aads

A Guided Tour of the Solar System From Someone Who’s Been There [Greg Laden's Blog]

I’ve been enjoying Worlds Fantastic, Worlds Familiar: A Guided Tour of the Solar System by Bonnie Buratti.

Burratti is a planetary astronomer at NASA’s JPL, and is the head of the Comets, Asteroids and Satellites Group. She was a key player in the Voyager program, and in the research done with the Cassini-Huygens, and New Horizons space ships.

Worlds Fantastic, Worlds Familiar: A Guided Tour of the Solar System is a personal exploration of what it is like to personally (via robots) explore our solar system, and at the same time, a systematic accounting of the solar system. The story is told, I think, as a geologist might tell it, about land forms and surface features. In other words, it is a somewhat finer scale look at the very big scale picture of the solar system, which is something that could not possibly have been done prior to the exploration of that solar system with these various flying robots. Which, Bonnie Buratti herself flew, directed, or otherwise played around with.



from ScienceBlogs http://ift.tt/2p1RgyW

I’ve been enjoying Worlds Fantastic, Worlds Familiar: A Guided Tour of the Solar System by Bonnie Buratti.

Burratti is a planetary astronomer at NASA’s JPL, and is the head of the Comets, Asteroids and Satellites Group. She was a key player in the Voyager program, and in the research done with the Cassini-Huygens, and New Horizons space ships.

Worlds Fantastic, Worlds Familiar: A Guided Tour of the Solar System is a personal exploration of what it is like to personally (via robots) explore our solar system, and at the same time, a systematic accounting of the solar system. The story is told, I think, as a geologist might tell it, about land forms and surface features. In other words, it is a somewhat finer scale look at the very big scale picture of the solar system, which is something that could not possibly have been done prior to the exploration of that solar system with these various flying robots. Which, Bonnie Buratti herself flew, directed, or otherwise played around with.



from ScienceBlogs http://ift.tt/2p1RgyW

What happens in 1 minute

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A minute might seem like a short amount of time, but a lot can happen in 60 seconds ….



from EarthSky http://ift.tt/2p22NOM

Our annual fund-raiser ends May 5. EarthSky needs your help to keep going! Please donate!

Want to donate via PayPal or send a check to EarthSky? Click here.

A minute might seem like a short amount of time, but a lot can happen in 60 seconds ….



from EarthSky http://ift.tt/2p22NOM

On Science and Politics [Significant Figures by Peter Gleick]

The ascendancy of Donald Trump to the presidency, the selection of his cabinet and senior advisers, and the actions of the GOP-dominated legislative branch have all raised new serious questions and concerns about the role of science, research, and analysis in national law and policy. These concerns have been worsened by elements of the new administration’s proposed budget that severely cut or eliminate core federal science efforts, Congressional hearings and actions that have been perceived to promote ideological viewpoints over scientific findings, presidential executive orders that attempt to override scientifically determined regulations and laws, and the failure of the administration to appoint qualified people to key science advisory and oversight positions.

These questions have led to growing public debate over the role of science in policy and politics. The recent outpouring of support for the March for Science and the Climate March in cities around the country is a manifestation of this growing public concern, but another is the expanding discussion about the proper role for science – and for scientists – and how politics may affect the integrity of science and scientists. Some commentators have argued that by getting involved in politics, scientists are becoming just another interest group.

Lost in this discussion is a key distinction, between the integrity of science itself and the ways in which scientists interacts with policy and policymakers.

The scientific process requires that scientists separate their biases and politics from their research in a way that ensures their work stands up to independent scrutiny and review. Bias may determine the questions individual scientists choose to tackle, but if scientific findings are tainted by politics (or economics or other factors), the very nature of the scientific process, independent peer review, and the competition inherent in advancing scientific knowledge will weed bad science out over time.

Caution Science and Society

Many scientists have little or no interest in connecting science to public policy or getting involved in messy public debates. But scientists are people too, with opinions, political views, and biases. And when their work has implications for the quality of life, health, environment, and the economy, scientists should be encouraged, not discouraged, from participating in policy discussions, communicating with the public, educating policymakers, and working with journalists and the media.

