P is for Plant Defences

plant defences rising ape

By Jonathan Farrow of the Thoughtful Pharaoh

As the great glam metal band Poison sang in 1988, “Every Rose Has Its Thorn“.

Like so many glam metal bands to grace the world’s stages before them,¬†none of Poison’s members were botanists. If they were, they might have known that roses actually have prickles, not thorns.

It’s an easy enough mistake to make. ¬†But because I am a pedant at heart, I want Poison to know that, technically, thorns¬†are¬†modified branches, spines are modified leaves, and prickles are modified skin. That means roses have prickles. I therefore petition that the lyrics of the chorus of the song be changed from:

Every rose has its thorn
Just like every night has its dawn
Just like every cowboy sings his sad, sad song
Every rose has its thorn

to the more scientifically accurate:

Every rose has its prickle
Just like brine turns veggies to pickles
Just like every cowboy is really quite fickle
Every rose has its prickle

Thorn (modified branch) from a citrus plant.
Thorn (modified branch) from a citrus plant. Image by Edgovan22
Spines (modified leaves) from a Pereskia grandifolia (aka rose cactus) plant
Spines (modified leaves) from a Pereskia grandifolia (aka rose cactus) plant  Image by Frank Vincentz
Rose_Prickles
Prickles (modified skin) from a rose bush.  Image by JJ Harrison

But how did plants come to develop¬†all of these different ways to impale gardeners’ fingers in the first place?

To answer that question, let’s imagine a world without thorns, spines, or prickles. No toxins, sap, poisons, or deterrents of any kind. ¬†In a world like that, as long as there were herbivores, plants wouldn’t last long. ¬†They’d get eaten up pretty quick and getting eaten generally isn’t good for your reproductive health (with a few noticeable exceptions *cough* black widow spider¬†*cough*). ¬†So there’s a lot of evolutionary pressure on plants to develop ways to avoid becoming lunch.

Predation from salad-eaters¬†isn’t the only pressure on plants, though. ¬†They also need to compete with other plants around them by growing to capture more sunlight and they need to devote resources to reproducing. ¬†This is called the growth-differentiation balance. ¬†Plants, with limited resources, must choose between straightforward growth and developing specialized defences. ¬†If this theory is¬†true, we would expect plants that didn’t have to worry about getting eaten would be less thorny. ¬†In October 2014, an international team of researchers showed that in an herbivore-free zone, like the favourite hangouts of leopards on an African savanna,¬†non-thorny plants thrive, whereas the thorny plants do best in the favourite hangouts of salad-eating impalas.

Salad-eaters (aka herbivores) don’t just take an evolutionary backseat to this escalation¬†of plant defences. ¬†Ever since the first animals¬†started emerging from the sea and started choosing¬†salad, plants have been trying¬†to send them back and animals have kept coming. ¬†It’s an evolutionary arms race.

And if the Cold War taught us anything, its that arms races lead to some pretty ridiculous specializations.  Here are a few of my favourites on the plant side of things:

Sorcerer Corn

Behold! Sorcerer Corn!  Image by Silverije
Behold! Sorcerer Corn! Image by Silverije

It looks like regular corn. ¬†And that’s because it is.

Regular corn seedlings, when exposed to a chemical in the saliva of beet armyworms, will release a chemical that summons a cloud (or, less dramatically, attracts) parasitoid wasps which will lay eggs inside of the armyworms.  These eggs will hatch after two days and eat their way through the armyworm from inside out.

Corn isn’t the only plant that releases signals like¬†this. ¬†In fact, you know the smell of freshly-cut grass? ¬†That turns out to be the plant equivalent of¬†screaming out to any relatives in the area to “GET READY! THERE’S SOMETHING THAT WILL HURT YOU NEARBY!”

Flinching Flowers

We normally think of plants as stationary things, unable to move.  This is usually true, but there are some plants which have the ability to quickly shut their flowers or droop on contact.  The most famous example of this is the Venus Flytrap, but that is more of an offensive flinch.

Image by Mnolf
Image by Mnolf

Mimosa pudica, or the sensitive plant, also has this flinching (thigmonastic) ability.  When touched, this species will close its flowers and fold away its leaves, thus decreasing its surface area and making it harder to see and eat.

I'm just going to fold away now...
I’m just going to fold away now… ¬†Image by Hrushikesh

Whether its by developing thorns, spines, prickles, the ability to fold up, or the ability to call helpful predators, plants have not been idle in the fight against salad-eaters. ¬†Every rose has its¬†prickles (not thorns!)¬†because of this ancient struggle and while they may be annoying, I guess we should be happy roses¬†haven’t evolved to attract parasitoid bears that will leave cubs inside of our stomachs to gnaw their way out over the course of a week.

Yet.

O is for Ocean Acidification

By Jonathan Farrow from the Thoughtful Pharaoh

We all know that CO2¬†emissions are warming the planet. ¬†Or at least,¬†most of us¬†do. ¬†What often goes unreported is the effect of carbon dioxide on the worlds’ oceans. ¬†A lot of the CO2¬† that we pump into the air makes its way to the water and is making it more and more difficult for shelled creatures like sea urchins, lobsters, and coral to survive.

Lobster
This is Bob the lobster. This is his “I’m sad because of the increased levels of anthropogenic carbon dioxide that are making my life harder” face. ¬†Image by Pedrosanch

In order to understand why this happens, we need to go back to secondary school chemistry.

Don’t worry, I’ll make sure Jared doesn’t pick on you.

Jared
No Jared! No!     Image public domain

The first lesson we need to recall is about acids.  What is an acid?

Something that bubbles in a flask?  Image by Joe Sullivan
Something that bubbles in a flask? Image by Joe Sullivan

Acids are compounds that have free hydrogen ions floating around. ¬†These hydrogen atoms are quite reactive, so it means the more free hydrogen you have floating around, the more reactive your compound. Acidity is usually measured in pH, which stands for the “power of hydrogen”. ¬†pH is measured on a scale (creatively named the “pH scale”) that ranges from 0 to 14.

