Physicists show how lifeless particles can become 'life-like' by switching behaviors

Emory graduate student Guga Gogia slowly “salted” micron-sized particles into a vacuum chamber filled with plasma, creating a single layer of particles levitating above a charged electrode. He kept a low gas pressure, so the particles could move freely. “After a few minutes I could see with my naked eye that they were acting strangely," Gogia says.

By Carol Clark

Physicists at Emory University have shown how a system of lifeless particles can become “life-like” by collectively switching back and forth between crystalline and fluid states — even when the environment remains stable.

Physical Review Letters recently published the findings, the first experimental realization of such dynamics.

“We’ve discovered perhaps the simplest physical system that can consistently keep changing behavior over time in a fixed environment,” says Justin Burton, Emory assistant professor of physics. “In fact, the system is so simple we never expected to see such a complex property emerge from it.”

Many living systems — from fireflies to neurons — switch behaviors collectively, firing on and then shutting off. The current paper, however, involved a non-living system: Plastic particles, tiny as dust specks, that have no “on” or “off” switches.

“The individual particles cannot change between crystalline and fluid states,” Burton says. “The switching emerges when there are collections of these particles — in fact, as few as 40. Our findings suggest that the ability for a system to switch behaviors over any time scale is more universal than previously thought.”

Watch a video to learn more and see the particles in action:


The Burton lab studies the tiny, plastic particles as a model for more complex systems. They can mimic the properties of real phenomena, such as the melting of a solid, and reveal how a system changes when it is driven by forces.

The particles are suspended in a vacuum chamber filled with a plasma — ionized argon gas. By altering the gas pressure inside the chamber, the lab members can study how the particles behave as they move between an excited, free-flowing state into a jammed, stable position.

The current discovery occurred after Emory graduate student Guram “Guga” Gogia tapped a shaker and slowly “salted” the particles one at a time into the vacuum chamber filled with the plasma, creating a single layer of particles levitating above a charged electrode. “I was just curious how the particles would behave over time if I set the parameters of the chamber at a low gas pressure, enabling them to move freely,” Gogia says. “After a few minutes I could see with my naked eye that they were acting strangely.”

From anywhere between tens of seconds to minutes, the particles would switch from moving in lockstep, or a rigid structure, to being in a melted gas-like state. It was surprising because the particles were not just melting and recrystallizing but going back and forth between the two states. 

“Imagine if you left a tray of ice out on your counter at room temperature,” Gogia says. “You wouldn’t be surprised if melted. But if you kept the ice on the counter, you would be shocked if it kept turning back to ice and melting again.”

Gogia conducted experiments to confirm and quantify the phenomenon. The findings could serve as a simple model for the study of emerging properties in non-equillibrium systems.

“Switching is an ubiquitous part of our physical world,” Burton says. “Nothing stays in a steady state for long — from the Earth’s climate to the neurons in a human brain. Understanding how systems switch is a fundamental question in physics. Our model strips away the complexity of this behavior, providing the minimum ingredients necessary. That provides a base, a starting point, to help understand more complex systems.”

Related:
Physicists crack another piece of the glass puzzle
The physics of falling icebergs

from eScienceCommons http://ift.tt/2ynbSWI
Emory graduate student Guga Gogia slowly “salted” micron-sized particles into a vacuum chamber filled with plasma, creating a single layer of particles levitating above a charged electrode. He kept a low gas pressure, so the particles could move freely. “After a few minutes I could see with my naked eye that they were acting strangely," Gogia says.

By Carol Clark

Physicists at Emory University have shown how a system of lifeless particles can become “life-like” by collectively switching back and forth between crystalline and fluid states — even when the environment remains stable.

Physical Review Letters recently published the findings, the first experimental realization of such dynamics.

“We’ve discovered perhaps the simplest physical system that can consistently keep changing behavior over time in a fixed environment,” says Justin Burton, Emory assistant professor of physics. “In fact, the system is so simple we never expected to see such a complex property emerge from it.”

Many living systems — from fireflies to neurons — switch behaviors collectively, firing on and then shutting off. The current paper, however, involved a non-living system: Plastic particles, tiny as dust specks, that have no “on” or “off” switches.

“The individual particles cannot change between crystalline and fluid states,” Burton says. “The switching emerges when there are collections of these particles — in fact, as few as 40. Our findings suggest that the ability for a system to switch behaviors over any time scale is more universal than previously thought.”

Watch a video to learn more and see the particles in action:


The Burton lab studies the tiny, plastic particles as a model for more complex systems. They can mimic the properties of real phenomena, such as the melting of a solid, and reveal how a system changes when it is driven by forces.

The particles are suspended in a vacuum chamber filled with a plasma — ionized argon gas. By altering the gas pressure inside the chamber, the lab members can study how the particles behave as they move between an excited, free-flowing state into a jammed, stable position.

The current discovery occurred after Emory graduate student Guram “Guga” Gogia tapped a shaker and slowly “salted” the particles one at a time into the vacuum chamber filled with the plasma, creating a single layer of particles levitating above a charged electrode. “I was just curious how the particles would behave over time if I set the parameters of the chamber at a low gas pressure, enabling them to move freely,” Gogia says. “After a few minutes I could see with my naked eye that they were acting strangely.”

From anywhere between tens of seconds to minutes, the particles would switch from moving in lockstep, or a rigid structure, to being in a melted gas-like state. It was surprising because the particles were not just melting and recrystallizing but going back and forth between the two states. 

“Imagine if you left a tray of ice out on your counter at room temperature,” Gogia says. “You wouldn’t be surprised if melted. But if you kept the ice on the counter, you would be shocked if it kept turning back to ice and melting again.”