We have the right – and some argue the responsibility – to raise our voices. History offers numerous examples, such as when an international group of scientists published the Russell-Einstein Manifesto in 1955 to speak out “as human beings” against the threat of nuclear war:

“In the tragic situation which confronts humanity, we feel that scientists should assemble in conference to appraise the perils that have arisen as a result of the development of weapons of mass destruction, and to discuss a resolution in the spirit of the appended draft… We are speaking on this occasion, not as members of this or that nation, continent, or creed, but as human beings, members of the species Man, whose continued existence is in doubt…We have to learn to think in a new way. We have to learn to ask ourselves, not what steps can be taken to give military victory to whatever group we prefer, for there no longer are such steps; the question we have to ask ourselves is: what steps can be taken to prevent a military contest of which the issue must be disastrous to all parties?… We appeal as human beings to human beings: Remember your humanity, and forget the rest. If you can do so, the way lies open to a new Paradise; if you cannot, there lies before you the risk of universal death.”

As is true of anyone in our society, it is the right of scientists as citizens to participate in the policy process. Reflecting this reality, the American Geophysical Union recently released a new statement “On the Rights and Responsibilities of Scientists.” That statement identifies three key responsibilities for scientists: demonstrating excellence in the conduct of research, adhering to the highest professional ethics and integrity in their scientific work, and supporting a diverse, inclusive professional environment. But in addition to these responsibilities, the statement identifies key “rights” for scientists, including the right to conduct science without fear of attack, to work with colleagues independent of political affiliation or opinion, and to freely and openly communicate their findings. It also explicitly identifies the right of scientists to respond to inaccurate portrayals or use of science.

“The right to oppose unethical or illegal actions, policies, procedures, or other directives that impact the conduct and publication of science, without fear of retaliation.”

and

“The right to respond to inaccurate portrayals of science by any individual or group including, government and institutional administrators, the media, private companies or industry representatives, and political entities.”

There comes a time when the dangers of inaction, or the wrong actions, become sufficiently threatening to individuals or the planet that scientists will have to enter the public arena and bring their voices to debates of critical societal importance. We see this now with the threat of global climate change, the destruction of ecosystems, risks of pandemics, and more. When scientists do speak up, they should be welcomed, not vilified, as servants of the public interest and as informed voices raised in defense of knowledge, informed policy, and humanity.

Peter Gleick



from ScienceBlogs http://ift.tt/2p1SIRB

The ascendancy of Donald Trump to the presidency, the selection of his cabinet and senior advisers, and the actions of the GOP-dominated legislative branch have all raised new serious questions and concerns about the role of science, research, and analysis in national law and policy. These concerns have been worsened by elements of the new administration’s proposed budget that severely cut or eliminate core federal science efforts, Congressional hearings and actions that have been perceived to promote ideological viewpoints over scientific findings, presidential executive orders that attempt to override scientifically determined regulations and laws, and the failure of the administration to appoint qualified people to key science advisory and oversight positions.

These questions have led to growing public debate over the role of science in policy and politics. The recent outpouring of support for the March for Science and the Climate March in cities around the country is a manifestation of this growing public concern, but another is the expanding discussion about the proper role for science – and for scientists – and how politics may affect the integrity of science and scientists. Some commentators have argued that by getting involved in politics, scientists are becoming just another interest group.

Lost in this discussion is a key distinction, between the integrity of science itself and the ways in which scientists interacts with policy and policymakers.

The scientific process requires that scientists separate their biases and politics from their research in a way that ensures their work stands up to independent scrutiny and review. Bias may determine the questions individual scientists choose to tackle, but if scientific findings are tainted by politics (or economics or other factors), the very nature of the scientific process, independent peer review, and the competition inherent in advancing scientific knowledge will weed bad science out over time.

Caution Science and Society

Many scientists have little or no interest in connecting science to public policy or getting involved in messy public debates. But scientists are people too, with opinions, political views, and biases. And when their work has implications for the quality of life, health, environment, and the economy, scientists should be encouraged, not discouraged, from participating in policy discussions, communicating with the public, educating policymakers, and working with journalists and the media.

