Category Archives: Space

Definitions or traditions? The Pluto Paradox

If you’re old enough to be reading this blog, then when you were in school, there were nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus (giggle), Neptune, and Pluto.  Which means that in August 2006, you felt the sting of betrayal when the International Astronomical Union (IAU) decreed that our beloved little Pluto was no longer a planet.  I’m sure there are many groups out there still claiming that this is all a plot by the Common Core, the liberal media, President Obama, President Bush, the tea party, or the academic elite to ruin and confuse the education of our precious little cherubim one planet at a time.  There’s even at least one petition begging that Pluto’s planetary status be reinstated by the IAU (though if you sign it, you can’t read my blog anymore).

Petitions and nostalgia aside, the debate about Pluto’s planet-ness is complete – Pluto is not a planet.  Why not?  There are a few reasons, mostly to do with gravity.  Pluto has always been an outlier in the cadre of nine planets.  Really far away, and much, much, much smaller than the others.  But Pluto isn’t actually all that lonely.  It orbits as part of an area of space known as the Kuiper Belt.

Kuiper Belt orbit. Credit: Don Dixon, by way of Universe Today
Kuiper Belt orbit. Credit: Don Dixon, by way of Universe Today

The Kuiper Belt is similar to the asteroid belt int that it contains a lot of debris – condensed bodies of matter that orbit the Sun in a specified area of space – there are over 1000 known objects in the Kuiper Belt, and counting.  .  Up until 2003, Pluto was the largest known body in the Kuiper Belt, and therefore retained its tenuous grasp on planethood.

In 2003, however, astronomers discovered the existence of Eris, a Kuiper Belt object larger than Pluto.  This led to a quandary of definitions.  If we were to insist that Pluto remain a planet, then we would have to declare Eris to be a planet as well.  And any other objects of similar size in the Kuiper Belt, of which there could be many that we simply haven’t spotted yet.  If the IAU went that route, then we could jump from 9 to 100 planets, most of which would not fit the one of the important requirements of planethood, which is to be gravitationally dominate in a region of space.  So instead of creating that level of future confusion, astronomers created a new class of celestial body, dwarf planets, with Pluto and Eris as the first representatives.  1

And the official planet count dropped to 8.

Enter Planet X.  Planet X has long been theorized, mythologized, and subsequently scoffed at by the scientific community.  Konstantin Batygin and Mike Brown (coincidentally the man who discovered Eris and thus “Killed Pluto“) of the California Institute of Technology (Caltech) in Pasadena say that this time, things are different, because this time, “we’re right.”

Planet X is a mathematically theorized planet outside of the orbit of Neptune with an extremely long orbit, about 15,000 years (or if you’re a resident of Planet X, one year).    As we’ve seen in our discussion of gravitational waves, much in science that deals with extreme size or distance, large or small, is only mathematically theorized.  Black holes, the Higgs particle for a long time, much of quantum mechanics, are either currently or were until recently only mathematically theorized.  Planet X is similar in that no one has actually observed it directly.  Like observing black holes by observing the consumptive destruction, Brown and Katygin theorized planet X by observing the strange orbits of 6 objects that orbit past Neptune.  Essentially, their orbits bring them close to the same area of space with quite a bit of regularity, too regularly for coincidence to be a likely explanation.  There’s probably something large and gravitationally dominant out there, tugging on their orbits.  Something like a Planet.

Showing the Orbit of Planet X versus the known planets. Source: Caltech/R. Hurt (IPAC), by way of NPR
Showing the Orbit of Planet X versus the known planets. Source: Caltech/R. Hurt (IPAC), by way of NPR

So the fate of the Terran Family of Planets hangs in the balance once more.  If Planet X does exist, then we’re back up to 9, with the little Kuiper belt dwarf planets separating the old stalwarts from the new, lonely inclusion. Statistical certainty aside, changing the number of acknowledges planets in the solar system is a process, a process of definitions, as we saw already with Pluto.  Planet X will almost certainly not be added to school-curriculum until somebody actually gets a picture of it, which could take a very long time, given the amount of area needed to scan to find it.  But someday, we may jump back up to nine planets, just a different nine planets.