Gogia conducted experiments to confirm and quantify the phenomenon. The findings could serve as a simple model for the study of emerging properties in non-equillibrium systems.

“Switching is an ubiquitous part of our physical world,” Burton says. “Nothing stays in a steady state for long — from the Earth’s climate to the neurons in a human brain. Understanding how systems switch is a fundamental question in physics. Our model strips away the complexity of this behavior, providing the minimum ingredients necessary. That provides a base, a starting point, to help understand more complex systems.”

Related:
Physicists crack another piece of the glass puzzle
The physics of falling icebergs

from eScienceCommons http://ift.tt/2ynbSWI

Fostering Diabetes Awareness through Student STEM

Learn more about K-12 STEM projects that support student exploration of questions about diabetes.

from Science Buddies Blog http://ift.tt/2imX7bJ
Learn more about K-12 STEM projects that support student exploration of questions about diabetes.

from Science Buddies Blog http://ift.tt/2imX7bJ

Alternative cancer therapies: the potential impact on survival

Patients have the right to decide what treatment, if any, they want to have. But it’s incredibly important that the decisions people make are based on accurate information, allowing them to weigh up the pros and cons of the treatment options before them.

But where can patients get this accurate information? Search the internet, and you’ll find trustworthy, evidence-based sources (like our web pages and the NHS website). But you’ll also quickly land on many promises of miracle cancer cures. While there’s often no scientific evidence to back many of the miracle claims made online, counter arguments put forward by those selling or advocating for alternative therapies often state that ‘there’s no evidence to say they don’t work either’.

Proving that something definitely doesn’t work is much harder than showing something does. We’ve written several articles questioning the claims behind alternative treatments, conspiracy theories, and the harms that alternative therapies can cause patients.

In this post, we’re using ‘alternative’ to describe treatment that’s used instead of conventional medicine.

Now, a researcher in the US has taken a step towards collecting robust evidence to measure the harm of alternative therapy. And the numbers he has calculated have helped put an estimate on the negative impact alternative therapies might be having on survival.

‘This was personal for me’

Radiotherapy specialist Dr Skyler Johnson, from Yale, began digging around the harms of alternative therapies for cancer after his family was directly affected.

The figures show that patients who opt for alternative therapies and decline conventional treatments are 2.5 times more likely to die within 5 years of being diagnosed. It’s a huge reduction in the chances of survival. – Dr Skyler Johnson

“It was during my second year of medical school when my wife was diagnosed with Hodgkin lymphoma,” says Johnson. “Despite the fact I was training to be a doctor, I did what many people probably do. I was curious and searched the internet.”

Johnson was shocked by the amount of lies, misinformation, and to use a popularly coined phrase ‘fake news’ that his search generated.

“Thankfully my wife had great treatment – conventional medicine – and made a full recovery,” he says. “But it left me wondering, if I, as a doctor, felt taken aback by all the promises of miracle treatments, how do other people cope when facing the same situation? So this research was personal for me.”

As a cancer specialist, Johnson had a first-hand account of some of the problems alternative therapies were causing patients. It often meant people were “self-treating” symptoms and delaying their cancer diagnosis, or refusing cancer treatments that “we know work”, he says.

The key point here is that those cases are anecdotes from individual patients, which isn’t the same as robust evidence that alternative treatments are causing harm.

‘The data was there, I just needed to analyse it’

On top of his clinical training, Johnson spends weekends and evenings engrossed in his passion – using Big Data to find factors that have an impact on cancer survival. “The study took me 7 months to a year to complete. The data was there, I just needed to comb through and analyse it,” he says.

Johnson used the US National Cancer Database as a source of information. The database is a collection of patient records sent from more than 1,500 cancer hospitals across the US and includes more than 70% of all newly diagnosed cancer cases.

In this study, published this summer in the Journal of the National Cancer Institute, Johnson looked at the records of patients with one of the four most common US cancers – breast, prostate, lung, and bowel – that hadn’t spread. The doctors use codes to represent the treatments that patients have, and one of the codes is ‘unproven treatments given by non-medical therapists’.

“To truly understand the impact of alternative medicine, we only included people who had unproven treatments and no conventional medicine at all,” says Johnson. “Even if they don’t return to hospital after their diagnosis, if they die from their cancer their death record is matched to their file, so we still have this information.”

Among the millions of records, there were 281 patients who opted solely for what Johnson defined as alternative therapy.

Choosing alternative therapies reduces the chances of surviving cancer

“The figures show that patients who opt for alternative therapies and decline conventional treatments are 2.5 times more likely to die within 5 years of being diagnosed”, says Johnson. “It’s a huge reduction in the chances of survival.”

Although there is already a big difference in survival, the effect of declining conventional treatment might be an underestimate because the study only followed patients for 5 years. Two of the four cancers analysed (breast and prostate) are often slow growing so the gap in survival may widen further over time.

When Johnson looked at cancer types individually, the results became more interesting. “For low and intermediate risk prostate cancers, choosing alternative therapy didn’t have any impact. But many prostate cancers are slow-growing, plus a high proportion don’t even need treating because they won’t ever cause harm. So this actually makes perfect sense,” he says.

“When it came to lung cancer, patients who opt out of conventional medicine are more than twice as likely to die within 5 years.” And this small effect probably reflects lung cancer being so hard to treat; survival is poor even for patients who choose conventional treatment.

“But when we look at breast and bowel cancer, both of which have good survival due to effective treatments being available, patients who chose alternative therapies were over 5 times more likely to die from their cancer in the 5 years after their diagnosis,” says Johnson.

