Physicists say they’ve found a way to detect naked singularities… if they exist.


But are we ready?

 

Black holes are weird: insanely dense objects that are crammed into such a small space they cause space-time to distort and the laws of physics to break down into a singularity.

Fortunately, the Universe shields us from this weirdness by wrapping black holes in event horizons. But now, physicists say they’ve found a way we could detect something even more extreme – a naked singularity – and most likely bend the laws of physics in the process.

 “A naked singularity, if such a thing exists, would be an abrupt hole in the fabric of reality – one that would not just distort space-time, but would also wreak havoc on the laws of physics wherever it goes and lead to a catastrophic loss of predictability,” explains Avaneesh Pandey for IB Times.

If that sounds a little too confronting, don’t worry, this whole study is purely theoretical, and is hinged on one very big assumption – that naked singularities actually exist in our Universe, something that scientists have never confirmed.

But according to Einstein’s theory of general relativity at least, and our best computer models to date, naked singularities are possible.

So, what are they? A singularity can form when huge stars collapse at the end of their lives into regions so small and dense, physics as we know it fails to explain what could happen there.

There are two general laws of physics that govern our understanding of reality: quantum mechanics, which explains all the small stuff, such as the behaviour of subatomic particles; and general relativity, which describes the stuff we can see, such as stars and galaxies.

When applied to singularities, both these schools of thought predict different and incompatible outcomes.

 And we’ve never really had to deal with that conundrum, because all the singularities we know of are inside black holes, wrapped in an event horizon from which not even light can escape – or at the very birth of our Universe, shrouded by radiation we can’t see past. Out of sight, out of mind, right?

But naked singularities are theoretical singularities that are exposed to the rest of the Universe for some reason.

Below you can see an illustration of a black hole wrapped in its event horizon (dotted line) on the left, and a naked singularity on the right. The arrows indicate light, which would be able to escape a naked singularity, but not a black hole.

canweseeasin

Assuming they do exist, the big question then is how would we be able to distinguish a naked singularity from a regular black hole, and this is where the new study comes in.

Researchers from the Tata Institute of Fundamental Research in India have come up with a two-step plan based on the fact that singularities, as far as we know, are rotating objects, just like black holes.

According to Einstein’s theory of general relativity, the fabric of space-time in the vicinity of any rotating objects gets ‘twisted’ due to this rotation. And this effect causes a gyroscopic spin and makes the orbits of particles around the rotating objects ‘precess‘, or change their rotational axis.

You can watch the hypnotic precession of a gyroscope below to see what we mean – its axis is no longer straight:

Gyroscope precession

Based on this, the researchers say that we could figure out the nature of a rotating objects by measuring the rate at which a gyroscope precesses – its precession frequency – at two fixed points close to the object.

According to the new paper, there are two possibilities:

  1. The precession frequency of the gyroscope changes wildly between the two points, which suggests the rotating object in question is a regular black hole.
  2. The precession frequency changes in a regular, well-behaved manner, indicating a naked singularity.

Obviously getting a gyroscope close enough to a black hole to perform these experiments isn’t exactly easy.

But that’s okay, because the team has also come up with a way to observe the same effect from here on Earth – measuring the precession frequencies of matter falling into either black holes or naked singularities using X-ray wavelengths.

“This is because the orbital plane precession frequency increases as the matter approaches a rotating black hole, but this frequency can decrease and even become zero for a rotating naked singularity,” the team’s press release explains.

Again, we have to make it clear that all of this is wildly speculative at this time – we have never found any candidate naked singularities, and we’re only just beginning to truly understand regular black holes.

It’s also worth noting that last week, another team of researchers suggested that even if naked singluarities exist, strange quantum effects could keep them hidden from us.

So there’s definitely no consensus right now on whether we’ll ever get the chance to study naked singularities.

And that’s not a terrible thing for now, because are we really ready to observe what goes on at the edge of our Universe?

Maybe, in our lifetime, we’ll find out.

Source:http://www.sciencealert.com

Scientists think they’ve pinpointed the group of brain cells that respond to meditation.