This saga of definitions intrigues me for what it says about science, and in particular how science changes.  It’s important to remember that Pluto wasn’t downgraded from planethood because science was wrong about Pluto, or because Pluto somehow ceased to exist, or became something other than what we thought it was.  Pluto is still the same size, Pluto is still in the same place, Pluto is still everything that we thought it was.  The fundamental data about Pluto never changed 2.  What changed was the context in which we understood the data about Pluto. What had to change was our definitions, the language that we use to describe it, based on new information as our knowledge of far-off things grew.  Likewise, Planet X does not change what we already know about the solar system – it just adds something new.  Obviously, there are scientific discoveries that fundamentally change everything – the structure of the atom, DNA, electricity, etc.  But there are other discoveries that simply require a reevaluation of our language, a shifting of definitions.  Tradition and nostalgia might cause us to instinctively rebel against these sorts of changes, because they seem on the surface to be unimportant.  Why couldn’t we call Pluto a planet, and Eris not a planet, especially in light of the fact that we’re well on our way to discovering a whole new planet!?  And I think the answer is that tradition and nostalgia can get in the way of accuracy and specificity.  Words have meanings because we agree that they have meanings, and sometimes it is important to change our agreed-upon meanings so that we can accurately represent the world as we understand it.  Even if that means saying goodbye to an old friend in the registry of planets.

Or saying hello to a new one.

Multimodal Gravitational Waves

Scientists as part of the LIGO Collaboration have made the first direct detection of gravitational waves, and black holes.  Up until now, both gravitational waves and black holes have existed largely in the realm of mathematics, starting with Einstein’s ideas of General Relativity.  Black holes could be observed indirectly by witnessing their consumptive, destructive effect on light-producing matter around them like stars, but because they don’t emit light of their own, they are all but impossible to see.  Gravitational waves have been even more invisible, because of just how faint they are.  But on the 14th of September, 2015, all that changed, and scientists at two facilities of the LIGO Collaboration, using a complex laser detection system, independently and near-simultaneously detected the gravitational waves of two black holes colliding a billion light years away.

The BBC has a fantastic group of articles explaining the discovery, the underlying science behind it, and why the discovery matters.  In a nutshell, gravitational waves are caused when objects with immense gravity, such as stars or black holes, suddenly have their gravity wells changed.  The disruption of space time sends ripples across the universe, much like tossing a rock into a pond.  Gravitational waves, once they get moving, are essentially unhindered by anything in their path – they pass through just about everything as if it weren’t even there.  This means that they can travel immense distances (a billion light-years, say), without degrading.  Scientists were finally able to detect them by using a laser system capable of measuring the minuscule fluctuations in space-time caused by these waves (less then the size of an atom). The discovery has finally confirmed the last piece of Einstein’s relativity, the mathematical framework upon which we understand much of the universe.

These articles, which all work together to make the information as accessible as possible, are rather rhetorically complex, and I thought it would be interesting to take a look at some of the ways that they are communicating this information.

The primary article from the BBC functions as one would expect – as an overview of what is happening.  It’s interesting that the BBC is working so hard to establish a certain ethos not for themselves, but rather for the discovery itself.  Multiple times throughout the article, they mention how this discovery is destined for a Nobel Prize in the same way that Luke Skywalker was destined to confront Vader.  Even if few people can name Nobel Prize winners in the sciences, everyone knows that Nobel Prizes mean big, important discoveries.  It’s worth noting, however, that this over-the-top Nobel shilling seems reminiscent of media pundits’ insistence that the upcoming presidential race would inevitably be Clinton and Bush – which is looking unlikely on the Republican side, and less of a landslide than expected on the Democratic.

To help establish ethical gravitas for their Nobel pick of the year, BBC also listed other discoveries that are on the same tier of importance – the discovery of the Higgs particle (though do people really know that one?), and the discovery of the structure of DNA (everyone knows that one – admit it, you immediately pictures the double helix with different colored rungs, didn’t you?).  They also have a separate page of “Reaction: Gravitation Wave Discovery“, with quotes from scientists you’ve never heard of about why this is so important.  Finally, they have the godfather of black holes himself, and arguably the single most recognizable scientist in the world, Dr. Stephen Hawking, featured both in the article and in his own video.  Even though he actually had nothing to do with the team that made the discovery.  The fact that Hawking is excited means that the rest of us should be excited too.

