1 in 2001 and 2005
• Japan launched Ikaros – the first solar sail flight in 2010
• LightSail2 was launched aboard SpaceX’s Falcon Heavy rocket in 2019
• LightSail2’s mission is to be the second-ever controlled solar sail flight and the first in Earth orbit

LightSail 2 has a limited lifespan and is doomed to be destroyed.

The spacecraft will eventually crash into the sun and burn as it continues its orbit.

The technology follows LightSail 1 which managed a much lower orbit on the same approach.

Ikaros: Japan's space craft was the first of its kind to carry out the journey

Ikaros: Japan’s space craft was the first of its kind to carry out the journey (Image: GETTY)

Last reversal of the Earth’s magnetic field took twice as long as previously thought

(THIS ARTICLE IS COURTESY OF PHYSICS WORLD)

 

Last reversal of the Earth’s magnetic field took twice as long as previously thought

12 Aug 2019
Geomagnetic field
(Credit: Dormy and Dion)

The last full reversal of the Earth’s geomagnetic field took at least 22,000 years to complete, researchers from the US and Japan have revealed. The finding, which was derived by combining volcanic, sedimentary and ice-core records, suggests that reversals can take several times longer than was previously thought. It also further challenges the notion that a future reversal might be completed within a human lifetime.

The geomagnetic field is produced by the motion of the Earth’s liquid outer core, which acts as a dynamo. Although superficially stable – and presently reliable enough to navigate by – the field does change with time. At present, for example, the magnetic North Pole is in the process of drifting towards Siberia, while the field strength has been decreasing steadily by around 5% for each century since human records began.

Records in the rocks

With magnetically aligned minerals in certain rocks having left us with a record of the magnetic field at the time they were formed, we know that such a weakening can be a precursor to a so-called excursion – in which the magnetic poles shift by up to around 45 degree – or a full blown reversal, in which the field flips and settles upside down. These events, products of growing instabilities in the geodynamo, appear to occur every several hundred thousands years or so.

“Reversals are generated in the deeper parts of the Earth’s interior, but the effects manifest themselves all the way through the Earth,” explains Brad Singer, a geologist at the University of Wisconsin Madison.

Exactly what impact a future reversal might have on human civilization, navigation and communications, however, is unclear. And scientists still don’t understand what causes them, how long a reversal would take, and what the warning signs of one might be.

“Unless you have complete, accurate and high-resolution record of what a field reversal really is like at the surface of the Earth, it’s difficult to even discuss what the mechanics of generating a reversal are,” Singer notes.

Better measurements

To help develop a more accurate picture, Singer and his colleagues took magnetic readings of rock samples from seven lava flows from the Canary Islands, the Caribbean, Chile, Hawaii and Tahiti. They also determined the age of the samples using a newly-enhanced method of potassium-argon radioisotope dating.

“Lava flows are ideal recorders of the magnetic field. They have a lot of iron-bearing minerals and when they cool, they lock in the direction of the field,” says Singer. “But it’s a spotty record. No volcanoes are erupting continuously. So we’re relying on careful field work to identify the right records.”

The team complemented their lava-flow records with two other sources of data on the historic orientation of the geomagnetic field. The first of these were magnetic readings taken from the sea floor, which are less precise than those taken from lava flows – due to variations in sediment rates, weaker magnetization, and biological disruption that can smear the preserved magnetic orientations – but can provide a more continuous record.

Secondly, the researchers took measurements of beryllium deposits across time, as preserved in Antarctic ice cores. Beryllium is produced when cosmos rays hit the atmosphere, which means that periods in which the magnetic field was weaker – and therefore allows more radiation to pass through it – can be identified by increased beryllium in the ice cores.

Combined together, the various records allowed the researchers to piece together the nature of the geomagnetic field over a 70,000-year period centered around the Matuyama-Brunhes reversal – the last time the field completely flipped over, around 784,000 years ago.

Longer reversal

Singer and colleagues found that the final reversal was relatively rapid by geological standards, taking less than 4000 years. However, it was preceded by two individual excursions within a period of instability lasting 18,000 years – more than twice as long as recent research had suggested reversals should take.

“I’ve been working on this problem for 25 years,” said Singer. “And now we have a richer and better-dated record of this last reversal than ever before.”

Andrew Roberts, an earth scientist from the Australian National University who was not involved in the present study, said: “I take these results to indicate that the last magnetic polarity reversal occurred during a prolonged period of time in which Earth’s magnetic field was weak and unstable.”

Roberts also notes that it is still possible that the main reversal occurred rapidly. “There have been other prolonged unstable periods, such the Blake and post-Blake events between 120 and 90 thousand years ago, during which the field has been demonstrated to have changed extremely rapidly.”

