While I don’t generally focus on alternative science models on this blog, I do like to talk about them from time to time. It’s a great way to show how we test scientific claims based on the evidence at hand. Fringe models aren’t rejected because they seem crazy. They’re rejected because the evidence doesn’t support them. So back in 2013 I started getting comments claiming astrophysics is wrong, and the truth is revealed in a new model called the Electric Universe, or EU for short. Over the next several months these comments got increasingly more common, so I figured I’d start looking into the model.

It’s a bit of an odd history. It’s origins can be traced back to The Electric Universe, published in 2007 by physicist Wallace Thornhill and comparative mythologist David Talbot. The broad claim is that traditional astrophysics is wrong, particularly in the way it deals with gravity, or prioritizes gravity in its models. As an alternative it presents a model where gravity plays a minor role. Planets, stars and galaxies are guided and even formed through electromagnetic forces. The universe is electric, not gravitational.

Dude, this plasma form looks like ancient artwork! Let’s rewrite physics!

Now it seems odd that a comparative mythologist would co-author a book on astrophysics, until you realize that The Electric Universe is a sequel to the 2005 book Thunderbolts of the Gods by the same authors. In this book the authors claim that many of the myths found in ancient civilizations were based on real astronomical events. As they write in the first chapter, after more than thirty years spent studying ancient history they have come to the shocking conclusion

The evidence suggests that only a few thousand years ago planets moved close to the earth, producing electrical phenomena of intense beauty and terror. Ancient sky worshippers witnessed these celestial wonders, and far-flung cultures recorded the events in the great myths, symbols, and ritual practices of antiquity.

They also write:

We contend that humans once saw planets suspended as huge spheres in the heavens. Immersed in the charged particles of a dense plasma, celestial bodies “spoke” electrically and plasma discharge produced heaven-spanning formations above the terrestrial witnesses. In the imagination of the ancient myth-makers, the planets were alive: they were the gods, the ruling powers of the sky.

That’s some pretty trippy stuff, but it seems to have roots in Immanuel Velikovsky’s 1950 book Worlds in Collision, where he claimed Venus was ejected from Jupiter thousands of years ago, passed by Earth changing its orbit and axial tilt, and the resulting geological catastrophes were recorded by early civilizations, such as Athena (not Venus, but close enough) springing out of the head of Zeus (Jupiter).

In other words, the electric universe began as a just-so story. The stories of ancient civilizations must be true, so the authors toss out established science to create a new field of astrophysics. One that can move Heaven and Earth to match their theory. But regardless of its origins, by 2014 the EU model was promoted as a legitimate scientific model. One based not on mythology, but on modern astronomical data. One that mainstream astronomers couldn’t accept because it would overturn their cherished cosmology.

Given its history, I could have just mocked the EU model as some kind of Chariots of the Gods kind of nonsense. But I wanted to give the model a fair shake. What are the actual claims of EU, and how do they compare to actual data? Weeding through various websites and videos can be a challenge, but fortunately EU had a great resource for beginners. A Beginner’s View of Our Electric Universe, by Tom Findlay. It was revised in 2013, making it reasonably up to date, and it was highly praised by Thornhill and other leading supporters of EU. As an extra bonus, the author made a PDF version freely available to the public, so anyone can check out the claims of EU for themselves. With this and other resources I was ready to write my post.

We will be returning to the idea of nuclear fusion-powered stars later to delve into why this, in fact, is not the way the Sun works and to take a close look at how all stars actually do work, electrically of course.

Image from Findlay’s book, showing the relation between current flow and stellar type.

In Chapter 6, Findlay explains that stars shine due to cosmic electric currents flowing through a star’s plasmasphere. Rather than nuclear fusion, stars are powered like an arc light. There are two big problems with this idea. One is that without nuclear fusion, the Sun would produce no neutrinos, but solar neutrinos have long been observed. The second is that plasma arc light doesn’t emit light in a continuous thermal spectrum, whereas the observed spectrum of the Sun is a thermal blackbody. Naturally, I pointed this out it my post, Testing the Electric Universe. And thus I sparked the fury of EU fans everywhere.

Their biggest complaint was that EU does not say fusion doesn’t occur. Which was evidence not only of my ignoble behavior, but also that scientists in general can’t be trusted. It doesn’t matter than Findlay clearly claims fusion doesn’t occur at all. Since other versions of EU say it might, I’m a lying liar. A couple of folks even tried to get me fired from my university position over this. To this day EU fans continue to demand I explain my unethical behavior, despite the fact that it’s been debated ad nauseam in the comments.

Of course the problem is that there isn’t just one EU model at this point, there are several conflicting versions of them. To my best current understanding, some EU models say fusion doesn’t occur at all, some EU supporters claim neutrinos don’t even exist, and some claim fusion occurs near stellar surfaces, but (as far as I know) all claim fusion does not occur in stellar cores. Again, to my understanding, if core fusion were shown to be valid, it would overturn the electric star claims of EU models, and thus most of EU in general.

If fusion occurred near a Sun’s surface, it would produce neutrinos, so the mere detection of solar neutrinos is consistent with both surface and core fusion models. However, we can do much more than detect solar neutrinos. We now have measurements of both the types (flavors) of neutrinos and their energy levels. We know the rate at which solar neutrinos are generated at various energy levels. What we find is that the energy of neutrinos follows a thermal distribution consistent with the thermal distribution we expect in the core (that is, produced by intense heat and pressure). Fusion produced by electromagnetic plasmas would have a different spectrum, which isn’t observed in solar neutrinos. We know this because we use particle accelerators (electromagnetic plasmas) to produce neutrinos in the lab. More recently we have finally detected neutrinos from the fundamental proton-proton collisions in the Sun’s core, which is consistent with core fusion.

Even if EU’s surface fusion model could be tweaked to mimic core fusion, there were still be the issue of high energy gamma rays. Any fusion of light elements produces not only neutrinos, but high energy photons (gamma rays). We’ve observed the Sun with gamma ray telescopes, and found no steady stream of gamma rays coming from the Sun. We sometimes observe bursts gamma rays coming from very intense solar flares, but this is not consistent with the electric Sun claims. The lack of observed gamma rays is consistent with the core fusion model. Gamma rays are produced in the solar core via fusion, but the photons soon collide with other nuclei in the core, transferring energy to the nuclei to generate heat. Thus the Sun is thermally heated through these gamma rays, which lose most of their energy before escaping the Sun.

The spectrum of a plasma arc is not a thermal blackbody.

