Exposing PseudoAstronomy

June 23, 2015

Podcast Episode 134: Big Bang Denial


The Big Bang theory:
Tot’ly explains the cosmos?
Or, is it a dud?

This episode follows a big from the Black Hole Denial episode, but this time with another aspect of cosmology: The Big Bang. I was able to use a few old blog posts, too, that I wrote practically 7 years ago.

As mentioned, I’m now on a weird – though backdating – release schedule due to the piling on of work as the New Horizons craft nears Pluto. But I’m still trying to do 2 episodes/month, at least.

June 12, 2015

Are We on the Verge of Discovering an Earth-Like Exoplanet?


I announced awhile ago that I was on episode 347 of the Canadian, “The Reality Check” poscast where I talked about exoplanets and some hype — deserved or otherwise — about almost but never quite yet discovering Earth-sized exoplanets.

While they post a lot of links and other things on their website, they don’t post transcripts of what we actually talk about. Since I spent a solid many minutes writing and editing my segment’s text, I thought I’d post it here:

There’s lots of ways to talk about exoplanets, but I’m going to take the traditional approach and start with a very broad but brief overview of how we have found the few-thousand known extra-solar planets, or “exoplanets” for short. There are five main ways.

The most obvious is the most difficult: Direct Imaging. This is where you take your telescope and would look at a star and see the planet around it. This is almost impossible with current technology, and we have less than 20 exoplanets found this way. It’s so hard because the star is so bright relative to the planet and because most star systems are so far away. And obviously, if the planet is larger and farther away from the star, it’ll be easier to see.

The second main method has also only produced about 20 planets so far: Gravitational Microlensing. Einstein showed that large masses bend light, and we can see this in space when an object that’s far away passes behind a massive object that’s a lot closer. The light from the background object gets distorted and magnified, much like a lens … a lens caused by gravity. If the foreground object happens to be a star, and that star has a planet, then that planet can make a detectable contribution to the lensing, not only in amount, but in the exact shape of the lensing effect.

The earliest actual successful method was a special form of what’s called the Timing Method, specifically in this case, pulsar timing. Pulsars are incredibly dense stars called neutron stars, and we get a blast of radio waves every time one of its poles sweeps in the direction of Earth. These are so regular that any tiny perturbation can be detected and attributed to something weird, like a tiny planet tugging on it and so changing that regular spinning signal.

This is the same concept as the highly successful method that found the most exoplanets until a few years ago: Radial Velocity. The idea is that we normally think of a planet, like Earth, orbiting the sun. But it doesn’t really. It *and* the sun orbit a mutual gravitational point called the “barycenter” that is between the two. For Earth and the sun, that point is VERY close to the sun’s center, but it’s not quite in the center. That means that over the course of a year, as Earth goes around that point, the sun will, too (on the opposite side of that point). So, it will wobble very very slightly as it orbits the barycenter.

We can’t possibly observe this tiny tiny motion of other stars. BUT, we can use the light that star emits to do it by using the Doppler shift. That’s the phenomenon where if something is moving towards you, the waves it emits become compressed, and if it’s moving away from you, the waves get stretched out. The common example is a train whistle going from high to low pitch, but in astronomy, this is where the light is shifted to blue and then to red.

So, if the planet around another star is at its closest point to us, the star emits light and we see it all normal. As the planet starts to move away from us, the star starts to move very slightly toward Earth, and so its light will be very slightly blue-shifted. Then, the planet gets to its farthest point, and starts to move towards Earth, which means the star starts to move away, and we see its light red-shifted. This is an incredibly tiny effect, and the smaller the planet, the smaller the shift in the light. Or the pulsar timing change.

There was a lot of progress throughout the late 1990s and early 2000s in very high-resolution spectroscopy in order to get better and better at observing smaller and smaller planets. The easiest ones to observe are the largest because they make the biggest shift in the star’s light, and ones that are closest to their star are easier because you don’t have to observe as long. To observe a planet that has a 10-day orbit, you just have to observe that star for about a month from Earth to get decent statistics.

That’s why all the exoplanets discovered early on were what are called “Hot Jupiters,” since they were very large and very close to their stars.