Compounds that get a 0 on the scale are exceedingly acidic, meaning they are made up of pretty much just free-floating Hydrogen ions. Compounds that rate 7 are perfectly neutral, like distilled water. Compounds on the other end, near 14, are called “basic” or “alkaline” and instead of having lots of hydrogen ions to give away, they have all sorts of space for hydrogen atoms. ¬†This makes them reactive because they can strip hydrogen from things that don’t usually want to give it away (like Edward Norton’s hand in Fight Club).

The other confusing bit to remember is that the pH scale is logarithmic, meaning that each number you jump actually indicates a multiplication by 10. For example, something with pH 3 (like soda) is 100 times more acidic than something with pH 5 (like coffee).  This means if a large body of water (like the ocean) shifts by even a small pH number, the effect can be very large.

Image by OpenStaxCollege
Image by OpenStaxCollege

The second lesson we need to recall is about equilibrium.

In chemistry, everything tends towards balance. If you combine equally strong acids and bases, they will react together until the result has a pH that is in between.  You might also get a volcano-themed science fair demonstration.

When CO2 combines with water (H2O), they form carbonic acid (H2CO3).  The carbonic acid will break up (dissociate) into bicarbonate (HCO3) and a hydrogen ion (H+).  In a basic environment, the bicarbonate will dissociate further into carbonate (CO32-) and the result will be two hydrogen ions (2H+).

We can visualize this path with a chemical equation:

H2CO3¬† —- ¬† H+ + HCO3– ¬†¬†—- ¬† 2H+ + CO32-

Where this path stops depends on the environment it is in.  In an acidic environment, the balance will tend towards the left, with more hydrogen bound up with the carbonate (because there is no space in the solution for more free hydrogen).  In a basic environment, the balance will tip to the right, releasing more hydrogen and freeing up the carbonate.

Currently, the pH of the ocean sits at about 8.1 (slightly alkaline). ¬†Because of this, there is plenty of carbonate available for creepy-crawly-shellfish to use to build their homes. ¬†Crustaceans and corals combine the free carbonate with calcium to form calcium carbonate (aka limestone, chalk, and Tums). They can’t use bicarbonate (HCO3) or carbonic acid¬†(H2CO3) and find it hard to form anything at all in an acidic environment.

This means that as we add CO2 to the water, we create more carbonic acid and contribute to the acidity of the ocean, dropping its pH.  Not only does this make it hard for the little guys down there trying to make a living, but it also endangers the big chompers that eat the little guys.

The ultimate big chomper.  This is what happens when you jokingly search for
The ultimate big chomper. This is what happens when you jokingly search for “chomper” on wikimedia.

A recent review¬†found that even under the most optimistic emissions scenario, the ocean’s pH is likely to drop to 7.95, affecting 7-12% of marine species that build shells. Under a high emissions scenario, the pH will go down to 7.8, affecting 21-32% of those species.

In order to keep track of the progress of this acidification, researchers from Exeter have proposed using satellites to monitor hard-to-reach bits of the ocean.

Regardless of the pace of the change, scientists agree one thing is certain: the oceans will become less hospitable for shell-builders.  The superficial impact of this for humans will be rising prices on shellfish, but there will be much deeper ramifications throughout marine ecosystems.

And I think we all know who is to blame.

Jared

Thanks Jared.

N is for Naming

By Jonathan Farrow of the Thoughtful Pharaoh

Next time you happen to be walking though the Chamela-Cuixmala nature reserve on the West Coast of Mexico, keep your eyes out for this parasitoid wasp:

Image from a paper by Alejandro Zaldívar-Riverón, Juan José Martínez, Fadia Sara Ceccarelli, and Scott R. Shaw
Image from a paper by Alejandro Zaldívar-Riverón, Juan José Martínez, Fadia Sara Ceccarelli, and Scott R. Shaw

Its scientific name is Heerz lukenatcha.  There is also a related wasp named Heerz tooya.  Who comes up with these things!?

Biologists, it turns out.

The current official naming system for animals is run by the International Commission on Zoological Nomenclature (ICZN).  This multi-national commission, based at the Natural History Museum in London, keeps track of all the rules as well as the accepted names.

[There are also separate codes for other types of organisms  Рsee this wikipedia page for a list of the codes and prepare to go down an Oryctolagus cuniculus hole]

Generally, the first person to find an organism, make sure it hasn’t been named yet, and submit a scientific paper naming it, will get to choose a name. ¬†While there is quite a bit of freedom, the ICZN does provide the following guidance: “Authors should exercise reasonable care and consideration in forming new names to ensure that they are chosen with their subsequent users in mind and that, as far as possible, they are appropriate, compact, euphonious, memorable, and do not cause offence.”

That guidance does get stretched sometimes…

Appropriate?

During a 1980 entomological expedition to the Andes, one member of the team kept shouting “sh*t man, f*ck!” every time something went wrong. ¬†I guess a lot of things went wrong, because before long the whole team started calling the expedition the SMF Expedition. ¬†When a new genus¬†of beetle was discovered, they named it Esemephe (pronounced SMF). ¬†They justified it to the ICZN by saying that it was a melding of the greek words essymenos (hurrying) and ephestris (mantle), but everyone else knew it was really a reference to SMF.

Not so compact, euphonious, or memorable

The longest accepted scientific name is Parastratiosphecomyia stratiosphecomyioides, a species of fly.  At 42 characters, its only three short of pneumonoultramicroscopicsilicovolcanoconiosis, the longest word in the English dictionary.

Straight up offensive

Some names were actually designed to be offensive.  Two paleontologists, Cope and Marsh, basically had a naming war at the end of the 19th century. Marsh seemingly struck the first blow, submitting Mosasaurus copeanus (-anus is a greek suffix meaning ringed).  Later, Cope named an extinct mammal Anisonchus cophater for all of his haters.  I guess he just wanted to shake it off.

