Scientists love precision. We love exploring the smallest details of a model that can enhance our understanding of the universe. That makes us terrible at communicating science. 

Take the following examples introducing black holes:

A black hole is a mathematically defined region of spacetime exhibiting such a strong gravitational pull that no particle or electromagnetic radiation can escape from it.

or

A journey into a black hole would be a one-way trip.

If you were writing a popular article on black holes, which do you think would be the better opening sentence? Both are reasonably accurate, but the former is filled with terms like “spacetime” and “electromagnetic radiation.” If you’re a regular reader of my blog you’re likely familiar with these terms, but many people aren’t. The jargon doesn’t really add much to the opening sentence, so why include it?

For an astrophysicist, the first sentence feels more precise. It’s impartial and uses the proper terminology rather than positing an imaginary journey. Jargon as scientific the comfort food. Unfortunately, jargon is bad for communicating ideas. The key to communicating a scientific idea clearly is to know what you want to convey (your target) and then stay on target. Jargon and needless details drive you away from your target, so if you don’t need a particular term, don’t use it.

Of course that’s easier said than done for scientists, because often we don’t recognize jargon for what it is. Take, for example, the phrase “solar activity.” What it defines is the amount of surface activity such as sunspots or solar flares. So when a research article predicts a 20% decrease in solar activity over the next 5 years, what it means is we’ll see less sunspots. Anyone familiar with solar physics knows this. But “solar activity” sounds like the amount of light and heat the Sun produces. A 20% decrease in solar activity sounds like lakes will be freezing in July.

Avoiding jargon is something I still struggle with, and as you read my articles you’ll notice I’ll do things like adding jargon terms as an aside, or hedge by words with phrases like “basically it’s…” when I don’t use jargon. Old habits die hard, but learning to be ever more clear in my writing is a worthy target.

The post Stay On Target appeared first on One Universe at a Time.

I’ve now written 1,000 science posts. More than half a million words on astronomy, astrophysics, and physics.

Over the past few years I’ve written on everything from the dawn of astronomy to the study of cosmic origins. I’ve written post series on the solar system, the foundations of physics, the quantum revolution, science in fiction, dark matter, Einstein’s research, the weak points of scientific models, and the fundamental forces of nature. I’ve done my best to explain some of the more subtle aspects of astrophysics, such as cosmic inflation, the big bang and black holes. I’ve tried to dispel some of the hype and push back against pseudoscience. I’ve made a few videos, and started a podcast.

While 1,000 is an arbitrary number, reaching that number of posts has me wondering where to go from here. When I started writing science posts, it was mostly about the textbook I was writing. It was a way to get out of the academic headspace after hours of writing. As I’ve continued to write over the years it’s become clear that there’s some interest in the work, and there’s clearly a need for as much clear science communication as we can get. That’s part of the reason why I’ve gradually put more emphasis on communicating science to the general public. If I’m going to keep doing this (and I plan to) then what efforts will have the greatest impact? Should I start making more videos? Give more public talks? Write longer blog posts?

My most popular posts so far have been ones that either debunk some crazy idea, or rant about always having to debunk ideas, and I certainly don’t want my blog to become an anti-fringe site. I’m not interested in increasing pageviews, but rather increasing understanding. That means I need to do more than satisfy long-term readers. It means broadening the appeal of science. It means making a serious effort to engage with folks about scientific habits of mind.

So I’m looking for ideas. How do we move beyond the circle of those who read about science for fun? How do we reach out to the doubters and the fearful in order to sow the seeds of understanding? How do we grow scientific understanding on a truly meaningful level?

With the first 1,000 down, it’s time to use the next 1,000 to change the world. Who’s with me?

The post A Thousand Points of Light appeared first on One Universe at a Time.

Yesterday I got an email outlining why black hole can’t possibly exist. Those of you who are regular readers might be quick to point out that black hole most certainly exist, but the author is right. Black holes make no sense. I, and other scientists, have been lying to you all along.