The final method is the Transit Method. If a fly passes in front of a bright light, you can see a slight decrease in the light. If a bird passes in front of a light, you’ll see a larger decrease in the light. Same thing here: A planet passes in front of the star and temporarily blocks part of the light from the star that we would see at Earth. The big issue with this method is that you have to have the fortuitous geometry alignment where the planet’s orbit is just right so that it passes in front of its star as seen from Earth. The first one wasn’t detected until 1999, but a decade later, the dedicated spacecraft COROT and then Kepler were launched to look for these, monitoring the same fields of the sky, tens of thousands of stars, moment after moment, looking for those brief transits. In 2014, Kepler released over 800 planets discovered with this method, more than doubling the total number known, and that was on top of its other releases and, to-date, it’s found over 1000.

The transit method, despite the issue of geometry, is probably the best initial method. If you have the planet going in front of its star, then you know its alignment and you can follow-up with the radial velocity method and get the mass. Otherwise, the radial velocity method can only give you a minimum mass because you don’t know how the system is oriented, you only know that radial component of velocity, hence its name.

With the transit method, you can see how much light is blocked by the planet. Knowing the star’s type, you can get a pretty good estimate for the star’s size, and knowing how much light is blocked means you can get the cross-sectional area of the planet and hence its diameter. For example, Jupiter would block 1% of the sun’s light, and since area is the square of length, that means Jupiter is about 10% the sun’s diameter. Since the sun is a type G V star, we have a good model for its radius, though of course we know its radius very well because we’re in orbit of it. But that means not only can we get mass, but we can get size and density.

The transit method also lets us see if there’s a large atmosphere. If the light from the star instantly blinks down to the level when the planet passes in front of it, then any atmosphere really thin or nonexistent. If there’s a gradual decrease, then it’s extended. If its extended, we can follow-up with something like the Hubble Space Telescope and actually figure out what that atmosphere is made of by looking at what colors of light from the star are absorbed as it passes through the planet’s atmosphere.

And as with the radial velocity and timing methods, we know how long it takes to go around its parent star, and along with the star’s mass from what kind of star it is, we can get the distance of the planet from the star.

Okay, so much for a brief overview. But for me, I’ve left out a lot.

Moving on, it should be somewhat apparent that the bigger the planet, and the closer to its star, the easier it is to observe with pretty much ANY of these techniques, except direct imaging or microlensing where you want a big planet that’s far from its star. Big means big effect. Fast orbit means you don’t have to observe it for very long to show that it’s a regular, repeating signal best explained by a planet.

So, the question is then, can we detect an Earth-sized planet, and can we detect an Earth-like orbit? These are really two different questions and they depend on the technique you’re using. If we want to focus on a the two main methods – radial velocity and transit – then the unsatisfying answer to the second is that we do finally have good enough technology, it is just a matter of finding it. With the 2014 Kepler data release, there were over 100 exoplanets that are less than 1.25 Earth’s size. With the 2015 release, there are a total of 5 planets smaller than Earth or Venus, but they orbit their 11.2-billion-year-old star in just 3.6 to 9.7 days.

Even if we have observations for more than a year or two, for something as small as Earth, the level of signal relative to noise in the experiment is still pretty small, and you want a big signal relative to the noise. It’s best to build up multiple years’ worth of data to average out the noise to be able to really say that we have an Earth-like planet. For something like Jupiter, which orbits our sun in about 12 years, we’d need to observe at least two transits, meaning we’re just now approaching the time when we would have a long enough baseline of data with some ground-based surveys, but that’s also assuming we catch that planet for the few hours or days when it goes in front of its star versus the years and years that it doesn’t, and that we do this repeatedly and don’t chalk it up to sunspots.

This is why we really need long-term, dedicated surveys to just stare at the same place in space, constantly, measuring the light output of these stars to see if we can detect any sort of dimming, that’s repeated, from a likely planet.

But, even if we find an Earth-like planet in terms of mass and diameter and location in its solar system, that’s not enough to say it’s Earth-like in terms of atmosphere and surface gravity and overall long-term habitability. It’s just a first step. A first step we have yet to truly reach, but one that is reasonably within our grasp at this point.

But it’s from the existing planets we know of that we get some of the hype that hits the headlines every few months, like “astronomers estimate billions of Earth-like planets exist in our galaxy alone.” I’m not going to say that’s fantasy, but it’s loosely informed speculation based on extrapolating from a few thousand examples we now have from a very, VERY young field of astronomy.