This trend was repeated in the 20’s with swedes Elsa Warburg and Orvar Isberg. In 1925, Warburg named a trilobite¬†Isbergia planifrons,¬†after Isberg’s apparently flat forehead (an insult in Scandanavia). ¬†In 1934, Isberg retaliated with a mussel he named¬†Warburgia crassa,¬†after Warburg’s girth (crassa=fat).

Just funny

Sometimes, biologists just feel silly.  Here are a few of my favourite scientific names, as a reminder that scientists can be funny.

There is a genus of fungus beetles called Gelae.  The species names are baen, belae, donut, fish, and rol.  Put those together and you get a whole bunch of tasty treats!  There is another genus of beetle called Agra, and one biologist in particular, Terry Erwin, has had a lot of fun over the years with some punny species names like cadabra, memnon, and vation.

Sometimes biologists go for the celebrity names, like a beetle named Scaptia beyonceae for the yellow fur on its behind or a fossil fly named Carmenelectra shechisme (pronounced Carmen Electra, She Kiss Me).  In 2013, Carmenelectra shehuggme was also added.

Other times, taxonomists like to make you read it a few times, like a moth named Eubetia bigaulae or a scarab in a large family named Cyclocephala nodanotherwon.

For hundreds of more interesting biological names, visit curioustaxonomy.net

M is for (exo)Moons

By Jonathan Farrow of the Thoughtful Pharaoh

With this post, rising-ape.com is now caught up with my website, thoughfulpharaoh.  From now on, I will be posting articles simultaneously on both sites, on Wednesdays.

Thanks to everyone for following along and as always, if there is a topic you have in mind, don’t hesitate to leave a comment below.

And now for this week’s article: exomoons.

There are 8 planets in our Solar System (sorry Pluto). ¬†Most of these planets have companions that follow them around, like obedient pets and criminal records. ¬†The total count of these moons is 181. ¬†We are all quite familiar with the big shiny one that orbits Earth (that may or may not be made of cheese), but what many people don’t know is the sheer number of¬†other¬†moons that exist in our Solar system.

Just like planets, these moons come in all different shapes and sizes. ¬†S/2009 S1 is only 400m across and orbits in one of Saturn’s rings, making it the very smallest moon. ¬†Ganymede, the solar system’s largest moon, measures in at about 5300km across, almost half the size of earth.

One of the biggest findings to come from¬†the Kepler mission is that most of the stars in the galaxy have planets. ¬†In other words, our solar system isn’t unique. ¬†That means our Solar System probably isn’t the only whose planets have moons. ¬†If our system, with 22 times more moons than planets, is any indication, there are a lot of moons to find.

This presents two immediate problems: firstly, why should we want to find them?  Secondly, how do we go about finding them?

Why find an exomoon?

The same thing that makes seawater rise and fall twice a day, tidal forces, can heat up a moon.  Tides are a result of the fact that the strength of the force of gravity is related to the distance between two objects.  On Earth, the water on the side close to the moon gets pulled out towards the moon stronger than the water on the other side, this creates bulges of water that move around as the earth spins: tides.

Tides stretch.  Image by Krishnavedala
Tides stretch. Image by Krishnavedala

The Earth is too small and our moon is too far away for much more than sea level change to happen, but Io, one of Jupiter’s moons, has over 400 active volcanoes¬†caused by extreme tides from the gravity of its host planet Jupiter. In this case, it’s not just bulges of water that are created, but bulges in the crust of the moon itself. ¬†This creates an immense amount of friction and heat.¬†Europa, another moon of Jupiter, gets enough energy to keep a planet-wide ocean of water liquid¬†under its icy crust. ¬†Some people think Europa might be habitable, even though it is so far away from the Sun.

If there are moons here in our Solar System that can be habitable at Jupiter-like distances,¬†there could be moons in other systems that orbit planets much closer, at Earth- or Mars-like distances. ¬†Some people, like Rene Heller at¬†McMaster University’s Origins Institute (a fine institution, if I do say so mystelf *full disclosure: I did my undergrad¬†there*), think exomoons might be our best shot for finding habitable places in the galaxy simply because of their abundance relative to planets (remember, there are 22 times more moons in our system than planets).

How to find an exomoon

This is the tricky part. ¬†It was hard enough finding exoplanets. Finding a transiting exoplanet is often compared to looking for the effect of a mosquito passing in front of a car’s headlight. ¬†In that analogy, finding an exomoon would be like finding out how many legs it has. ¬†No easy task.

It’s not impossible, though. ¬†Moons do have effects on their planets and if we look carefully enough, we can find them.

One way to find exomoons in transit data takes advantage of the fact that, viewed edge-on, a moon will appear more often at the edges of its orbit.

ExoMoonTransit
Image by Rene Heller

If you capture many transits over time, you can begin to see these wingtips in the transit data.

Image by Rene Heller
Image by Rene Heller

The grayscale bar in the image above represents the average effect of a moon orbiting a planet.  What astronomers can look for in the transit data is a preliminary dip (1) that starts off severe then levels off, followed by the regular planetary transit (2), followed by another characteristic dip (3) as the other wingtip passes in front of the star.

This method only works if you have a lot of data, but luckily Kepler was operational for four years and gathered just the right kind of data.

So now the search will begin. ¬†Who will find the first exomoon? ¬†And what if it turns out to be “no moon” at all?

An artist's impresison of a view from an exomoon with a triple star system.  Far out, dude.  Image by NASA/JPL-Caltech
An artist’s impresison of a view from an exomoon with a triple star system. Far out, dude. Image by NASA/JPL-Caltech

L is for Loch Ness

By Jonathan Farrow from The Thoughtful Pharaoh

Loch Ness, in the middle of the Scottish Highlands, has more fresh water in it than all the lakes and rivers in England and Wales combined.  It is neither the deepest lake in Britain nor the largest by surface area, but since it comes a close second in both categories, it claims the top spot for volume.  The loch is home to eels, salmon, and char and its shores support a healthy population of deer and waterfowl.  The area has historical significance as well, with Urquhart castle being instrumental in the war of Scottish independence.