Gillian Turner, a geophysicist from the Victoria University of Wellington who also was not involved in the study, agrees: “As the accuracy and resolution of dating both volcanic rocks and sedimentary sequences continues to improve, we should expect to see excursion activity associated with successful polarity reversals more and more often.”

The research is described in the journal Science Advances.

What determines blood type?

(THIS ARTICLE IS COURTESY OF TRIVIA GENIUS)

 

What determines blood type?

Have you ever donated blood? If so, you probably remember them asking you for your blood type. But you might not know that even if you tell them your type with confidence, they still test your blood to confirm this information. So, what’s the big deal about blood types? What does it mean and why is it so important?

What is blood type?

Credit: nzphotonz / iStock

Let’s take a step back to your high school biology class. You remember that our blood is composed primarily of red blood cells and plasma. Of course, there are other items like platelets and white blood cells, but that’s a topic for a different article. For some red blood cells, there can be what’s called antigens which act as identifiers. Not everyone has these antigens on their blood cells. And based on their presence on the cell’s surface—or lack thereof—and antibodies within the plasma, medical professionals can determine your blood type. In total, there are four main blood types: A, B, AB, and O. Depending on your blood type, there may be antibodies present in your plasma that will be the opposite of your type. However, there are exceptions.

● Type A will present A antigens on cell surfaces with B antibodies in plasma

● Type B will present B antigens on cell surfaces with A antibodies in plasma

● Type AB will present A and B antigens on cell surfaces with no antibodies in plasma

● Type O will present no antigens on cell surface with A and B antibodies in plasma

How is your blood type determined?

Credit: wakila / iStock

Blood types can be identified with a simple screening test for the antigens mentioned above. But genetics is the real factor behind your blood type. You get your blood type from your parents, and the genes can be dominant or recessive. Your blood type is determined by three distinctive genes. Types A and B are dominant while O is recessive. So, if one parent passes an A gene, but the other gives an O, you will be type A. However, if one parent passes an A, and the other a B, the co-dominant genes result in a type AB child. The possible combinations include:

● Type A: AA or AO

● Type B: BB or BO

● Type AB: AB

● Type O: OO

What about this positive and negative thing?

Credit: Richard Villalonundefined undefined / iStock

Now we’ll go a step further and talk about the Rhesus or Rh factor. You’ve probably heard people say whether they’re positive or negative. This essentially means that in addition to their blood type, their red blood cells either contain or lack an additional antigen. So, there are four antigens that are screened when testing blood. The only two options with an Rh screen is to be Rh negative or positive. If you are positive, it means that your blood cells do contain this antigen. And of course, a negative result means your blood cells don’t have this antigen, but you do have Rh antibodies.

The importance of blood types

Credit: DieterMeyrl / iStock

Because of the potential for antibodies in your plasma, it’s crucial that blood is properly categorized. Giving someone the wrong blood type, or the right blood type but the wrong Rh factor, causes their body to reject the blood. An Rh-positive person can receive blood from both positive and negative donors while an Rh-negative person can only accept Rh-negative blood.

Pregnancy and Rh factors

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Any woman who’s ever been pregnant knows that one of the first tests your obstetrician will perform is to confirm not just your blood type, but your Rh factor. For Rh-positive women, there is no concern, and they can continue on as normal. For an Rh-negative mother, there is a risk of Rh incompatibility. If the fetus is Rh positive, the blood between mother and fetus could potentially mix, and the mother’s antibodies could attack the fetus and cause complications. While this usually isn’t an issue for first-time Rh negative mothers, it can be a real concern in later pregnancies. Because of this, pregnant women who are Rh-negative usually receive a Rhogam shot to avoid developing antibodies.

So how many blood types are there?

Credit: Major-Kord / iStock

If your head isn’t swirling yet, here are the possible combinations:

● A+/A-

● B+/B-

● AB+/AB-: AB+ can receive blood from anyone because they lack antibodies for blood type and Rh factor

● O+/O-: O- is the universal donor because they lack all antigens for blood types and Rh factor

Blood types and personalities

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In many parts of Asia, blood type is treated like your horoscope sign and is said to influence your personality. Just like with Western star signs, some blood types are viewed more favorably depending on the person’s gender. Type A is considered the most ideal for anyone while type B men are viewed unfavorably as playboys.

Did you learn anything new about blood types that you didn’t know before? Do you know your blood type? While it’s not something that you might need on a daily basis, it’s always a good idea to have that information on hand in case of an emergency.

