news sciences: Comments of the Week #172: From sodium-and-water to the most dangerous comet of all [Starts With A Bang]

“Life is not a miracle. It is a natural phenomenon, and can be expected to appear whenever there is a planet whose conditions duplicate those of the Earth.” ―Harold Urey

It’s been yet another fascinating week of scientific stories here at Starts With A Bang! But as of the last 48 hours, there’s something I absolutely have to talk about: the “Unite The Right” hate rally in Virginia, accompanied by violence and murder. They say that in order for evil to triumph, all that you need is for good people to stand by and do nothing. When I was a kid — small, young, weak, inexperienced — I saw lots of people get beaten up, taken advantage of, mugged, robbed… and I didn’t do anything. Why? Because I was afraid for myself, for what would happen to me if I did. But I look at the world now, and I see it differently: what happens to us all if I don’t do anything? What happens if none of us stop this madness? It’s time to stand up alongside one another and demand equal treatment, legally, for everyone.

We live in a country where a black man will be criticized and even blacklisted from his job for taking a knee during the national anthem because he’s making a statement about equal rights and protections under the law, but the rights of neo-nazi murderers to hatch terrorism plots and violently attack counter-protesters (two pretty illegal things, by the way) are not even addressed by our country’s leadership. In 2017, more than 70 years after the world united to defeat fascism and white supremacy and oppression, actions like these are not condemned by the president. My grandfathers fought those Nazis, alongside the rest of the free world. It is up to every one of us — whether we’re white or persons of color; whether we’re men, women, or non-binary; whether we’re Christian or not; whether we’re cis or straight or citizens or not — to recognize that we’re all human beings, and that we have every right to demand those same human rights: life, liberty, and the pursuit of happiness. That is what America is about.

The (public domain) State Flag of Virginia. No joke.

Virginia, you have the most hateful state flag in the entire country. You changed it in 1861, after you seceded, to make it about murdering what you perceived as a tyrannical leader, in a Shakespearian scene. Four years later, theatre actor John Wilkes Booth did exactly this, acting out a scene from his favorite play in a way, murdering Lincoln the same way Brutus and Cassius murdered Caesar. Those three infamous words, sic semper tyrannis, are from Shakespeare, are emblazoned on the Virginia flag, and were shouted by Booth as he shot Lincoln in the head. We have a long heritage of hate, slavery, and murder in this country, and it is up to all of us to renounce rather than celebrate these awful parts of our nation’s past. We are moving forward, and no amount of hatred or demonization or violence is going to solve any of our nation’s problems. We will fight this hate with our words, with our bodies, and if necessary, with our lives. And in the end, just like always, hate will lose.

I had to say that. I cannot stand by and only talk about science when there are these other atrocities happening right here. It’s time to make a difference. It’s time to get involved. And it’s time to speak out. Nazis cannot make us afraid, and everyone needs to know that all of America is united against this hate. Even if the President is silent about it.

With that said, let’s get into the science. There’s been a lot to explore, question, and go over, despite all the things we disagree with one another on. Thankfully, there are scientific truths that, whether we agree with one another or not, are all true nonetheless. (And thank you to those who left positive comments over the last week. I came, I saw, I appreciated!) Here are the six stories we’ve told that have given you plenty to think about over the past week:

I’ll tell you all that there are at least three new podcasts coming out where I’m a guest — all related to Treknology, as far as I know — and for those of you who’ll be down at Brooks Winery in Salem next Sunday and Monday for the total solar eclipse, I’ll see you there! With all that said and done, let’s get right into our comments of the week!

32 images of the 2016 eclipse were combined in order to produce this composite, showcasing not only the corona and the plasma loops above the photosphere with stars in the background, but also with the Moon’s surface illuminated by Earthshine. Image credit: Don Sabers, Ron Royer, Miloslav Druckmuller.

From Michael Hutson on why eclipse science is still important: “Why is ground observation of total eclipses still so important when we have had manned and unmanned observation from orbit for decades?”

It’s absolutely true that we have space-based observation of the Sun and its corona; we’ve used radio astronomy to measure the shifting positions of stars over the course of a year; we’ve used gravitational lenses to better test and constrain relativity; and it’s things like stereographic satellite imagery and lunar laser ranging that have enabled us to determine the shape of the Moon’s shadow on Earth. Yes, the vast majority of scientifically useful eclipse data is historic, from validating relativity to measuring the coronal temperature and nature to the discovery of plasma loops to coronal mass ejections.