Loch Ness, in all of its Google Map glory.  Not pictured: the monster.
Loch Ness, in all of its Google Map glory. Not pictured: the monster.

Despite all of this, when people read or hear “Loch Ness”, the next word they think of is almost always “monster”. ¬†This is a shame, because sadly, Nessie does not exist.

We know this for sure. ¬†There have been numerous, comprehensive reviews of the ‘evidence’ and a recent sonar survey of the entire loch failed to turn up anything even close to a giant sea monster. ¬†If Nessie is supposed to be a plesiosaur, you might think a population of giant, carnivorous sea creatures that somehow survived extinction and has been living in the same lake for 65 million years would make more of an impact on people in the region. ¬†There would be lots of stories about sea monsters, and old ones too. ¬†There aren’t really any credible mentions of this monster until the 1930s. ¬†No songs, folk tales, or myths, despite the area¬†being populated for thousands of years.

Not a sea monster, 1934.  Photo by Robert Wilson, published in the Daily Mail
Not a sea monster, 1934. Photo by Robert Wilson, published in the Daily Mail
Also not a sea monster, 1977.  Photo by Anthony Shiels
Also not a sea monster, 1977. Photo by Anthony Shiels
Still not a sea monster, 2012.  Photo by George Edwards
Still not a sea monster, 2012. Photo by George Edwards

My favourite little tidbit from my reading into the series of Nessie¬†hoax photographs is a photo of a supposed flipper which was used to name a new species in¬†Nature¬†in 1975. ¬†The scientific name of the Loch Ness Monster, according to Profs. Peter Scott and Robert Rines, is¬†Nessiteras rhombopteryx. ¬†I leave it up to the reader to decide if it is a coincidence that the name is an anagram for “monster hoax by Sir Peter S”.

The 1972 'flippers' in question.  Hard to see much at all, I think. Photo by Academy of Applied Science/Loch Ness Investigation Bureau
The 1972 ‘flippers’ in question. Hard to see much at all, I think. Photo by Academy of Applied Science/Loch Ness Investigation Bureau

While it is undoubtedly good fun to trash pseudoscience, the focus on the monsters of Loch Ness (or lack thereof) takes attention away from what I think is much more interesting: Loch Ness is part of the very same geological feature as the fjords in Norway, the hills in Newfoundland, the Gulf of St. Lawrence, and the Appalachian mountains in the southern USA.

Loch Ness is part of the Great Glen Fault, a crack in the Earth’s crust that runs in a straight line across Scotland, through the Irish Sea, and into Northern Ireland. ¬†This crack is very old, pre-dating even Pangea.

When two pieces of the Earth's crust slide against each other like this, it is called a transcurrent, or strike-slip, fault.  Image by Hellinterface
When two pieces of the Earth’s crust slide against each other like this, it is called a transcurrent, or strike-slip, fault. Image by Hellinterface

In fact, the process that brought the continents together into¬†the supercontinent of Pangea is the very same one that created mountains along this fault line. ¬†Back in those days, over 400 million years ago, the Atlantic ocean didn’t exist. ¬†As the plates of Baltica (modern-day Scandinavia and North-Eastern Europe) collided with Laurentia (modern-day North America and Greenland) and the small microcontinent of Avalonia (modern-day England, Wales, and parts of Northern France), bits of the crust were pushed up. ¬†This formed mountains.

As the plates collided, the highlighted area became raised.  The grey lines in this image are the current coastlines.  Image by Woudloper.
As the plates collided, the highlighted area became raised. The grey lines in this image are the current coastlines. Image by Woudloper.

Over time, the plates continued to move, and the Mid-Atlantic Ridge pushed Europe and North America apart, forming the Atlantic Ocean.  While Laurentia and Baltica are still around as the bases of the North American and Eurasian Plates, Avalonia was essentially spread to the winds.

Avalonia definitely got the roughest deal out of the three colliding plates. Image by Woudloper
Avalonia definitely got the roughest deal out of the three colliding plates.
Image by Woudloper

This is why, if you walk the Highlands of Scotland or the Appalachians, you will find the same rock types.  They were born in the same place in the same way, and have become separated by an ocean.

Loch Ness is an incredibly poignant way to visualize this separation because, just by looking at a map, you can see a crack in the earth.  If you look at the Northeastern part of Newfoundland, you can see the same crack with the same angle.

[For another explanation of this 400 million year old connection, watch this video by Tom Scott.]

Loch Ness is a wonderful place, not only for its natural beauty, but also for its geology. ¬†So do go visit, but don’t expect to find a monster.

K is for Kepler

“Truth is the daughter of time, and I feel no shame in being her midwife.”¬†Johannes Kepler

These words, written by Johannes Kepler in 1611, are profound.  At the time, Galileo had just discovered the Galilean moons (including Europa) in Florence but was being persecuted for his belief that the Earth orbits the sun.  Kepler, a staunch supporter of heliocentrism, was working as the Imperial Mathematician in Prague.  When word that Galileo had used a telescope to find the moons reached Kepler, he was so fascinated and impressed that he wrote an enthusiastic letter of support and scrawled that pithy aphorism.

While Kepler enjoyed some social status as Imperial Mathematician and was much more free to contradict Aristotle¬†than his Italian counterparts, his life was by no means a charmed one. ¬†The son of “an immoral, rough and quarrelsome soldier” (his own words), Kepler managed to carve himself a place in history¬†based on his skill as a mathematician and astronomer. ¬†He kept on working through many family disasters, including the deaths of his wife and his seven year old son and a witch trial about his mother.

Kepler was a devout Christian and grew up Lutheran but was excommunicated due to his rejection of the Augsburg Confession.  This left him neither a Lutheran nor a Catholic and between sides when the Thirty Years War broke out in 1618.