Since the Sun is heated internally through nuclear fusion, its surface emits light with a thermal spectrum distribution. This is known as blackbody radiation. We see this effect in lots of things from heated metal to stars. Objects that have (close to) a blackbody spectrum produce their light through internal heat rather than electron band gaps and such. This is why if you look at light from an incandescent light bulb you will see a smooth rainbow (thermal light), but if you look at a fluorescent light or LED light through a prism you will see specific colors (non-thermal light). If sunlight were produced by surface fusion in the low-density outer layer of the Sun, the light produced wouldn’t be a thermal blackbody. Now, you could argue for some unspecified process that takes the light produced by surface fusion and heats the (more dense) photosphere to produce a thermal spectrum. That would be consistent with the sunlight we observe, because regardless of how the photosphere is thermally heated (core or surface) the spectrum would be pretty much the same.

But there’s a problem with a surface-heated photosphere model. If the Sun is surface heated rather than core heated, the surface should be hotter than the interior. Some EU folks actually claim this. But we know from observations that the deeper layers of the photosphere are hotter than the surface layer. So surface heating can’t be right given standard physics. To get around this, some folks such as Pierre-Marie Robitaille now claim that the blackbody law isn’t valid, and that the surface of the Sun is some kind of liquid metal. It gets pretty strange beyond that point. Basically you have to start tossing out well-proven physics left and right just to cobble together a model that can match observation, when the core fusion model already matches observation extremely well and in multiple ways.

As I wrote in 2014, the Electric Universe model is contradicted by observational evidence. Neutrinos or no, EU is provably wrong. That fact hasn’t changed over the years, and isn’t likely to.

If you’re an EU fan reading this, it’s probably because you tried to argue about my 2014 post, and I sent you this link in reply. Congratulations on making it to the end. It’s been four years since I wrote that post, and I’ve grown tired of constantly being asked to rebut your just-so story.

The post Just-So Story appeared first on One Universe at a Time.

In four days, Nibiru will strike the Earth, raining destruction upon us all. September 23, 2017 to be precise. At least according to a YouTube video with nearly 3 million views. Of course, that’s crazy. There is no Nibiru, and nothing remotely planet sized has any chance of striking Earth. But that hasn’t stopped people from sending astronomers emails, or calling local science centers to ask about the apocalypse. Even when we assure them there’s no risk, or explain how we know Nibiru doesn’t exist, they still have doubts. We’re probably lying, or haven’t looked at the “real” evidence. 

It’s the same pattern for other topics. The Earth is flat, vaccines are dangerous, the Sun is electric, climate change is a hoax. In every case, there is a wealth of scientific evidence to disprove these claims. In every case, supporters point to the “real” evidence, and claim that scientists are ignorant of the facts, or intentionally lying. The loudest skeptics of climate change use the same type of arguments as the loudest skeptics of a round Earth.

It’s deeply troubling, because it means there is no longer a common basis of scientific knowledge. The number of people who think the Earth is flat is rising. People who think vaccines are poison are digging in their heels, and the majority party of the United States claims that global warming is a lie. The facts don’t matter. The more evidence you present, the more entrenched the skeptics become.

I wish I had a solution, but I don’t. I only know that I used to be amused by emails claiming Nibiru is going to kill us or the Earth is flat. I’m not amused any more. It is a sign that our society is becoming increasingly detached from the wealth of hard won knowledge. Knowledge we have spent centuries gathering and testing. Knowledge that has made us healthier, wealthier and more peaceful. If we walk away from that, we will have a world of famine, ignorance, and a harsher life for our descendants.

I don’t want that future for humanity. I suspect skeptics of climate change or a flat Earth don’t want that either. But until we can find common ground, it is the future that awaits us.

The post Nibiru, Climate Change, and Other Pseudoscience appeared first on One Universe at a Time.

I get a lot of email from folks with pseudoscience claims. It could be that the Earth is actually flat, or that the Sun is powered by electricity, or that Einstein was wrong about gravity. Bonus points if the email also calls me an idiot or part of the astronomical illuminati. But in the world of pseudoscience another popular approach is to make a claim based upon some image. There’s no referenced source or clear history of the image, just a picture and a claim. But even for pseudoscience, this is just being lazy, because in the information age images can often be tracked to their source with minimal effort.

Hmmm. What could it be?

Let’s look at an example. Here’s an image I got in the mail this week. It looks like some strange winged planet or star, and it is claimed this is an image of Nibiru. Depending on who you listen to, Nibiru is red dwarf near the Sun, or a hidden planet in the outer solar system, or the Sun’s stellar companion. The only thing Nibiru folks seem to agree upon is that it’s heading our way and could kill us all. If you do a quick Google image search, sure enough you find several YouTube videos and blog posts claiming it’s an image of Nibiru. None of them give any source to the image, so no joy there.

But there are a few things we can tell from the image right off the bat. The first that it’s in color, so it’s probably a composite false-color image. In astronomy we don’t take color images, we take black and white images at specific wavelength ranges. If we want a color image, we have to combine images taken at different wavelengths to create a color image. Sometimes this is done with the goal of making the image as true to life as possible, but often we create “false color” images to make certain features more prominent. We do this because we want to capture as much light as possible, and color digital cameras aren’t very good at that. There is also some text written on the side:

IRIS 1473:3 (NI2b) 2003UB313
21.10.2003

The object as seen in Google Sky. Credit: DSS Consortium, SDSS, NASA/ESA, as screencapped from Google Sky.

It all looks official and government like, but was probably added to the image, since raw images aren’t stamped on the image. They are usually FITS files that have the timestamp and such as metadata. IRIS is the name of a solar satellite, the Interface Region Imaging Spectrograph. But it wasn’t even launched until June of 2013. 2003UB313 is the designation for the dwarf planet Eris, and NI2b might refer to nickel boride. It’s hard to say. IRIS couldn’t have taken an image in 2003, and Eris doesn’t remotely look like this. But going through the Google Image links, I came across a reference noting that the object could be seen in Google Sky, at Right Ascension 5h 42m 21.0s, and Declination 22° 36′ 45.7.  Sure enough, if you look up that location, you find a similar object. Now we’re getting somewhere.