A physical link between deep breathing and a calm mind.

 For centuries, people have slowed their breathing to calm their minds. For some of us, this takes the form of meditation or yoga; for others, it’s 10 deep breaths before a panic attack sets in.

Regardless of what you call it, scientific evidence has backed up the fact that our breath can induce a feeling of tranquillity – although no one has ever been able to figure out exactly how that happens. Now, researchers think they might have finally found the answer, pinpointing a small group of neurons in the brain stems of mice that connect the breath with feelings of calm.

 To be clear, the research so far is limited to mice – scientists are yet to replicate the results in humans.

But the mouse brain has many similarities to the human brain, so it’s a good starting point that could begin to explain on a physical level how practices such as meditation and pranayama yoga can bring on feelings of calm and euphoria.

“This study is intriguing because it provides a cellular and molecular understanding of how that might work,” said lead researcher Mark Krasnow from Stanford University School of Medicine.

The group of cells in question belongs to the pre-Bötzinger complex, an area of neurons deep within the brain stem that are known to fire each time we breathe in or out – like a breathing pacemaker.

This structure was first discovered in mice back in 1991, but a similar structure has also been found in humans.

“The respiratory pacemaker has, in some respects, a tougher job than its counterpart in the heart,” said Krasnow.

 “Unlike the heart’s one-dimensional, slow-to-fast continuum, there are many distinct types of breaths: regular, excited, sighing, yawning, gasping, sleeping, laughing, sobbing.”

“We wondered if different subtypes of neurons within the respiratory control centre might be in charge of generating these different types of breath,” he added.

Last year, Krasnow and his team found evidence that a small group of neurons within this pre-Bötzinger complex were solely responsible for generating sighs – without them, mice never sighed, and when they were simulated, the animals couldn’t stop sighing.

In this latest paper, they found a separate group of neurons in the complex that have a more zen function – they appear to regulate states of calm and arousal in response to our breath.

To figure this out, the team identified two genetic markers called Cdh9 and Dbx1 that they noted were active in the pre-Bötzinger complex and appeared to be linked to breathing.

They then genetically engineered mice without any of the neurons that expressed these two genes – taking out a subpopulation of about 175 neurons in the brain stem.

Interestingly, the mice without these neurons still breathed normally, but with key one difference – they breathed more slowly than normal mice.

“I was initially disappointed,” said Kevin Yackle, one of the research team, now at the University of California, San Francisco.

But after a few days, the team noticed something else strange going on – the mice without the Cdh9 and Dbx1 neurons were extraordinarily calm compared to their control group peers. They still showed varieties of breathing, but they were all at a much slower pace.

“If you put them in a novel environment, which normally stimulates lots of sniffing and exploration,” said Yackle, “they would just sit around grooming themselves.” For mice, that’s taken as evidence of a zen state of mind.

“We were totally surprised,” Yackle told Diana Kwon over at Scientific American. “It certainly wasn’t something we expected to find.”

Upon further investigation, the team found evidence that the neurons were forming connections with the locus coeruleus – a region of the brain stem that’s involved in modulating arousal and emotion, and is responsible for waking us up at night and triggering anxiety and distress.

The team concluded that rather than regulating breathing, this little group of neurons was responding to it and reporting their findings to the locus coeruleus so that it could regulate our mood in response.

“If something’s impairing or accelerating your breathing, you need to know right away,” said Krasnow. “These 175 neurons, which tell the rest of the brain what’s going on, are absolutely critical.”

You can see below the pathway (green) that directly connects the brain’s breathing centre to the arousal centre and the rest of the brain.

image 0.img.full.high

The work is definitely a promising step forward, but we need to keep in mind that there’s still a lot we have to learn about how the pre-Bötzinger complex works, particular in humans.

Still, the new paper raises the possibility that “any form of practice – from yoga, pranayama to meditation – that is actively manipulating respiration might be using this pathway to regulate some aspects of arousal,” neurobiologist Antoine Lutz from the French National Institute of Health and Medical Research, who wasn’t involved in the research, told Scientific American.

