How Dogs and Cats Drink

cat drinkingLike a lot of other people, I assumed that when dogs and cats lap water out of a bowl they scoop the water up with their tongues. Some recent research in the field of fluid dynamics that makes use of high-speed photography and some neatly designed physical modeling has shown that isn’t what’s happening at all. Dogs and cats have to solve an interesting problem when they drink and they solve this problem in different but related ways.

First, the problem. Like most vertebrates (humans being an exception) cats and dogs usually have to drink from water that lies in a horizontal plane that is lower than their head which means they have to find a way to defeat gravity and raise the water up to their mouth. Like most carnivores, cats and dogs have what are called incomplete cheeks which allow them to open their mouths really wide to get a grip on prey.  Incomplete cheeks pose a problem for drinking, however, because they do not allow the animal to close their mouth fully enough to create suction.  In other words, cats and dogs can’t suck the water up from the bowl into their mouth.  Humans have complete cheeks and are able to create suction when closing the mouth.  People suck, their pets don’t.

tongue curl 2If dogs and cats solved this problem by scooping the water up into their mouths, you would expect them to curl their tongue upward (like people who can curl their tongues do) to make the scoop.  But that’s not what they do.  When they drink both cats and dogs curl their tongue back and up so that it forms something like a “J” shape which you can see in the picture of the dog’s tongue on the right.

The hook in the “J” looks something like a ladle which suggests that cats and dogs bring the water into their mouths in the cup of the ladle.  There may be a small amount of water brought into the mouth this way (for dogs, not so much for cats as we will see) but most of the water is brought into the mouth by a different mechanism.  After their tongue is in contact with the water both dogs and cats pull their tongue back into their mouth at a very high speed.  The small volume of water that is in contact with the tongue is drawn into the mouth and the surface tension of the water causes a much larger column of water to rise up into the mouth following the tongue.  This rising jet of water  is caught in a battle between inertia from the upward motion caused by the speed of the tongue and gravity that pulls the water back down into the bowl.  At the moment when gravity overcomes inertia and the column of water begins to fall, the animal closes its mouth and swallows the water.

Dogs and cats both make use of this basic method to get water into their mouths.  They differ, however, in how they bring their tongues into contact with the water.  Dogs form a deeper J-shape when they curl their tongue and splash their tongue into the water.  The deep J brings more of the tongue into contact with the water which results in a larger column of water rising under the tongue into the mouth.  You can see this process in action in this slo-mo video.

The splash when the tongue enters the water combined with the large quantity of water brought into the dog’s mouth (which can be more than the dog’s incomplete cheeks can contain) explains why dogs tend to be sloppy drinkers.  Also, the volume of water raised by the fast tongue pull is exponentially related to the area of the tongue that is brought into contact with the water which is why large dogs tend to be sloppier drinkers than small dogs.

cat tongueCats also produce a rising column of water under the tongue when they drink but they don’t splash their tongue into the water like dogs do.  Cats form a shallow J-shaped curl and bring the bottom of the curled portion of the tongue lightly and gently into contact with the surface of the water. Then, like dogs, they pull the tongue back into their mouth very quickly and close their mouth over the column of water just as gravity overcomes the inertia from the fast pull. You can just see the shallow J-shaped curve at the tip of the cat’s tongue in the photo above.

Here’s a slo-mo video of a cat drinking milk.  Notice how much smaller the column of fluid is compared to the dog.  The cat’s cheeks are better able to handle this smaller volume of water which is why cats tend to be neat or dainty drinkers.

Posted in Science | Tagged , , , , , | Leave a comment

What Does Xbox One Sales Have “More Than Tripled” Mean?

xbox 1

We’re often told that something increased or decreased by a certain percentage.  This isn’t very useful unless we’re also given some additional information.  Here’s an example.

In mid November online media and news websites that cover gaming and digital technology widely reported that Yusuf Mehdi, the Head of Xbox Business Strategy and Marketing at Microsoft, announced in a blog post that Xbox One (XBO) sales “have more than tripled”. Sales increasing by more than 300% sounds very good.  Is it as good as it sounds?  Did the gaming and technology press ask this question?