Our mystery object as captured by the POSS I. Credit: STScI Digitized Sky Survey

As an interesting side note, several of the Nibiru posts talk about a conspiracy where Google blocked out that section of Google Sky when people found it, presumably to hide Nibiru from the general public. But Google is very clear about its sources. They give credit to the DSS Consortium, SDSS and NASA/ESA. The DSS Consortium is a Digitized Sky Survey that has digitized photographic plates from early sky surveys, most significantly the Palomar Observatory Sky Survey (POSS). The initial sky survey (POSS I) was done in 1958. A second, higher resolution survey (POSS II) was done in the 1980s and 1990s. These have been digitized and are freely available to the general public. Pick what part of the sky you want to see, and you can get the actual images. The only catch is that the site wants locations in decimal degrees rather than the old school hours, minutes, seconds. I could convert it by hand, but why not let an online converter do the heavy lifting. Bada bing, bada boom, and we have RA: 85.5875, DEC: 22.6125. Plug these into the online DSS archive, and we have our images. By default the site gives you the raw FITS files, which is what astronomers use, but it will also give you a GIF if you like. The resolution is pretty low, but it does confirm that this is the object in question.

Left: DSS color composite. Middle: 2MASS composite. Right: WISE composite. Credit: ADS All Sky Survey

The nice thing about sky surveys is that they are still doing them, and most of the data is publicly available. So why not look up the object in other surveys? One good resource is the ADS All Sky Survey, which has data from several sources. The nice thing about this particular site is that once you find your object, you can select images from several sky surveys. The image above shows three of them. The one on the left uses the DSS data we found before to create a “real color” image. The middle image uses data from the Two Micron All-Sky Survey (2MASS), which focuses on infrared wavelengths close to the visible spectrum. The image on the right is from the Wide-field Infrared Survey Explorer (WISE), which looks at longer infrared wavelengths.

It’s pretty clear that this object is bright in the infrared as well as the visible, and that the odd wing features are most apparent at visible wavelengths. This is a common characteristic of T Tauri type stars. These are young stars still in the process of forming. Unlike our Sun, which generates its heat from nuclear fusion, T Tauri stars are generating heat through their own gravitational weight. They tend to be brighter and warmer than main sequence stars of a similar mass, and they also tend to be near other gas and dust. The light from the star often reflects off this dust, creating bright reflection nebulae. This would explain the wing-like feature near the star.

Just to be sure, we can look up the object on an astronomical database known as SIMBAD (the Set of Identifications, Measurements, and Bibliography for Astronomical Data). If it is a known object, it will likely be listed there. Entering in the RA and Dec we got from the Nibiru fans, it looks like SIMBAD finds 2 objects: GN 05.39.2, which is a reflection nebula, 2MASS J05422123+2236471, which is a T Tauri type star. It has an apparent magnitude of about 12, and is probably about 700 to 1,000 light years away. We’ll know its exact distance when the Gaia spacecraft starts releasing its data. At magnitude 12, it can even be seen with a small telescope in dark rural skies. Amateur astronomer Scott Ferguson has not only done this, he’s made videos showing his work.

One of the most amazing things about astronomy is how accessible the data is. Most of the data from large telescopes and sky surveys are publicly available for free. Any site who posts an image like the one sent to me without providing sources is simply being lazy. Science isn’t about being lazy, it’s about getting things right, and that’s one of the reasons citations are always needed.

The post Citation Needed appeared first on One Universe at a Time.

Yesterday I got an interesting request from a therapist. She works with folks who are terrified that some large object like Nibiru is going to collide with Earth and kill us all, known as cosmophobia. Unfortunately there’s a lot of YouTubers out there that say these fears are quite reasonable, including “a physicist” who claims that Eris is a brown dwarf heading our way. When the therapist presents evidence contradicting the “physicist,” her patients argue that she’s not an expert, and can’t possibly know what the physicist knows. I am “a physicist,” specifically an astrophysicist, so she asked if I would disprove the claim as an expert. So here’s how we know that Eris isn’t a brown dwarf, and isn’t heading our way. By “an astrophysicist.” 

According to A. Physicist, Brown Dwarf stars are electric bodies surrounded by a cloud of gas, so let’s start with that. In astronomy (like any other science) definitions matter. They need to be precise, we have to agree to use the same definitions so that we can be clear about what the research says. Anyone who uses a different definition is either confused about the terminology of the field, or is intentionally misusing the terminology. This is a huge red flag from the get go, because it’s not how astronomers define brown dwarfs.

The general definition for a brown dwarf is that it’s an object that is more massive than a planet, but less massive than a star. A star is defined as a body that is massive enough to fuse hydrogen in its core. This means a star has to be about 80 times more massive than Jupiter. The upper cutoff for a planet is that it isn’t massive enough for any nuclear fusion to occur in its interior. At about 13 times the mass of Jupiter, objects become just massive enough to fuse deuterium to create a bit of heat, so we can say a brown dwarf is basically any object that has a mass between 13 and 80 times that of Jupiter.

Light from stars and brown dwarfs approximate the blackbody radiation curve, where the peak color can tell us their temperature. Credit: Swinburne

Observationally we can distinguish brown dwarfs by their spectral class. That is, when we look at the light coming from an object, there is a specific wavelength (color) which is the brightest. This peak color determines the spectral class, and it’s also a good measure of an object’s surface temperature. The longer the wavelength (the more red) the peak color, the cooler the object. The smallest stars, known as red dwarfs are M-class stars, and have a surface temperature of about 2,800 K, which is about half the temperature of the Sun’s surface. Brown dwarfs are L-class or T-class stars, and can have temperatures as high as 2,000 K or as low as 700 K. Since brown dwarfs don’t produce much heat by nuclear fusion, they gradually cool down as they age. By comparison, Jupiter (which even A. Physicist would admit is a planet) has a surface temperature of about 180 K.

The spectra from a red dwarf (blue) and two brown dwarfs (purple and magenta). Notice how each curve approximates a blackbody. Jupiter on the other hand (red) has a very different spectrum, since it is a planet. Figure from Marley & Leggett 2009 (adapted from Cushing et al. (2006))

The spectrum of Eris. Notice it doesn’t look like a brown dwarf spectrum. Credit: Alvarez-Candal, et al.

Although we don’t categorize planets by spectral type, we can look at the spectrum of light from planet-like bodies to determine their surface temperature. Astronomers have done this with the spectrum of Eris, so we know its surface temperature is much cooler, about 50 K. So Eris is far too cold to be a brown dwarf, and isn’t the right spectral type. So by the accepted definition (the ones astronomers use) Eris is not a brown dwarf.

Now A. Physicist might argue that since Eris is electric and surrounded by gas (it’s not, but we’ll let that slide for now) and such, the spectrum can’t be trusted. There are actually limitations to spectral class. For example, small red dwarf stars have the same surface temperatures as red giant stars, so we can’t always assume that an M-class star is small. We also have to look at other evidence. Fortunately Eris has a moon known as Dysnomia, and that means we can calculate the mass of Eris using good ol’ Newtonian gravity.