While other teams will now need to pursue this research further in mice and eventually humans, Krasnow and his team are now continuing to get a better understanding of what other secrets could be hiding in the pre-Bötzinger complex.

“The pre-Bötzinger complex now appears to play a key role in the effects of breathing on arousal and emotion, such as seen during meditation,” said Feldman.

“We’re hopeful that understanding this centre’s function will lead to therapies for stress, depression and other negative emotions.”

Source:.sciencealert.com

Largest Ever Brain Cancer Study Provides Key Insight Into One of Its Deadliest Forms


This could change the way we think about brain tumours.

 
As far as cancers go, one of the worst is a type of brain cancer called glioma – the disease has a five-year survival rate of just 5 percent, and no reliable method for early detection.

A giant study that pooled genetic data from tens of thousands of people could change that, finding more than a dozen new mutations for physicians to hunt for in an effort to identify who is at risk of developing glioma.

 The results could end up boosting the chances of an early diagnosis, and saving lives in the process.

Together with researchers from the US and Europe, scientists from the Institute of Cancer Research in the UK carried out two studies on the human genome in an effort to spot differences that could result in cancer of the brain’s glial cells.

Our central nervous system relies on neurons to do its ‘thinking’ work, but they’re far from the only cell in the neighbourhood. For example, glial cells provide support for the neurons by insulating them, holding them in place, and helping them access nutrients.

But like a number of tissues in the body, changes in the genes inside these ‘nanny’ brain cells can cause them to grow out of control, prompting cancerous tumours to develop.

Glioma can be further broken down into categories, depending on the type of glial cell they started out as. Glioblastoma multiforme (GBM), for example, is a common form of brain cancer that begins as a type of glial cell called an astrocyte.

Tumours that grow into glioblastomas are particularly aggressive, killing around 95 percent of patients within five years.

 GBM develops in around 3 out of every 100,000 people, mostly striking in those over the age of 60, and claiming approximately 13,000 lives in the US and 5,000 lives in the UK each year.

While many researchers have been looking for new and innovative ways to treat gliomas, early detection has often been more accidental than intentional.

An Ohio State University study conducted in 2015 identified interactions between a pair of proteins and the newly developed tumour which could lead to a test that allows oncologists to diagnose a tumour as much as five years before symptoms appear.

But by identifying the genes that increase the risk of developing glioma later in life, researchers could potentially produce a program of diagnosis and quick treatment that might prevent tumours from growing in the first place.

This recent study didn’t stop at scanning the genome; it also analysed over 30,000 people included in a number of previous studies on GBM and non-GBM cancers, producing the largest ever study into brain cancer research.

All up, the research compared 12,496 cases of glioma with 18,190 people who didn’t have the cancer, finding 13 new locations on the genome which – if changed – could lead to glioma.

“The changes in the way we think about glioma could be quite fundamental,” says Richard Houlston from the Institute of Cancer Research.

“So, for example, what we thought of as two related sub-types of the disease turn out to have quite different genetic causes which may require different approaches to treatment.”

In total, researchers now have strong evidence for 26 locations on the genome that individually increase the risk of developing a form of glioma, in one case by up to 15 percent.

That might not seem like a lot, but when the odds are stacked against those with a metastatic brain tumour, every clue could make the difference between life and death.

“Understanding the genetics of glioma in such detail allows us to start thinking about ways of identifying people at high inherited risk, and will open up a search for new treatments that exploit our new knowledge of the biology of the disease,” said Houlston.

Combining past studies to increase the pool of data is a useful way to spot small differences which have otherwise been missed.

Hopefully this is one record we’ll see broken some time soon.

Source:http://www.sciencealert.com

Not Kidding – a Comet Is Making Its Closest Pass to Earth Since Its Discovery This April Fool’s Day


Watch it live!

An iconic comet will be zooming past Earth this weekend, just in time for April Fool’s Day. Which, admittedly, does sound a little suspicious, but we promise this is definitely not a prank.

