From Science Alert: “We Now Have More Evidence For The Existence of Planet Nine…”

Science Alert

Artist’s rendering of a Jupiter-sized lonely planet. NASA/JPL

18 JUL 2017
MATT WILLIAMS

…And maybe even Planet Ten?

In January of 2016, astronomers Mike Brown and Konstantin Batygin published the first evidence that there might be another planet in our Solar System.

Known as “Planet 9”, this hypothetical body was estimated to be about 10 times as massive as Earth and to orbit that our Sun at an average distance of 700 AU. Since that time, multiple studies have been produced that either support or cast doubt on the existence of Planet 9.

While some argue that the orbits of certain Trans-Neptunian Objects (TNOs) are proof of Planet 9, others argue that these studies suffer from an observational bias.

The latest study [MNRAS], which comes from a pair of astronomers from the Complutense University of Madrid (UCM), offers a fresh perspective that could settle the debate.

Using a new technique that focuses on extreme TNOs (ETNOs), they believe the case for Planet 9 can be made.

Extreme Trans-Neptunian Objects are those that orbit our Sun at average distances greater than 150 AU, and therefore never cross Neptune’s orbit.

As the UMC team indicate in their study [see above], which was recently published in the Monthly Notices of the Royal Astronomical Society, the distances between the ETNOs nodes and the Sun may point the way towards Planet 9.

These nodes are the two points at which the orbit of a celestial body crosses the plane of the Solar System. It is at these points that the chances of interacting with other bodies in the Solar System is the greatest, and hence where ETNOs are most likely to experience a drastic change in their orbits (or a collision).

By measuring where these nodes are, the team believed they could tell if the ETNOs are being perturbed by another object in the area.

As Carlos de la Fuente Marcos, one of the authors on the study, explained in an interview with The Information and Scientific News Service (SINC):

“If there is nothing to perturb them, the nodes of these extreme trans-Neptunian objects should be uniformly distributed, as there is nothing for them to avoid, but if there are one or more perturbers, two situations may arise.

One possibility is that the ETNOs are stable, and in this case they would tend to have their nodes away from the path of possible perturbers, he adds, but if they are unstable they would behave as the comets that interact with Jupiter do, that is tending to have one of the nodes close to the orbit of the hypothetical perturber”.

For the sake of their research, Doctors Carlos and Raul de la Fuente Marcos conducted calculations and data mining to analyse the nodes of 28 ETNOs and 24 extreme Centaurs (which also orbit the Sun at average distances of more than 150 AUs).

What they noticed was that these two populations became clustered at certain distances from the Sun, and also noted a correlation between the positions of the nodes and the inclination of the objects.

This latter find was especially unexpected, and led them to conclude that the orbits of these populations were being affected by the presence of another body – much in the same way that the orbits of comets within our Solar System have been found to be affected by the way they interact with Jupiter.

As De la Fuente Marcos emphasised:

“Assuming that the ETNOs are dynamically similar to the comets that interact with Jupiter, we interpret these results as signs of the presence of a planet that is actively interacting with them in a range of distances from 300 to 400 AU.

We believe that what we are seeing here cannot be attributed to the presence of observational bias”.

As already mentioned, previous studies that have challenged the existence of Planet 9 cited how the study of TNOs have suffered from an observational bias.

Basically, they have claimed that these studies made systematic errors in how they calculated the orientations in the orbits of TNOs, in large part because they had all been directed towards the same region of the sky.

By looking at the nodal distances of ETNOs, which depend on the size and shape of their orbits, this most recent study offers the first evidence of Planet 9’s existence that is relatively free of this bias.

At the moment, only 28 ETNOs are known, but the authors are confident that the discovery of more – and the analysis of their nodes – will confirm their observations and place further constraints on the orbit of Planet 9.

In addition, the pair of astronomers offered some thoughts on recent work that has suggested the possible existence of a Planet 10.

While their study does not take into account the existence of a Mars-sized body – which is said to be responsible for an observable “warp” in the Kuiper Belt – they acknowledge that there is compelling evidence that such a planet-sized body exists.

As de la Fuente Marcos said:

“Given the current definition of planet, this other mysterious object may not be a true planet, even if it has a size similar to that of the Earth, as it could be surrounded by huge asteroids or dwarf planets.

In any case, we are convinced that Volk and Malhotra’s work has found solid evidence of the presence of a massive body beyond the so-called Kuiper Cliff, the furthest point of the trans-Neptunian belt, at some 50 AU from the Sun, and we hope to be able to present soon a new work which also supports its existence”.

It seems that the outer Solar System is getting more crowded with every passing year.

And these planets, if and when they are confirmed, are likely to trigger another debate about which Solar bodies are rightly designated as planets and which ones aren’t.

If you thought the “planetary debate” was controversial and divisive before, I recommend staying away from astronomy forums in the coming years!

See the full article here .

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From Science Alert: “The Yellowstone Supervolcano Has Just Seen 878 Earthquakes in Two Weeks”

Science Alert

29 JUN 2017
CARLY CASSELLA

Suzi Pratt / shutterstock.com

But don’t freak out just yet.

Yellowstone has had a turbulent June. In just two weeks, the supervolcano that lies underneath the national park was hit with 878 earthquakes. The dense series of earthquakes, called an earthquake swarm, began on June 12. Within one week, the USGS had already recorded 464 earthquakes.