The orbit of Dysnomia around Eris, and observed by the Hubble and Keck telescopes. Note how well the data (open circles) matches the calculated orbit.

The planets orbit the Sun because the Sun’s gravity pulls on them. As Newton demonstrated, this is due to the mutual attraction between their masses. It turns out that the orbit of a planet around a star, or a moon around a planet depend upon their masses and how far apart they are. So if you watch one object orbit another, you can calculate the mass of each object. The math is pretty easy (it’s a calculation I have my introductory astronomy students do). By watching Dysnomia orbit Eris, we know exactly how massive each of them are. It turns out Eris has a mass of (1.66±0.02)×10²² kg, or about a fourth the mass of the Moon.  The Moon is warmer than Eris, and is four times more massive than Eris, and it is not a brown dwarf. Eris is a small, icy world, and wae know that definitively.

A figure taken from a paper by A. Physicist, including the caption. The author assumes that since a magnified, low resolution image is blurry it must be due to a cloud of gas…

So let’s go back to the claim of A. Physicist that Eris is an electric body surrounded by a cloud of gas. The electric part is based on the electric universe model, which I’ve debunked before. But the key part of the argument is that Eris seems to be surrounded by an irregularly shaped cloud of gas, as seen in the image above. This is an excellent example of how images can be used to promote pseudoscientific ideas. A. Physicist doesn’t provide a source for these images (a big no-no in science), but a Google search confirms that they are images taken by the Keck telescope in Hawaii. The Keck observatory is a ground-based telescope consisting of two 10-meter mirrors. Although Keck is on Mauna Kea at an elevation of 13,600 ft, it still has to contend with atmospheric distortions. What looks like a cloudy blur is actually due to the fact that our atmosphere blurs it a bit. The image is also a bit over exposed, so that you can see Dysnomia. The purpose of the image was to track the position of Dysnomia over time to calculate its orbit, so the blurriness isn’t a problem for astronomers.

A Hubble image of Pluto and Charon, which has a similar “fuzzy cloud” around them. The image is actually over exposed in order to see Pluto’s smaller moons, Nix and Hydra. The inset upper left is a Hubble image of Pluto and Charon that is not over exposed. The inset upper right shows Pluto and Charon as seen by the New Horizon spacecraft. Notice there is no thick cloud surrounding them.

You can see a similar effect with a Hubble image of Pluto, where they are over exposed in order to see Pluto’s smaller moons Nix and Hydra. This doesn’t mean Pluto is surrounded by a cloud of gas. As you can see in the image above, a similar Hubble view of Pluto and Charon doesn’t have that effect, and when the New Horizons spacecraft flew past Pluto, it captured images of an icy planetary surface, with no thick cloud surrounding it. Like Pluto, Eris might have a thin atmosphere, but that’s about it.

A time lapse animation showing the motion of Eris over a period of 3 hours. Credit: Mike Brown/Caltech

The orbit of Eris compared to the rest of the solar system. Credit: Wikipedia

Now that we’ve established that Eris is a small, cold, moon-like world, let’s look at the last claim that Eris could be heading toward Earth. The basic claim of A. Physicist is that astronomers may have the orbit wrong because they think Eris is small instead of being a large brown dwarf. It’s a nonsensical argument because the orbit of Eris is calculated by its apparent motion, not its apparent size. Eris can be observed moving relative to distant background stars. Its apparent position depends upon the location of Eris and the location of Earth, so we can calculate not only its motion, but its distance. This allows us to calculate the orbit of Eris. And these calculations only depend upon observed position, not size. We can calculate Jupiter’s orbit the same way. We know beyond a shadow of a doubt that Eris is well beyond the orbit of Neptune, and will never come close to Earth.

Take it from an astrophysicist. Eris is not a brown dwarf. It is a small, icy world in the outer solar system, and poses no threat to Earth.

The post Is Eris A Brown Dwarf? appeared first on One Universe at a Time.

Science isn’t easy. It isn’t supposed to be. The process of open publication, peer review and clear data are a part of science because they help us understand how the Universe works. It can be inconvenient and contentious, but it works. Through this process, new ideas are faced with an uphill battle. This is particularly true of ideas that would contradict the foundational theories of physics. So it’s tempting to react to such opposition by playing a different game. Rather than addressing criticism, you start building a story where your idea is obviously right, and others are simply too closed-minded to see it. Down that path lies pseudoscience, and sometimes you can watch it happening. Take for example, Mike McCulloch‘s theory of Modified inertia by a Hubble-scale Casimir effect (MiHsC), also known as quantized inertia.

McCulloch’s model has been in the works since 2008, but it has become popular in recent years due to its connection to the EMDrive. You might recall this as the device that (according to its proponents) can create a thrust without any traditional propellant which could revolutionize space travel and take us to the stars. The EMDrive has created quite a stir among the general public because of the tremendous possibilities if it succeeds. Meanwhile, scientists have noted that even the best experimental results can’t be distinguished from background noise, and that such a device would violate basic physics. McCulloch argued that the effect was not only real, but that it could be explained in the context of his model.

The basic idea of MiHsC is that inertia is caused by Unruh radiation. Inertia is a basic property of matter, and means that the velocity of an object will remain constant unless a force acts on it. It is the basis of Newton’s first law of motion. Unruh radiation has never been observed, but it appears in quantum physics. In quantum theory, empty space can be described as being filled with a quantum field. A vacuum, in this view, is simply the lowest possible energy state for these fields. In most cases empty space looks like a vacuum as we’d expect, but for an accelerating observer the field has an observed energy. As a result, an accelerating observer would be heated by quantum particles known as Unruh radiation. McCulloch argues that when an object accelerates it interacts with Unruh radiation, which causes the object to resist a change of motion. Thus inertia is an effect of acceleration rather than an inherent property of matter.

There are problems with this idea from the get-go. For one thing, the Unruh effect in standard quantum theory is extraordinarily small. If you accelerated a trillion times greater than Earth gravity, you’d only see a thermal temperature of 40 billionths of a degree above absolute zero. Furthermore, since Unruh radiation comes from all directions, it couldn’t create the effects of inertia on its own. But rather than be deterred by this, McCulloch adds other effects into the mix. Since the observable universe is finite, the wavelengths of Unruh radiation is limited, and combined with a cosmic Casimir effect and a bit of information theory, can somehow produce the effect of inertia. The Unruh effect, Casimir effect and information theory are all well established in modern physics, but their hodge-podge combination in MiHsC is misapplied.

Credit: EM Drive prototype by NASA/Eagleworks, via NASA Spaceflight Forum.