Or, we’ll get articles where the first sentence says, “Astronomers have discovered two new alien worlds a bit larger than Earth circling a nearby star.” It’s in the next paragraph that we learn that “a bit larger than Earth” means 6.4 and 7.9 times our mass, and they orbit their star in just a few days.

So as always, this is a case where, when we see headlines, we need to be skeptical, NOT susceptible to the hype, and read deeper. But that said, it is entirely possible that any day now we will find an exoplanet that is at least like Earth in mass, size, and distance from its host star.

June 2, 2015

Podcast Episode 133: Element 115 and the Credibility of Bob Lazar’s Claims


Ununpentium’s
Existence: Does it save Bob
Lazar’s U’FO claims?

A return to the roots of the podcast: A simple exploration of a claim, and what was found. Sort of. The first third of the episode is a look into the story of Bob Lazar, a man who is often credited (in part) with re-invigorating the UFO community in the late 1980s / early 1990s. It’s important for context, because embedded within that story is a general lack of credibility for his claims.

Enter element 115, which when it was discovered in 2003, became a rallying point for Bob Lazar’s supporters: The very existence of something that had not yet been discovered when Bob Lazar made the claim, means that his claims must be true. We see this a lot of times in the UFO field, but I really focused in this episode on this specific claim and the specific set of claims about element 115 made by Bob Lazar, before its “mainstream” discovery.

This episode does get a little technical because I talk about some basic particle physics, but I think it’s on par with most of my other episodes in terms of technical jargon and concepts.

And, that’s about it. There’s a short logical fallacy segment, where I ask your help in identifying the main logical fallacy for the episode, which I’ll then discuss next time.

It’s also important to note that the podcast is on Stitcher, and I should’ve checked my stats before I mentioned them at the end of the episode: I’m now on 33 peoples’ playlists and I’m ranked in the 3000s, not on 22 peoples’ playlists and ranked in the 5000s. Not bad for only being entered in late March and not doing much to promote it.

May 26, 2015

Podcast Episode 132 – In Search Of Planet X (Live from Denver ComicCon)


In Search: Planet X.
An overview of common
Ideas about it.

This episode is another recording of one of my live presentations, modeled a little after Leonard Nimoy’s “In Search Of” television series. It was presented in front of a live audience at the Denver ComicCon on May 24, 2015, to about 75-100 people. I was bordered on two sides by other sessions that had more people and a lot of laughter, so I played to that a little bit when there were opportune moments. I also suffered a minor A/V issue in the middle but recovered, so you’ll hear some fumbling there.

Unfortunately, there is also some popping that comes in about 10 minutes into the recording. I exploited all the filters that I know of in my Audacity toolkit, and they are less of an issue than they were, but they are definitely present.

I also need to announce that it is that time of year when work is going to get crazy, so episodes may come out a little less regularly, especially during July. I’m still going to keep to the two per month schedule, but they may not be out on exactly the first and sixteenth of the month.

And with that in mind, I have to head to the airport in 45 minutes for more work, after just being back home for 3.5 days. So …

May 9, 2015

The Reality Check Podcast Episode 348 – Me on Exoplanets, Others on Other Stuff


Episode 348 of “The Reality Check,” a weekly Canadian podcast that explores a wide range of scientific controversies and curiosities using science and critical thinking, is posted, and I take the first (and longest) of the three segments, where I discuss exoplanets.

I was originally contacted to discuss this topic because the hosts had some skepticism about the hype that we get every few weeks or months about how we are just on the verge of discovering an Earth-like exoplanet. The issue is that “Earth-like” can have a lot of different requirements and qualifications: Do you mean Earth-sized? Earth-like orbit? Habitable zone around the star? Atmosphere like ours? Etc.

Unfortunately, for my linear thinking, that meant I had to spend about 20 minutes going through an overview of how we find exoplanets, what the limitations are of each technique, and what information about the planet each technique can give us, and how different techniques and follow-up observations can be used to give complementary information (for example, if you detect an exoplanet using the transit method, you can use the radial velocity method to get the mass of the planet, and if you detect an atmosphere with the transit method, you could use spectroscopy with the Hubble Space Telescope to measure the atmosphere’s composition).