As well as only having followed the patients for a short period post diagnosis, the data might also underestimate the full harms of alternative therapies because the records only capture patients’ first treatment choice. Some people who chose alternative therapies at the beginning might have decided to return to conventional medicine if their disease worsened.

Lax legislation costs lives

When Johnson did some digging around the type of person more likely to opt out of conventional treatments, he found some interesting trends.

“Our analysis shows that patients opting for alternative therapies tend to be younger, female, in general better health, and have a higher income and level of education,” says Johnson.

“Furthermore, they more often live in areas in the US where legislation is more favourable towards practices offering alternative therapies, for example the West coast. This indicates that certain states in the US really need to do more when it comes to regulating alternative therapy practices, which form a multi-billion dollar industry.”

The growth of alternative, unproven therapies in regions of relative affluence and high levels of education also points to a failure of education around science – a problem not unique to the US. Many people are not being empowered to critically analyse scientific or medical claims.

“In a ‘post-truth era’, the mountain of misinformation available is just serving to confirm some people’s entrenched bias against big institutions, including medicine,” Johnson thinks. “But it’s my hope that studies like this can still reach and engage people who are unsure and seeking facts, and help them have better conversations with their doctors about their options.”

Our advice regarding alternative therapies

This is only one study from the US tracking patients with 4 types of cancer over 5 years following diagnosis. We’ll need bigger, longer studies to get a more reliable measure of the impact on survival for those who decline conventional medicine.

But Johnson’s research shows that for the cases in this study, choosing alternative therapy over conventional, evidence-based medicine reduced the chances of surviving.

“Cancer patients often go through a very difficult and emotional time,” says Martin Ledwick, head information nurse at Cancer Research UK.

“Patients can feel like there is nothing in their life that they can still control, and deciding to refuse conventional treatment and opt for an alternative therapy can sometimes give them back a sense of control.”

Doctors aim to be as truthful as possible with patients and give as much information as they can, so people with cancer can make informed decisions about what treatments they want to have. Sometimes this means being honest about there being no guarantees that a treatment will work, or in some circumstances that the best that can be achieved is extra time.

“Even if a treatment works for 99% of people, there’s still 1% who don’t benefit. Cancer patients can, understandably, find this uncertainty hard to deal with,” says Ledwick. “And for some people, the news their doctor gives them isn’t what they want to hear. In these circumstances, it’s understandable that claims made by those promoting alternative therapies might seem very beguiling.”

It’s against the law for individuals or companies to advertise any cancer treatment (whether proven to work or not) directly to patients in the UK. But the internet is global, and not all countries have similar regulations in place to protect patients from misleading advertisements. Unfortunately, this can leave the door open for some individuals and companies to exploit cancer patients.

“Some people selling alternative therapies are out to make money and there’s no proof their remedies work or, in some cases, are even safe,” says Ledwick.

We’ve also written before about how the harm of alternative therapies extends beyond people’s finances. It’s the risk of postponing or declining conventional treatments that might otherwise prolong or even save a patient’s life. It’s the harm that can be caused by travelling overseas when ill, forgoing palliative care to ease pain and other symptoms, and loss of precious time that could be spent with loved ones.

Every patient has the right to decide what treatments to have. But we want people to make these decisions based on discussions with qualified health professionals and factual information, not from unsubstantiated claims lacking any scientific evidence to back them up.

Emma

References:

Johnson et al, 2017, JNCI J Natl Cancer Inst, Jan 1;110(1). doi: 10.1093/jnci/djx145

If you or someone you know has questions about cancer and treatment, please give our Cancer Information nurses a call – they’re on freephone 0808 800 4040, 9am-5pm Monday to Friday, or you can send them an email.



from Cancer Research UK – Science blog http://ift.tt/2lD9l53

Patients have the right to decide what treatment, if any, they want to have. But it’s incredibly important that the decisions people make are based on accurate information, allowing them to weigh up the pros and cons of the treatment options before them.

But where can patients get this accurate information? Search the internet, and you’ll find trustworthy, evidence-based sources (like our web pages and the NHS website). But you’ll also quickly land on many promises of miracle cancer cures. While there’s often no scientific evidence to back many of the miracle claims made online, counter arguments put forward by those selling or advocating for alternative therapies often state that ‘there’s no evidence to say they don’t work either’.

Proving that something definitely doesn’t work is much harder than showing something does. We’ve written several articles questioning the claims behind alternative treatments, conspiracy theories, and the harms that alternative therapies can cause patients.

In this post, we’re using ‘alternative’ to describe treatment that’s used instead of conventional medicine.

Now, a researcher in the US has taken a step towards collecting robust evidence to measure the harm of alternative therapy. And the numbers he has calculated have helped put an estimate on the negative impact alternative therapies might be having on survival.

‘This was personal for me’

Radiotherapy specialist Dr Skyler Johnson, from Yale, began digging around the harms of alternative therapies for cancer after his family was directly affected.

The figures show that patients who opt for alternative therapies and decline conventional treatments are 2.5 times more likely to die within 5 years of being diagnosed. It’s a huge reduction in the chances of survival. – Dr Skyler Johnson

“It was during my second year of medical school when my wife was diagnosed with Hodgkin lymphoma,” says Johnson. “Despite the fact I was training to be a doctor, I did what many people probably do. I was curious and searched the internet.”

Johnson was shocked by the amount of lies, misinformation, and to use a popularly coined phrase ‘fake news’ that his search generated.

“Thankfully my wife had great treatment – conventional medicine – and made a full recovery,” he says. “But it left me wondering, if I, as a doctor, felt taken aback by all the promises of miracle treatments, how do other people cope when facing the same situation? So this research was personal for me.”