As the author clearly points out:

 1. If time dilation increases the closer one approaches the event horizon of a black hole and from our perspective we see time essentially stop at the event horizon, how will a black hole ever form in our universe if nothing can ever cross the event horizon relative to us and the rest of the universe?

2. The explanation used for the creation of a black hole is that gravity increases due to an increase in the density of the material within the stellar object. Since gravity is many orders of magnitude less powerful than even the electrical forces being experienced between the nuclei of the matter in question how does the gravitational force overcome the repulsion between nuclei. I understand that the electrons will provide some neutralisation of the positive charges. However, even in standard forms of matter there are various electrical forces that occur, even though the atoms are technically neutral.

3. Thirdly, the event horizon is defined where the escape velocity is defined as being the speed of light. However, the escape velocity is defined by a specific criteria and circumstance, which is clearly understood in engineering circles does not apply to powered movement. That is the actual velocity by which you transition from from solar body to another can be as low as you like. Hence, you can cross any boundary, including an event horizon, under power at any speed (under the speed of light).

It seems very clear then that black holes defy logic, so why do we scientists keep claiming they exist? Because the arguments outlined above are based on a pack of lies.

When I say that I’ve been lying to you, this doesn’t mean I’ve intentionally tried to deceive you. It means that I’ve been intentionally feeding you information that isn’t entirely true in order to give you an understanding of what is really going on. For example, take these three points.

1. From our viewpoint, stuff takes forever to fall into a black hole, so a black hole can never form.

The position of an infalling object as seen from outside the black hole (black) and from the object itself (red).

One of the standard things said about black holes is that as material falls into a black hole it will be seen from the outside to never quite reach the event horizon. While this is true, it’s also true that from the viewpoint of the material it readily crosses the event horizon. What we often leave out in this discussion is that this is a rather simplistic description of the situation from only two vantage points. One of the central aspects of relativity is that all vantage points are valid, even when they seem contradictory. What this means is that to really describe the situation you have to look at all of spacetime as a whole. When you do this, it is clear that matter really does cross the event horizon, and black holes really do form. From the material’s vantage point you can see this, but from the exterior view you can’t. Of course to describe the whole of spacetime requires tensor calculus, so we typically omit that from the popular science tale.

2. Gravity is weaker than electromagnetism.

Again, at a basic level this is true. Certainly if we were to put two protons close to each other, the repulsive force of their electric charge would be much, much stronger than the attractive gravitational force due to their masses. That would seem to contradict the common claim that black holes form when a star’s gravity causes it to collapse under its own weight. But gravity doesn’t cause a star to collapse. It’s the electric force that does it. Imagine a table standing in the middle of a room. The atoms and molecules of the table interact with each other through electric forces, which is what gives the table its rigidity. The table is perfectly capable of supporting its own weight, because the electric forces are much stronger than gravity. But suppose I were to start stacking books on the table. Eventually the weight of the books would cause the table to collapse.

In that case, what caused the table to collapse? Gravity? No, it’s actually the force of the books right on the table’s surface. They push on the table so strongly (with the electric forces of the atoms and molecules) that the table can’t withstand it. Granted, the lowest books can push so hard because books on top of it are pushing on them, and all of this is due to gravity giving each layer of books a little tug. But technically gravity doesn’t cause the table to collapse, gravity just helps the electric force build so that it collapses the table. The same is true with a collapsing star. It is the electric and nuclear forces pushing against each other in the interior that cause the collapse. Gravity just helps those forces work together.

But all of that is complicated, so we usually just say “gravity causes the star to collapse.”

3. The event horizon is where the escape velocity is the speed of light, but that doesn’t keep us from escaping with a slower than light rocket.

This is one of the biggest lies we tell about black holes. On one level it is true. If you calculate the escape velocity at the event horizon (according to Newtonian gravity), then it is the speed of light. It makes for a simple way to describe black holes and event horizons. The problem with the idea is that escape velocity is defined as the speed it takes to escape forever. But if I tossed a ball at just under the escape velocity, it would rise very, very high before falling back down. Using escape velocity gives the impression that a rocket could escape, just as we use rockets to escape Earth’s gravity.