And for the record, when I practiced the segment without interruptions, it was 11 minutes. It stretched into almost 30 minutes on the show. And for regular listeners of TRC, you should recognize a quote from former-host Elan (I think) that I incorporated into the end of my segment.

It was toward the end that I finally got to the question about whether media reporting is hype. And, to put it concisely: Yes. But with that said, we really do, at this point, finally have the technology to detect an Earth-sized planet (and have) in an Earth-like orbit (have not) with potentially an Earth-like atmosphere (have not, and this tech may not *quite* be there, but if it isn’t, it’s close).

I haven’t listened to it yet, but of course I was there when it was being recorded, and I don’t remember embarrassing myself too much. They do tend to all talk more slowly, though, when recording at 1x versus how I listen to podcasts at about 1.2–1.3x. Also, three of the 4 outtakes (they have outtakes at the end of the show) are things I said or contributed — I guess I was humorous (or humourous? since it’s Canadian?).

I will add that doing a panel show is VERY different from doing a monologue as is my normal podcast. Or even doing an interview on the podcast. The dynamics are (obviously) completely different, and you almost have to build in pauses to what you’re talking about in case of questions from others. I think I stepped over some people, too. For example, there was one point maybe half-way through my segment where I stopped and asked if anyone was there because I wanted to make sure my internet connection (and theirs’) was still up since we had been having issues. They were all there, but then there were something like 3-4 questions that they asked because they had just been developing while I was talking and not pausing enough to let them ask.

If they’re kind enough to invite me back, I’ll keep this in mind and build that in. And work more at editing myself down.

Oh yes— There were two other segments. One was a guessing game as to “which came first,” while the other segment was about whether you should plan to visit Israel last if you go to the Middle East because other countries won’t let you in if you have an Israeli stamp in your passport.

May 2, 2015

Podcast Episode 131 – Clip Show #3: Blood Moons, Ceres’ Bright Spots, MESSENGER’s Death, and Funding in Science Follow-Up


Blood moons, science cash,
And spacecraft conspiracies
Are topics du jour.

Clip Show #3 is a big catch-up on several miscellaneous topics: The latest lunar eclipse, Ceres’ mysterious bright spots, MESSENGER’s death plunge into Mercury, and a large follow-up to episode 126 which was my interview with Dr. Pamela Gay about funding in science. This episode also had a logical fallacy section – cherry picking and anomaly hunting – and a feedback/Q&A about whether NASA has created a Warp Drive, and finally my long-foreshadowed tribute to Leonard Nimoy, with how he or his characters influenced myself and you in some way.

There’s really not too much else to say about this episode. The next one will likely by about Big Bang Denial (along similar lines to episode 125 about Black Hole Denial and a future one about Dark Matter Denial). And, this Friday/Saturday, I should be back on “The Reality Check” podcast discussing exoplanets and that we’ve been on the cusp of detecting an Earth-like planet … for many years.

April 23, 2015

How Do We Know How Old Stuff Is on the Moon?


Introduction

While this movie is branded under “Exposing PseudoAstronomy” for legal reasons, it has less to do with popular misconceptions/conspiracies/hoaxes and more to do with real science. This is my third more modern, lots of CGI movie, and my second to explain a research paper that I wrote.

In the movie, I go through how the lunar crater chronology is the fundamental basis for how we estimate the ages of surface events across the solar system. I also explain how my work affects the lunar crater chronology and what can be done to better constrain it.

I’m still waiting for a young-Earth creationist to claim that because of a factor of 2 uncertainty, 4.5 billion becomes 6.019 thousand.

I also wrote a blog post about this for The Planetary Society. Because it was posted there over two weeks ago, I think it’s fair game to repost here. You can click on any of the images for larger versions, and all of them are screenshots from the YouTube movie.

Planetary Society Blog Post

Three years ago, I started a project to replicate work done by various groups in the 1970s and 1980s. When the project was completed, the result implied that much of what we think we know about when events happened in the solar system were wrong, needing to be shifted by up to 1 billion years. I presented this in a talk at the recent Lunar and Planetary Science Conference at 8:30 AM, when most people were learning about the latest results from Ceres.