Very well.  I believe you, BBC – this is important, because all of these scientists say it is!  Well done.  However, I’m still confused.  Help?

Fortunately, BBC anticipated that as well, and has created a decently multi-modal experience to help explain what’s going on.  First and foremost, they’ve taken full advantage of one of the major affordances of web-based articles by creating multiple pages about different facets.  Rather than trying to explain everything in one large, clunky, difficult to understand article, they break it down.  The primary article has enough information that you can get it, but doesn’t go into huge detail.  Another article, which we’ve already talked about, showcases reactions.  Yet another article features anticipated questions that people might have about this discovery, with digestible answers that get into the more nitty gritty of the science.  They also have:

Unfortunately, this plethora of articles all about the same subject are only sort of connected, in the auto-generated “Related articles” section.  Only the primary article features links to all of the others – BBC missed an opportunity by not creating a dedicated landing page where all of this information could be accessed quickly and easily, without scrolling to the bottom of a several thousand word article.  Even with that said, however, the breadth and depth of the content that they’ve created around this discovery simply enhances the ethos of the discovery.  If the BBC is willing to spend this much time, money, and energy on these gravitational waves, then they must be important.

When Failure Counts

On January 18, 2016, SpaceX attempted once more to land their Falcon 9 rocket on a barge in the ocean.  The resulting failure was pretty spectacular (there were no people aboard, and no one was injured):

Throughout most of the history of SpaceX, Elon Musk has been quite public about his company’s many successes, and occasional misfires/spectacular explosions.  Let’s remember what the SpaceX team is trying to do – land a rocket that has flown to space and delivered a payload, in an effort to make rockets reusable, and thus bring down the cost of spaceflight.  Before SpaceX, this was something that had never been done before.  And prior to this attempted landing, SpaceX has succeeded several times, with varying levels of both precision and difficulty in the attempt.

No matter what, however, within days, Elon Musk releases the video of the attempt.  In the case of the failed landing and explosion video, he accompanied it with a simple, brief technical explanation of a possible cause:

“Falcon lands on droneship, but the lockout collet doesn’t latch on one the four legs, causing it to tip over post landing. Root cause may have been ice buildup due to condensation from heavy fog at liftoff.”

No attempt to make excuses, or assure anyone that this will never happen again, or cowtow to shareholders in the company.  What SpaceX is attempting to do is really, really, really hard, and explosive results are an inevitable part of that.  Can you imagine GM releasing that kind of statement if one of their brand new concept cars didn’t start at a car show?  Of course not – there would be apologies and finger-pointing and people would be fired.  Think back to the Obama administration’s investments in renewable energy companies a few years ago.  The companies that we remember are the ones that went bankrupt after the Department of Energy loan – Solyndra, Fisker, and Abound.  Companies who received the assistance defaulted on $780 million dollars – which is only a 2.28% default rate.  That means that over 97% of the loaned money was not defaulted on.  In fact, a few years later, and the government is turning an overall profit from those loans.  But still, the thing that we remember about that program, and the thing that many people judge that program on, are the few companies that did fail, the small percentage that did default.  This is demonstrative of a failure-adverse culture that is becoming prevalent.  Many teachers I think would recognize this in their students – top students are looking to be told what to do, how to get an A, rather than exploring and experiments and risking the possibility of failure.

However, failure is a major part of success.  Progress cannot be made without risk, and with risk comes not the potential, but the reality of failure.  Greatness and progress come when failure is overcome, as Elon Musk and the SpaceX team are doing.  While I can’t speak for Mr. Musk’s motivations in posting videos of failure, I can see a potential attempt to shift our thinking.  By sharing his failures publicly and with no apology, Mr. Musk is embracing his failures, learning from them – and helping us to learn along with them.  I sincerely hope that he continues this trend with all of his companies, and that other companies who could push the limits take comfort, and perhaps a bit of courage, in witnessing the failures of others, so that they can equally embrace and learn from their own.  After all, that’s how we progress as a society.

And besides.  When Elon Musk fails, it’s usually accompanied by a big explosion.  Which always makes for a fun video.