“This is the highest number of earthquakes at Yellowstone within a single week in the past five years,” reported the USGS in a statement [U Utah] released last week.

The majority of the earthquakes were no greater than a magnitude of 1, but the largest reached a magnitude of 4.4, which is the biggest earthquake experienced in Yellowstone since March 2014.

But, thankfully, we don’t need to freak out anytime soon. It is extremely unlikely that these swarms will set off the supervolcano. In fact, the USGS sets the probability of the supervolcano erupting in the coming year at 1 in 730,000, and has kept its volcano alert level at green.

“Swarms in Yellowstone are a common occurrence,” Jamie Farrell, a research professor at the University of Utah, which is part of the Yellowstone Volcano Observatory (YVO), told Newsweek.

“On average, Yellowstone sees around 1,500-2,000 earthquakes per year. Of those, 40 to 50 percent occur as part of earthquake swarms.”

And while the most recent swarm is larger than average, Farrell says there isn’t any evidence that the activity is related to magma moving in the subsurface.

Geologists are constantly monitoring the Yellowstone supervolcano for unusual activity. If the volcano was about to blow, Farrell says they would start seeing increased seismicity, large changes in surface deformation, changes to the hydrothermal system and changes in gas output.

“Typically if we see just one of these things, it doesn’t necessarily mean there is an eruption coming. If we start to see changes in all these things, then a red flag may be raised,” said Farrell.

The Yellowstone supervolcano doesn’t blow very often. In the past two million years, it has only experienced three major eruptions.

But even if it did erupt, Jacob Lowenstern, a scientist in charge of the YVO, says it would be fairly inconsequential.

“If Yellowstone erupts, it’s most likely to be a lava flow, as occurred in nearly all the 80 eruptions since the last ‘supereruption’ 640,000 years ago,” he told Newsweek’s Hannah Osborne.

“A lava flow would be a big deal at Yellowstone, but would have very little regional or continental effect.”

Regardless, Farrell and the rest of the team at the University of Utah assure us they are continuing to monitor the swarm. So there won’t be any nasty surprises sneaking up out of Yellowstone anytime soon.

See the full article here .

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From Gowanda Research via Science Alert: “This Amazing Map Fills a 500-Million Year Gap in Earth’s History”

Science Alert

28 JUN 2017

ALAN COLLINS
ANDREW MERDITH

Earth is estimated to be around 4.5 billion years old, with life first appearing around 3 billion years ago. To unravel this incredible history, scientists use a range of different techniques to determine when and where continents moved, how life evolved, how climate changed over time, when our oceans rose and fell, and how land was shaped.

Tectonic plates – the huge, constantly moving slabs of rock that make up the outermost layer of the Earth, the crust – are central to all these studies.

Along with our colleagues, we have published the first whole-Earth plate tectonic map of half a billion years of Earth history, from 1,000 million years ago to 520 million years ago.

In the visualisation above, the colours refer to where the continents lie today. Light blue = India, Madagascar and Arabia, magenta = Australia and Antarctica, white = Siberia, red = North America, orange = Africa, dark blue = South America, yellow = China, green = northeast Europe.

The time range is crucial. It’s a period when the Earth went through the most extreme climate swings known, from “Snowball Earth” icy extremes to super-hot greenhouse conditions, when the atmosphere got a major injection of oxygen and when multicellular life appeared and exploded in diversity.

Now with this first global map of plate tectonics through this period, we (and others) can start to assess the role of plate tectonic processes on other Earth systems and even address how movement of structures deep in our Earth may have varied over a billion year cycle.

Below you can see: (a) map of Precambrian cratonic crust used in the reconstruction in their present-day locations; (b) present day geographical map of the world with Precambrian cratonic crust used in the reconstruction in grey.

Fig. 2, Mueller et al., Gondwana Research (2017)

The Earth moves under our feet

Modern plate tectonic boundaries. But how do we map the Earth like this in the past? NASA’s Earth Observatory

The modern Earth’s tectonic plate boundaries are mapped in excruciating detail.

In the modern Earth, global positioning satellites are used to map how the Earth changes and moves. We know that up-welling plumes of hot rock from over 2,500 km (1,553 miles) deep in the planet’s mantle (the layer beneath the Earth’s crust) hit the solid carapace of the planet (the crust and the top part of the mantle). This forces rigid surface tectonic plates to move at the tempo of a fingernail’s growth.

On the other side of the up-welling hot rock plumes are areas known as subduction zones, where vast regions of the ocean floor plunge down into the deep Earth. Eventually these down-going oceanic plates hit the boundary between the core and mantle layers of Earth, about 2,900 km (1,801 miles) down. They come together, forming thermal or chemical accumulations that eventually source these up-welling zones.

It’s fascinating stuff, but these processes also create problems for scientists trying to look back in time. The planet can only be directly mapped over its last 200 million years. Before that, back over the preceding four billion years, the majority of the planet’s surface is missing, as all the crust that lay under the oceans has been destroyed through subduction.

Oceanic crust just doesn’t last: it’s constantly being pulled back deep into the Earth, where it’s inaccessible to science.

Mapping the Earth in deep time

So what did we do to map the Earth in deep time? To get at where plate margins were and how they changed, we looked for proxies – or alternative representations – of plate margins in the geological record.