As a cancer specialist, Johnson had a first-hand account of some of the problems alternative therapies were causing patients. It often meant people were “self-treating” symptoms and delaying their cancer diagnosis, or refusing cancer treatments that “we know work”, he says.

The key point here is that those cases are anecdotes from individual patients, which isn’t the same as robust evidence that alternative treatments are causing harm.

‘The data was there, I just needed to analyse it’

On top of his clinical training, Johnson spends weekends and evenings engrossed in his passion – using Big Data to find factors that have an impact on cancer survival. “The study took me 7 months to a year to complete. The data was there, I just needed to comb through and analyse it,” he says.

Johnson used the US National Cancer Database as a source of information. The database is a collection of patient records sent from more than 1,500 cancer hospitals across the US and includes more than 70% of all newly diagnosed cancer cases.

In this study, published this summer in the Journal of the National Cancer Institute, Johnson looked at the records of patients with one of the four most common US cancers – breast, prostate, lung, and bowel – that hadn’t spread. The doctors use codes to represent the treatments that patients have, and one of the codes is ‘unproven treatments given by non-medical therapists’.

“To truly understand the impact of alternative medicine, we only included people who had unproven treatments and no conventional medicine at all,” says Johnson. “Even if they don’t return to hospital after their diagnosis, if they die from their cancer their death record is matched to their file, so we still have this information.”

Among the millions of records, there were 281 patients who opted solely for what Johnson defined as alternative therapy.

Choosing alternative therapies reduces the chances of surviving cancer

“The figures show that patients who opt for alternative therapies and decline conventional treatments are 2.5 times more likely to die within 5 years of being diagnosed”, says Johnson. “It’s a huge reduction in the chances of survival.”

Although there is already a big difference in survival, the effect of declining conventional treatment might be an underestimate because the study only followed patients for 5 years. Two of the four cancers analysed (breast and prostate) are often slow growing so the gap in survival may widen further over time.

When Johnson looked at cancer types individually, the results became more interesting. “For low and intermediate risk prostate cancers, choosing alternative therapy didn’t have any impact. But many prostate cancers are slow-growing, plus a high proportion don’t even need treating because they won’t ever cause harm. So this actually makes perfect sense,” he says.

“When it came to lung cancer, patients who opt out of conventional medicine are more than twice as likely to die within 5 years.” And this small effect probably reflects lung cancer being so hard to treat; survival is poor even for patients who choose conventional treatment.

“But when we look at breast and bowel cancer, both of which have good survival due to effective treatments being available, patients who chose alternative therapies were over 5 times more likely to die from their cancer in the 5 years after their diagnosis,” says Johnson.

As well as only having followed the patients for a short period post diagnosis, the data might also underestimate the full harms of alternative therapies because the records only capture patients’ first treatment choice. Some people who chose alternative therapies at the beginning might have decided to return to conventional medicine if their disease worsened.

Lax legislation costs lives

When Johnson did some digging around the type of person more likely to opt out of conventional treatments, he found some interesting trends.

“Our analysis shows that patients opting for alternative therapies tend to be younger, female, in general better health, and have a higher income and level of education,” says Johnson.

“Furthermore, they more often live in areas in the US where legislation is more favourable towards practices offering alternative therapies, for example the West coast. This indicates that certain states in the US really need to do more when it comes to regulating alternative therapy practices, which form a multi-billion dollar industry.”

The growth of alternative, unproven therapies in regions of relative affluence and high levels of education also points to a failure of education around science – a problem not unique to the US. Many people are not being empowered to critically analyse scientific or medical claims.

“In a ‘post-truth era’, the mountain of misinformation available is just serving to confirm some people’s entrenched bias against big institutions, including medicine,” Johnson thinks. “But it’s my hope that studies like this can still reach and engage people who are unsure and seeking facts, and help them have better conversations with their doctors about their options.”

Our advice regarding alternative therapies

This is only one study from the US tracking patients with 4 types of cancer over 5 years following diagnosis. We’ll need bigger, longer studies to get a more reliable measure of the impact on survival for those who decline conventional medicine.

But Johnson’s research shows that for the cases in this study, choosing alternative therapy over conventional, evidence-based medicine reduced the chances of surviving.

“Cancer patients often go through a very difficult and emotional time,” says Martin Ledwick, head information nurse at Cancer Research UK.

“Patients can feel like there is nothing in their life that they can still control, and deciding to refuse conventional treatment and opt for an alternative therapy can sometimes give them back a sense of control.”

Doctors aim to be as truthful as possible with patients and give as much information as they can, so people with cancer can make informed decisions about what treatments they want to have. Sometimes this means being honest about there being no guarantees that a treatment will work, or in some circumstances that the best that can be achieved is extra time.

“Even if a treatment works for 99% of people, there’s still 1% who don’t benefit. Cancer patients can, understandably, find this uncertainty hard to deal with,” says Ledwick. “And for some people, the news their doctor gives them isn’t what they want to hear. In these circumstances, it’s understandable that claims made by those promoting alternative therapies might seem very beguiling.”

It’s against the law for individuals or companies to advertise any cancer treatment (whether proven to work or not) directly to patients in the UK. But the internet is global, and not all countries have similar regulations in place to protect patients from misleading advertisements. Unfortunately, this can leave the door open for some individuals and companies to exploit cancer patients.

“Some people selling alternative therapies are out to make money and there’s no proof their remedies work or, in some cases, are even safe,” says Ledwick.

We’ve also written before about how the harm of alternative therapies extends beyond people’s finances. It’s the risk of postponing or declining conventional treatments that might otherwise prolong or even save a patient’s life. It’s the harm that can be caused by travelling overseas when ill, forgoing palliative care to ease pain and other symptoms, and loss of precious time that could be spent with loved ones.