However even this isn’t enough to explain the EMDrive. In his paper on the EMDrive, McCulloch argued that photons have mass, and that photon mass varies with time. The time-varying inertia allows the EMDrive accelerate. The idea not only violates Newton’s third law of motion, it violates special relativity, general relativity and Noether’s theorem. Since these are each well tested theories that form the basis of countless other theories, their violation would completely overturn all of modern physics. It’s no wonder most scientists have been aggressively skeptical of the idea. This criticism could be overcome by working out the specific details of  MiHsC, clearly addressing these kinds of problems. But that would be extremely difficult given just how strongly verified these theories are. The alternative is to double down, count the EMDrive as a win, and start looking at other strange effects to explain. Because once you allow yourself to ignore basic physics in your theory, all sorts of phenomena can be explained.

McCulloch’s model vs MoND and Newton for some dwarf galaxies. Credit: M.E. McCulloch.

In his most recent work, McCullogh claims MiHsC can explain the odd behavior of rotating galaxies. It’s long been known that galaxies rotate faster than expected. Given the amount of mass we can directly see in a galaxy, most of them should simply fly apart. The most popular solution to this conundrum is that galaxies contain dark matter, but other ideas such as Modified Newtonian Dynamics (MoND) have been proposed. Like MoND, MiHsC proposes that the inertia of an object is less at small accelerations, so the weak gravity of a galaxy can keep stars from flying away. Starting with an equation for modified inertial mass, the paper derives the predicted rotation speeds for several dwarf galaxies. It then compares observed rotation speeds with the predictions of Newtonian gravity (without dark matter), MoND, and MiHsC. Newtonian gravity fails (as has long been known), and the other two models agree with the data equally well, though with uncertainties on the order of 30% calling the data a good fit is a bit generous. McCullogh then argues that MiHsC is inherently better than MoND, since MoND relies upon an adjustable parameter. Nevermind the fact that MiHsC violates established physics, while MoND is simply descriptive.

By itself this is pretty standard for a speculative paper: here’s a wild idea, it can kinda explain a strange physical effect, maybe it’s worth exploring further. It’s a kind of “what if” paper that could lead to interesting models, but doesn’t really prove anything. Sure, MiHsC roughly agrees with the galaxy rotation curves, but so do a dozen other speculative models.  But McCullogh claims on his blog that the model not only predicts galactic rotation curves without dark matter, it predicts cosmic expansion without dark energy, solves the Pioneer anomaly and the flyby anomaly, could be used to create free energy through sonoluminescence, etc. It’s everything we could ever wish for. These claims reiterated in the popular press without any critical analysis. As a result, the model has built up a fan following who think that skeptical scientists are just haters trying to bury the next Einstein.

But that’s not how science is done. To be a viable model MiHsC will have to address its contradictions with established theories, and that will prove extremely difficult. Claiming victory is easier, but it’s an approach that will only get you lost in the woods.

Paper: M.E. McCulloch. Low-acceleration dwarf galaxies as tests of quantised inertia. Astrophysics and Space Science (2017)

Paper: M.E. McCulloch. Testing quantised inertia on the emdrive. arXiv:1604.03449 [physics.gen-ph] (2016)

Paper: M. E. McCulloch. Modelling the Pioneer anomaly as modified inertia. MNRAS,376,338-342 (2007)

The post Doing It Wrong appeared first on One Universe at a Time.

Devil’s tower, a laccolithic butte in Wyoming, is the stump of an ancient silicon tree. This amazing fact was sent to me by a reader complete with YouTube link for proof. If only I would watch the video with an open mind, I would learn the error of my scientific ways. 

The video itself follows a common pattern, where an amazing claim is made, and the evidence presented is simply that two things look similar. Since an intrusion of magma through Earth’s crust looks somewhat similar to a tree stump, it must be a giant tree stump. It is the same method used by those who claim the Earth is flat, deny global warming and evolution, or espouse young Earth creationism, the electric universe, the doomsday planet Nibiru, that vaccines cause autism, and even that our solar system moves in a helical vortex. Their arguments are buttressed by claims that science is closed-minded, arrogant and dogmatic, or simply covering up the truth to protect their jobs.

It’s tempting to laugh these ideas off. After all, fringe ideas have always been proposed throughout history. But the difference is that with the rise of YouTube and social media this ideas spread faster and can become more ingrained in the minds of followers. The “Devil’s tower is a tree stump” video has more than half a million views, and is posted by someone with nearly three quarter of a million subscribers. That’s more than subscribe to the Sixty Symbols video series, for example. I can almost guarantee that in response to this post supporters of some of the pseudoscience I listed above will send me long diatribes about how their model shouldn’t be lumped in with the others. As wrong as these ideas are, they have staunch supporters willing to defend them. Not only do supporters of pseudoscience defend their ideas, but they vote and drive political conversations. Our society is shaped in part by these ideas, whether we like it or not. So it’s important to push back against these claims.

That might sound like I’m saying people are stupid, and that they need to be told what to think by intelligent and knowledgeable scientists like me. I’m not. Being wrong about a particular concept doesn’t make you stupid, and being open to new ideas even when they sound crazy at first is part of the curiosity science tries to foster. The problem isn’t stupidity or ignorance, it’s a failure of critical thought. And it’s not just a problem with pseudoscience advocates. Most modern scientific discoveries are promoted through press releases and media packets, many of which don’t even link to the actual research. They use exactly the same approach as the video above, where a few pretty pictures are used to support a wild scientific claim without linking to any actual evidence. A press release made without citing research is just as pseudoscientific as a YouTube video making unsubstantiated claims. We’re all capable of being intellectually lazy.

The good news is that critical analysis and intellectual discourse can be encouraged and promoted. The same tools that are used to promote pseudoscientific ideas can be used to raise the bar on scientific discussion. But making that change depends upon those of us who want to see a richer and more thoughtful exploration of knowledge. It’s easy to point fingers at the fringe and declare how poorly they behave. It’s more difficult to look at ourselves with a critical eye. That means calling out press releases and popular news stories that don’t cite actual research. It means taking the time to present ideas clearly as well as the evidence behind them. And it means having the patience to engage in discussions with those of opposing ideas, even though sometimes it will feel like feeding the trolls. If we want to promote knowledge and critical thought, as lovers and promoters of scientific ideals we have to encourage it ourselves.

If we don’t do this, then we are simply peddling ignorance in the name of knowledge.

The post Ignorance Peddling In The Age Of YouTube appeared first on One Universe at a Time.