You've got to love that frilly collar.  Just like Shakespeare!  Actually, come to think of it, Kepler actually lived at the exact same time as Shakespeare.  I wonder if they ever met and what they might say to each other at a dinner party.  Image is public domain.
You’ve got to love that frilly collar. Just like Shakespeare! Actually, come to think of it, Kepler lived at the same time as Shakespeare. I wonder if they ever met and what they might say to each other at a dinner party. Image is public domain.

Despite all of this, Kepler revolutionized astronomy by formulating mathematical laws that accurately describe the motions of the planets. ¬†These are still taught in astronomy today and are called Kepler’s Laws.

The first law is that planets orbit in ellipses with the sun at one focus.  Before Kepler, most Western astronomers modelled the orbits of planets as circles and had to invoke a strange concepts like epicycles and equant points.

1. Planets orbit in ellipses, not circles.
1. Planets orbit in ellipses, not circles.  Image my own

The second law is that a line between a planet and a star will sweep out equal area in equal time. In other words, planets move faster when they are closer to their star and slower when they are further away.  This law is better understood with a diagram:

asd
2. Planets don’t have constant speed ¬†Image by RJHall

The third law, formulated after the first two, is that the time it takes a planet to make an orbit (orbital period) is directly proportional to its distance from the star.  This law allows astronomers to calculate how far a planet is from its star based only on information about the length of its year and the mass of the star.  Remember this one, because it will become important later.

As you can see, Kepler’s Laws are fundamental to our understanding of how planets move, or orbital dynamics. ¬†It will come as no surprise then that every young astronomer is all too familiar with Kepler’s laws. ¬†This isn’t the only reason he’s familiar though. ¬†He is also shares a name with the most successful exoplanet hunter the world has ever produced. ¬†The Kepler Space Telescope.

Kepler: Planet Hunter is kind of Like Abraham Lincoln: Vampire Hunter.  Except more real.  And frankly, a little more impressive.    Image by Wendy Stenzel at NASA
Kepler: Planet Hunter is kind of like Abraham Lincoln: Vampire Hunter. Except more real. And frankly, a little more impressive. Image by Wendy Stenzel at NASA

Launched in 2009, the Kepler Space Telescope used 42 image sensors to continuously observe over 145,000 stars. ¬†Unlike a lot of other telescopes that try to take magnified images, Kepler wasn’t interested in images. ¬†It wanted accurate data on brightness. ¬†It basically had a staring contest with these 145,000+ stars, waiting for them to blink. ¬†I say blink because Kepler was waiting for the brightness to go down and back up. ¬†The brightness of stars can vary for all sorts of reasons, but planets passing in front of their stars make the brightness dip in a particular way. ¬†This dip is called a transit and finding transits¬†was Kepler’s mission.

When a transit occurs, the size of the brightness dip corresponds to the size of the planet and the length of the dip corresponds to the time it takes a planet to orbit (as well as the size of the star). ¬†Remembering Kepler’s third law,¬†¬†if we know the time it takes to orbit, we can figure out the distance to the star. ¬†And if we know the brightness of a star and the distance, we can figure out how much energy¬†the planet receives. ¬†Plug all that in to a¬†simple(ish)¬†equation, and out pops temperature.

Stars, just like planets and people, come in all different shapes and sizes.  That means light curves also vary widely.   Image from Planethunters.org
Stars, just like planets and people, come in all different shapes and sizes. That means light curves also vary widely. Image from Planethunters.org, a great citizen science project that combines people’s natural pattern-finding ability with Kepler data to find planets.

So thanks to the Keplers (both Johannes and the Space Telescope) we can start to look for alien worlds that have temperatures similar to the ones we find here.  The hope is that one day we will find evidence of life on another planet.  And then we can begin our transition into any one of several sci-fi galactic civilizations (my personal favourite is Foundation, but some people prefer Star Wars, Star Trek, or Eve Online).

Unfortunately, in May 2013 one of the components that kept Kepler (the telescope) stable failed, meaning the mission was apparently over.  The mission had been hugely successful, discovering over 1000 confirmed planets, with 4000 other planet candidates waiting to be confirmed.  It turns out that most stars probably have planets and that a lot of planets in the galaxy might be the right temperature to be habitable.

Astronomers are nothing if not persistent though, so an ingenious method was devised to make sure Kepler can continue observing even without its stabilizer.  This new mission, dubbed K2, uses the radiation pressure from the sun itself to balance the telescope.  Instead of continuously observing the same 145 000 stars, K2s targets will change periodically as it orbits the sun.  There will be far less data coming down, but as of this writing four new planets have already been found since K2 began in earnest in June 2014.

There's a lot of information there, but I think the most impressive bit is that K2 is metaphorically balancing a pencil on a fingertip, remotely, from 150 million km away.  Image by NASA
There’s a lot of information there, but I think the most impressive bit is that K2 is metaphorically balancing a pencil on a fingertip, remotely, from 150 million km away. Image by NASA

Currently, while there are all sorts of really interesting exoplanets out there (from hot jupiters like 51 peg b to mirror earths like Kepler-438b), we have yet to find signs of life.  But I think that before too long, we will.  Just as the truth of heliocentrism eventually came out thanks to Kepler, a telescope with his name will be instrumental in uncovering the truth of life elsewhere in the universe.  Just like he said,

“Truth is the daughter of time, and I¬†feel no shame in being her midwife” Johannes Kepler

J is for Jupiter’s Great Red Spot

By Jonathan Farrow from the Thoughtful Pharaoh

If you look up in the night’s sky and point even a simple pair of binoculars at Jupiter, like Galileo did with a rudimentary telescope 405 years ago, you will see what he did: a reddish-pink planet with swirling masses of clouds. These clouds are beautiful in their own right, but there is one particular feature that has drawn the eyes and the fascination of people for over four centuries. The Great Red Spot.

This swirling, gurgling red super-storm could fit three earths inside of it and has been raging on the gas giant ever since we’ve been keeping records. How it has lasted for so long and why it has such a different colour has long been a mystery.