We have the right – and some argue the responsibility – to raise our voices. History offers numerous examples, such as when an international group of scientists published the Russell-Einstein Manifesto in 1955 to speak out “as human beings” against the threat of nuclear war:

“In the tragic situation which confronts humanity, we feel that scientists should assemble in conference to appraise the perils that have arisen as a result of the development of weapons of mass destruction, and to discuss a resolution in the spirit of the appended draft… We are speaking on this occasion, not as members of this or that nation, continent, or creed, but as human beings, members of the species Man, whose continued existence is in doubt…We have to learn to think in a new way. We have to learn to ask ourselves, not what steps can be taken to give military victory to whatever group we prefer, for there no longer are such steps; the question we have to ask ourselves is: what steps can be taken to prevent a military contest of which the issue must be disastrous to all parties?… We appeal as human beings to human beings: Remember your humanity, and forget the rest. If you can do so, the way lies open to a new Paradise; if you cannot, there lies before you the risk of universal death.”

As is true of anyone in our society, it is the right of scientists as citizens to participate in the policy process. Reflecting this reality, the American Geophysical Union recently released a new statement “On the Rights and Responsibilities of Scientists.” That statement identifies three key responsibilities for scientists: demonstrating excellence in the conduct of research, adhering to the highest professional ethics and integrity in their scientific work, and supporting a diverse, inclusive professional environment. But in addition to these responsibilities, the statement identifies key “rights” for scientists, including the right to conduct science without fear of attack, to work with colleagues independent of political affiliation or opinion, and to freely and openly communicate their findings. It also explicitly identifies the right of scientists to respond to inaccurate portrayals or use of science.

“The right to oppose unethical or illegal actions, policies, procedures, or other directives that impact the conduct and publication of science, without fear of retaliation.”

and

“The right to respond to inaccurate portrayals of science by any individual or group including, government and institutional administrators, the media, private companies or industry representatives, and political entities.”

There comes a time when the dangers of inaction, or the wrong actions, become sufficiently threatening to individuals or the planet that scientists will have to enter the public arena and bring their voices to debates of critical societal importance. We see this now with the threat of global climate change, the destruction of ecosystems, risks of pandemics, and more. When scientists do speak up, they should be welcomed, not vilified, as servants of the public interest and as informed voices raised in defense of knowledge, informed policy, and humanity.

Peter Gleick



from ScienceBlogs http://ift.tt/2p1SIRB

Where’s the moon? Waxing gibbous

Waxing gibbous moon by Patrick Casaert. He posted it at EarthSky Facebook and also on his page Les Avions et la Lune (The Planes and the Moon) on Facebook.

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A waxing gibbous moon appears high in the east at sunset. It’s more than half-lighted, but less than full.

That’s another way of saying that a waxing gibbous moon phase falls between a first quarter moon and a full moon. Next full moon comes on May 10, 2017 at 21:42UTC; translate to your timezone).

Relative to a new moon – which is more or less between the Earth and sun, located near the sun along our line of sight – a waxing gibbous moon has moved in its orbit so that it’s now relatively far from the sun in our sky.

A waxing gibbous moon rises during the hours between noon and sunset. It sets in the wee hours after midnight.

Point of interest on a waxing gibbous moon: Sinus Iridum (Bay of Rainbows) surrounded by the Jura Mountains. Photo by Lunar 101-Moon Book in Toronto, Canada.

Another shot of the waxing gibbous moon, with Sinus Iridum (Bay of Rainbows) clearly visible, from P. Weeks in Greenville, North Carolina. Watch for it!

People often see a waxing gibbous moon in the afternoon, shortly after moonrise, while it’s ascending in the east as the sun is descending in the west. It’s easy to see a waxing gibbous moon in the daytime because, at this phase of the moon, a large fraction of the moon’s day side is facing our way.

Thus a waxing gibbous moon is more noticeable in the sky than a crescent moon, with only a slim fraction of the lunar day side visible. Also, a waxing gibbous moon is far from the sun on the sky’s dome, so the sun’s glare isn’t hiding it from view.

Any moon that appears more than half lighted but less than full is called a gibbous moon. The word gibbous comes from a root word that means hump-backed. A gibbous moon can also be a waning gibbous, in the week between full moon and last quarter moon.

As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

Four keys to understanding moon phases

Where’s the moon? Waxing crescent
Where’s the moon? First quarter
Where’s the moon? Waxing gibbous
What’s special about a full moon?
Where’s the moon? Waning gibbous
Where’s the moon? Last quarter
Where’s the moon? Waning crescent
Where’s the moon? New phase



from EarthSky http://ift.tt/1j8UWzb

Waxing gibbous moon by Patrick Casaert. He posted it at EarthSky Facebook and also on his page Les Avions et la Lune (The Planes and the Moon) on Facebook.