We found rocks that formed above subduction zones, in continental collisions, or in the fissures where plates ripped apart. Our data came from rocks found in locations including Madagascar, Ethiopia and far west Brazil. The new map and associated work is the result of a couple of decades of work by many excellent PhD students and colleagues from all over the world.

We now have more details, and a view to way further back in geological time, than were previously available for those studying the Earth.

Using other methods, the latitudes of continents in the past can be worked out, as some iron-bearing rocks freeze the magnetic field in them as they form.

This is like a fossil compass, with the needle pointing into the ground at an angle related to the latitude where it formed – near the equator the magnetic field is roughly parallel to the Earth’s surface, at the poles it plunges directly down. You can see this today if you buy a compass in Australia and take it to Canada: the compass won’t work very well, as the needle will want to point down into the Earth.

Compass needles are always balanced to remain broadly horizontal in the region that they are designed to work in.

But, these so-called “palaeomagnetic” measurements are hard to do, and it is not easy finding rocks that preserve these records. Also, they only tell us about the continents and not about plate margins or the oceans.

Why map ancient plate tectonics?

The lack of ancient tectonic maps has posed quite a problem for how we understand our Earth.

Tectonic plates influence many processes on Earth, including the climate, the biosphere (the sphere of life on the outer part of the planet), and the hydrosphere (the water cycle and how it circulates around the planet and how its chemistry varies).

By simply redistributing tectonic plates, and thereby moving the positions (the latitudes and longitudes) of continents and oceans, controls are placed on where different plants and animals can live and migrate.

Plate boundary locations also govern how ocean currents redistribute heat and water chemistry. Different water masses in the ocean contain subtly different elements and their various forms, known as isotopes.

For example, water in the deep oceans was often not at the surface for many many thousands of years, and has different composition from the water presently on the ocean’s surface. This is important because different water masses contain different amounts of nutrients, redistributing them to different parts of the Earth, changing the potential for life in different places.

Tectonic plates also influence how much of the Sun’s radiation gets reflected back out to space, changing the Earth’s temperature.

How fast tectonic plates move have also varied over time. At different periods in Earth history there were more mid-ocean volcanoes than there are today, creating water movement such as pushing up ocean waters over the continents. At these times, some types of volcanic eruptions were more frequent, pumping more gas into the atmosphere.

Mountain ranges form as tectonic plates collide, which affect oceanic and atmospheric currents as well as exposing rocks to be eroded. This locks up greenhouse gases, and releases nutrients into the ocean.

Understand ancient plate tectonics and we go someway to understanding the ancient Earth system. And the Earth as it is today, and into the future.

The research reported in this article was conducted by a team of researchers from The University of Sydney, The University of Adelaide and Curtin University.

Abstract from Gowanda Research paper on Science Direct

Abstract

Neoproterozoic tectonic geography was dominated by the formation of the supercontinent Rodinia, its break-up and the subsequent amalgamation of Gondwana. The Neoproterozoic was a tumultuous time of Earth history, with large climatic variations, the emergence of complex life and a series of continent-building orogenies of a scale not repeated until the Cenozoic. Here we synthesise available geological and palaeomagnetic data and build the first full-plate, topological model of the Neoproterozoic that maps the evolution of the tectonic plate configurations during this time. Topological models trace evolving plate boundaries and facilitate the evaluation of “plate tectonic rules” such as subduction zone migration through time when building plate models. There is a rich history of subduction zone proxies preserved in the Neoproterozoic geological record, providing good evidence for the existence of continent-margin and intra-oceanic subduction zones through time. These are preserved either as volcanic arc protoliths accreted in continent-continent, or continent-arc collisions, or as the detritus of these volcanic arcs preserved in successor basins. Despite this, we find that the model presented here still predicts less subduction (ca. 90%) than on the modern earth, suggesting that we have produced a conservative model and are likely underestimating the amount of subduction, either due to a simplification of tectonically complex areas, or because of the absence of preservation in the geological record (e.g. ocean-ocean convergence). Furthermore, the reconstruction of plate boundary geometries provides constraints for global-scale earth system parameters, such as the role of volcanism or ridge production on the planet’s icehouse climatic excursion during the Cryogenian. Besides modelling plate boundaries, our model presents some notable departures from previous Rodinia models. We omit India and South China from Rodinia completely, due to long-lived subduction preserved on margins of India and conflicting palaeomagnetic data for the Cryogenian, such that these two cratons act as ‘lonely wanderers’ for much of the Neoproterozoic. We also introduce a Tonian-Cryogenian aged rotation of the Congo-São Francisco Craton relative to Rodinia to better fit palaeomagnetic data and account for thick passive margin sediments along its southern margin during the Tonian. The GPlates files of the model are released to the public and it is our expectation that this model can act as a foundation for future model refinements, the testing of alternative models, as well as providing constraints for both geodynamic and palaeoclimate models.

Full paper available here.

See the full article here .

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From Science Alert: “Here’s How to Backup Life on Earth Ahead of Any Doomsday Event”

Science Alert

20 JUN 2017
JONATHAN ROBERTS

solarseven/Shutterstock.com

Just in case…

There are ten asteroids that the space organisation NASA said last month have been classified as “potentially hazardous” based on their size and their orbits in our Solar system.