More than 2/3 of the American population is within a single day’s driving distance of the path of totality. This could create the worst traffic jam in American history. Image credit: Michael Zeller / greatamericaneclipse.com.

But there are still things we can do from the ground that have advantages, particularly the ones that are Earth-related. The uninterrupted land mass that this eclipse will pass over allows for the opportunity to understand atmospheric and temperature changes, the relationship between the Moon’s shadow and phenomena here on Earth’s surface, and the short-term but continuous variation in the Sun’s luminosity. Yes, we can do many things better from space, but we live here on Earth, and there’s still more science to be done!

A room where the walls, even if completely covered with mirrors, would never have every location illuminated, was a mathematically interesting conjecture that was only solved recently. Image credit: Mathematical Sciences Research Institute (MSRI) / Numberphile / Brady Haran / Howard Masur.

From dean on how certain problems in math have incremental progress made towards them: “More directly, a slightly simpler version may be attacked first, with interest as much on the process used to solve it as the solution. As restrictions on the problem statement are weakened work (often) goes to modifying what worked earlier in hopes on the more general problem.”

This is true, and is quite a precise and laudable statement. We do this in physics, too, except in physics we simplify deliberately. Think about what you’d need to know to successfully model a physical system accurately: the physical properties of all the particles in the Universe, relative to one another, their interrelationships and entanglements, and all the forces between them, as well as how it all evolves over time in a well-defined, relativistic and quantum context. Sounds like a tall order, doesn’t it?

The big strength of physics is its ability to simplify. The strength of physicists is in modeling: in knowing how to chew on the meat and throw away the bones of the problem. If you can boil down a problem to its key essence and solve that simplified version, that’s huge. If you could take the entire Universe and simulate all the physical interactions taking place, it would be interesting, too, but it would take a computer with the computing power of the entire Universe to do it, and it wouldn’t teach you anything new. Relating equations, theories, and models to physical phenomena is where it’s at.

The fabric of spacetime, illustrated, with ripples and deformations due to mass. A new theory must be more than identical to General Relativity; it must make novel, distinct predictions. Image credit: European Gravitational Observatory, Lionel BRET/EUROLIOS.

From CFT on a perceived weakness in relativity: “…there is no known solution to even TWO masses (much less more than two) in the same space time matrix. That’s not a little thing to gloss over like a minor typo.”

Nope; it’s a testament to how complicated and intricate a theory like General Relativity is. But just because we can model a system that is too difficult to solve exactly (or analytically) doesn’t mean it’s any less valid. Reread that last sentence a few times; if you can absorb the information in it, you’ll understand why your argument for the “wrongness” of relativity (or the Navier-Stokes equation, or pretty much any complex physical system) holds no water.

Signs and protesters from the 2013 March Against Monsanto in Vancouver, BC. While there may be legitimate complaints over our modern agricultural system, GMOs are not the evil technology that people make them out to be. Image credit: Rosalee Yagihara of Wikimedia Commons.

From John on making a difference in science: “The subjective portion is deciding what parts of Science are “fringe”.”

This is true, and I fully admit that I have my own opinions on that matter. I am aware that although there are objective criteria in there, all of the ones I use are not (and cannot be, by their nature) objective. The danger comes when we present a subjective criterion as an objective one, and that’s something we’re all at risk for. I hope you enjoyed my review of the Little Black Book of Junk Science, whose authors have a right-wing bias, but that doesn’t make the science they present any less valid. It’s important to consider views that challenge our own, otherwise we’ll never learn anything new or be open to possibilities that are foreign to us.

In warm-weather years, which are statistically more likely with global warming, large, more powerful hurricanes, like 1985’s Hurricane Elena, are more likely, but there will be fewer of them. Image credit: Image Science and Analysis Laboratory, NASA-Johnson Space Center.

From Paul Dekous on Hurricane Elena: “Damn, I thought you were using that Hurricane Elena image on top of the page to answer how ‘Black Holes’ at the center of large galaxies could be voids.”

Nope, just to talk about hurricanes and other weather-based natural disasters. Black holes can’t really be “voids” in any meaningful sense, but the similarities between an “eye” of a storm and the cloud bands and an event horizon of a black hole and its accretion disk can be visualized in an analogous fashion. I’d say that’s fair!

The stars within and beyond the Pillars of Creation are revealed in the infrared. While Hubble extends its view out to 1.6 microns, more than twice the limit of visible light, James Webb will go out to 30 microns: nearly 20 times as far again. Image credit: NASA, ESA/Hubble and the Hubble Heritage Team.