Every patient has the right to decide what treatments to have. But we want people to make these decisions based on discussions with qualified health professionals and factual information, not from unsubstantiated claims lacking any scientific evidence to back them up.

Emma

References:

Johnson et al, 2017, JNCI J Natl Cancer Inst, Jan 1;110(1). doi: 10.1093/jnci/djx145

If you or someone you know has questions about cancer and treatment, please give our Cancer Information nurses a call – they’re on freephone 0808 800 4040, 9am-5pm Monday to Friday, or you can send them an email.



from Cancer Research UK – Science blog http://ift.tt/2lD9l53

Is telekinesis real?

With the premiere of the new season of Netflix’s creepy, 1980s adventure Stranger Things, neuroscientist S. Marc Breedlove examines the reality behind the power wielded by the mysterious character Eleven: telekinesis — the ability to manipulate and move objects with the mind.

Breedlove, professor of neuroscience at Michigan State University, is an expert on the development of the nervous system. In this video, he talks about the history of telekinesis and the complexity of the human brain.

And … what about the Upside Down? Do parallel universes exist? Here’s a video on that topic. Michigan State University astrophysicist Johannes Pollanen travels back to the 1980s to analyze the strange and supernatural world of the Upside Down. Pollanen, an expert on experimental condensed matter physics, discusses the possibility and science of parallel universes.

Bottom line: In the Netflix series Stranger Things, the mysterious and powerful Eleven moves objects with her mind. Possible, or total sci-fi? A video explores the science of telekinesis. Plus a video on the Upside Down. Do parallel universes exist?

Via Michigan State University



from EarthSky http://ift.tt/2ykRdTk

With the premiere of the new season of Netflix’s creepy, 1980s adventure Stranger Things, neuroscientist S. Marc Breedlove examines the reality behind the power wielded by the mysterious character Eleven: telekinesis — the ability to manipulate and move objects with the mind.

Breedlove, professor of neuroscience at Michigan State University, is an expert on the development of the nervous system. In this video, he talks about the history of telekinesis and the complexity of the human brain.

And … what about the Upside Down? Do parallel universes exist? Here’s a video on that topic. Michigan State University astrophysicist Johannes Pollanen travels back to the 1980s to analyze the strange and supernatural world of the Upside Down. Pollanen, an expert on experimental condensed matter physics, discusses the possibility and science of parallel universes.

Bottom line: In the Netflix series Stranger Things, the mysterious and powerful Eleven moves objects with her mind. Possible, or total sci-fi? A video explores the science of telekinesis. Plus a video on the Upside Down. Do parallel universes exist?

Via Michigan State University



from EarthSky http://ift.tt/2ykRdTk

A rare chance to scrutinize a comet’s jet

On July 3, 2016, when Comet 67P sent a jet of dust into space, all 5 instruments aboard the orbiting Rosetta spacecraft were able to record the event. This image shows the dust plume, which originated from the Imhotep region on the comet. Image via ESA/ Rosetta/ UPD/ LAM/ IAA/ SSO/ INTA/ UPM/ DASP/ IDA/ MPS.

The Max Planck Institute for Solar System Research (MPS) in Germany reported on October 26, 2017 on scientists’ analysis of a very conveniently placed jet of dust that had erupted from Comet 67P/Chruyumov-Gerasimenko a year earlier. ESA’s Rosetta spacecraft, which was orbiting the comet at that time, passed serendipitously right through the jet and was able to use all five of its instruments to record it. Subsequent analysis of this goldmine of data from Rosetta is now complete. The scientists said it revealed a more intricate process driving the jets of comets than had been previously supposed.

It was known that the jets of comets are driven by the sublimation of frozen water, the process by which a solid turns into a gas without going through a liquid stage. But, in addition, these scientists said:

… further processes augment the outbreaks. Possible scenarios include the release of pressurized gas stored below the surface or the conversion of one kind of frozen water into an energetically more favorable one.

The analysis of the July 3, 2016 jet from 67P has now been published in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society.

Before the Rosetta spacecraft, who knew comets could look like this? This is Comet 67P/Churyumov-Gerasimenko – aka Chury – via Rosetta.

Thanks to Rosetta, researchers had previously discovered a day-night cycle of activity on Comet 67P. The comet’s “day,” that is, its day-night cycle (a single rotation on its axis) takes about 12.4 hours. Data from Rosetta had shown that, as the comet spins, and as the sun rises and shines on each new part of the comet, that area becomes most likely to produce jets. A statement from MPS explained:

When the sun rose over the Imhotep region of Rosetta’s comet on July 3, 2016, everything was just right: As the surface warmed and began to emit dust into space, Rosetta’s trajectory led the probe right through the cloud. At the same time, the view of the scientific camera system OSIRIS coincidentally focused precisely on the surface region of the comet from which the fountain originated. A total of five instruments on board the probe were able to document the outburst in the following hours.

Jessica Agarwal of MPS led the study. She said:

This was an amazing stroke of luck. It is impossible to plan something like this.

Prior to this event, the spacecraft had been able to point perhaps one of its instruments – from afar – toward an erupting jet on 67P. Agarwal said:

From the extensive measurement data of July 3, 2016, we were able to reconstruct the progress and the characteristics of the outburst as detailed as never before.

The July 3, 2016 dust plume was spotted within the ice-filled depression close to the large boulder near the bottom of this image. The image is a false-color composite, where the pale blue patches highlight the presence and location of water-ice. Image via ESA/ Rosetta/ UPD/ LAM/ IAA/ SSO/ INTA/ UPM/ DASP/ MPS.