In 2000, on the way to Saturn, an ESA mission called Cassini aimed to give us some clues when it flew within 9.7 million kilometres of Jupiter and looked more closely at the spot than we had ever done before or since. 9.7 million kilometres sounds like a lot, but consider that is only about 1% of the distance between Jupiter and Saturn. (As a side note, did you know that Jupiter and Saturn are further away from each other than Jupiter and Earth? I didn’t!).

It might have looked kind of like this, but with Jupiter instead of Saturn in the background.  Cassini's main mission was to Saturn and its moons.
It might have looked kind of like this, but with Jupiter instead of Saturn in the background. Cassini’s main mission was to study Saturn and its moons. ¬†Image by NASA

With its flyby, Cassini found out that the clouds that form the spot are up to eight kilometres higher than the surrounding clouds and started to understand the chemical composition of the clouds.

14 years later, in November 2014, NASA scientists released results that combine data from the Cassini flyby with lab experiments on Earth. They showed that the colour must come from the interaction of ultraviolet (UV) light from the sun and the ammonia and acetylene in the top layers of the storm. Once the red particles are produced, they are trapped by the circular winds of the storm. This overturns the previous theory that it was the bottom clouds which provided the colour. The NASA scientists compare the colour of the storm to a sunburn rather than a blush.

So, thanks to NASA and the Cassini mission, we have a better idea about how the spot gets its colour, but last spring the astronomy world was in a tizzy because news came that the spot has been shrinking.

That's some pretty serious shrinkage!
That’s some pretty serious shrinkage! ¬†Image by NASA

Since it is so noticeable, the storm has been recorded as far back as the 1800s, when it was believed to be about 41000 km across (roughly equal to the circumference of Earth).  The most recent image, from 2014, puts the size at only 16500 km (less than the length of the great wall of China).  Not only is it much smaller than it used to be, but the rate of shrinkage is increasing.

Totally, 100% peer-reviewed, recollection of secondary school math to figure out when the spot will disappear.
Totally 100% peer-reviewed recollection of secondary school math to figure out when the spot will disappear.  Image my own

If my calculations are correct, and if the storm keeps shrinking the way it has been, it will disappear entirely in about 35 years, in 2059.  That means we may be among the last people to ever see the spot that Galileo spied on that fateful night in 1610.

Instead of relying on me and my calculations, however, NASA sent a spacecraft to go investigate.  Juno left in 2011 and by now is more than halfway to its destination. When it arrives in July 2016, Juno will study the gas giant in a variety of ways and hopefully get the bottom of this whole shrinking storm mystery.

JUNO
Image by NASA

I is for Island Evolution

By Jonathan Farrow from The Thoughtful Pharaoh

Unbeknownst to the rest of us, a debate has been raging in the world of biogeography.¬†¬†The debate stems from a simple observation made by a young Canadian scientist in 1964: island animals are weird. ¬†Sometimes they’re way bigger than normal, like the Tenerife Giant Rat, and other times they are way smaller than normal, like the Elephas falconeri, a tiny species of elephant.

A Rodent of Unusual Size, the (now extinct) Tenerife Giant Rat.  Image by Wikimedia user M0rph
A Rodent Of Unusual Size, the (now extinct) Tenerife Giant Rat. It reached sizes of up to 1.14m  Image by Wikimedia user M0rph
Elephas_skeleton
An itty-bitty extinct elephant thought to have weighed only 200kg. Image by Ninjatacoshell at the North American Musueum of Ancient Life

J.B. Foster published a short, two-page paper in the April 1964 edition of Nature positing that rodents get bigger and lapidomorphs (rabbits), carnivores, and artiodactyls (deer/goats) get smaller on islands.  This, he thought, was because small animals found the isolation of islands to be liberating.  They no longer had to worry about predators and could grow to fill their new space.  Larger animals, however, might be restricted by the relative paucity of resources on islands and would have immense evolutionary pressure to become smaller.

This led to Foster’s Rule, also known as the Island Rule. ¬†It states that in general, big animals get small on islands and small animals get big. ¬†They also do so very quickly (in evolutionary terms). ¬†For instance, red deer on Jersey, an island in the English Channel, were shown to have shrunk to to 1/6th their original size in only 6000 years.

There’s a problem, though. ¬†Like pretty much every rule in biology, there are lots of exceptions. ¬†Sometimes small animals get smaller (like Brookesia micra, the world’s tiniest chameleon) and relatively big animals get bigger (like Haast’s eagles).

So cute, right!?  Image by Frank Glaw, Jörn Köhler, Ted M. Townsend, Miguel Vences
You’ve heard of angels on the head of pin, but what about chameleons on the head of a match. So cute, right!? Image by Frank Glaw, J√∂rn K√∂hler, Ted M. Townsend, Miguel Vences
The giant, moa-hunting Haast's Eagle of New Zealand.  Almost as scary as terror birds.
The giant, moa-hunting Haast’s Eagle of New Zealand. Almost as scary as terror birds. ¬†Image by John Megahan

A 2011¬†article by a joint Israeli-Italian-British team of researchers calls the whole theory into question, showing that the smallest species in any given group is no more likely to be from an island than would be expected by chance. Size extremes, they say, exist everywhere. ¬†Islands don’t have some sort of monopoly. ¬†They do concede that large mammals tend to get smaller, but they think the idea that small animals get bigger only seems like common sense because they are easier to notice.

A British paper from 2008 throws even more confusion into the mix, showing that depending on the kinds of statistical tests you use, you can show that the island rule either exists or doesn’t. ¬†They suggest that the island rule should be looked at¬†in “taxonomically restricted studies” – biologist-speak for “case-by-case basis”. ¬†That seems to kind of defeat the purpose of a nice heuristic, though.

One thing we know for sure is that islands isolate organisms.  This isolation means that evolution can work differently for the island population and might lead to all sorts of interesting changes.  This type of evolutionary change is also called allopatric speciation and is responsible for the variation that Darwin saw in Galapagos finches.  Whether islands always create a particular kind of change is still up for discussion, but nobody can doubt that when organisms of unusual size appear, they deserve attention.