This animation shows asteroids and comets observed in infrared by NASA’s Near-Earth Object Wide-field Survey Explorer (NEOWISE) mission. Since the mission was restarted in December 2013, NEOWISE has discovered 114 near-Earth objects and characterized 693 others. Credits: NASA/JPL-Caltech/PSI

NASA has now identified 693 near-Earth objects thanks to the Wide-field Infrared Survey Explorer spacecraft that’s been looking for potential threats to Earth since 2013.

NASA/WISE Telescope

The organisation doesn’t specify what kind of hazard these ten asteroids pose.

But Earth has been hit by objects in the past, with devastating effects. Scientists largely agree that it was an asteroid or comet impact that started the chain of events that wiped out the dinosaurs around 60 million years ago.

Every year several previously unseen asteroids whizz past Earth, sometimes with only with a few days’ warning. This year two of these asteroids came very close to Earth, with one in May sailing past only 15,000km away.

On cosmic scales, that was a very close shave.

But impacts from objects in space are just one of several ways [Science] that humanity and most of life on Earth could suddenly disappear.

We are already observing that extinctions are happening now at an unprecedented rate. In 2014 it was estimated that the extinction rate is now 1,000 times greater than before humans were on the Earth.

The estimated number of extinctions ranges from 200 to 2,000 species per year.

From all of this very worrying data, it would not be a stretch to say that we are currently within a doomsday scenario. Of course, the “day” is longer than 24 hours but may be instead in the order of a century or two.

So what can we do about this potential prospect of impending doom? We can try to avoid some of the likely scenarios.

We should act to tackle climate change and we can develop new asteroid-tracking systems and put in place a means to deflect an asteroid on a collision course with Earth.

But the threats we face are so unpredictable that we need to have a backup plan. We need to plan for the time after our doomsday and think about how a post-apocalyptic Earth may recover and humanity will flourish again.

A backup plan

Some efforts to backup life on our planet have already started. Since the 1970s scientists around the world began to store seeds of potentially endangered plants. There are now dozens of seed banks or vaults scattered around the world.

The most famous is the Svalbard Global Seed Vault, located on a remote Norwegian island about 1,300 kilometres from the North Pole. The location was deliberately chosen to afford the project safe and secure long-term storage in cold and dry rock vaults.

But there were reports earlier this year that the vault had suffered issues with water from the surrounding melting permafrost (caused by global warming) gaining entry to parts of the structure.

Less common are vaults for storing biological material from animals. There are a handful of so-called frozen zoos around the world.

They store embryos, eggs, sperm and more recently DNA of endangered animals. So far, sperm, eggs and embryos that have been frozen for roughly 20 years have been shown to be viable.

All of the storage methods that involve freezing have the same problem that the material is at risk of thawing out if the freezing methods fail. Storing frozen biological material for centuries or even millennia on Earth is not realistic.

Humans can now sequence a whole genome of a living organism and the cost has reduced to the point where it costs less than US$1,000 to sequence the human genome. This process effectively turns the information from any organism’s cells into data.

If future scientists can create living DNA from the genome data and can then create living organisms from that DNA, then having the data alone may be sufficient to backup the Earth’s living organisms.

Where to store the backups?

But where should humanity store the backups? As French president Emmanuel Macron said recently, “there is no plan B because there is no planet B”, echoing 2014 comments from Ban Ki-moon when he was secretary general of the United Nations.

Backing up on Earth seems a high-risk strategy, equivalent to having a computer backup on an external hard drive that sits right next to your computer.

So given that the motivation for backing up Earth’s organisms is the likelihood of Earth itself suffering a catastrophe, it follows that our planet is not the best location for the backups.

The partial flooding of the Svalbard Global Seed Vault illustrates that perfectly.

Perhaps the obvious place to locate the backups is in space.

Seeds have already been taken to space for short periods (six months) to test their viability back on Earth. These experiments so far have been motivated by the desire to eventually grow plants in space itself, on space stations, or on Mars.

Space is a harsh environment for biological material, where cells are exposed to potentially very high doses of radiation that will damage DNA.

Storage of seeds in low Earth orbit is desirable as Earth’s magnetic field provides some protection from space radiation. Storage outside of this zone and in deep space would require other methods of radiation protection.

The other question is how you would get seeds and other biological material safely back to Earth after a global disaster. Now we get to the robotics that can help, as autonomous re-entry of biological material from orbit is totally feasible.

The tricky part is for our orbiting bio-backup to know when its cargo is required and where to send it to. Perhaps we need a global limited robot crew – such as David in the recent Alien films – that would wake up the orbiter when it is needed.

Alternatively, it could be staffed by a rotating crew of wardens similar to the International Space Station. These people could carry out other important scientific work too.

Other locations in space for storage of biological material or data include the Moon, and the moons of our solar system’s gas planets asteroids or deep space itself on free flying spacecraft.

Such projects have been proposed and groups around the world have begun planning such ventures.

It seems that some people have already accepted the fate of humanity version 1.0 and that it will end sometime in the relative near term. The movement to create our backup ready for humanity version 2.0 has already begun.

See the full article here .