The researchers were able to see the starting point of the jet as a circular area on the comet, about 30 feet (10 meters) in diameter, and located within a depression on the comet’s surface. As the data show, this area contains frozen water at the surface. In general, scientists assume that frozen gases on a comet’s surface, such as water, are responsible for dust production.

The new study shows, though, that sublimation of water ice by itself can’t explain the event of July 3, 2016. The dust production from this region was measured at approximately 40 pounds per second (18 kilograms per second), and hence the jet is much dustier than conventional models had predicted. Agarwal explained:

An additional energetic process must be at play – energy must have been released from beneath the surface to support the plume.

The scientists statement elaborated further:

It is conceivable, for example, that under the surface of the comet there are cavities filled with compressed gas. Upon sunrise, the radiation begins to warm the overlying surface, cracks develop and the gas escapes. According to another theory, deposits of amorphous ice beneath the surface play a decisive role. In this type of frozen water, the individual molecules are not aligned in a lattice-like structure, as is customary in the case of crystalline ice, but arranged in a far more disorderly fashion. Since the crystalline state is energetically more favorable, energy is released during the transition from amorphous to crystalline ice. Energy input through sunlight can start this transformation.

[However],exactly which process took place on July 3, 2016 is still unclear.

Matt Taylor, Rosetta Project Scientist at ESA, said:

There’s a particular focus now within the Rosetta science community on looking to combine data from 67P with modelling, simulations, and laboratory work here on Earth, to address the question of what drives such activity on comets.

Here’s a Rosetta spacecraft selfie with Comet 67P/Churyumov–Gerasimenko in background taken by the CIVA camera onboard the Philae Lander on September 7, 2014. The spacecraft and comet were separated by about 31 miles (50 km) at the time. Two frames were taken and merged due to the high contrast. Image via ESA/ Rosetta/ Philae/ CIVA. Read more about this image.

Bottom line: Outbursts of dust from comets appear without warning. But on July 3, 2016 – as Comet 67P erupted with a plume of dust – the orbiting Rosetta spacecraft happened to pass right through the dust cloud.

Via Max Planck Institute for Solar System Studies



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On July 3, 2016, when Comet 67P sent a jet of dust into space, all 5 instruments aboard the orbiting Rosetta spacecraft were able to record the event. This image shows the dust plume, which originated from the Imhotep region on the comet. Image via ESA/ Rosetta/ UPD/ LAM/ IAA/ SSO/ INTA/ UPM/ DASP/ IDA/ MPS.

The Max Planck Institute for Solar System Research (MPS) in Germany reported on October 26, 2017 on scientists’ analysis of a very conveniently placed jet of dust that had erupted from Comet 67P/Chruyumov-Gerasimenko a year earlier. ESA’s Rosetta spacecraft, which was orbiting the comet at that time, passed serendipitously right through the jet and was able to use all five of its instruments to record it. Subsequent analysis of this goldmine of data from Rosetta is now complete. The scientists said it revealed a more intricate process driving the jets of comets than had been previously supposed.

It was known that the jets of comets are driven by the sublimation of frozen water, the process by which a solid turns into a gas without going through a liquid stage. But, in addition, these scientists said:

… further processes augment the outbreaks. Possible scenarios include the release of pressurized gas stored below the surface or the conversion of one kind of frozen water into an energetically more favorable one.

The analysis of the July 3, 2016 jet from 67P has now been published in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society.

Before the Rosetta spacecraft, who knew comets could look like this? This is Comet 67P/Churyumov-Gerasimenko – aka Chury – via Rosetta.

Thanks to Rosetta, researchers had previously discovered a day-night cycle of activity on Comet 67P. The comet’s “day,” that is, its day-night cycle (a single rotation on its axis) takes about 12.4 hours. Data from Rosetta had shown that, as the comet spins, and as the sun rises and shines on each new part of the comet, that area becomes most likely to produce jets. A statement from MPS explained:

When the sun rose over the Imhotep region of Rosetta’s comet on July 3, 2016, everything was just right: As the surface warmed and began to emit dust into space, Rosetta’s trajectory led the probe right through the cloud. At the same time, the view of the scientific camera system OSIRIS coincidentally focused precisely on the surface region of the comet from which the fountain originated. A total of five instruments on board the probe were able to document the outburst in the following hours.

Jessica Agarwal of MPS led the study. She said:

This was an amazing stroke of luck. It is impossible to plan something like this.

Prior to this event, the spacecraft had been able to point perhaps one of its instruments – from afar – toward an erupting jet on 67P. Agarwal said:

From the extensive measurement data of July 3, 2016, we were able to reconstruct the progress and the characteristics of the outburst as detailed as never before.

The July 3, 2016 dust plume was spotted within the ice-filled depression close to the large boulder near the bottom of this image. The image is a false-color composite, where the pale blue patches highlight the presence and location of water-ice. Image via ESA/ Rosetta/ UPD/ LAM/ IAA/ SSO/ INTA/ UPM/ DASP/ MPS.

The researchers were able to see the starting point of the jet as a circular area on the comet, about 30 feet (10 meters) in diameter, and located within a depression on the comet’s surface. As the data show, this area contains frozen water at the surface. In general, scientists assume that frozen gases on a comet’s surface, such as water, are responsible for dust production.

The new study shows, though, that sublimation of water ice by itself can’t explain the event of July 3, 2016. The dust production from this region was measured at approximately 40 pounds per second (18 kilograms per second), and hence the jet is much dustier than conventional models had predicted. Agarwal explained:

An additional energetic process must be at play – energy must have been released from beneath the surface to support the plume.