I have a theory. Maybe the Sun isn’t powered by the fusion of hydrogen in its core, maybe it’s powered by chickens. Now, I don’t have a fancy Ph.D. in chickenology, but I’ve raised chickens. I know chicken behavior when I see it. It seems pretty obvious that the Sun is powered by chickens. Don’t believe me? Just watch this YouTube video that proves it. 

Lab experiments show that chicken can emit thermal radiation.

Now those of you who continue to cling to the idea of core fusion might argue something about the Sun’s surface having a thermal spectrum, which is not chicken-like at all, but experiments in the lab have shown that chicken when heated does emit a thermal spectrum. Yes, core fusion could also explain the Sun’s spectrum, but until a Sun is created in the lab, we can’t be sure. However, if scientists would just put a roasted chicken near the Sun, they would confirm the chicken universe model.

Gonzo was a visionary genius who was shunned by the scientific establishment.

Unfortunately, in order to keep their cushy academic jobs, scientists continue to hinder chicken research. Chicken physics papers submitted to their “peer reviewed” journals are rejected out of hand. Their adherence to the standard model is almost religiously dogmatic. They claim that chicken cosmology has long been disproved, but they only consider frictionless spherical chickens in a vacuum. As anyone who has raised chickens knows, real chickens have physical properties dogmatic astronomy can’t explain.

For example, when large numbers of chickens are packed into small chicken coops, the temperature of the coop greatly increases. So much heat is produced that often cooling systems must be used to remove excess heat. This supports the idea of hen fusion, where hens in large numbers can generate significant heat. In the chicken Sun model, the surface of the Sun is covered with chickens. The density of the chickens is so great that they emit the heat and light we see as sunshine.

Industrial farming, or hen fusion research? You decide.

If you watch chickens in a large coop, you’ll notice that often the chickens will cluster in such a way that gaps form, revealing the ground below. This could explain the presence of sunspots, where gaps in solar surface chickens reveal the cooler, darker layer below. The excrement of chickens also contains the building blocks for life, and has been demonstrated to encourage plant growth in the lab. Clearly there are aspects of the model that need to be further developed, but chicken physics makes more sense that inventing things like dark matter, dark energy and the big bang to explain the cosmos.

Chicken cosmology could not only answer some of the biggest mysteries of astrophysics, it could provide us with limited free energy. Chicken propulsion technology could give us access to the stars. But that will only happen when scientists stop acting like religious zealots and look at the evidence with an open mind.

Paper: Doug Zongker. Chicken Chicken Chicken: Chicken Chicken. Chicken, 10(3):307–314, 2000.

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

The reactionless thruster known as the EmDrive is back in the news. This time the buzz arises from a new theoretical paper that attempts to explain just how the device can seem to violate basic physics. While this new work begins with some basic quantum physics, it quickly veers into uncharted (and highly speculative) theoretical waters to achieve its goal. 

The EmDrive is highly controversial because it is claimed to create a thrust without a corresponding propellant. Such a “reactionless drive” would violate Newton’s third law of motion, which is one of the basic tenets of classical physics. Usually this kind of thing is quickly tossed onto the compost pile of fringe science, but in this case several independent groups have claimed to observe a thrust from this kind of device. While this might seem like solid evidence, there are several reasons to be skeptical. To begin with, none of the work has yet been peer reviewed. It was announced last month that some of the experimental work is currently undergoing peer review, but no peer-reviewed paper has yet appeared. This is important because the supposedly observed thrust are extremely small, and it is notoriously difficult to rule out more mundane causes for these kinds of odd tiny effects. Secondly, if the EmDrive actually works, it would violate known physics. There is currently no theoretical explanation for why such a thrust might occur. While you don’t need a theoretical explanation for a clear experimental result, it would help to have a theoretical model one could test. This new work attempts to create such a theoretical model.

The model begins with an idea out of quantum physics known as the Unruh effect. In quantum theory, empty space can be described as being filled with a quantum field. A vacuum, in this view, is simply the lowest possible energy state for these fields. For an inertial observer (one that isn’t accelerating) this field has effectively zero energy, and empty space looks like a vacuum just as we’d expect. However, for an accelerating observer the field has an observed energy, and the observer would observe a sea of particles in thermal equilibrium. As a result, an accelerating observer would be heated by quantum particles. While this might seem odd, it’s actually a well known effect, and is somewhat similar to Hawking radiation. While the Unruh effect isn’t controversial, it’s never been observed because it is such an extremely tiny effect. An acceleration of a trillion gees would create a temperature of less than a millionth of a Kelvin. The Unruh effect raises an interesting question for accelerating particles, specifically whether an accelerating particle interacting with an Unruh thermal background will emit radiation that can be observed by a non-accelerating observer. This would be known as Unruh radiation, and there are theoretical models both for and against it. While it seems reasonable that Unruh radiation should exist, it’s also reasonable to be skeptical.

In the theoretical model for the EmDrive, it’s assumed that Unruh radiation is real. Furthermore, the author of the model argues that Unruh radiation is the source of inertia. The basic idea is that an accelerating mass would experience a kind of drag due to the Unruh effect, which we describe as the inertial resistance to acceleration seen in classical physics. This effect would be largely indistinguishable from the usual behavior of inertia, but the author argues that subtle differences would show up as anomalies, such as the flyby anomaly seen in some spacecraft. From there it gets even more speculative, because the author claims that photons can also have inertial mass due to the Unruh effect, and thus give the EmDrive a reactionless thrust.

The overall shape of the EmDrive is somewhat conical. As electromagnetic radiation is is bounced around in this conical cavity, the allowed energy levels of photons at the narrow end are slightly different from the allowed energy levels at the wider end. So photons can transition between energy levels within the cavity of the device. In the model, photons at different energy levels have different inertial mass. So when photons transition from higher energy levels at the narrow end to lower energy at the wider end, their inertia changes. By Newton’s third law, there must be a reaction force on the drive itself. In short, this model buries Newton’s third law in quantum speculation. Through this model the EmDrive can defy Newton’s law by thrusting against the vacuum of space rather than violating the law directly.

In its defense the work does at least strive to make clear and testable predictions. Not only does it predict discrete levels of thrust based upon the geometry of the cavity, it also predicts that one should see a reversal of thrust direction given a cavity of certain dimensions. But it also isn’t something to get too excited about. This new work doesn’t prove the effect is real. It does not even agree with claimed results that strongly. The model also raises further theoretical problems, such as requiring that the speed of light changes within the cavity, which would violate the central property of special relativity. Even if the EmDrive works as this model claims, it still violates well tested laws of physics.

In all honesty I’d love to see a device like this actually work, but I’m not convinced the effect is real. While this new work is interesting, it doesn’t make the effect more convincing.