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From Science Alert- “Stephen Hawking: “I Am Convinced That Humans Need to Leave Earth”

Science Alert

20 JUN 2017
DOM GALEON

lwpkommunikacio/Flickr/CC BY 2.0

Back in May, renowned physicist Stephen Hawking made yet another doomsday prediction. He said that humanity has 100 years left on Earth, which knocked 900 years off the prediction he made in November 2016, which had given humanity 1,000 years left.

With his new estimate, Hawking suggested the only way to prolong humanity’s existence is for us to find a new home, on another planet.

Speaking at the Starmus Festival in Trondheim, Norway on Tuesday, Hawking reiterated his point: “If humanity is to continue for another million years, our future lies in boldly going where no one else has gone before,” he explained, according to the BBC.

Specifically, Hawking said that we should aim for another Moon landing by 2020, and work to build a lunar base in the next 30 years – projects that could help prepare us to send human beings to Mars by 2025.

NASA’s lunar stopover. Credit: NASA

“We are running out of space and the only places to go to are other worlds. It is time to explore other solar systems. Spreading out may be the only thing that saves us from ourselves. I am convinced that humans need to leave Earth,” Hawking added.

Hawking’s plea comes almost 45 years since NASA’s last lunar mission, and he’s not the only one thinking about revisiting the Earth’s cosmic satellite.

Even US president Donald Trump wants to put a human on the Moon by 2020. Various plans, both from government space agencies as well as private ones, are already in the works. NASA’s mission to Mars, for example, notes that setting up an orbital lunar station would be a key step for a future mission to the Red Planet.

Other nations are also working towards the same goal: China and Europe also hope to reach the Moon by the 2020s, and other countries are scrambling to set up their own lunar bases, too. It’s an echo of the Cold War era space race – except now, there are more nations in play.

For private space agencies, the Moon seems to be more of a special tourist attraction than a permanent domicile: SpaceX is already preparing for its first privately-funded round trip to the Moon, while Jeff Bezos envisions an opportunity for a special delivery service to facilitate the construction of any permanent off world settlement.

For Hawking, though, aiming for the Moon (again) is not only about survival, but strengthening humanity while we’re still on Earth – for however many years we have left here.

“I hope it would unite competitive nations in a single goal, to face the common challenge for us all,” he said.

“A new and ambitious space program would excite (young people), and stimulate interest in other areas, such as astrophysics and cosmology”.

See the full article here .

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From Science Alert: “This New Treatment Could Provide Weeks of Glucose Control For Type 2 Diabetes Patients”

Science Alert

Syda Productions/Shutterstock

6 JUNE 2017
SIGNE DEAN

No more daily insulin shots.

To control their blood sugar levels, people with type 2 diabetes constantly need to rely on medication, but it’s a tricky condition to manage, especially if you need daily insulin shots.

Researchers have been working on a new method for delivering diabetes drugs to make them last longer in the body. Now a recent study using both mice and monkeys has shown potential for treatments that would only require a couple of injections a month.

Some of the latest-generation type 2 diabetes drugs contain a molecule called GLP1 (glucagon-like peptide-1), which stimulates insulin production in the body only when it needs more glucose.

That sounds ideal, but unfortunately, GLP1 has a really short half-life – it breaks down in the body quickly, making it an impractical long-term treatment on its own.

By combining it with other molecules, it’s possible to extend the half-life of GLP1. But that method still only gets us to about 3-7 days.

Right now, patients in the US already have some options that can be injected weekly, but scientists are looking for a way to slow down the release of the drug itself.

Now a team from Duke University has managed to combine GLP1 with a biopolymer molecule that starts out as a liquid in colder temperatures, but thickens into a gel-like substance in reaction to body heat.

This means the solution can be administered with a simple injection, but once it gets into the body, the drug is released very slowly, so it can control blood glucose levels for longer with just one dose.

To test how their new solution would work for actual diabetes treatment, the researchers tried the drug in both mice and in rhesus monkeys – two species with well-established diabetes models.

They got exciting results in both: in mice, the new GLP1 solution controlled glucose levels for 10 days after just one injection; in monkeys, whose metabolism is slower, the effects lasted up to 17 days.

More than two weeks for one injection is better than any diabetes drug currently on the market.

The team thinks that because human metabolism is even slower than in monkeys, theoretically the drug could last longer in people, perhaps requiring just one injection a month.

“Preclinical data presents compelling evidence that this construct would require no more than two injections a month for humans, and possibly as few as one per month, especially given the dose-stacking potential of this system,” the researchers write in the paper.

The team thinks their new approach to ‘trapping’ GLP1 in the gel-like substance could be applied to other types of medication, too.

Of course, it’s important to note that so far the method has only worked in animal studies, and scientists will need to do more research to see how the principles would translate to human use.

GLP1-based medications are currently not the first-line treatment for people with type 2 diabetes, but this sounds like an exciting step towards making diabetes management easier for many.

The study was published in Nature Biomedical Engineering.

See the full article here .

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From Science Alert: “This Simple Blood Test Can Predict Cancer Years Before Symptoms Appear”

Science Alert

6 JUN 2017
SIGNE DEAN

Science Photo/Shutterstock

A new type of non-invasive cancer test has just delivered promising results in an early-stage feasibility study, paving the way for a future when we’ll be able to get highly accurate cancer screening with a simple blood test.

The technology, which involves scanning the blood for bits of DNA shed by tumours, is also referred to as a ‘liquid biopsy’, and these new results are getting us one step closer to a major upgrade in cancer diagnostics.