How Venus Turned Into Hell, and How the Earth Is Next

(THIS ARTICLE IS COURTESY OF SPACE.COM)

 

How Venus Turned Into Hell, and How the Earth Is Next

The bizarre and hellish atmosphere of Venus wafts around the planet's surface in this false-color image from the Japanese Aerospace Exploration Agency's Akatsuki spacecraft. Citizen scientist Kevin Gill processed the image using infrared and ultraviolet views captured by Akatsuki on Nov. 20, 2016.

The bizarre and hellish atmosphere of Venus wafts around the planet’s surface in this false-color image from the Japanese Aerospace Exploration Agency’s Akatsuki spacecraft. Citizen scientist Kevin Gill processed the image using infrared and ultraviolet views captured by Akatsuki on Nov. 20, 2016.
(Image: © Kevil Gill/JAXA/ISAS/DARTS/Flickr)

Paul M. Sutter is an astrophysicist at The Ohio State University, host of Ask a Spaceman and Space Radio, and author of “Your Place in the Universe.” Sutter contributed this article to Space.com’s Expert Voices: Op-Ed & Insights

Everyone wants to get off the planet Earth and go explore the solar system, without realizing just how good we’ve got it down here. We’ve got a lot of air, more liquid water than we know what to do with, a nice strong planetary magnetic field that protects us cosmic radiation, and nice strong gravity that keeps our muscles strong and our bones thick.

All things considered, Earth is pretty nice.

Related: What Would It Be Like to Live on Venus?

But still, we look to our planetary neighbors for places to visit and maybe even live. And Mars has all the attention nowadays: it’s so hot right now, with everyone practically climbing over each other’s rockets to get there in to build a nice little red home.

But what about Venus? It’s about the same size as the Earth and the same mass. It’s actually a little bit closer than Mars. It’s definitely warmer than Mars. So don’t why don’t we try going for our sister planet instead of the red one?

Oh, that’s right: Venus is basically hell.

Dante’s journey

It’s hard to not exaggerate just how bad Venus is. Seriously, imagine in your head what the worst possible planet might be, and Venus is worse than that.

Let’s start with the atmosphere. If you think that the smog in LA is bad, you should take a whiff of Venus. It’s almost entirely carbon dioxide and chokingly thick with an atmospheric pressure at the surface 90 times that of Earth. That’s the equivalent pressure of a mile beneath our ocean waves. It’s so thick that you almost have to swim through it just to move around. Only 4% of that atmosphere is nitrogen, but that’s more nitrogen total than there is in the Earth’s atmosphere.

And sitting on top of this are clouds made of sulfuric acid. Yikes.

Sulfuric acid clouds are highly reflective, giving Venus its characteristic brilliant shine. The clouds are so reflective, and the rest of the atmosphere so thick, that less than 3% of the sun’s light that reaches Venus actually makes it down to the surface. That means that you will only vaguely be aware of the difference between day and night.

But despite that lack of sunlight, the temperature on Venus is literally hot enough to melt lead, at over 700 degrees Fahrenheit (370 degrees Celsius) on average. In some places, in the deepest valleys, the temperature reaches over 750 degrees Fahrenheit (400 degrees Celsius), which is enough for the ground itself to glow a dull red.

And speaking of day and night — Venus has one of the most peculiar rotations in the solar system. For one, it rotates backward, with the sun rising in the west and setting in the east. Second, it’s incredibly slow, with one year lasting only two days.

Additionally, Venus once had plate tectonics that shut off long ago, and its crust is locked.

Yeah, Venus is hell.

Related: Photos of Venus, the Mysterious Planet Next Door

Straight to the inferno

So how did Earth’s sister end up so twisted?

Because Venus is made of pretty much the same stuff as our Earth, and has roughly the same size and mass, scientists are pretty sure that, back in the early days of the solar system, Venus was kind of nice. It probably supported liquid water oceans on the surface and white fluffy clouds dotting a blue sky. Actually, quite lovely.

But four and a half billion years ago, our sun was different. It was smaller and dimmer. As stars like our sun age, they steadily grow brighter. So back then Venus was firmly planted in the habitable zone, the region of the solar system that can support liquid water on the surface of a planet without it being too hot or too cold.

But as the sun aged, that habitable zone steadily moved outward. And as Venus approached the inner edge of that zone, things started to go haywire.

As the temperatures rose on Venus, the oceans began to evaporate, dumping a lot of water vapor into the atmosphere. This water vapor was very good at trapping heat, which further increased the surface temperatures, which caused the oceans to evaporate even more, which caused even more water vapor to get in the atmosphere, which trapped even more heat, and so on and so on as things spiraled out of control.

Eventually, Venus became a runaway greenhouse with all the water dumped into the atmosphere trapping as much heat as possible, with the surface temperatures continuing to skyrocket.