Our annual fund-raiser ends May 5. EarthSky needs your help to keep going! Please donate!

Want to donate via PayPal or send a check to EarthSky? Click here.

A waxing gibbous moon appears high in the east at sunset. It’s more than half-lighted, but less than full.

That’s another way of saying that a waxing gibbous moon phase falls between a first quarter moon and a full moon. Next full moon comes on May 10, 2017 at 21:42UTC; translate to your timezone).

Relative to a new moon – which is more or less between the Earth and sun, located near the sun along our line of sight – a waxing gibbous moon has moved in its orbit so that it’s now relatively far from the sun in our sky.

A waxing gibbous moon rises during the hours between noon and sunset. It sets in the wee hours after midnight.

Point of interest on a waxing gibbous moon: Sinus Iridum (Bay of Rainbows) surrounded by the Jura Mountains. Photo by Lunar 101-Moon Book in Toronto, Canada.

Another shot of the waxing gibbous moon, with Sinus Iridum (Bay of Rainbows) clearly visible, from P. Weeks in Greenville, North Carolina. Watch for it!

People often see a waxing gibbous moon in the afternoon, shortly after moonrise, while it’s ascending in the east as the sun is descending in the west. It’s easy to see a waxing gibbous moon in the daytime because, at this phase of the moon, a large fraction of the moon’s day side is facing our way.

Thus a waxing gibbous moon is more noticeable in the sky than a crescent moon, with only a slim fraction of the lunar day side visible. Also, a waxing gibbous moon is far from the sun on the sky’s dome, so the sun’s glare isn’t hiding it from view.

Any moon that appears more than half lighted but less than full is called a gibbous moon. The word gibbous comes from a root word that means hump-backed. A gibbous moon can also be a waning gibbous, in the week between full moon and last quarter moon.

As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

Four keys to understanding moon phases

Where’s the moon? Waxing crescent
Where’s the moon? First quarter
Where’s the moon? Waxing gibbous
What’s special about a full moon?
Where’s the moon? Waning gibbous
Where’s the moon? Last quarter
Where’s the moon? Waning crescent
Where’s the moon? New phase



from EarthSky http://ift.tt/1j8UWzb

No, mysterious signals from space are not dark matter (Synopsis) [Starts With A Bang]

“Two recent studies by teams in the U.S. and the Netherlands have shown that the gamma-ray excess at the galactic center is speckled, not smooth as we would expect for a dark matter signal. Those results suggest the speckles may be due to point sources that we can’t see as individual sources…” -Eric Charles

When NASA’s Fermi satellite began operations, it didn’t take long before we had constructed the most accurate, comprehensive gamma ray map of the galaxy. While many outstanding astrophysics findings ensued, including the discovery of many new pulsars, there was one particular mystery that came about as well: an unexplained excess of gamma rays from the galactic center. Many possible explanations emerged, but one gathered a disproportionately large and exciting amount of attention: that of dark matter annihilations.

According to models and simulations, all galaxies should be embedded in dark matter halos, whose densities peak at the galactic centers. However, unless the dark matter obeys very particular models and exhibits specific properties, it will be difficult to account for a gamma ray excess with dark matter. Image credit: NASA, ESA, and T. Brown and J. Tumlinson (STScI).

According to models and simulations, all galaxies should be embedded in dark matter halos, whose densities peak at the galactic centers. However, unless the dark matter obeys very particular models and exhibits specific properties, it will be difficult to account for a gamma ray excess with dark matter. Image credit: NASA, ESA, and T. Brown and J. Tumlinson (STScI).

In some models of dark matter, it’s a particle that’s its own antiparticle. If dark matter/dark matter annihilation occurs, it could produce excessive gamma rays, as well as cascades of new particle/antiparticle pairs that would result in a photon signal peaked at 511 keV, as positrons annihilated with electrons. After a huge effort to uncover the nature of this gamma ray excess, Fermi finally has an answer.

An excess of gamma-rays coming from the center of the Milky Way is likely due to a population of pulsars – rapidly spinning, very dense and highly magnetized neutron stars that emit 'beams' of gamma rays like cosmic lighthouses. Image credit: NASA/CXC/University of Massachusetts/D. Wang et al.; Greg Stewart/SLAC National Accelerator Laboratory.