Comet 41P/Tuttle-Giacobini-Kresak was first detected back in 1858, and circles the sun every 5.5 years. This year, it will be making the closest flyby of Earth since its discovery, allowing us to catch an unprecedented glimpse as it zooms past at a very safe distance of around 21.2 million km (13.2 million miles) away.

 That’s a distance of 0.14AU, or a little over a tenth of the distance between Earth and the Sun.

Northern Hemisphere stargazers with small telescopes and potentially even binoculars will have the chance to see the comet from dark vantage points between dusk and dawn from now until mid-April, when it will be passing across the stars of the constellations Ursa Major and Draco.

But on April 1, the viewing will be particularly good, with the comet at its closet point to Earth since its discovery more than 150 years ago.

If you’re more of a hobby skywatcher, are located in the Southern Hemisphere, or are struggling with bad weather, don’t worry, you can watch it live here via Slooh’s coverage from its telescopes on the Canary Islands, starting at Friday 31 March, 8.30pm EDT (Saturday 1 April, 00:30am UTC).

So what can you expect to see? Well, unlike the green comet that streaked past earlier this year, Comet 41P isn’t particularly dazzling.

Comet 41P, as it’s known for short, belongs to a group of comets known as Jupiter comets, which have been captured by Jupiter’s massive gravity, and are now in orbit between the Sun and the gas giant.

 It’s also not particularly large – usually it appears in the night sky as a diffuse blob of light, no brighter than 8th magnitude, which means it’s only as visible as Neptune in the night sky, and is roughly 50 times too faint to be seen with the naked eye.

Good binoculars or small telescopes will be needed to pick it out, as well as a dark, clear, moonless night.

But, this year could provide an exceptional opportunity – scientists are predicting that the comet could undergo a dramatic outburst in brightness as it approaches the Sun.

This happened back in May 1973, just before the comet arrived at perihelion – its closest point to the Sun.

Unexpectedly, the comet’s brightness surged by 10 magnitudes, which meant it became 10,000 times brighter over just a few days, making it visible to the naked eye.

“Nobody knows for sure why the comet abruptly flared in 1973, but careful scrutiny of recent approaches to the sun in 1995, 2001, and 2006 suggest that outbursts in brightness tend to occur around the time [the comet] is passing closest to the Sun,” explains astronomer Joe Rao, from New York’s Hayden Planetarium, for Space.com.

The good news is that this year, perihelion occurs on April 12, just a little over a week after it zooms past Earth, which means we could be in store for another brightening event.

How dramatic that will be, or if it’ll occur at all, is anyone’s guess.

Just in case, we’re going to be watching it from the comfort of our couches over at Slooh.

If nothing else, it’s a good excuse to escape all the craziness of the internet on April Fool’s Day with some much needed perspective about the vast scale of our Solar System, and all the fascinating objects that travel through it.

Happy skywatching!

Source: http://www.sciencealert.com

This Mind-Bending Theory Joins Black Holes, Gravitational Waves & Axions to Find New Physics


We haven’t seen physicists this excited for a while.

Scientists have proposed a new theory that combines some of the most mysterious phenomena in the Universe – black holes, gravitational waves, and axions – to solve one of the most confounding problems in modern physics. And it’s got experts in the field very excited.

The theory, which imagines a Universe filled with colossal ‘gravitational atoms’ that are capable of producing vast clouds of dark matter, predicts that it could be possible to detect entirely new kinds of particles using a giant gravitational wave detector called LIGO.

 “This is probably the most promising paper I’ve seen so far on the new physics we might probe with gravitational waves,” MIT particle physicist Benjamin Safdi, who wasn’t involved in the research, told Nature.

“It’s an awesome idea,” adds particle astrophysicist Tracy Slatyer, also from MIT. “The [LIGO] data is going to be there, and it would be amazing if we saw something.”

Before we dive headfirst into the crazy physics of this new theory, let’s run through the major players.