The liquid water that had been on the surface helped keep the tectonic plates nice and flexible, in a sense adding lubrication to the process of plate tectonics. But without the oceans, plate activity ground to a halt, locking the surface of Venus in place. Plate tectonics play a crucial role in regulating the amount of carbon dioxide in the atmosphere. Essentially, carbon binds to elements in dirt and rocks, and those dirt and rocks eventually get buried far beneath the surface over the course of millions of years as the plates rub up against each other and sink below each other.

But without this process, carbon that was locked in the dirt just slowly outgassed or dumped out in massive volcanic events. So, once the oceans evaporated, the carbon problem on Venus became even worse with nothing to sequester it. Over time, the water vapor in the atmosphere got hit by enough sunlight to break it apart, sending the hydrogen into space, with all that mass being replaced by carbon dioxide rising up out of the surface.

The once and future Earth

And as that atmosphere grew thicker, the conditions on the surface grew even more hellish.

The atmosphere might even have had enough drag to literally slow down the rotation of Venus itself, giving it its present-day sluggish rates.

Once this process was complete, which probably took 100 million years or so, the potential for any life on Venus was snuffed out.

And here’s the worst part about the story of Earth’s twisted sister. This is our fate, too. Our sun isn’t done aging, and as it grows older, it grows brighter, with the habitable zone steadily and inexorably moving outward. At some point within the next few hundred million years, the Earth itself will approach the inner edge of the habitable zone. Our oceans will evaporate. Temperatures will spiral upward. Plate tectonics will shut off. Carbon dioxide will dump into the atmosphere.

And by that time, our solar system will be home to not just one hell but two.

Learn more by listening to the episode “What Turned Venus Into Hell?” on the Ask A Spaceman podcast, available on iTunes and on the Web at http://www.askaspaceman.com. Thanks to @ross_trower, Russel S., and @papermonster12 for the questions that led to this piece! Ask your own question on Twitter using #AskASpaceman or by following Paul @PaulMattSutterand facebook.com/PaulMattSutter

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French inventor makes ‘beautiful’ flight across Channel on hoverboard

(THIS ARTICLE IS COURTESY OF CNN)

 

French inventor makes ‘beautiful’ flight across Channel on hoverboard

Zapata soars over Bastille Day celebrations on flying board.

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Zapata soars over Bastille Day celebrations on flying board. 00:32

(CNN)French inventor Franky Zapata has successfully crossed the Channel on a jet-powered hoverboard for the first time, after a failed attempt last month.

Zapata took off from Sangatte, northern France early on Sunday morning and landed in St. Margarets Bay, near Dover in England. The journey took just over 20 minutes, according to Reuters news agency.
“I had the chance to land in an extraordinary place. It’s beautiful. My first thought was to my family. It was huge. Thanks to my wife who always supports me in crazy projects. We worked very hard,” he told CNN affiliate BFMTV.
Franky Zapata flies past the Calais city hall on Sunday after starting his Channel crossing attempt.

The inventor said that he tried to “take pleasure in not thinking about the pain,” even though “his thighs were burning.”
Zapata, a former jet ski racing champion, took to the skies in July on his Flyboard Air vehicle but missed a platform mounted on a boat as he tried to land midway for refueling. The 40-year-old was uninjured in the fall into the sea, and said that he worked “15 to 16 hours a day to rebuild the machine.”
Franky Zapata stands on his jet-powered "flyboard" next to helicopters as he arrives at St. Margaret's Bay in Dover.

In an interview after he completed his journey across the Channel, Zapata said that for his next challenge he was working on a flying car and had signed contracts, but for now he “was tired” and “wants a vacation,” he told BFMTV.
The inventor captured the world’s imagination when he took to the skies above Paris at Bastille Day parade in July with the board that can reach an altitude of nearly 500 feet — with the potential to go much higher — and a speed of 87mph.
Franky Zapata on his jet-powered "flyboard" lands at St. Margaret's Bay in Dover.

Zapata has worked with the US and French militaries, with the French investing $1.4 million to pay for tests of the board. French special forces are interested in the flying board for several uses, including as a possible assault device, said Armed Forces Minister Florence Parly, according to CNN affiliate BFMTV.
The English Channel has been crossed in many innovative ways over the years — including by hovercraft, hot air balloon, monoski, gondola, pedalo and glider and parachute.
On 25 July 1909, French aviator Louis Blériot made the first airplane flight between continental Europe and Great Britain in a monoplane.
In 1875, British marine captain Matthew Webb was the first to swim from Dover to Calais, completing the journey in 21 hours and 45 minutes.