The project started simply enough: I downloaded some of the amazing images taken by NASA’s Lunar Reconnaissance Orbiter’s Wide-Angle Camera (WAC) that showed the Apollo and Luna landing sites. Then, I identified and measured the craters (my dissertation work included creating a massive global crater database of Mars, numbering about 640,000 craters).

The reason to do this is that craters are the only proxy we have for ages on solid surfaces in the solar system. We can determine the relative age of one surface to another (is it older or younger?) by looking at which has more craters: The surface with more craters will be older because, when you assume that craters will form randomly across the body, then the surface with more craters has had more time to accumulate them.

How to Use Craters to Understand Ages

Basic principle behind this work. (Background image © NASA/ASU; composite © S.J. Robbins.)

If we want to use craters for an absolute timeline – as in, actually put numbers on it – then we need some way to tie it to real ages. This was made possible only by the United States’ Apollo and the USSR’s Luna missions that returned rocks from the moon that could be radiometrically dated in labs on Earth.

With these radiometric ages, we then identify the craters on the surface those rocks were gathered and say that a surface with that many craters per unit area is that old.

That’s the lunar crater chronology: The spatial density of craters larger than a standard size versus radiometric age (we use 1 km as that standard size). This crater chronology is then scaled and used as a basis for the chronology across the rest of the solar system. When you hear someone say that something on the surface of Mars is X number of years old, chances are that’s based on the lunar samples from the 1960s and 70s and the crater counting done 40 years ago.

Apollo 15 Landing Site

Example landing site area, Apollo 15 (yellow star). Blue outlined areas indicate regions on which craters were identified, blue shaded areas were removed because they are a different type of impact crater, and blue circles are the craters mapped and measured. (Background image © NASA/ASU; data and composite © S.J. Robbins.)

And, that’s where my project came in. While the rock samples have continued to be analyzed over the decades, the craters were not. It’s easy to assume that the researchers back then did a great job, but by the same token, science is about replication and re-testing and we have developed new ways of doing things in the crater community since the Apollo era. A simple example is that the crater chronology requires a spatial density, and therefore you need to know the area of the surface on which you have identified craters. Over the past 40 years, we have better understood the shape of the moon and now have computers to allow for much more precise area calculations. This can result in changes by 10s of percent in some cases.

When I had finished my reanalysis, my results differed for many of the landing sites, in some cases by a factor of 2 from what the standard is in the field. I was surprised. I checked my work and couldn’t find any mistakes. So, I combed through the literature and looked to see what other people had published. I ended up finding a range of values, and only in one case was my result at the extreme low or high of all the published results. I showed my work to colleagues and none of them could find any issue with it. So, eventually I published it, early last year.

The Lunar Crater Chronologies

The new (blue) and old (red) chronologies and the data used to fit the model. The vertical axis shows the spatial density of impact craters larger than or equal to 1 km in diameter, and the horizontal axis shows the age of the surface from radiometric dating of collected rock samples. (© S.J. Robbins)

When I fit my crater data to the radiometric ages, my fit function showed a difference with the standard that has been used for three decades: Surfaces assigned a model age of about 3.5 to 3.7 billion years under the old chronology were older, by up to 200 million years. And, surfaces younger than about 3.4 billion years under the old chronology are younger, by up to about 1 billion years.

Differences Between the Lunar Crater Chronologies

The new and old chronologies in blue and red (top), and the difference between them in terms of model surface age. (© S.J. Robbins)

There are a lot of implications for this. One is that volcanism on the terrestrial planets may have extended to more recent times. This would imply that the planets’ cores stayed warmer longer. Another implication is that the large reservoirs of water thought to exist around 3 billion years ago may have existed for another 500 million years, with implications then for favorable environments for life.

But, something that I added near the end of my LPSC talk was the question, “Am I right?” The answer is an unsatisfying, “I don’t know.” I of course would not have published it if I thought I was wrong. But by the same token, this type of science is not about one person being right and another being wrong. It’s about developing a model to fit the data and for that model to be successively improved as it gets incrementally closer to explaining reality.

And, there are ways to improve the lunar chronology. One that I’m a big advocate of is more lunar exploration: We need more data, more samples gathered from known locations on the moon’s surface. We can then date those samples – either in situ or in labs on Earth – and along with crater measurements add more tie points to the lunar crater chronology function. Right now, there is a glaring gap in the sample collection, one that spans 2 to 3 billion years of lunar history. A single point in there could help differentiate between my model and the classic model. And more data would be even better.