Behavior of light cones near an event horizon. Credit: John D. Norton.

But in relativity, the energy of the rocket would actually work against you. To really look at the structure of a black hole, you need to look at how light behaves globally. This is often visualized using light cones to show the effects of gravity. When you look at the details you find that while the event horizon does have a light-speed escape velocity, what really makes it different is that it folds space to the point where there is no possible trajectory where you can leave. All roads lead to Rome, as the saying goes, or in this case to the singularity. So if you were really at the event horizon of a black hole, any direction you tossed a ball would be “downward,” and it would be physically impossible for you to toss the ball “up.”

So the author is right about black holes not being logical, if what we typically say about black holes were actually true. But they aren’t. And therein lies one of the dangers of popularizing science. To make things clear, we often simplify things to the point where they aren’t fully true. We lie a bit to convey the central ideas rather than getting bogged down in the details. That’s fine if you just want to get a basic understanding of things. But it’s important to keep in mind that the analogies we use shouldn’t be taken literally.

When you find contradictions in the pop-science description of an established scientific idea, it doesn’t mean the science is wrong, it means the truth is more complicated than we’ve been letting on.

The post Lies My Teacher Told Me appeared first on One Universe at a Time.

When I was in graduate school, a friend of mine asked about my research. I was studying aspects of black holes in the early universe, so I explained a bit about black holes, the big bang and such in broad terms. Afterwards she shook her head and responded: “Bull poopy.” Our conversation went for a bit longer, with her arguing that I couldn’t possibly know what I was claiming to be true, and me trying to explain how I knew these things, but it was clear that opinions wouldn’t change. The simple fact was that she didn’t trust me. I was either confused or lying, so nothing I said could possibly change her mind.

As a scientist striving to convey an understanding of science, trust is essential. I can try to write about astrophysics in a way that is clear and honest, but if you don’t trust me it’s all rather moot. So in all of my writings, while I try to be clear and sometimes entertaining, I also to build a level of trust with my readers. Hopefully over time you’ll come to trust that I’m being honest and earnest about our understanding of the universe.

If you’ve been following my posts for a while, you’ve probably noticed an overall pattern. I don’t sensationalize topics. When I talk about current research I link the original source, not just a press release. When there are legitimate opposing views I explain the evidence behind why one view is accepted over another. When there is unfounded opposition to a concept I explain why it is unfounded. When there are misconceptions I work to dismantle them. I say “we don’t know” when we really don’t know. There’s a reason why I follow this method. I’m a scientist.

This doesn’t mean that scientists are more honest than others. What it means is that the way I present ideas in my posts parallels the modern scientific method. Document sources of data, be open to criticism, be prepared to defend your ideas, be willing to admit when you’re wrong or don’t know. If you don’t follow this approach, the peer review process will eat you alive. Peer review is not about taking things on trust, it’s about requiring you to prove what you claim. Being open and honest about your work lets the peer review process go a bit more smoothly.

Keeping posts honest and informative isn’t easy. It would be easier to simply post jokes, or gorgeous photographs with emotional phrases on them. But while that can make us feel good about the science we love, it doesn’t raise our understanding of science and scientific thinking. It doesn’t raise the level of scientific understanding.

Science matters. It’s worth doing, and it’s worth sharing. That’s why I write about astrophysics. It’s why I’m willing to dress in a science costume to teach science to kids (as you can see above). It’s why I try to engage with readers about science every day.

I trust I’m doing okay so far.

The post Trust Me, I’m a Scientist appeared first on One Universe at a Time.

Something is amiss in the universe. There appears to be an enormous deficit of ultraviolet light in the cosmic budget.