The scientists statement elaborated further:

It is conceivable, for example, that under the surface of the comet there are cavities filled with compressed gas. Upon sunrise, the radiation begins to warm the overlying surface, cracks develop and the gas escapes. According to another theory, deposits of amorphous ice beneath the surface play a decisive role. In this type of frozen water, the individual molecules are not aligned in a lattice-like structure, as is customary in the case of crystalline ice, but arranged in a far more disorderly fashion. Since the crystalline state is energetically more favorable, energy is released during the transition from amorphous to crystalline ice. Energy input through sunlight can start this transformation.

[However],exactly which process took place on July 3, 2016 is still unclear.

Matt Taylor, Rosetta Project Scientist at ESA, said:

There’s a particular focus now within the Rosetta science community on looking to combine data from 67P with modelling, simulations, and laboratory work here on Earth, to address the question of what drives such activity on comets.

Here’s a Rosetta spacecraft selfie with Comet 67P/Churyumov–Gerasimenko in background taken by the CIVA camera onboard the Philae Lander on September 7, 2014. The spacecraft and comet were separated by about 31 miles (50 km) at the time. Two frames were taken and merged due to the high contrast. Image via ESA/ Rosetta/ Philae/ CIVA. Read more about this image.

Bottom line: Outbursts of dust from comets appear without warning. But on July 3, 2016 – as Comet 67P erupted with a plume of dust – the orbiting Rosetta spacecraft happened to pass right through the dust cloud.

Via Max Planck Institute for Solar System Studies



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What’s the birthstone for November?

Photo via Orbital Joe/Flickr

The word ‘topaz,’ birthstone for the month of November, comes from a Sanskrit word meaning “fire.” And in ancient lore, the topaz could be used to control heat. It was said to have the power to cool boiling water, as well as excessive anger. As medication, topaz was used to cure fever.

Topaz occurs in a range of magnificent colors – blue, pale green, varying shades of yellow, pink, red, brown and even black. Pure topaz itself is a colorless stone. Red and some pink topaz get their colors from chromium that is substituted for aluminum in the crystals. But most other colors occur due to minor element substitutions and defects in the crystal. Some colors are unstable and can fade away; for example, brown topaz mined in Siberia can be bleached by sunlight. In other stones, color changes can be induced by heating. High energy irradiation and moderate heat treatment of colorless topaz can transform it to blue gemstones.

Chemically, topaz is known as aluminum silicate fluoride hydroxide. Because of strong chemical bonds within this mineral, topaz is the hardest of silicate minerals. Topaz gemstones occur in a large variety of sizes, from tiny crystals to large rocks. The biggest uncut stone, a specimen found in Brazil weighing almost 600 pounds, is on display at the American Museum of Natural History in New York. A famous cut topaz in history is found among the crown jewels of Portugal, a magnificent yellow stone weighing 12 ounces.

This gem, with its lively fire, clarity, beautiful colors and hardness is ideal for jewelry such as clips, necklaces, brooches and bracelets. Pure topaz, when brilliantly cut, can be often mistaken for a diamond. Because of its rarity, topaz is an expensive gem. The most valued and rarest color is red. Imperial topaz-sherry colored varieties of brownish-yellow, orange-yellow and reddish brown-are the most popular topaz stones and command high prices, as do pink colored stones. Light blue and pale yellow topaz are of less value, but are nevertheless stunning in beauty.

Brazil is the largest producer of topaz, the most notable source being the Minas Geranis region. Gems are also found in Russia, the Ukraine, Pakistan, Scotland, Japan and Sri Lanka. In the United States, the gemstones have been found in Colorado and California.

During the Middle Ages, the topaz was used mostly by royalty and clergy. A 13th century belief held that a topaz engraved with a falcon helped its wearer cultivate the goodwill of kings, princes and magnates.

Topaz was once thought to strengthen the mind, increase wisdom, and prevent mental disorders. It was thought to guard against sudden death. Powdered topaz added to wine was used to prevent asthma and insomnia. A cure for weak vision called for immersing the stone in wine for three days and nights, then rubbing the liquid on the eyes.

Find out about the birthstones for the other months of the year:
January birthstone
February birthstone
March birthstone
April birthstone
May birthstone
June birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

Image Credit: Captmondo



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Photo via Orbital Joe/Flickr

The word ‘topaz,’ birthstone for the month of November, comes from a Sanskrit word meaning “fire.” And in ancient lore, the topaz could be used to control heat. It was said to have the power to cool boiling water, as well as excessive anger. As medication, topaz was used to cure fever.

Topaz occurs in a range of magnificent colors – blue, pale green, varying shades of yellow, pink, red, brown and even black. Pure topaz itself is a colorless stone. Red and some pink topaz get their colors from chromium that is substituted for aluminum in the crystals. But most other colors occur due to minor element substitutions and defects in the crystal. Some colors are unstable and can fade away; for example, brown topaz mined in Siberia can be bleached by sunlight. In other stones, color changes can be induced by heating. High energy irradiation and moderate heat treatment of colorless topaz can transform it to blue gemstones.

Chemically, topaz is known as aluminum silicate fluoride hydroxide. Because of strong chemical bonds within this mineral, topaz is the hardest of silicate minerals. Topaz gemstones occur in a large variety of sizes, from tiny crystals to large rocks. The biggest uncut stone, a specimen found in Brazil weighing almost 600 pounds, is on display at the American Museum of Natural History in New York. A famous cut topaz in history is found among the crown jewels of Portugal, a magnificent yellow stone weighing 12 ounces.