Darwin's famous finches.  He observed that some beaks were better suited for cracking seeds and others for tearing fruit.
Darwin’s famous finches. ¬†Image from The Voyage of the Beagle

H is for Helium

By Jonathan Farrow from The Thoughtful Pharaoh

Say goodbye to¬†foil¬†floating hearts on Valentines, shimmering floating shamrocks on St. Patty’s, and the prospect of tying thousands of balloons to your house and abducting a neighbourhood boy scout. ¬†The world’s Helium reserve is going to run out, and sooner than you might think.

Sorry Carl, but I'm not sure your pension is enough to pay for the 1.5 million cubic feet of helium required to lift your house and the abducted boy scout. Image by Walt Disney Pictures
Sorry Carl, but I’m not sure your pension is enough to pay for the 1.5 million cubic feet of helium required to lift your house and the abducted boy scout. Image by Walt Disney Pictures

Helium is the universe’s second most abundant element and we’ve never had real cause to worry about it before, so what has changed that we need to start hoarding Helium? ¬†The short answer: the U.S. is selling off their strategic reserve and getting out of the Helium game, meaning prices are going to skyrocket as demand outstrips supply.

The longer answer begins with the fact that Helium has always been a non-renewable resource here on Earth. ¬†It is produced underground¬†by radioactive materials like Uranium and Thorium and then floats up into the atmosphere and out into space unless it gets trapped by natural gas in the Earth’s crust. Once the radioactive materials decay and release Helium, there is no putting it back.

Sometimes an alpha particle (aka Helium nucleus) just needs to spread its wings and fly!
Sometimes an alpha particle (aka Helium nucleus) just needs to spread its wings and fly!

When we extract this gas, we can collect the Helium and use it to fill party balloons, make our voices squeaky, pack fuel into rockets, or cool superconducting electromagnets to four degrees above absolute zero (-269C).

Why might we want to do that last one when the first three¬†are so much fun, you might ask? ¬†Magnetic Resonance Imaging (MRI) machines, the Large Hadron Collider (LHC), and other scientific Three Letter Initialisms (TLI)¬†have advanced our understanding of the human body and its diseases, the universe and its composition, and have contributed to widespread confusion over the difference between “acronym” and “initialism”.

MRIs and the LHC capitalize on the unique properties of Helium: it is inert and has the lowest boiling point of any element, allowing it to bring the temperature of metals down enough to make them superconducting.  These more scientific uses of the substance have ballooned (pun kind of intended) in the past two decades, putting real pressure on producers.

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One of the reasons why Helium demand is increasing and this awesome research about the sense of humour of dead fish happens                   Image by Jan Ainali

We don’t think of Helium as scarce, partially because of its perceived strategic value in the 1920s. ¬†The¬†U.S. felt that¬†airships were the way of the future and so set up a government-owned strategic reserve in 1925. ¬†Given that the only real demand on this stockpile was the occasional rocket test or airship, this reserve built up over 70 years.

The U.S. government has long dominated the world¬†Helium market (in 2006, U.S. helium reserves accounted for two thirds of the world’s total) and has been gradually selling off reserves, keeping prices artificially low. ¬†Maintaining the infrastructure to keep and distribute the gas isn’t cheap though, and the government wants out.

In 1996, Congress mandated the shutdown of the world’s largest (and only) strategic helium reserve by 2013. ¬†This was delayed by a last-minute law passed by Congress which averted a¬†dreaded “helium cliff” that would have seen MRIs go silent. ¬†The new shut-down date is 2021.

Algeria and Qatar are trying to pick up the slack in time, but prices are rising by as much as a factor of 2.5 every year.  Some scientists think that before long, a simple Helium-filled party balloon will cost upwards of $100.

If Slate’s Nina Rastogi’s calculations about the number of balloons required to lift Carl’s house in Up are to be believed, that would put Carl’s Helium bill at nearly one billion dollars. ¬†If there is going to be an Up 2, either someone’s going to have to be a billionaire, or they might just have to risk it with Hydrogen.

It's probably best for all involved if we just stay away from sequels.
It’s probably best for all involved if we just stay away from sequels.

G is for Gravity Waves

By Jonathan Farrow from the Thoughtful Pharaoh

Deep in Antarctica, right on top of the geographic South Pole, there is a research station that peers back in time to the very beginning of our universe. Named the Amundsen-Scott Station, it is home to instruments such as the creatively named South Pole Telescope (SPT), the Keck Array, and the BICEP experiments.

The temperature is currently sitting at about -30C and it’s the height of summer. ¬†The sun won’t set at the station until March 23rd and once it sets, it won’t rise again until September. ¬†So why the heck (or, one might say…Keck)¬†would we build an observatory there?

Because the temperature is so low and the altitude is so high (2743m) at the South Pole, the air is thin and dry, reducing blurriness normally caused by¬†the atmosphere. ¬†There are no cities nearby to cause light pollution and there are months of nonstop night, allowing for¬†continuous observation. ¬†It’s an astronomer’s dream. ¬†Except the nearly-constant -30C temperatures. ¬†And the remoteness. ¬†But otherwise, dreamlike.

Damn that looks cold! Photo from 2003
The perfect place to set up a top-secret laboratory from which to take over the world!… I mean… uh… from which to observe the beginnings of the universe. ¬†Yeah, that’s what we’re doing. ¬†Definitely that. ¬†Image credit: NASA

So what are astronomers looking for all the way down there at the end of the world? ¬†They are searching for clues as to how the universe started. ¬†Ever heard of the Big Bang Theory? ¬†No, not these clowns, the theory about the beginnings of the universe. Although, come to think of it, the theory is actually pretty well summed up by the first line of the Barenaked Ladies’ theme song to the Big Bang Theory (yes, those clowns):

Our whole universe was in a hot dense state,
Then nearly fourteen billion years ago expansion started. Wait…

That’s really the core of the¬†theory: ¬†everything used to be really hot and dense and now its¬†not. ¬†What happened in between is what the astronomers at the South Pole are trying to figure out.