Until we land robotic missions to send back samples from other planets or that can date samples there, the moon is still our key to ages across the solar system.

April 16, 2015

Podcast Episode 130: Dealing with Pseudoscience at Scientific Conferences (and #LPSC2015)


The Iv’ry Tower
Of science: Who can get in,
And who remains out?

Second in the three-part series: Have you ever wondered how decisions are made about who can and who cannot present at a scientific conference? Then listen to this episode! I interviewed Dr. Dave Draper, who chairs the program selection committee for the largest annual planetary science conference in the world. We talked about a lot of things, from the basics on the (incredibly minimal) requirements of submitting a presentation request to how decisions are made. We also discussed a few hypotheticals using real-world examples of pseudoscience that I’ve talked about on the blog and podcast.

The episode, like most of my interviews have been, is nearly an hour long, but I found it an interesting discussion and learned some things, so hopefully you will, too. There were not other segments in this episode, though I did do a follow-up because of what happened to air on Coast to Coast that evening, a mere 12 hours after Dave and I had finished recording, and it led me to disagree with him at least a bit on one point.

The next episode is going to be a bit of a catch-up on things that have been piling up since I started the Hale-Bopp saga back in March. I’ll do a bit of pseudoscience with whether or not the lunar eclipse we had in April was really a full one – and implications for the “Blood Moon” crapola – a lot of feedback including discussion about some points raised by Pamela Gay in episode 130, and the Leonard Nimoy tribute.

February 1, 2015

Podcast Episode 125: The Black Hole Conspiracy


Black holes: Are these dense,
Massive objects for realz, or
Are they just Sci Fi?

This is a bit different from a straight-up old-school “debunking” episode where the emphasis is more on the process of science and process of elimination rather than solid, cannot-be-dismissed evidence for something. That’s because, by definition (we think), black holes cannot be directly observed. That’s why I use a part of a blog post by Mike Bara as a very rough outline to go through some of the theoretical reasons for why we think black holes exist and then some of the observational evidence from material interacting with the theoretical objects.

This episode continues the Logical Fallacies segment and introduces you to the Burden of Proof fallacy. Which is a tricky one. There are also some old stalwarts like Argument from incredulity, argument from ridicule, ad hominem, straw man, and argument from authority.

And, for the first time in what seems like a year, there’s Q&A!!!

I’m still doing my listening “research” for the Hale-Bopp episodes, which is looking like there’s so much material that I may turn it into a three-parter. We’ll see. Hard to say at this point. It’s slated to be the next episode, but I may have to postpone that if I haven’t finished listening in time, and I’ll do a different episode instead. I’m also trying to line up at least two future interviews, but given past experience, I’m loathe to announce them before they’re recorded.

April 24, 2013

Podcast #72: Solar System Mysteries “Solved” by PseudoScience, Part 1 – Iapetus


Exploding planets,
Alien spaceships … Why is
Iapetus weird?

The subject of this episode is Saturn’s moon, Iapetus, and two mysteries about it that various branches of pseudoscience have claimed to solve: the brightness dichotomy via an exploded planet, and the equatorial ridge via a spaceship.

This is the first of what I plan to be a series much like “The Fake Story of Planet X” series — different mysteries of the solar system that have a pseudoscientific explanation and may or may not have a real science (agreed upon) explanation. Let me know what you think of the concept. Future ideas for shows are the Pioneer Anomaly and Mars’ crustal dichotomy.

Otherwise, there’s a bit of feedback and then I get into the puzzler from last time and one announcement.

Well, I sorta snuck in a second announcement — I’m headed to Australia, December 18 – January 20. I’ll be centered in Melbourne (which I enjoy pronouncing as “Mel-born-EE”) for most of the trip though should make it up to Sydney (I wanna see the Great Barrier Reef!). So, dinner in each city if I can round up enough interest. I’m slowly learning that Australia is not just a 5-hr drive across, so I’m less likely to make it to the eastern half. We’ll see if I can increase my Australian listenership in the meantime to make a dinner here or there worth organizing.

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