An excess of gamma-rays coming from the center of the Milky Way is likely due to a population of pulsars – rapidly spinning, very dense and highly magnetized neutron stars that emit ‘beams’ of gamma rays like cosmic lighthouses. Image credit: NASA/CXC/University of Massachusetts/D. Wang et al.; Greg Stewart/SLAC National Accelerator Laboratory.

Did you bet on dark matter? You shouldn’t have! Come find out how pulsars are likely responsible, and why dark matter is disfavored for the gamma ray excess seen in the Milky Way.



from ScienceBlogs http://ift.tt/2pcy9OH

“Two recent studies by teams in the U.S. and the Netherlands have shown that the gamma-ray excess at the galactic center is speckled, not smooth as we would expect for a dark matter signal. Those results suggest the speckles may be due to point sources that we can’t see as individual sources…” -Eric Charles

When NASA’s Fermi satellite began operations, it didn’t take long before we had constructed the most accurate, comprehensive gamma ray map of the galaxy. While many outstanding astrophysics findings ensued, including the discovery of many new pulsars, there was one particular mystery that came about as well: an unexplained excess of gamma rays from the galactic center. Many possible explanations emerged, but one gathered a disproportionately large and exciting amount of attention: that of dark matter annihilations.

According to models and simulations, all galaxies should be embedded in dark matter halos, whose densities peak at the galactic centers. However, unless the dark matter obeys very particular models and exhibits specific properties, it will be difficult to account for a gamma ray excess with dark matter. Image credit: NASA, ESA, and T. Brown and J. Tumlinson (STScI).

According to models and simulations, all galaxies should be embedded in dark matter halos, whose densities peak at the galactic centers. However, unless the dark matter obeys very particular models and exhibits specific properties, it will be difficult to account for a gamma ray excess with dark matter. Image credit: NASA, ESA, and T. Brown and J. Tumlinson (STScI).

In some models of dark matter, it’s a particle that’s its own antiparticle. If dark matter/dark matter annihilation occurs, it could produce excessive gamma rays, as well as cascades of new particle/antiparticle pairs that would result in a photon signal peaked at 511 keV, as positrons annihilated with electrons. After a huge effort to uncover the nature of this gamma ray excess, Fermi finally has an answer.

An excess of gamma-rays coming from the center of the Milky Way is likely due to a population of pulsars – rapidly spinning, very dense and highly magnetized neutron stars that emit 'beams' of gamma rays like cosmic lighthouses. Image credit: NASA/CXC/University of Massachusetts/D. Wang et al.; Greg Stewart/SLAC National Accelerator Laboratory.

An excess of gamma-rays coming from the center of the Milky Way is likely due to a population of pulsars – rapidly spinning, very dense and highly magnetized neutron stars that emit ‘beams’ of gamma rays like cosmic lighthouses. Image credit: NASA/CXC/University of Massachusetts/D. Wang et al.; Greg Stewart/SLAC National Accelerator Laboratory.

Did you bet on dark matter? You shouldn’t have! Come find out how pulsars are likely responsible, and why dark matter is disfavored for the gamma ray excess seen in the Milky Way.



from ScienceBlogs http://ift.tt/2pcy9OH

The Inescapable Vagueness of Academic Hiring [Uncertain Principles]

Inside Higher Ed ran a piece yesterday from a Ph.D. student pleading for more useful data about job searching:

What we need are professional studies, not just anecdotal advice columns, about how hiring committees separate the frogs from the tadpoles. What was the average publication count of tenure-track hires by discipline? How did two Ph.D. graduates with the same references (a controlled variable) fare on the job market, and why? What percentage of tenure-track hires began with national conference interviews? These are testable unknowns, not divine mysteries.

From the age-old Jobtracks project (ended in 2001, archived here) to those 21st-century methods such as the American Historical Association’s jobs-to-Ph.D.s ratio report, many studies have examined the employment trajectory of Ph.D. students. Few, however, have cross-referenced the arc of tenure-track success with the qualifications of the students on the market. Instead, only two types of applicant data are typically deemed significant enough to gather in these and other job reports: (1) the prestige and affluence of their alma mater, and (2) their age, race or gender.

Thank you so much for the detailed information about all the things in my application that I can’t improve.

I have a lot of sympathy for this. As a profession, academia is awful about even collecting data on critical topics, let alone sharing it with people who might make use of it. This can be maddening when it comes time to apply for jobs, or to seek tenure or promotion. The criteria for hiring and promotion seem to be shrouded in mystery, and you can never seem to get a straight answer to simple questions.