Paper: M.E. McCulloch. Testing quantised inertia on the emdrive. arXiv:1604.03449 [physics.gen-ph] (2016)

The post The Theoretical Dream Of The EmDrive appeared first on One Universe at a Time.

You won’t believe what they’ve done this time.

If you’ve read this far, I want to be clear that the headline was linkbait. This post isn’t about some new transgression from IFLScience, but rather about why hype in science reporting is so harmful. For my regular readers I promise never to pull this kind of thing again. For those who have come because of the outrageous headline, hear me out.

If you’re not part of the solution, you’re part of the precipitate. Credit: Kim Martini

A few days ago I wrote a post callout out IFLScience for misrepresenting research on solar cycles. It created a bit of a firestorm, with lots of people defending the site’s use of linkbait headlines:

Who cares if they grab some attention with their headlines. They’re pulling people away from main stream media which is a good thing.

These science websites have to bring in the non-science-degreed people.

I don’t blame IFLscience for having the odd attention grabbing article/headline, anything that gets more people into science and away from celebrity obsession is a good thing.

Hypothetically, the word “sun spots,” “ice age,” and “science,” were used in a conversation between two adults whose lives probably very rarely revolve around this. They’ve gotten people into the discussion. I don’t care how.

There was also a great deal of accusation that I was being elitist by calling out IFLScience:

IFLScience isn’t a technical journal, and it’s not pretending to be. It’s trying to make science news accessible to the masses.

IFLS is not a scientific journal, and as a social media page it should not be held to the standards of a scientific journal, or even a scientific news source such as Scientific American.

The fact is IFLS isn’t a peer-reviewed scientific journal. It’s a science and entertainment site.

What I find most disheartening about these kinds of comments is how deeply they underestimate people’s intelligence. It reinforces a common misconception that science is only for “smart” people, and it isn’t relevant to most people’s lives. Neither of these are true. People don’t need to be coddled or lied to in order to interest them in science, they need to be engaged in a clear and honest way. Science isn’t perfect, but it is a deeply powerful method for gaining knowledge. The more knowledge we have about the universe, the more readily we can face the challenges ahead. Hyping results and misrepresenting research only serves to strengthen the argument that scientists don’t really know what they’re talking about. That’s why it’s anti-science, and that’s why I called IFLScience out. They can be a voice for good, but when they willfully mislead it is deeply harmful. The same is true for any site that misrepresents scientific research.

The main argument of those defending hyped and misleading headlines is that it starts a conversation. To them I would say use this to start a conversation. Feel free to share this post with your friends, but better yet write your own. We deserve better than hyped headlines to spark a discussion.

Note: The image for this post? It was created by Andy Brunning as seen on (you guessed it) IFLScience.

The post More Lies on IFLScience appeared first on One Universe at a Time.

Have you heard about the coming ice age? You may have seen articles with titles such as “Thanks To Reduced Solar Activity, We Could Be Heading For A Mini Ice Age In 2030.” and “‘Mini Ice Age’ Not a Reason to Ignore Global Warming.” Of course such sensational headlines led to rebuttal articles such as “No, We Aren’t Heading Into A ‘Mini Ice Age’” Once again, a hyped headline is used to drive page views, and which only serves to mislead readers. Hence a follow up article on how “The ‘Mini Ice Age’ Hoopla Is A Giant Failure Of Science Communication.” Here’s the thing, though. All of these articles are from IFLS also known as “I’ll use profanity in my website title so people will think I’m edgy and cool.”

You might think IFLS just made a mistake and then made an honest effort to correct it. They didn’t. After their first article hit the press, there were soon legitimate science communicators writing rebuttals. It was clear from the get-go that the research presented did not support a mini ice age in 2030, but IFLS printed it anyway. They published their second article to double down on their hyped claims. Of course, once it was crystal clear that IFLS was wrong, they could have made a correction in the original article and linked to one of the better rebuttals. They didn’t. Instead, they retitled their second article “There Probably Won’t Be A “Mini Ice Age” In 15 Years” and linked to that at the bottom of the page. To this date, they still haven’t made clear that their first article is in error. Why correct your “mistakes” when your lies get you nearly 76,000 likes on Facebook? The last two articles aren’t even ones IFLS wrote. They were actually written on The Conversation and then reprinted on IFLS. Heaven forbid you direct traffic to another site.

This isn’t a failure in science communication. It is the willful promotion of ignorance. So I think a new name for the site is in order: “We’re Just Interested In Pageviews. The Science Can F Itself.”

HT to Yvette d’Entremont for pointing these articles out. You can also read a follow up on this topic.

The post A Failure to Communicate appeared first on One Universe at a Time.

The unchanging speed of light in a vacuum is a foundational fact of relativity. This constant speed has been tested to unprecedented accuracy, but there are some that argue that isn’t enough. In special relativity, it is assumed that the speed of light doesn’t depend upon what direction the light is traveling in, or where it is in space. Physical processes might affect the speed of light, but mere location and direction doesn’t. This is actually part of a broader metaphysical idea that the universe is homogeneous and isotropic. Basically, it’s the assumption that the laws of physics (whatever they might be) are the same everywhere in the universe. This is in contrast to ideas such as geocentrism, which assumes that Earth holds a special place in the cosmos. It’s been an assumption as far back as Newton, though it has been tested in several ways, and has held up so far. But what if the assumption about light is wrong? What if the speed of light is actually anisotropic?

The initial verification of an invariant speed of light comes from the Michelson-Morley experiment in 1887, which showed that the speed of light didn’t depend upon the motion of the Earth. This implied there wasn’t an absolute reference frame, or a luminiferous aether through which light propagated. Over the years the speed of light has been measured with ever greater precision, and it’s always appeared to be a physical constant. But most of these experiments rely upon light to make a round trip in two directions, so technically it’s a measure of the “two-way” speed of light. What hasn’t been done is a direct “one way” speed of light measurement. You might think that’s easy enough to do, simply measure the start and finish time of a photon, for example. But to do that you’d need to synchronize your clocks, which means you’d have to set them at the same time when they are side by side, then move one clock to the finish line. Of course, when you do that, the motion of the clock would affect its measure of time, and you can’t be sure they they are still in sync without assuming some model like special relativity.

Suppose then that the speed of depended upon its direction of motion? Suppose it travelled almost instantly when heading toward us, but at half the “speed of light” when traveling away from us. The round trip time would be the same as relativity predicts with a constant speed of light. Most physicists don’t worry about this kind of thing since relativity keeps passing all the tests, but philosophers love to explore these kinds of metaphysical weaknesses. So the “one-way light problem” appears every now and then in the literature.