From Brian K. Grimm on why we can’t all just get along: ” I do not understand the type of people that can look at a suite of scientific data, then pull specific corner cases from that data and say ‘all these hundreds of other analyses can’t be right, because of this one.’ I don’t just see it in physics either. I see it in finance/economics, politics, history, and religious discussions. Why is it so hard to agree on what reality is?”

I’m not a psychologist, and I don’t know that psychologists — even the ones that study bias and the Culture Wars — have the answer, so what you’re getting from me is a guess. My guess is that, for some people, particularly when it comes to some topics, getting a specific answer or reaching a specific conclusion is more important than those other things. If it’s part of your very identity that the world be flat, then your options are either to accept a round Earth and deny your core identity, or to hold onto your core identity and insist that the world is flat… and that’s when the logical and rhetorical gymnastics enter.

Some people love that game: the arguing and the argument-crafting, but I’m not one of them. I’d rather just earnestly ask after the truth, find the best answers we can arrive at, and share those results. Those of you who find your core identity in disagreement with my own (or what you perceive my own to be) will find an avenue to attack that too, but don’t worry. By this time next year, I’ll be 40, which, according to Mike Gundy, means I’ll be able to take the heat.

An artist’s impression of the three LISA spacecraft shows that the ripples in space generated by longer-period gravitational wave sources should provide an interesting new window on the Universe. LISA was scrapped by NASA years ago, and will now be built by the European Space Agency, with only partial, supporting contributions from NASA. Image credit: EADS Astrium.

From Michael Mooney on the ridiculousness of relativity: “I pointed out how totally ridiculous that claim is.”

Well, to someone who’s unwilling to accept the Universe as it is, the Universe is ridiculous. Electricity is ridiculous; gravitation is ridiculous; motion is ridiculous; and just wait until you get to quantum physics. It is not up to the Universe to bow to your claims of what makes sense and what doesn’t; the Universe does what it does and it’s up to us to decode how that works, and what predictions we can make in a variety of physical scenarios. Relativity has been doing that, correctly, for over 100 years. You are an onlooker, pointing and laughing, all the while reaping the benefits of relativity. Try using a GPS device (if you can find one) that doesn’t use relativity, and see how that works for you; you won’t like it.

This artist’s impression shows the magnetar in the very rich and young star cluster Westerlund 1. Image credit: ESO / L. Calçada.

From eric on the “z” of a neutron star: “Unless that neutron star is in a *very* empty region of space, there will be a constant infallinng of particles. If the stuff falling in has protons (and it probably will), there will be some time required for those protons to be converted.”

Oh, you don’t need to go there! A neutron star only has about 90% of its mass in the form of neutrons; the outer 10% of its mass is more like a mix of protons, neutrons and even electrons. There ought to be atoms on a neutron star’s surface. Without those charged particles, you’d never be able to get a magnetic field in your neutron star, and yet they have the strongest magnetic fields in the Universe! The question, though, is whether it’s fair to consider the entire star as a single nucleus, or only a fraction of the core, and I think it’s the latter. But I am uncertain that the matter has been scientifically settled.

The increased emission of greenhouse gases, notably CO2, can have a massive impact on Earth’s climate in just a few hundred years. We’re witnessing that happen today. Image credit: U.S. National Parks Service.

From Another Commenter on a challenge to the climate consensus: “Herer’s (sic) an interesting news item about of reliable the data is from the signatories to Paris Climate Accord.
http://ift.tt/2uB7HzV“

That is interesting. What it says, for those who won’t read it, is that a number of nations may be lying about what their actual emissions are versus their reported emissions. Veritas, my friends.

A remote camera captures a close-up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center. Hydrogen is preferred as a fuel source in rockets due to its low molecular weight and the great abundance of oxygen in the atmosphere for it to react with. Image credit: NASA.

From Alan G. on calling out my rocket fuel caption: “The rocket engine photo caption is curious. Rocket engines don’t use atmospheric gaseous oxygen when running. They have to carry all of their own oxidizer with them also, along with their fuel.”

I’m impressed at how diligent you were to catch this! Yes, in principle, there’s a great abundance of oxygen in the atmosphere, and if you had O2 intake, you could react it with the hydrogen fuel inside.