Right now, our best method for detecting cancer is a biopsy – cutting out a small piece of the tumour tissue for lab analysis. But biopsies are often painful and invasive, and you need to already have a tumour or at least a suspect tumour to cut something out of it.

That’s why scientists have been working on devising blood tests that can do the same thing without any surgery, and with the promise of delivering a diagnosis much earlier.

Finding cancer in the blood is possible when scientists focus on DNA fragments shed into the bloodstream by tumours. This is called circulating tumour DNA (ctDNA).

In recent years, scientists have been working on finding the best method for detecting ctDNA, using samples from patients who already have diagnosed cancer.

The latest study, which was just presented at the 2017 meeting of the American Society of Clinical Oncology (ASCO), has turned up the dial on what scientists can find when they scan for ctDNA.

“Our findings show that high-intensity circulating tumour DNA sequencing is possible and may provide invaluable information for clinical decision-making, potentially without any need for tumour tissue samples,” says lead researcher Pedram Razavi [American Society of Clinical Oncology] from Memorial Sloan Kettering centre.

The team used blood and tissue samples from 124 metastatic breast cancer, lung cancer, and advanced prostate cancer patients.

They scanned the samples for 508 different gene mutations, going over the specific regions of the genome up to 60,000 times. According to the scientists [Reuters], this method generates 100 times more data than other sequencing approaches.

To see whether the method could catch any tumour DNA floating around in the blood, the team compared the results with those from tissue samples and genetic material from the patients’ own white blood cells.

“Our combined analysis of cell-free DNA and white blood cell DNA allows for identification of tumour DNA with much higher sensitivity, and deep sequencing also helps us find those rare tumour DNA fragments,” says Razavi.

The researchers detected 864 genetic changes across all three types of cancers in the tissue samples, and found 73 percent of those in the blood tests as well.

In 89 percent of the patients, they found at least one mutation in both tumour tissue and in blood. For breast cancer, for which liquid biopsies are more established, the success rate was 97 percent.

A huge benefit of having sensitive ctDNA tests is the chance of finding cancer years earlier than is possible with a biopsy, catching it before it has time to spread through the body.

The new method was developed with researchers from Grail, a genomics company dedicated to early cancer detection, backed by philanthropic funding from people like Jeff Bezos and Bill Gates.

Grail’s Mark Lee, who was one of the study co-authors, told Reuters that the company is now planning to use this new test to gather large-scale data from hundreds of thousands of people, both with and without cancer.

While the results are promising so far, the team will be needing a lot more research before this technology becomes an early detection tool that we all can benefit from in a routine check-up.

“It’s an important first step. We show that what we call a high-intensity approach works,” Razavi told Reuters.

The results were presented at the ASCO Annual Meeting, and have been accepted for publication in the Journal of Clinical Oncology.

See the full article here .

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From Science Alert: “Russia Just Reactivated 3 Mystery Satellites – And We Still Don’t Know Why They Exist”

Science Alert

22 MAY 2017
DANIEL BROWN

SES

They’re on the move.

Three Russian satellites that were sent into low orbit in 2013 are on the move again, and no one knows what they are for, The Daily Beast reports.

Having been idle for more than a year, one of the satellites went hundreds of metres off its orbit last month to within 1,200 metres of a piece of a Chinese weather satellite that China smashed in a 2007 anti-satellite rocket test.

The manoeuvre, which is pretty impressive for such a small spacecraft, is also rather close by orbital standards.

No one quite knows what the satellites are for, but some experts say they could be “technology-demonstrators” or even “precursors to orbital weapons”, according to The Daily Beast.

Code named Kosmos-2491, Kosmos-2499 and Kosmos-2504, the three satellites manoeuvred several times in the last three years to within a few dozen feet of their old booster shells.

This means that they could be inspection satellites that can scan and match the orbit of other spacecraft, possibly even interact with it physically for repairs, modifications or to dismantle it.

It’s also possible that these satellites could be used for warfare. “You can probably equip them with lasers, maybe put some explosives on them,” Anatoly Zak, an independent expert on Russian spacecraft, told The Beast in 2015.

“If [one] comes very close to some military satellite, it probably can do some harm.”

In 2012, US intelligence completed a report analysing “the growing vulnerability of US satellites that provide secure military communications, warn about enemy missile launches, and provide precise targeting coordinates”, anonymous sources told Reuters.

The report raised many concerns about China’s ability to disrupt satellites in higher orbits, possibly putting sensitive US spacecraft at risk, the sources told Reuters.

But Russian space agency chief Oleg Ostapenko claimed in 2014 that the satellites were for peaceful purposes.

Read the full article from The Daily Beast here.

See the full article here .

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From Science Alert: “Einstein’s ‘Spooky’ Entanglement Is Guiding Next-Gen Gravitational Wave Detectors”

Science Alert

19 MAY 2017
DAVID BLAIR

Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib

Breaking the standard quantum limit.

The first direct detection of gravitational waves, a phenomenon predicted by Einstein’s 1915 general theory of relativity, was reported by scientists in 2016.

Armed with this “discovery of the century”, physicists around the world have been planning new and better detectors of gravitational waves.