Black holes are an easy one – vast, matter-annihilating objects that are so remarkably strange, when Albert Einstein’s equations first predicted their existence, he didn’t believe they could actually be real.

Black holes maintain such powerful gravitational fields, when two of them collide with each other, they produce gravitational waves.

Confirmed for the first time last year, but predicted by Einstein more than a century ago, gravitational waves are ripples in the fabric of space-time that emanate from the most violent and explosive events in the Universe.

 And axions? Well, they’re a bit more tricky, because unlike black holes and gravitational waves, we’re not even sure if axions exist – and we’ve been searching for them for the past four decades.

Axions are one of the many candidates that have been proposed for dark matter – a mysterious, invisible substance whose gravity appears to hold our galaxies together, and is predicted to make up 85 percent of all matter in the Universe.

Axions are predicted to weigh around 1 quintillion (a billion billion) times less than an electron, and if we can prove their existence, these super-light particles could solve some major theoretical problems with the standard model of physics.

Okay, now that we have all the pieces in place, let’s get to this mind-bending new theory. (And yes, we’re calling it a theory, not a hypothesis, because it’s based on a mathematical framework. More on that here).

A team of physicists led by Asimina Arvanitaki and Masha Baryakhtar from the Perimeter Institute for Theoretical Physics in Canada have proposed that if axions exist and have the right mass, they could be produced in the form of vast clouds of particles by a spinning black hole.

This process would be enough to produce gravitational waves like the ones that were detected last year, and if so, we can use gravitational wave detectors to finally observe the signature of dark matter, and close the gaps in the standard model.

“The basic idea is that we’re trying to use black holes… the densest, most compact objects in the Universe, to search for new kinds of particles,” Baryakhtar told Ryan F. Mandelbaum at Gizmodo.

You can think of this scenario like this: a black hole is like the nucleus at the centre of a giant, hypothetical gravitational atom. Axions get stuck in orbit around this nucleus, whizzing around like electrons do in regular atoms.

“[E]lectrons interact via electromagnetism, so they let out electromagnetic waves, or light waves. Axions interact via gravity, so they let out gravitational waves,” Mandelbaum explains.

If an axion strays too close to the black hole’s event horizon, the spin of the black hole will ‘supercharge’ it, and due to a process called superradiance that has been shown to multiply photons (light particles) in many experiments in the past, this will cause the axions to multiply within a black hole.

These multiplying axions would interact with the black hole in the same way as the original axion near the event horizon, resulting in 1080 axions – “the same number of atoms in the entire Universe, around a single black hole”, says Mandelbaum.

“It’s so cool, and I haven’t read a paper that talked about [superradiance] in years,” Chanda Prescod-Weinstein, a University of Washington axion expert who wasn’t involved in the research, told him.

“[I]it was really fun to see superradiance and axions in one paper.”

These multiplying axions wouldn’t just pop into existence randomly – they’d group together in huge quantum waves like the electron clouds you see in an atom.

Within this cloud, any axions that collide with each other would produce gravitons – another hypothetical particle thought to mediate the force of gravitation.

Gravitons are to gravitational waves as photons are to light, and Baryakhtar and her team propose that they would set off continuous waves into the Universe at a frequency set by the axion’s mass.

With improved sensitivity, LIGO should be able to spot thousands of these axion signals in a single year, the researchers predict, finally giving them a way to observe the signature of dark matter – something that has eluded scientists for decades.

Of course, grand theories like these always come with some caveats – in order to work, the axions must have a very specific mass, and that mass doesn’t necessarily gel well with current predictions on dark matter.

But physicists are still excited by the idea, and with LIGO expected to increase greatly in sensitivity in the next couple of years, it might not be too long before we can test it out for real.

Source:http://www.sciencealert.com

How Much Energy Would You Need to Power an Actual Time Machine?


There are two hypotheses for time travel that are most popular: wormhole tunneling and cosmic strings. A wormhole is a hypothetical, bi-directional tunnel connecting two space-time locations.