But in practice, the act of taking in oxygen to react with the hydrogen will cost you more in terms of air resistance and the collisions of particles at those high relative speeds (plus your lack of ability to control the reaction rate as you went to low-oxygen elevations) means that it’s better to bring your oxygen liquid fuel with you, too. Well spotted, and thanks for coaxing me to go the extra mile!

A plume of smoke from wildfires burning rises over Fort McMurray in this aerial photograph taken in Alberta, Canada. The entire Pacific Northwest region of North America is suffering from severe wildfires, and the season hasn’t even peaked yet. Image credit: Darryl Dyck/Bloomberg.

From PJ on wildfires in Oregon: “Would need to get the good words of warning out to the general public and overseas travelers who may not be aware of the local conditions.”

Between the fires, the unpredictable winds, and cloud cover — including the haze cover from smoke in the copious Canada wildfires — a great many locations in the three westernmost states to see the 2017 eclipse will be at risk of having the Sun obscured during totality. Going to the coast may not solve the issue, either. Like over a million others, I’ll be rolling the dice a week from Monday!

Relic microbes revealed by a scanning electron microscope in the ALH84001 meteorite, which originated on Mars. It is unknown whether the microbes are of Martian origin or not. Image credit: NASA, 1996.

From jvj on wanting to be NASA’s planetary protection officer: “I’m perfect for the job. Have seen all the Star Trek TV shows & movies. I enjoy giving orders to menials. Our motto: “We come in Peace.” We can enslave any life forms we find & dig up all the diamonds & gold & drill for oil everywhere on each planet we take over.”

The great danger of contamination is a real one, and it may have already taken place naturally. Do you see this image above? That’s a fragment of a meteor that came from Mars, but it was found on Earth. When you get a massive impact from space on a rocky world — planet, asteroid, moon, or Kuiper belt object — it kicks up debris that can sometimes go back into space and travel to another world. If we find Mars rocks on Earth, does it not stand to reason that Earth rocks made their way to other worlds in the Solar System, too?

It’s worth thinking about, because despite our best efforts to decontaminate our spacecraft before we send them out exploring (and we may have failed at that with our earlier missions to Mars, for example), it may already be too late.

Correctly calibrated satellite data, as well as the more recent temperature data up through 2016, shows that climate predictions and observations are perfectly in line with one another. Image credit: HadCRUT4.5, Cowtan & Way, NASA GISTEMP, NOAA GlobalTemp, BEST, via Ed Hawkins at Climate Lab Book.

From Denier on a nice try: “First of all, you should at least be honest about what you are trying to do. You are trying to de-platform scientific evidence that fails your personal political litmus test. It has nothing to do with ‘good’ science. Santer (2017) is good science. Nature thinks so. You summarily dismissed it without reason. You simply didn’t like what it said. It didn’t support your political narrative so you wished it into the corn field.”

It is a nice try. I appreciate the thoughtfulness of the argument you made, because it’s a well-crafted narrative and it’s very compelling. And yes, I agree that Santer et al. (2017) is good science; Santer is one of the top scientists in the field of climate science. But, as always, what I’ve urged you to do in climate arguments is to be quantitative. Yes, the paper itself says that near-term, recent warming has been overestimated, elucidated why, and quantified by how much. It seems we’re in agreement there.

So tell me, then, how much has the warming been overestimated by the models? What percentage of the models overestimated the warming, before the Santer paper came out? (Hint: it’s less than the 95% that Heartland and UAH claimed, which is a claim that you defended, and which is data that you referenced, repeatedly, claimed was accurate, and never backed down from.) How well do the models do now that they have this improvement?

Yes, I didn’t address it, because it was a small contribution that has only mild relevance to a much larger story. You are crafting a narrative of “Ethan is dismissing evidence because he doesn’t like what it says” when in fact that is what I have witnessed not only you but literally everyone saying the same things as you doing for more than two decades now. (History tells me it may be longer than that, but I wasn’t really aware of the basic scientific story until the mid-1990s.) This is the Trump strategy — accuse your opponents of doing the exact thing you’re guilty of — and it worked for him. You add in the strategy of “focusing on the one factual detail where you are correct, exaggerate its importance, and try to derail the rest of the argument.”

Daffy Duck is smart enough to see what’s going on in a situation, but never figures out how to control what happens.