Some of this is, like every irritating thing in modern life, the fault of lawyers. Criteria are vague because giving more specific values opens the door to lawsuits from people who meet one stated criterion, but are manifestly unsuitable for some other reason– someone who has more publications than the stated threshold, say, but 75% of those are in vanity journals. If you try to get a little bit specific, you quickly find yourself having to plug stupid loopholes, with wildly multiplying criteria, until you need a degree in contract law to read the job ads.

(And if you don’t believe there would be lawsuits over that kind of nonsense, well, I’d like to request political asylum in your world. I could tell you stories about idiotic things that people have threatened to sue over. That is, I could, if it wouldn’t be wildly inappropriate for me to do so, so instead I’ll just darkly mutter that there are stories to be told…)

The bigger problem, though, is that most of the stats that could readily be reported are noisy garbage, subject to wild misinterpretation. As nicely demonstrated by the paragraphs where the author tries to highlight real data of the type he’d like to see:

However, secondary data analysis of other studies that have been generously made public can reveal clues that the job reports don’t care to. For example, a 2016 study that measured the publications and impact of STEM Ph.D. students happened to simultaneously measure the average number of their publications while in grad school, cross-referenced to their later hireability. The average number of publications for each future tenure-track hire was 0.5, a surprisingly low number that would likely be higher in humanities disciplines.

Another study from 2014 measured similar survey data with similar results, but it added that publishing rates among graduate students have been steadily increasing over time, while hiring rates have been steadily decreasing. That study placed the average number of publications around 0.8. It is clear that standards are shifting, but how much? And how do those standards vary by field?

Those numbers both registered as wildly implausible to me, so I looked up the papers, and they’re both misrepresented here. The first study, showing half a publication per tenure-track hire is restricted to Portugal, which the authors describe as “a developing higher education system” that is “still characterized by poorly qualified academics– only 68% of academics in public universities hold a Ph.D.” The number from the second study is a flat-out misquote– the 0.8 publications per student number is for publications by students who did not publish with their advisor as a co-author. Those who did co-author papers with their advisor, as is common practice in STEM fields, had 3.99 articles pre-Ph.D.; averaging them all together you get 1.88 publications before the doctorate for all the students considered in the paper, more than twice the figure quoted.

Even if you crunch the numbers correctly, though, these statistics are not all that meaningful, because acceptable publication rates vary wildly between subfields, even within a single discipline. I had a total of 5 publications before I finished my Ph.D. (though one of those was a theory paper to which my only contribution was delivering a floppy disk full of experimental data to the theorists upstairs), which is pretty respectable for an experimentalist in my field. I came into an established lab, though, and just picked up on an experiment that was already working. I know of grad students who were involved in lab construction projects who ended up with only one or two publications, but who were well-regarded scientists in the field because of the scale of the work they did building up an experiment that would go on to churn out lots of papers. In a very different field, on the other hand, a former student who went into theory had eight papers pre-Ph.D., which is more in line with expectations in his field.

And the noisiness of the data only gets worse. People working in fields like nuclear and particle physics, where papers are published by large collaborations, can end up with their names on dozens of papers, because everybody in the collaboration gets listed on every paper from that collaboration. (I don’t think grad students are generally included as full members in this sense, though junior faculty often are.) You can, of course, attempt to divide things up by subfield, but as always, the more finely you subdivide the pool, the less reliable the data gets, from simple statistics.

I’m not going to say there aren’t hiring committees doing simple paper-counting as an early weed-out step, but it’s not remotely a good metric for making final decisions.

In the end, the question comes back to a point raised earlier in the piece, namely what factors the candidate can control. Hireability is not a matter of hitting some threshold number of publications, it’s about making the most of the opportunities available to you, and being able to make a persuasive case that you have done so, and will be able to do so in the future, as a faculty member. What counts as “enough” publications to get a degree or go on the job market isn’t a bright-line rule, it’s a judgement call, and making a reasonable decision about when you have “enough” is part of the transition from student to scholar.

The factors a job applicant can control are making that central decision– what constitutes “enough,” in consultation with the advisor(s)– and making the case that the decision was a good one. When we’re doing a search and trying to separate “frogs from tadpoles,” we’re not just counting papers, we’re reading statements, and (speaking for myself) a clear and convincing research statement putting past work in context and showing how it carries through to future work carries a lot more weight than an extra paper or two on the CV.