Caltech/MIT Advanced aLigo Hanford, WA, USA installation

Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project

Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib

ESA/eLISA the future of gravitational wave research

Physicist Professor Chunnong Zhao and his recent PhD students Haixing Miao and Yiqiu Ma are members of an international team that has created a particularly exciting new design for gravitational wave detectors.

The new design is a real breakthrough because it can measure signals below a limit that was previously believed to be an insurmountable barrier. Physicists call this limit the standard quantum limit. It is set by the quantum uncertainty principle.

Proposal for gravitational-wave detection beyond the standard quantum limit through EPR entanglement
Yiqiu Ma, Haixing Miao, Belinda Heyun Pang, Matthew Evans, Chunnong Zhao, Jan Harms, Roman Schnabel & Yanbei Chen

The new design, published in Nature Physics this week, shows that this may not be a barrier any longer.

Abstract

In continuously monitored systems the standard quantum limit is given by the trade-off between shot noise and back-action noise. In gravitational-wave detectors, such as Advanced LIGO, both contributions can be simultaneously squeezed in a broad frequency band by injecting a spectrum of squeezed vacuum states with a frequency-dependent squeeze angle. This approach requires setting up an additional long baseline, low-loss filter cavity in a vacuum system at the detector’s site. Here, we show that the need for such a filter cavity can be eliminated, by exploiting Einstein–Podolsky–Rosen (EPR)-entangled signals and idler beams. By harnessing their mutual quantum correlations and the difference in the way each beam propagates in the interferometer, we can engineer the input signal beam to have the appropriate frequency-dependent conditional squeezing once the out-going idler beam is detected. Our proposal is appropriate for all future gravitational-wave detectors for achieving sensitivities beyond the standard quantum limit.

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Using this and other new approaches may allow scientists to monitor black hole collisions and ‘spacequakes‘ across the whole of the visible Universe.

During a spacequake, Earth’s magnetic field shakes in a way that is analogous to the shaking of the ground during an earthquake. Image credit: Evgeny Panov, Space Research Institute of Austria.

How gravitational wave detectors work

Gravitational waves are not vibrations travelling through space, but rather vibrations of space itself.

They have already told us about an unexpectedly large population of black holes. We hope that further study of gravitational waves will help us to better understand our Universe.

But the technologies of gravitational wave detectors are likely to have enormous significance beyond this aspect of science, because in themselves they are teaching us how to measure unbelievably tiny amounts of energy.

Gravitational wave detectors use laser light to pick up tiny vibrations of space created when black holes collide. The collisions create vast gravitational explosions.

They are the biggest explosions known in the Universe, converting mass directly into vibrations of pure space.

It takes huge amounts of energy to make space bend and ripple.

Our detectors – exquisitely perfect devices that use big heavy mirrors with scarily powerful lasers – must measure space stretching by a mere billionth of a billionth of a metre over the four kilometre scale of our detectors. [LIGO, above.]

These measurements already represent the smallest amount of energy ever measured.

But for gravitational wave astronomers this is not good enough. They need even more sensitivity to be able to hear many more predicted gravitational ‘sounds’, including the sound of the moment the Universe was created in the big bang.

This is where the new design comes in.

A spooky idea from Einstein

The novel concept is founded on original work from Albert Einstein.

In 1935 Albert Einstein and co-workers Boris Podolsky and Nathan Rosen tried to depose the theory of quantum mechanics by showing that it predicted absurd correlations between widely spaced particles.

Einstein proved that if quantum theory was correct, then pairs of widely spaced objects could be entangled like two flies tangled up in a spider’s web. Weirdly, the entanglement did not diminish, however far apart you allowed the objects to move.

Einstein called entanglement “spooky action at a distance”. He was sure that his discovery would do away with the theory of quantum mechanics once and for all, but this was not to be.

Since the 1980s physicists have demonstrated time and again that quantum entanglement is real. However much he hated it, Einstein’s prediction was right and to his chagrin, quantum theory was correct. Things at a distance could be entangled.

Today physicists have got used to the ‘spookiness’, and the theory of entanglement has been harnessed for the sending of secret codes that cannot be intercepted.

Around the world, organisations such as Google and IBM and academic laboratories are trying to create quantum computers that depend on entanglement.

And now Zhao and colleagues want to use the concept of entanglement to create the new gravitational wave detector’s design.

A new way to measure gravitational waves

The exciting aspect of the new detector design is that it is actually just a new way of operating existing detectors. It simply uses the detector twice.

One time, photons in the detector are altered by the gravitational wave so as to pick up the waves. The second time, the detector is used to change the quantum entanglement in such a way that the noise due to quantum uncertainty is not detected.

The only thing that is detected is the motion of the distant mirrors caused by the gravitational wave. The quantum noise from the uncertainty principle does not appear in the measurement.

To make it work, you have to start with entangled photons that are created by a device called a quantum squeezer. This technology was pioneered for gravitational wave astronomy at Australian National University, and is now an established technique.

Like many of the best ideas, the new idea is a very simple one, but one that took enormous insight to recognise. You inject a minuscule amount of squeezed light from a quantum squeezer, and use it twice!

Around the world physicists are getting ready to test the new theory and find the best way of implementing it in their detectors.