Or, so I’m told. I was asked by a few readers about a new study showing there is less light in the universe than expected. They heard of this from various articles showing up on the web. Like this one on Phys Org, or this one from the University of Colorado Boulder, or the original press release from the Carnegie Institute for Science. That single phrase appears on more than 4,000 pages according to Google. Mostly copied from the original press release, and most of them making no reference to the actual research article.

In researching the work, I also learned “It’s as if you’re in a big, brightly lit room, but you look around and see only a few 40-watt lightbulbs” as one of the authors was quoted.  That quote shows up on nearly 400 websites, including Popular Mechanics, IFLScience, Forbes Magazine and The Daily Mail. Over and over, the same tweaked variations of the press release. Copy pasta after copy pasta.

I realize this is how much of science journalism is done. Websites are funded by page views, and for that you need lots of content. Press releases are an easy source of content, and can be used either outright, or tweaked to fit your needs. Unfortunately press releases are designed to put the work in the best possible light, and often over state the impact of the research. Those who have been following me also know this can lead to lots and lots of misconceptions.

Honestly, any website that is interested in actually communicating science can do better. Several do. Any website that thinks otherwise should talk to me or any other scientist who writes about their research field.  There’s no need to resort to copy pasta journalism.

By the way, the actual journal article is cited below.  It is behind a paywall, but you can read the arxiv version here. I’ll probably write about it in the near future, but not today.

Paper: Juna A. Kollmeier et al. The Photon Underproduction Crisis ApJ 789 L32 (2014)

The post Copy Pasta appeared first on One Universe at a Time.

[av_video src=’http://youtu.be/iBY4HaAngaA’ format=’16-9′ width=’16’ height=’9′]

This video is on RIT’s Escharian Stairwell. The Escharian Stairwell is a stairwell that loops back upon itself. So if you walk up a flight of stairs you find yourself back where you started. It’s inspired by M. C. Escher’s Ascending and Descending. At this point you probably recognize that the stairwell is nonsense. The video was created as the project of an RIT graduate student. It is well done, but clearly not real. Surprisingly (or perhaps not surprisingly) many people think it is.

I’ve watched this project unfold because Kevin in the video is my friend +Kevin Schoonover. He’s an actor, photographer, puppeteer, and graphic designer, as well as the creative director for the +Prove Your World project I’m a part of. As a result I’ve watched the video go from obscure post to viral hit. I’ve had students ask about the stairwell. I’ve been asked about how it works. While most people recognize it as nonsense, there are enough people taking it to be real that it now has its own Snopes page.

The video is an excellent demonstration of the power of visual storytelling. That power is part of the reason I’m a part of Prove Your World. But it also shows the challenge of communicating science to the general public. There are compelling videos that show evolution is wrong and global warming is false, for example, and it is much harder for the non-specialist to separate science from non-science in these videos. They can be countered by equally compelling videos on the science behind evolution and global warming, but are they enough?

In a world driven by social networks and visual presentations, how do we ensure that scientific literacy is enhanced rather than diminished? Is it enough to present honest science in a clear and understandable way?

I don’t really have an answer, but the success of this video makes me wonder if we should work harder to communicate science as an engaging story with powerful visuals.

The post Science and Non-Science appeared first on One Universe at a Time.

Last month there was an annular eclipse, but unless you happen to live in Antarctica, you probably didn’t get a chance to see it. You can, however make your own solar observation to measure the size of the Sun. This experiment uses the principle of parallax, and all you need is a sunny window, some cardboard, a pencil, and a tape measure.

Image from Mr. Wizard’s experiments for young scientists, by Don Herbert.

Start with a sunny window, and block off as much of the light as you can, except for an area you will over with a piece of cardboard (or poster board). You don’t have to block all the light, but the more you block off, the easier it will be do to the experiment. Then poke a small hole in the cardboard and put in into position. As a result, you should have a single beam of light which shines through the hole. If you move your hand closer or farther away in the beam, you should see an image of the Sun on your hand which gets larger the farther away your hand is from the hole. Next take a piece of paper or cardboard and draw two parallel lines on it, an inch apart. Then place this in the beam of light, and move it closer or farther along the beam until the disk of light just fills the space between your lines. Try to ensure that your disk looks circular, and not oblong. When you are lined up in the beam, measure the distance from the image. Once you have your measurement, all you need is a little math.