That is, I realize, maddeningly vague. I’ve been through the process, and been maddened by it. But as comforting as it might be to have more stats about the process, that comfort would be an illusion, because most of the readily available measures are junk.

(And, of course, everything comes back to the central problem, namely the vast gulf between the number of qualified candidates and the number of available jobs…)



from ScienceBlogs http://ift.tt/2p15tfg

Inside Higher Ed ran a piece yesterday from a Ph.D. student pleading for more useful data about job searching:

What we need are professional studies, not just anecdotal advice columns, about how hiring committees separate the frogs from the tadpoles. What was the average publication count of tenure-track hires by discipline? How did two Ph.D. graduates with the same references (a controlled variable) fare on the job market, and why? What percentage of tenure-track hires began with national conference interviews? These are testable unknowns, not divine mysteries.

From the age-old Jobtracks project (ended in 2001, archived here) to those 21st-century methods such as the American Historical Association’s jobs-to-Ph.D.s ratio report, many studies have examined the employment trajectory of Ph.D. students. Few, however, have cross-referenced the arc of tenure-track success with the qualifications of the students on the market. Instead, only two types of applicant data are typically deemed significant enough to gather in these and other job reports: (1) the prestige and affluence of their alma mater, and (2) their age, race or gender.

Thank you so much for the detailed information about all the things in my application that I can’t improve.

I have a lot of sympathy for this. As a profession, academia is awful about even collecting data on critical topics, let alone sharing it with people who might make use of it. This can be maddening when it comes time to apply for jobs, or to seek tenure or promotion. The criteria for hiring and promotion seem to be shrouded in mystery, and you can never seem to get a straight answer to simple questions.

Some of this is, like every irritating thing in modern life, the fault of lawyers. Criteria are vague because giving more specific values opens the door to lawsuits from people who meet one stated criterion, but are manifestly unsuitable for some other reason– someone who has more publications than the stated threshold, say, but 75% of those are in vanity journals. If you try to get a little bit specific, you quickly find yourself having to plug stupid loopholes, with wildly multiplying criteria, until you need a degree in contract law to read the job ads.

(And if you don’t believe there would be lawsuits over that kind of nonsense, well, I’d like to request political asylum in your world. I could tell you stories about idiotic things that people have threatened to sue over. That is, I could, if it wouldn’t be wildly inappropriate for me to do so, so instead I’ll just darkly mutter that there are stories to be told…)

The bigger problem, though, is that most of the stats that could readily be reported are noisy garbage, subject to wild misinterpretation. As nicely demonstrated by the paragraphs where the author tries to highlight real data of the type he’d like to see:

However, secondary data analysis of other studies that have been generously made public can reveal clues that the job reports don’t care to. For example, a 2016 study that measured the publications and impact of STEM Ph.D. students happened to simultaneously measure the average number of their publications while in grad school, cross-referenced to their later hireability. The average number of publications for each future tenure-track hire was 0.5, a surprisingly low number that would likely be higher in humanities disciplines.

Another study from 2014 measured similar survey data with similar results, but it added that publishing rates among graduate students have been steadily increasing over time, while hiring rates have been steadily decreasing. That study placed the average number of publications around 0.8. It is clear that standards are shifting, but how much? And how do those standards vary by field?

Those numbers both registered as wildly implausible to me, so I looked up the papers, and they’re both misrepresented here. The first study, showing half a publication per tenure-track hire is restricted to Portugal, which the authors describe as “a developing higher education system” that is “still characterized by poorly qualified academics– only 68% of academics in public universities hold a Ph.D.” The number from the second study is a flat-out misquote– the 0.8 publications per student number is for publications by students who did not publish with their advisor as a co-author. Those who did co-author papers with their advisor, as is common practice in STEM fields, had 3.99 articles pre-Ph.D.; averaging them all together you get 1.88 publications before the doctorate for all the students considered in the paper, more than twice the figure quoted.