Physicist Michio Kaku doesn’t entirely rule this possibility out, but he cautions that powering a time machine to travel in this way is beyond human capabilities right now, and would demand either negative energy or the energy of a star.

 

Physicist Brian Greene, a string theory expert, doubts that this kind of approach could ever work.

The other popular hypotheses focuses on cosmic strings – thin energy tubes that theoretically stretch all the way across the Universe, which is continually expanding.

Some predict that these narrow spaces, holdovers from the earliest days of the cosmos, contain tremendous amounts of mass. This mass would allow the strings to warp whatever space-time surrounds them.

Princeton astrophysicist J. Richard Gott points out that cosmic strings are either in the shape of loops without ends or are infinite. If two such strings were configured the right way, they might bend space-time in a way that could allow for time travel, in theory.

However, according to Gott, this would be capable only for a “super civilisation” much higher on the Kardashev scale.

 Bill Nye answers this question for kids by referring to heat and energy which always spread out – entropy.

Without outside intervention, heat will not spontaneously concentrate somewhere. Instead, it will disperse towards cooler places.

What does this have to do with time travel? When something spreads outward and moves across a distance, it does so over time.

This, he says, means that time and the spreading out of energy are closely related. It is this intimate connection that prevents us from building time machines.

Source:http://www.sciencealert.com

Brain Cells We Thought Were Just Fillers Might Actually Be the Key to Our Body Clocks


Neurons aren’t everything.

Scientists have discovered that brain cells that were once considered to be simple place-holders for neurons could actually play an important role in helping to regulate our circadian behaviour.

Astrocytes are a kind of glial cell – the support cells that are often called the glue of the nervous system, as they provide structure and protection for neurons. But a new study shows that astrocytes aren’t just gap-fillers, and may be crucial for keeping time in our inner body clock.

 Scientific consensus has long regarded our internal clock as being controlled by the suprachiasmatic nuclei (SCN), a brain region in the hypothalamus made up of around 20,000 neurons. But there’s about 6,000 star-shaped astrocyte cells in the same area, the exact function of which has never been fully explained.

Now, a team from Washington University in St. Louis has figured out how to independently control astrocytes in mice – and by altering the astrocytes, the scientists were able to slow down the animals’ sense of time.

“We had no idea they would be that influential,” says one of the researchers, Matt Tso.

It was once thought the suprachiasmatic nuclei was the only part of the brain that regulated circadian rhythms, but scientists now understand that cells throughout the body all have their own circadian clocks – including the cells that make up our lungs, heart, liver, and everything else.

In 2005, one of the team, neuroscientist Erik Herzog, helped figure out that astrocytes also include these clock genes.

By isolating the brain cells from rats and coupling them with a bioluminescent protein, Herzog’s team showed that they glowed rhythmically – evidence that they were capable of keeping time like other cells.

 It took more than a decade for the researchers to figure out how to measure the same astrocyte behaviour in a living specimen, by using CRISPR-Cas9 gene-editing to delete a clock gene called Bmal1 in the astrocytes of mice.

Left to their own devices, mice have circadian clocks that last for approximately 23.7 hours. We know this because mice in constant darkness will start running on a wheel every 23.7 hours, and usually don’t miss their time slot by more than 10 minutes.

Humans also miss the 24-hour mark slightly – a Harvard University study in 1999 found that our internal clocks run a tad overlong, on a daily cycle of 24 hours, 11 minutes.

But even though Herzog had demonstrated in 2005 that astrocytes were involved in keeping time, the team didn’t necessarily expect mice without Bmal1 to be affected, because most research surrounding the suprachiasmatic nuclei has demonstrated the controlling effect of neurons, not astrocytes.

“When we deleted the gene in the astrocytes, we had good reason to predict the rhythm would remain unchanged,” says Tso.

“When people deleted this clock gene in neurons, the animals completely lost rhythm, which suggests that the neurons are necessary to sustain a daily rhythm.”

But, to the researchers’ surprise, deleting the clock gene in the astrocytes saw the mouse internal clocks run slower – beginning their daily run about 1 hour later than usual.