I feel like Daffy Duck in this situation. You know those old Warner Bros. cartoons with Bugs, Daffy, and Elmer Fudd? Elmer Fudd is not only unable to control the situation, but he’s unable to comprehend it, and always comes out on the losing side. Bugs understands the situation, and is able to manipulate the situation to his advantage; he controls it. Daffy is a tragicomic figure, though, who understands the situation but finds himself unable to control it, even though he sees how Bugs is manipulating it and hates the unfairness of it all. Who knows? You’re fighting your battle in the court of public opinion, and you’re a lawyer. Maybe it’ll work for you, too?

But irrespective of that, I will give you mad props for reading Gavin Schmidt and Ben Santer; their work is top notch. You and I may always disagree on policy, but if you’re reading their work, we may someday wind up agreeing on the facts.

This illustration of a black hole, surrounded by X-ray emitting gas, showcases one of the major ways black holes are identified and found. Based on recent research, there may be as many as 100 million black holes in the Milky Way galaxy alone. Image credit: ESA.

From Omega Centauri on black holes in the Milky Way: “Those are remarkably large numbers. I would think the dwarf galaxies would resemble (in terms of metalicity and BH mass spectrum), the early larger galaxies. In the later category, have enough non-so-low metalicity stars formed to overwhelm the initial distribution?”

That’s part of what’s so exciting; dwarf galaxies aren’t similar to the Milky Way. Bigger galaxies have:

larger gas fractions (because the gas doesn’t get ejected during star formation),
more generations of stars (because of more major and minor mergers),
higher mass stars (because of more mass available, on average),
but higher metallicity (because of more generations and more mass),
so their high-mass stars shed more mass during their lives,

leading to smaller but far more numerous black holes. There are, if you’re curious, about ten times as many neutron stars as black holes in each galaxy.

Front cover of the hard copy of the Little Black Book of Junk Science. Image credit: American Council on Science and Health.

From Christopher Winter on Junk Science and ideology: “Having read Science Left Behind, of which Alex [Berezow] is co-author with Hank Campbell, I would be very reluctant to put credence in this book. The negative review on Amazon calls it “A pseudoscientific attempt to debunk pseudoscience.” That’s about what I’d expect.”

People with different ideologies than you will, in fact, take the same facts, the same data, and pick out different points to highlight that are still true. That’s what I saw in Science Left Behind, and also what I saw in the Little Black Book of Junk Science. Yes, not all of their contentions are the full story; for example, Agent Orange and DDT are dangerous, but not for the reasons that many (on the left!) claim they are. Organic food may represent one step towards more sustainable agricultural practices, but it’s also a flawed and limited scheme with what it can accomplish. (And yes, many of its effects are negative.)

There’s a lot to think about, and listening to someone who challenges the way you think has a lot to say for it. But I’m happy to share your thoughtful review; personally I agree with you about much of what’s in there, particularly about false equivalence.

Radiation dose chart. (Click to enlarge.) By XKCD, public domain.

From Anonymous Coward on the banana-radioactivity scale: “A single banana is slightly radioactive due to the presence of radioactive Potassium-40. As Sinisa Lazarek points out, an x-ray scanner’s intensity is around 0.1 µSv, which is roughly the same amount of radiation exposure as you would get from eating a single banana.”

Looks like I need to start eating bigger bananas if I want to take that trip to Iran!

The comet that gives rise to the Perseid meteor shower, Comet Swift-Tuttle, was photographed during its last pass into the inner Solar System in 1992. The influence of the gravity of the other planets has the potential to dramatically change its orbit, however. Image credit: NASA.

And finally, from Denier on cometary orbits: “The thing that amazes me is that an impact is possible at all. The solar system is 5 billions years old. Swift-Tuttle has had to make this loop hundreds of millions of times.”

This is actually a lot more fun than that; the data tells us the Swift-Tuttle is young as a comet! Remember when, a couple of years ago, we got the “Camelopardalids” for the first time? These gravitational interactions in the outer solar system (or the asteroid belt) happen relatively frequently, and comets don’t last long. Swift-Tuttle has likely been doing its dance for thousands of years, but probably not more than tens of thousands. And after the 4479 interaction, we can’t predict its motion well at all! That’s why it may get ejected, it may get hurled into the Sun, but it may (less likely, but still possible) collide with Earth. 1-in-a-million odds aren’t very high, but when you’re talking about human extinction, I’d be a lot happier with lower odds for sure!

If we get that long-term asteroid deflection program up and running, maybe giving Swift-Tuttle a nudge in the “get away from Earth” direction might not be the worst idea!

Thanks for a great week, folks, and see you back here for more science starting tomorrow!

from ScienceBlogs http://ift.tt/2vvf3sv