Even if you crunch the numbers correctly, though, these statistics are not all that meaningful, because acceptable publication rates vary wildly between subfields, even within a single discipline. I had a total of 5 publications before I finished my Ph.D. (though one of those was a theory paper to which my only contribution was delivering a floppy disk full of experimental data to the theorists upstairs), which is pretty respectable for an experimentalist in my field. I came into an established lab, though, and just picked up on an experiment that was already working. I know of grad students who were involved in lab construction projects who ended up with only one or two publications, but who were well-regarded scientists in the field because of the scale of the work they did building up an experiment that would go on to churn out lots of papers. In a very different field, on the other hand, a former student who went into theory had eight papers pre-Ph.D., which is more in line with expectations in his field.

And the noisiness of the data only gets worse. People working in fields like nuclear and particle physics, where papers are published by large collaborations, can end up with their names on dozens of papers, because everybody in the collaboration gets listed on every paper from that collaboration. (I don’t think grad students are generally included as full members in this sense, though junior faculty often are.) You can, of course, attempt to divide things up by subfield, but as always, the more finely you subdivide the pool, the less reliable the data gets, from simple statistics.

I’m not going to say there aren’t hiring committees doing simple paper-counting as an early weed-out step, but it’s not remotely a good metric for making final decisions.

In the end, the question comes back to a point raised earlier in the piece, namely what factors the candidate can control. Hireability is not a matter of hitting some threshold number of publications, it’s about making the most of the opportunities available to you, and being able to make a persuasive case that you have done so, and will be able to do so in the future, as a faculty member. What counts as “enough” publications to get a degree or go on the job market isn’t a bright-line rule, it’s a judgement call, and making a reasonable decision about when you have “enough” is part of the transition from student to scholar.

The factors a job applicant can control are making that central decision– what constitutes “enough,” in consultation with the advisor(s)– and making the case that the decision was a good one. When we’re doing a search and trying to separate “frogs from tadpoles,” we’re not just counting papers, we’re reading statements, and (speaking for myself) a clear and convincing research statement putting past work in context and showing how it carries through to future work carries a lot more weight than an extra paper or two on the CV.

That is, I realize, maddeningly vague. I’ve been through the process, and been maddened by it. But as comforting as it might be to have more stats about the process, that comfort would be an illusion, because most of the readily available measures are junk.

(And, of course, everything comes back to the central problem, namely the vast gulf between the number of qualified candidates and the number of available jobs…)



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Earth clouds from space

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At any given time, nearly 70 percent of Earth’s surface is covered by clouds. The satellite images in this video gallery highlight some of the more unusual and beautiful clouds observed in recent years from all across our planet.

Love cloud images? Bastiaan Van Diedenhoven is a cloud scientist at NASA. Every few days, while browsing satellite imagery, Van Diedenhoven notices a unique cloud feature and shares it on Twitter. But you won’t see many storm images, Bastiaan said:

Storms are interesting, but they’re kind of obvious I guess I’m looking for things that other people won’t see.

The value in looking at clouds from space, according to Van Diedenhoven, is the big picture. For example, the wide, satellite view might show that clouds that are dropping rain on us today are actually part of a system that formed days ago over a completely different part of the planet. He added:

You’re really getting the perspective of the Earth as a whole, and as a complex system where many things interact. You don’t get that perspective if you look from below.

Bototm line: NASA video gallery of satellite images of Earth’s clouds.

Read more about clouds at NASA’s Earth Observatory.



from EarthSky http://ift.tt/2p92Nrr

Our annual fund-raiser ends May 5. EarthSky needs your help to keep going! Please donate!

Want to donate via PayPal or send a check to EarthSky? Click here.

At any given time, nearly 70 percent of Earth’s surface is covered by clouds. The satellite images in this video gallery highlight some of the more unusual and beautiful clouds observed in recent years from all across our planet.

Love cloud images? Bastiaan Van Diedenhoven is a cloud scientist at NASA. Every few days, while browsing satellite imagery, Van Diedenhoven notices a unique cloud feature and shares it on Twitter. But you won’t see many storm images, Bastiaan said:

Storms are interesting, but they’re kind of obvious I guess I’m looking for things that other people won’t see.

The value in looking at clouds from space, according to Van Diedenhoven, is the big picture. For example, the wide, satellite view might show that clouds that are dropping rain on us today are actually part of a system that formed days ago over a completely different part of the planet. He added:

You’re really getting the perspective of the Earth as a whole, and as a complex system where many things interact. You don’t get that perspective if you look from below.

Bototm line: NASA video gallery of satellite images of Earth’s clouds.

Read more about clouds at NASA’s Earth Observatory.



from EarthSky http://ift.tt/2p92Nrr

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