In another experiment, the team studied mice with a mutation that caused their circadian clocks to run fast. By repairing this gene in the animals’ astrocytes – but not fixing the defect in their neurons – they weren’t sure what the affect would be.

“We expected the SCN to follow the neurons’ pace,” says Tso. “There are 10 times more neurons in the SCN than astrocytes. Why would the behaviour follow the astrocytes?”

With the mutation fixed in the animals’ astrocytes, the mouse began their running routine 2 hours later than mice that hadn’t had the mutation repaired (in either astrocytes or neurons).

“[These results] suggests that the astrocytes are somehow talking to the neurons to dictate rhythms in the brain, and in behaviour,” Herzog told Diana Kwon at The Scientist.

While the researchers acknowledge that they don’t fully understand the extent to which astrocytes control circadian behaviour, it’s clear something powerful is going on.

Of course, we can’t guarantee yet whether astrocytes in humans are regulating body clocks in the same way, but that’s something that later studies may be able to confirm.

We’ll have to wait to see the results of future research to know more, but until then, one thing’s for sure – these brain cells are definitely there for a lot more than just neuron padding.

Source:http://www.sciencealert.com

This new hypothesis might finally explain the physics behind why water splashes.


It’s way more complex than we thought.

 

There’s some complex science behind a simple water splash, but scientists now think they’re closer than ever to understanding what happens during a splash at the microscopic level.

A new mathematical model shows how incredibly thin layers of air on surfaces can cause upward splashes from water droplets thousands of times larger, with air pressure and viscosity also affecting the chances of a splash.

 In fact, these air layers are so thin, they’re the equivalent of a 1 cm-thick (0.39 inch) layer of air stopping a tsunami wave as it hits a beach, according to mathematician James Sprittles from the University of Warwick in the UK.

The model suggests that a microscopic layer of air just 1 micron in size – 50 times smaller than the width of a human hair – is enough to get in the way of a 1-millimetre (0.039-inch) water droplet and cause it to splash up, rather than spread out evenly across a surface.

“The air layer’s width is so small that it is similar to the distance air molecules travel between collisions, so that traditional models are inaccurate and a microscopic theory is required,” explains Sprittles.

splash-animation finalAnimation showing the model in action. 

While the idea of air layers affecting splashes has been suggested before, the new model goes into greater detail to explain what’s happening at the smallest scale as the air and liquid interact under different circumstances.

One such circumstance is at the top of mountains, where air pressure is lower and splashes are less likely to occur, because the air can more easily escape from under the liquid.

But the benefits of this kind of research go way beyond helping mountaineers predict whether their split drinks are going to cause splashback.

Understanding how and why splashes occur could benefit researchers in everything from analysing blood spatter at a crime scene to knowing exactly what speed to spray fertiliser on plants to avoid splash-back.

“Most promisingly, the new theory should have applications to a wide range of related phenomena, such as in climate science,” says Sprittles, “to understand how water drops collide during the formation of clouds or to estimate the quantity of gas being dragged into our oceans by rainfall.”

As previous research has shown, even the temperature of water can change how it splashes around, and Sprittles says combining his new hypothesis with existing models shouldn’t be too difficult.

The next step is to build more complex models on top of this basic framework, and then we’ll have an even better ability to predict what kind of splashes will occur in different kinds of circumstances.

“You would never expect a seemingly simple everyday event to exhibit such complexity,” Sprittles says.

Source:http://www.sciencealert.com

A British Teenager Has Corrected a Mistake in NASA’s Data


Kids these days…

 A British school student recently contacted NASA to point out that there was an error in data recorded on the International Space Station (ISS), earning him thanks from the US space agency.

Miles Soloman, a 17-year-old student from Tapton School in Sheffield, was working on the TimPix project, which lets school students in the UK access data recorded by radiation detectors during British astronaut Tim Peake’s six-month stay on the ISS.

 

Amongst other projects, Peake participated in a research program that aims to understand the impact of space radiation on humans. Radiation on the ISS is monitored with USB-shaped Timepix detectors, which are plugged into computers and regularly send data back to Earth.