The ratio of the diameter of your image (1 inch) and the distance of your image from the hole (which you’ve measured) is the same as the ratio of the diameter of the Sun (which you want to know) and the distance from the hole to the Sun (93,000,000 miles). If we call your distance measurement x in inches, and the diameter of the Sun D, then D divided by 150,000,000 (the distance to the Sun in kilometers) is the same as 1 divided by x. That is, : D/150,000,000 = 1/x.

If you solve this equation, you’ll find that the diameter of the Sun in miles is simply 93,000,000 divided by the distance you measured in inches. If you give this experiment a try, see how your result compares to the actual diameter of the sun, which is 1,400,000 km. Since total eclipses occur, we also know the Moon has about the same apparent diameter as the Sun, so you can use the same equation, but with the Moon’s distance (380,000 km) to determine the size of the Moon.

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If you are fortunate, you have come across a book or two that has deeply impacted your life. One such book for me is by Roy A. Gallant: The National Geographic Picture Atlas of Our Universe.

I was interested in astronomy and things science at a young age, and in the Fall of 1980 a new series on astronomy called Cosmos began to air. Every Sunday evening that Fall I watched Carl Sagan explain the universe to me. The last episode of Cosmos aired on the 21st of December. Then on the 25th, my Grandmother gave me the book you see below.

It’s hard to describe the impact this book had on my childhood. It is a book that changed my view of the universe. Every page is rich with color images and diagrams. The writing is clear enough for a child, but not written in a condescending or belittling tone. It contains facts and figures on everything from the size of our galaxy to history of life on Earth. Coming off the Sagan high, it was exactly the book I needed to learn more, and I devoured it. I read it cover to cover, over and over. I memorized the facts and figures it contained. The book also came with a “Space Kit” that included a flimsy record called SpaceSounds with recordings of things like pulsars and whalesong, and a star wheel to help you navigate the night sky in your backyard.

My Grandmother didn’t give me the book intending for me to be an astrophysicist, or even imagining I might become a scientist. She simply saw an interest I had and wanted to encourage it. As she once put it, “That boy needs an education. A real job would kill him.” But sometimes small gestures can have large impacts.

It’s all a part of living in our universe.

The post Our Universe appeared first on One Universe at a Time.

Let me begin by saying there is no evidence that dark matter killed the dinosaurs.  None whatsoever.  Unfortunately the idea was posted on Nature’s blog, and from there it went to Scientific American and elsewhere.  The various social media took the story and it has spread like a prairie wildfire.  The actual preprint is much less sensational (and doesn’t mention dinosaurs) but it is still very speculative.  

Illustration of the Sun’s motion through the galaxy. Credit: Nature/C. Carreau-ESA.

The idea comes from the fact that the Sun does not follow a flat orbit around the galaxy.  Instead, its motion wobbles above and below the galactic plane, crossing the galactic plane every 35 million years.  This isn’t unusual, as lots of stars follow similar paths, but it has led some to speculate that perhaps this periodicity could explain periodic mass extinctions in the geologic record.

The problem is, there isn’t any strong evidence for cyclic mass extinctions.  Some analysis of the data has hinted at a pattern, but the correlation isn’t very strong.  Of course that hasn’t stopped people from proposing everything from companion stars to Nibiru to explain these periodic extinctions.  There been similar proposals that every time the Sun crosses the galactic plane the Oort cloud would be disrupted, causing comets to sweep into the inner solar system and bombard the Earth.