So what if the speed of light isn’t the same when moving toward or away from us? Are there any observable consequences? Not to the limits of observation so far. We know, for example, that any one-way speed of light is independent of the motion of the light source to 2 parts in a billion. We know it has no effect on the color of the light emitted to a few parts in 10²⁰. Aspects such as polarization and interference are also indistinguishable from standard relativity. But that’s not surprising, because you don’t need to assume isotropy for relativity to work. In the 1970s, John Winnie and others showed that all the results of relativity could be modeled with anisotropic light so long as the two-way speed was a constant. The “extra” assumption that the speed of light is a uniform constant doesn’t change the physics, but it does make the mathematics much simpler. Since Einstein’s relativity is the simpler of two equivalent models, it’s the model we use. You could argue that it’s the right one citing Occam’s razor, or you could take Newton’s position that anything untestable isn’t worth arguing over.

Models such as anisotropic light are useful and interesting as a way of exploring the limits of what our scientific theories can tell us, but unfortunately they’re also used in a range of pseudoscientific models. In this case, the idea of a young Earth. One of the basic challenges for young Earth models is the starlight problem. If the universe is only a few thousand years old, how can we see light from the edge of our galaxy, much less other galaxies. One way to address this issue was to propose that the speed of light was much faster in the past, allowing distant starlight to reach us in a short time. But observations of line spectra from distant nebula shows that speed of light has changed no more than one part in a billion over the past 7 billion years. Then in 2010 Jason Lisle revived the idea of anisotropic light. If light moving toward us travelled at infinite speed, and away from us at half the traditional speed of light, then it would allow the most distant light in the young universe to reach us while still agreeing with relativity.

As crazy as that might sound, Lisle is right in claiming that such an effect would be indistinguishable from relativity, and this has made the work popular with young Earth supporters. However agreement with relativity isn’t enough. If light did actually reach us from distant galaxies instantly, we would expect galaxies at all distances (or more formally redshifts) to all look the same age. In fact, what we see is that more distant galaxies are younger than closer ones. If Lisle’s idea was correct, we wouldn’t see the magnification of distant galaxies due to cosmic expansion, nor fluctuations in a cosmic background, nor galaxy clustering in agreement with dark energy, nor a host of other observational results.

On its own, relativity doesn’t require isotropy and homogeneity, even though we generally assume it to be true. But when we combine relativity with the confluence of evidence we have in astronomy, we find that assumption is not only justified, but valid to the limits of observation so far.

Paper: Md. Farid Ahmed, et al. Results of a one-way experiment to test the isotropy of the speed of light. arXiv:1310.1171 [gr-qc]

Paper: John Winnie. Special relativity without one way velocity assumptions. Philosophy of Science, Vol. 37, No. 2 (1970)

Paper: Jason P. Lisle. Anisotropic Synchrony Convention—A Solution to the Distant Starlight Problem. Answers Research Journal 3 191–207 (2010)

The post Burden of Proof appeared first on One Universe at a Time.

The image above is a planetary nebula known as M2-9. It’s also known as the Butterfly nebula, but there are lots of other nebulae by that name. Planetary nebulae occur when red giant stars cast off their outer layers as they begin a transition toward becoming a white dwarf. The cast off material is caused to glow when the exposed interior of the star illuminates it with ultraviolet light, causing the material to ionize into a glowing plasma. We call them planetary nebulae because William Herschel first observed them as circular or “planetary” in shape, but we now know they come in a wide range of forms, including the layered, double-lobed shape of M2-9. Just how planetary nebulae produce such varied complexity is something we don’t fully understand. While we’re still trying to understand what the underlying mechanisms are, we do know very clearly what they aren’t.

The idea for this post came about because of a discussion with someone whose scientific interests lean toward the electric universe model. Regular readers will know I don’t find the electric universe model remotely compelling for several reasons. One of the EU ideas that has gained popularity is the idea that lobed planetary nebulae such as M2-9 are caused by plasma z-pinches in the great currents of cosmic plasma. The idea is ridiculous to anyone who’s studied astrophysics, but how do we know it’s wrong? After all, the EU folks have clearly studied this in detail, what makes me so arrogant as to tacitly dismiss the idea?

The pinch effect can crush beer cans too. Credit: Bert Hickman, Stoneridge Engineering

For those who aren’t familiar with plasma physics, a z-pinch is an effect which can occur when a plasma is constrained by a surrounding magnetic field. The magnetic force on a current is always perpendicular to the direction of the current, so when a current of plasma flows into a cylindrical magnetic field, the magnetic forces squeeze the plasma inward, causing a pinch. The pinch effect has been studied for nearly a century, and has been used in everything from crunching beer cans to work on harnessing fusion. If you look at M2-9, it’s easy to imagine a z-pinch. The plasma current flows in, pinches in the center, and flows out the other side. This is what Donald Scott and other EU folks claim, and I would agree there’s certainly a resemblance. However Scott goes further to argue that because it looks like a z-pinch, that’s what it must be. This is a classic “quacks like a duck” fallacy, which most scientists are pretty wary of. Doubly so if what it looks like would turn a hundred years of astrophysics on its head.

But this is one of those cases where there is a clear prediction from the EU model. That is, the flow of plasma is through the pinch. This means if you look at the Doppler shift of light coming from the nebula you should clearly see that the material flows in on one side and out on the other. The standard red giant model makes a very different prediction. It says the Doppler measurements should show material flowing out from the center on both sides. It turns out we’ve made Doppler observations of M2-9, and sure enough it agrees with the standard red giant model.

While this might seem like a pretty clear refutation of the z-pinch idea, but the counter argument seems to be that you could have two layers of current flow so that it goes in both directions (also contradicted by Doppler observations) or all manner of complex plasma phenomena that might explain away the Doppler data. But that isn’t very compelling because tweak theories are weak theories.

The other counter argument raised in the discussion was that astrophysicists don’t entirely understand the nebula either. If you read through the cited paper you’ll see a discussion of several models for the behavior of the lobes, peppered with phrases such as “possibly” and “might be.” It’s clear there’s a lot we don’t understand about M2-9. That’s because good scientists are cautious about making unsupported claims. We tend focus on the known unknowns.

But that’s how science pushes forward toward better models, instead of clinging to ones that clearly don’t work.

Paper: Doyle, et al. The Evolving Morphology of the Bipolar Nebula M2-9. AJ, 119:1339-1344 (2000)

The post Known Unknowns appeared first on One Universe at a Time.