History of Universe
For a bit of a primer on this diagram, check out A Short History of (The Universe), an essay I wrote which introduces the origins of the universe.  Image by NASA

Astronomy is awesome because when we look up, we are actually looking back in time. ¬†The distances involved are so great that it can take years (or billions of years) for light to reach us. ¬†So, what if we just looked as far as we could, wouldn’t we be able to see the Big Bang happening? ¬†What would that even look like?

Unfortunately, because everything was so hot and dense right at the start of the universe, nothing could stick together so the universe was just a soup of energetic particles.  Any light that was emitted was bounced around like the light from a flashlight in thick fog.  About 380 000 years after the Big Bang , the universe had cooled and expanded enough to let atoms form and collect electrons.  Atoms are mostly empty space, which means that unless they are packed very close together like in a solid or liquid, they are transparent.  What resulted was light spreading pretty evenly throughout the universe, starting 13.7996 billion years ago.  This is what is called the Cosmic Microwave Background Radiation (CMBR).  Cosmic because it comes from space, Microwave because it has lost a lot of energy since the Big Bang and is now only 2.7 degrees above absolute zero, Background because it is there no matter which direction you look, and Radiation because it is light.

WMAP
A map of the Cosmic Microwave Background Radiation. The different colours represent slight anomalies (about 10^-5 degrees C difference). Red is a little bit hotter, dark blue is a little bit colder.  Image by NASA

So, no matter how far you try to look, this map is all that you see.  It is all that can be seen because it is the oldest light that escaped.  Sounds kind of disappointing, but astronomers think that that image (what some refer to as the baby picture of the universe) holds clues to what happened before.

If there was inflation, faster-than-light expansion of space and time (again, check out my essay on the history of the universe¬†if you’re confused), that process should have produced gravitational waves.

“Woah, woah, woah. ¬†Hold up. ¬†I understand gravity, apples falling on heads, etc etc… ¬†How the Keck could there be gravity¬†waves?”

One of Einstein’s key contributions to science was the understanding that space and time are¬†linked and that they are¬†influenced by mass. ¬†He described space-time as a fabric that could be warped by the presence of mass. ¬†All that¬†gravity is, he said, is the curvature of space-time around mass. ¬†A simplified way to understand this is by thinking of¬†space-time as a trampoline. ¬†If you put a mass on the trampoline, it will create a depression. ¬†The heavier the mass, the more extreme the depression. ¬†Now, if you have an extreme depression and move it very quickly back and forth, it will create waves in the same way that a moving hand in a pool will create waves. ¬†Astronomers think that inflation must have created gravity waves with a very specific signature. They also think that very heavy stars moving quickly, like binary neutrino stars, would create these gravitational waves.

Loooook into my gravity waaaaves.  You are not getting sleepy.  You are paying attention, commenting below, and sharing this with your friends.
Loooook into my gravity waaaaves. You are not getting sleepy. You are paying attention, commenting below, and sharing this with your friends.  Image by NASA

If (or, once they are discovered for sure, when) gravity waves pass through you, it is space itself which is expanding and contracting.  You are not moving, but as the wave passes through your arm, your arm will be closer to your body than it was before and time for it will move slower.

The thing about gravity, though, is that it is by far the weakest of the fundamental interactions (Electromagnetic, Weak, Strong being the other, stronger ones).  By a factor of about a nonillion (1 with 30 zeroes after it).  This makes the waves it creates very difficult to detect.  While your arm is probably having a taste of timelordery as you read this, there is no way you could possibly feel it.  Gravity waves are not interesting for how they make us feel, but rather for the challenge they present in detecting, for the possible confirmation of our current physical model, and for what they can tell us about the origin of the universe.

So let’s come back¬†back to the barren, frigid wasteland of Antarctica and the astronomers freezing their buns off for science. ¬†BICEP2, the second iteration of the¬†Background Imaging of Cosmic Extragalactic Polarization experiment, looked at the¬†CMBR and looked for patterns in the light. ¬†These patterns, called b-mode polarization, can be produced by gravity waves, but also by interstellar dust.

In order to cancel out the effect of dust, the BICEP2 team used data from Planck, a European satellite launched in 2009 with a very similar mission: to study the early universe. ¬†Whereas BICEP2 could only look at one particular wavelength with high sensitivity, Planck could look in a few different wavelengths but didn’t have quite as much sensitivity for these b-modes. ¬†Dust doesn’t leave the same polarization patterns in¬†light in¬†different wavelengths, so by comparing the results from different wavelengths from Planck, the BICEP2 team was able to show that the b-modes weren’t from dust and so had to be from gravity waves from the early universe. ¬†Proof of inflation! ¬†Proof of the standard model! A possible Nobel Prize!

./b_over_b_rect.eps
Those swirls are the b-mode polarization that astronomers were looking for. ¬†This diagram, while confusing as Keck (it’s going to catch on!) and quite complicated, was EVERYWHERE when the announcement was made. ¬†Image by BICEP2 team

So, understandably excited and with a positive result in hand, there was a big announcement at the Harvard-Smithsonian in March of last year.  Unfortunately, the data they used was preliminary.  In September, new data was released and the effect of dust seems to have been larger than they thought.  The team reduced the confidence in their findings but still stood by a significant result.  Just last month, in January 2015, another set of data was released that makes the BICEP2 findings inconclusive.

It seems the team jumped the gun a little bit, were blinded by the impact of their apparent discovery, and had too much confidence in preliminary data. The result of all this is that there is still no direct evidence of inflation or of gravitational waves and the teams at Planck and BICEP are going to work together now with the strengths of their instruments.  Within a few years, the effect of dust should be able to be cancelled out and we will be able to see whether we were right about the beginning of the universe.  And all the frostbite will have been worth it.