What’s new here is that the authors propose that dark matter within the plane of the galaxy is doing the disrupting.  As I wrote about last week, there is a hint of dark matter seen in gamma ray observations of the center of our galaxy.  One model that could account for these gamma rays is type of dark matter that would lie within the galactic plane.  So if this type of dark matter exists, and if it disrupts the Oort cloud when the Sun crosses the galactic plane, and if that caused comets to fling into the inner solar system and bombard the Earth, and if that bombardment caused periodic mass extinctions, then you should see some evidence in the geologic record.

So what evidence is there?  None.  Well, not quite none.  If you assume the model is true, and then look for a periodicity in the cratering record of Earth, you find that the cratering record agrees with the model about three times better that it agrees with random cratering.  Scientifically, that isn’t very convincing data.  It makes for a mildly interesting paper, but it’s mostly speculation at this point.

But Nature and several other websites have decided to take this speculative idea, add the word dinosaurs to the title, and imply that scientists are proposing dark matter killed the dinosaurs.  No one is proposing that.  It’s link-bait noise that makes the job of communicating real science all that more difficult.  So if you see one of these sensationalized titles, don’t share it on social media.  Tell your friends that share the articles that it’s speculative nonsense.  Hopefully we can drown this noise and get back to real science.

Because honestly, science is interesting enough without the hype.

Paper:  Lisa Randall, Matthew Reece. Dark Matter as a Trigger for Periodic Comet Impacts. arXiv:1403.0576 [astro-ph.GA] (2014).

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One of the benefits of the Prove Your World project is that it brings together scientists and educators to create a show which is both scientifically accurate and educationally sound.  It is also one of the challenges, because in many ways scientists and science educators speak completely different languages.

As a case in point, consider a story about how and why.  A common shorthand in inquiry education is that “why” questions are bad.  Instead they should be changed to “how” or “what” questions.  It is a deeply rooted shorthand.  So deeply rooted that for some educators “why” questions are considered taboo.  As a scientist the ban on “why” makes no sense.  Asking “Why is the sky blue?” is a perfectly valid question.  Changing it to “How is the sky blue?” doesn’t change the question, so why the fixation on not using “why”?

In reality the “how” and “why” are shorthand for what educators refer to as “investigable” and “non-investigable” questions.  A non-investigable question is one that is too simplistic, too complex (for students) or philosophical.  So “What is the mass of Jupiter?” is non-investigable because you can just look it up.  “Why do bad things happen?” is non-investigable because it’s philosophical.  “How did life appear on Earth?” is non-investigable because it is too complex for students to answer on their own.

When you listen to children’s questions, most of them are non-investigable, and most of them begin with why:  “Why is the sky blue?”  “Why did my plant die?”  “Why do I have to finish my green beans?”  As a young educator you learn to key in on “why” questions as non-investigable questions.  Hence the shorthand: “why” questions are bad.

The challenge is to use a child’s “why” questions as the path toward investigable questions.  These are questions that focus on classification (What materials float in water?), relationships (How does temperature affect mold growth?)  and hypothesis testing (What experiment could prove or disprove your model?)  It is the investigable questions that can help give a child scientific understanding, and teaching children to ask investigable questions is a big part of teaching them to think scientifically.

It all makes sense, once you understand why.

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I’ve been watching lots of science demonstrations lately as part of work on Prove Your World, and I’ve started to notice a recurring theme: scientists are bullies.

As a case in point, take a look at the video above.  It follows the typical demonstration video, where the “scientist” is always in control, and the lovely volunteer is distracted and teased.  When she expresses concern for her safety, those concerns are downplayed and mocked.  There are times when she is visibly uncomfortable, but that apparently makes for good television.

Granted, you could argue that this is not science but rather entertainment, and it follows the same form as magic shows and comedy routines, but this is what’s often presented as science.  It reinforces common stereotypes: scientists don’t smile;  scientists decide what is true and what is not; scientists are smarter than you.  So just give them your lunch money or else.

At least those are the thoughts floating in the back of my mind after watching dozens of videos.  I’d love to hear what others think.

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