One of these is the GEO gravitational wave detector at Hannover in Germany, which has been a test bed for many of the new technologies that allowed last year’s momentous discovery of gravitational waves.

http://www.geo600.org GEO600 aims at the direct detection of Einstein’s gravitational waves by means of a laser interferometer.

See the full article here .

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From Science Alert: “Stephen Hawking And 32 Top Physicists Just Signed a Heated Letter on The Universe’s Origin”

Science Alert

12 MAY 2017
FIONA MACDONALD

Inflationary Universe. NASA/WMAP

For centuries, people have puzzled over how our Universe began. But the heat just got turned way up on a debate that’s quietly been raging between cosmologists, with 33 of the world’s most famous physicists publishing a letter angrily defending one of the leading hypotheses we have for the origin of the Universe.

The letter is in response to a Scientific American feature published back in February, in which three physicists heavily criticised inflation theory – the idea that the Universe expanded just like a balloon shortly after the Big Bang. The article went as far as claiming that the model “cannot be evaluated using the scientific method” – the academic equivalent of saying it isn’t even real science.

In response, 33 of the world’s top physicists, including Stephen Hawking, Lisa Randall, and Leonard Susskind, have fired back by publishing their own open letter in Scientific American. The Cliff’s note version is this: they’re really angry.

Alan Guth

Inflation theory was first proposed by cosmologist Alan Guth, now at MIT, back in 1980.

It’s based on the idea that a fraction of a second after the Big Bang, the Universe expanded rapidly, spinning entire galaxies out of quantum fluctuations.

“By the time it slowed down, what had been a tiny, quivering quantum realm was stretched out until it looked smooth and flat, save for speckles of denser matter that later became galaxies, stars, and planets,” writes Joshua Sokol for The Atlantic.

In the following years, Guth’s original idea was improved and updated by Stanford physicists Andrei Linde, and they’ve since spent their careers refining the inflation model – which has become the leading theory for how the Universe was born.

In fact, most of us were taught inflation theory at high school and university when discussing the Universe’s origins.

Guth and Linde, along with cosmologists David Kaiser and Yasunori Nomura, were the ones who recruited the other 29 signees behind this week’s letter.

Interestingly, one of Guth and Linde’s former colleagues, physicist Paul Steinhardt, is part of the trio they’re rallying against. Guth, Linde, and Steinhardt all shared the prestigious Dirac prize “for development of the concept of inflation in cosmology” back in 2002.

But in the years since, Steinhardt has gone rogue, and has become an active critic of inflationary theory. He was one of the authors of Scientific American’s February feature, originally titled “Pop goes the Universe”, along with Princeton physicist Anna Ijjas, and Harvard astronomer Abraham Loeb.

That article highlighted recent research into the cosmic microwave background, which doesn’t match up with the predictions of inflationary theory.

It also criticised the fact that inflation would have generated primordial gravitational waves, which have never been found.

“The data suggest cosmologists should reassess this favoured paradigm and consider new ideas about how the universe began,” summarises an ‘In Brief’ wrap up of the article.

That criticism in itself wasn’t a huge deal – these kinds of arguments are healthy in the science world.

But what really pissed off Guth, Linde, and the 31 other signees, was the suggestion that inflationary theory couldn’t actually be tested in the first place, and therefore wasn’t really science.

“They [made] the extraordinary claim that inflationary cosmology ‘cannot be evaluated using the scientific method’ and go on to assert that some scientists who accept inflation have proposed ‘discarding one of [science’s] defining properties: empirical testability,’ thereby ‘promoting the idea of some kind of nonempirical science’,” the physicists write in their open letter.

“We have no idea what scientists they are referring to. We disagree with a number of statements in their article, but in this letter, we will focus on our categorical disagreement with these statements about the testability of inflation.”

Their argument is that inflation theory is based on many models, and there’s no illusion that all of these models are correct. Over the past 37 years, some of the models have made correct, testable predictions – including the average mass density of the Universe, and its flat shape. Many are still unresolved.

But either way, these models are all testable, which means they’re proper science, and they can be proven or disproven depending on the evidence we find in the coming years.

Ryan F. Mandelbaum has done incredible coverage of this feud over at Gizmodo, and points to a blog entry by Sean Carroll, one of the physicists who signed the letter, on the controversy:

“We judge theories by what predictions they make that we can test, not the ones they make that can’t be tested. It’s absolutely true that there are important unanswered questions facing the inflationary paradigm. But the right response in that situation is to either work on trying to answer them, or switch to working on something else (which is a perfectly respectable option). It’s not to claim that the questions are in principle unanswerable, and therefore the field has dropped out of the realm of science.”

The authors of the original article have since responded to the letter with their own extended FAQ on the debate. And they maintain their position – that inflation was once testable, but “what began in the 1980s as a theory that seemed to make definite predictions has become a theory that makes no definite predictions”.

Which takes us right back to where we started… some cosmologists have publicly slammed inflation theory, and others have angrily responded.

Unfortunately there’s no neat resolution to this debate on the horizon, with both sides standing pretty firm. The one thing they both agree on is the fact that inflation theory isn’t perfect, and we should all keep an open mind about what really happened at the birth of our Universe as new data comes in.

Or as Guth told Mandelbaum in the ultimate mic drop when asked what would happen next: “I think we’ll all continue on with our research.”

You can read the original article here, the responding open letter here, and the original authors’ response here.

See the full article here .

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