Soloman and his fellow students were given these Timepix measurements in a giant pile of Excel spreadsheets, allowing them to practice data analysis on real-world scientific information.

When they sorted the data by energy levels, Soloman noticed something odd.

“I went straight to the bottom of the list, and went to the lowest bits of energy there were,” he told BBC Radio 4’s World at One current affairs program.

“I noticed that where we should have no energy, where there was no radiation, it was actually showing -1. The first thing I thought was ‘Well you can’t have negative energy,’ and then we realised that this was an error.”

Soloman and his physics teacher James O’Neill jumped into action and emailed NASA straight away.

 As Soloman explained to BBC Radio, researchers at NASA responded that they were aware of the error, but thought it had only been happening once or twice a year. They were wrong.

“What we actually found was that they were happening multiple times a day,” says Soloman.

“They thought they had corrected for this,” said physicist Lawrence Pinsky from the University of Houston, who is involved with the TimPix project, and is a collaborator of the radiation monitoring project on ISS.

“The problem is that some of the algorithms which converted the raw data were slightly off, and therefore when they did the conversion, they wound up with a negative number.”

Prompted by BBC’s World at One host Martha Kearney on whether such a revelation by a schoolboy was embarrassing, Pinsky answered that he didn’t think so.

“It was appreciated more so than being embarrassing,” he said. “The idea that students get involved at a real level means that there’s an opportunity for them to find things like this.”

The TimPix project is one of many initiatives organised by IRIS (the Institute for Research in Schools), a UK-based charitable trust that gives students and teachers opportunities to do actual scientific research at school.

IRIS has partnered with organisations such as CERN, NASA, Wellcome Trust, and the UK Royal Horticultural Society to bring real science projects into the classroom and get kids excited about pursuing careers in science.

“We’re also tapping into the potential of young minds and what they can do,” said Soloman’s teacher O’Neill. “As far as I’m concerned, the greatest research group we can form is our students around the country.”

Apart from analysing radiation exposure on ISS, students have also been doing genetic research into cardiovascular disease, analysing the atmosphere of Mars, and taking part in the MoEDAL experiment at the Large Hadron Collider, looking for signs of a magnetic monopole.

There’s even a project in the works that will let kids build a replica of the Large Hadron Collider in Minecraft, working in collaboration with the particle physics team from the University of Oxford.

At least for Miles Soloman, IRIS has definitely given him inspiration to pursue more science, although he hastens to explain that he wasn’t trying to outsmart NASA researchers when he pointed out the data error.

“I’m not trying to prove NASA wrong, I’m not trying to say I’m better, because obviously I’m not – they’re NASA,” he said. “I want to work with them and learn from them.”

Source:http://www.sciencealert.com

This mesmerising time-lapse of cell division is real, and it’s spectacular.


This is life.

 If you’ve ever wondered what cell division actually looks like, this incredible time-lapse by francischeefilms on YouTube gives you the best view we’ve ever seen, showing a real-life tadpole egg dividing from four cells into several million in the space of just 20 seconds.
 Of course, that’s lightening speed compared to how long it actually takes – according to Adam Clark Estes at Gizmodo, the time-lapse has sped up 33 hours of painstaking division into mere seconds for our viewing pleasure.

The species you see developing here is Rana temporaria, the common frog, which lays 1,000 to 2,000 eggs at a time in shallow, fresh water ponds.

According to the team behind the footage, they had to build their own equipment to film it like this, and had to devise a way to get the lighting and microscope set-up just right.

“The whole microscope sits on anti-vibration table. [I]t doesn’t matter too much what microscope people use to perform this,” francischeefilms describe on their YouTube page.

“There are countless other variables involved in performing this tricky shot, such as: the ambient temperature during shooting; the time at which the eggs were collected; the handling skills of the operator; the type of water used; lenses; quality of camera etc.”

Check out the footage. URL:https://youtu.be/Wz4igVjNGq4

Source:http://www.sciencealert.com