This gem, with its lively fire, clarity, beautiful colors and hardness is ideal for jewelry such as clips, necklaces, brooches and bracelets. Pure topaz, when brilliantly cut, can be often mistaken for a diamond. Because of its rarity, topaz is an expensive gem. The most valued and rarest color is red. Imperial topaz-sherry colored varieties of brownish-yellow, orange-yellow and reddish brown-are the most popular topaz stones and command high prices, as do pink colored stones. Light blue and pale yellow topaz are of less value, but are nevertheless stunning in beauty.

Brazil is the largest producer of topaz, the most notable source being the Minas Geranis region. Gems are also found in Russia, the Ukraine, Pakistan, Scotland, Japan and Sri Lanka. In the United States, the gemstones have been found in Colorado and California.

During the Middle Ages, the topaz was used mostly by royalty and clergy. A 13th century belief held that a topaz engraved with a falcon helped its wearer cultivate the goodwill of kings, princes and magnates.

Topaz was once thought to strengthen the mind, increase wisdom, and prevent mental disorders. It was thought to guard against sudden death. Powdered topaz added to wine was used to prevent asthma and insomnia. A cure for weak vision called for immersing the stone in wine for three days and nights, then rubbing the liquid on the eyes.

Find out about the birthstones for the other months of the year:
January birthstone
February birthstone
March birthstone
April birthstone
May birthstone
June birthstone
July birthstone
August birthstone
September birthstone
October birthstone
November birthstone
December birthstone

Image Credit: Captmondo



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Venus and Spica close at dawn

Around dawn in early November, 2017, the dazzling planet Venus pairs up with Spica, the constellation Virgo’s brightest star. They’ll appear closest before sunrise on November 2. Venus ranks as the third-brightest celestial body to light up the heavens, after the sun and moon. Spica, shining at 1st-magnitude brightness, is one of the sky’s most brilliant stars. Nonetheless, this star pales next to Venus, which outshines Spica by about about 90 times.

In fact, unless your sky is very dark and pure, and unless you happen to catch the pair at just the right moment before sunrise – when the two are high enough above the eastern horizon to be visible, yet the sky is still not too washed with dawn’s light for Spica to be seen – you might need binoculars to view Spica in the same binocular field with Venus in the November 2 morning sky.

Venus is much lower in the sky now than it was, and it has also shifted southward on the sky’s dome. Its rising time varies around the world. At mid-northern latitudes, Venus comes up more than an hour before sunrise. As you go southward on the globe, Venus rises closer to sunrise – just an hour before, at and around the equator – less than an hour before from temperate latitudes in the Southern Hemisphere. Click here for a recommended sky almanacs; they can tell you when Venus rises in your sky. Spica rises around that same time … but of course Spica is much fainter, so you won’t see it as easily.

Around the world this month, Venus will be sinking toward the glare of sunrise day by day, while Spica is climbing away it. Venus will disappear in the sun’s glare by late November or December; but Spica will rise some 2 hours earlier by late November. Around late November, Spica will rise well before dawn’s first light.

Also, in late November, Spica will be in conjunction with the planet Mars in the predawn sky. You can actually see Mars in the morning sky now, and it’ll be visible all through November, if you’re up when the sky is still dark (75 to 90 minutes before sunrise). Mars is easily visible to the unaided eye in the predawn sky.

Spica is somewhat more than twice as bright as Mars in early November. Mars will brighten slightly throughout the month; and by the time that Spica and Mars are in conjunction on November 29, Spica will be a touch less than twice the brightness of Mars.

Bottom line: Dazzling planet Venus and Spica, Virgo’s brightest star, are in the same binocular field before sunrise on or around November 2, 2017.



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Around dawn in early November, 2017, the dazzling planet Venus pairs up with Spica, the constellation Virgo’s brightest star. They’ll appear closest before sunrise on November 2. Venus ranks as the third-brightest celestial body to light up the heavens, after the sun and moon. Spica, shining at 1st-magnitude brightness, is one of the sky’s most brilliant stars. Nonetheless, this star pales next to Venus, which outshines Spica by about about 90 times.

In fact, unless your sky is very dark and pure, and unless you happen to catch the pair at just the right moment before sunrise – when the two are high enough above the eastern horizon to be visible, yet the sky is still not too washed with dawn’s light for Spica to be seen – you might need binoculars to view Spica in the same binocular field with Venus in the November 2 morning sky.

Venus is much lower in the sky now than it was, and it has also shifted southward on the sky’s dome. Its rising time varies around the world. At mid-northern latitudes, Venus comes up more than an hour before sunrise. As you go southward on the globe, Venus rises closer to sunrise – just an hour before, at and around the equator – less than an hour before from temperate latitudes in the Southern Hemisphere. Click here for a recommended sky almanacs; they can tell you when Venus rises in your sky. Spica rises around that same time … but of course Spica is much fainter, so you won’t see it as easily.

Around the world this month, Venus will be sinking toward the glare of sunrise day by day, while Spica is climbing away it. Venus will disappear in the sun’s glare by late November or December; but Spica will rise some 2 hours earlier by late November. Around late November, Spica will rise well before dawn’s first light.

Also, in late November, Spica will be in conjunction with the planet Mars in the predawn sky. You can actually see Mars in the morning sky now, and it’ll be visible all through November, if you’re up when the sky is still dark (75 to 90 minutes before sunrise). Mars is easily visible to the unaided eye in the predawn sky.

Spica is somewhat more than twice as bright as Mars in early November. Mars will brighten slightly throughout the month; and by the time that Spica and Mars are in conjunction on November 29, Spica will be a touch less than twice the brightness of Mars.

Bottom line: Dazzling planet Venus and Spica, Virgo’s brightest star, are in the same binocular field before sunrise on or around November 2, 2017.



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