Simply stating that something increased or decreased by X% doesn’t really tell you very much. You need more information to determine if the increase or decrease is large enough to be important.  The first and most basic thing you need to know is what was the original number that increased or decreased.  If the original number is small, the increase or decrease will also be small.  To take an extreme example, if Microsoft had only sold 1 XBO, their sales would triple if they sold 3 more. To take a real example, book sales for my book business, Monkey Books, more than doubled from September to October.  That doesn’t sound as good as XBO sales more than tripling but it still sounds pretty good.  In actuality, October was a little better than average for Monkey Books but September was the worst month we’ve had in almost two years.  October sales were over 200% better because September sales were so low.  If you don’t know the original number, you don’t know very much at all when you are told that something increased or decreased by a certain percent.  This is so basic and fundamental that reporting the original number should be automatic.

The second thing you need to know when you hear one of these “sales increased by X%” statements is what the time frame is. Did XBO sales triple from one day to the next? One week to the next? One month to the next? One quarter to the next?  Sales tripling from one day to the next is not likely to mean very much; sales tripling from one quarter to the next could be important.

Finally, to evaluate a statement like Mehdi’s you need to have a context for comparison. Mehdi’s blog post appeared in mid November when Christmas shopping shifts into high gear.  Are console sales typically higher in November than October? Less than three times higher? More?

mehudiThe Playstation 4 (PS4) and the XBO both launched in October 2014 and the PS4 had outsold the XBO every month since launch when Mehdi posted his “sales have tripled” announcement. He posted the announcement about two weeks after Microsoft cut the price of the XBO by $50 for the holiday sales season. For the most part the gaming and technology press responded to Mehdi’s post by either dutifully reporting the increase as fact or citing it as evidence that the price cut was successful and the XBO was gaining ground on the PS4.  With only one notable exception, the basic and important questions of what was the base number of sales that tripled, what are the time frames involved, and how much do console sales usually increase in November, were not pursued or even mentioned by many online media sources that cover gaming or digital technology.

Unfortunately it’s impossible to answer questions about how many XBOs have been sold to date or when those sales took place. In April Microsoft announced that 5 million units had been shipped to retailers but did not provide any information about how many of those consoles had been sold through to customers. Since April Microsoft has tended to make announcements about “XBox sales” that combine XBO sales and Xbox 360 sales in a single number.  Sony, meanwhile, has reported that the PS4 is averaging roughly 1 million units sold to customers per month since launch. What evidence is available indicates that this more, and maybe a whole lot more, than the XBO is selling.

question markAlthough questions about how many XBOs were sold in October and November cannot be definitively answered, the gaming and digital media should have brought these questions up.  The “sales have tripled” claim is empty if you don’t know how many sales you’re talking about.  If Microsoft matched Sony’s 1 million units sold to customers in October and tripled that number in November, they had a great month.  If they sold 100K units in October and 300K units in November, they’re in serious trouble.

The time frame over which XBO sales tripled was provided by Mehdi in his blog post when he wrote “. . . sales have skyrocketed since the new price took effect on Nov. 2. Compared to the previous week, Xbox One sales in the US have more than tripled . . .” Mehdi and Microsoft deserve praise for giving us this basic and necessary information.  Unfortunately, the fact that sales tripled in the week following a major price cut when compared to the week preceding the price cut makes the sales increase much less impressive.  First, a single week is much too small a time period to provide any important information about the overall performance of a new game console.  Too many factors can skew sales one way or the other during such a small time frame.

More important, there is an obvious factor involved in the two week period that Mehdi reported that leads you to think that sales tripling during this period may have little or no importance.  Microsoft announced the price cut for the XBO a week before the reduction went into effect and the impending discount was widely reported in the gaming and technology press.  This would lead you to suspect that anyone knowledgeable about the consoles who had been considering buying an XBO would wait a week until the $50 price reduction went into effect.  If this happened, Mehdi’s “previous week” may well have seen a markedly reduced number of XBO sales while the following week may have seen an inflated number of sales as people who had been waiting bought the console as soon as the sale went into effect.  If those two things happened, sales tripling over this particular two week period isn’t very impressive.

The gaming and technology press should have pointed this out as it’s critical for evaluating the “sales have tripled” announcement. As far as I know, no one did.

The only online source that covers gaming that I saw that brought up the issue of providing a context for comparison for the “sales have tripled” announcement was an article in Forbes that pulled together Xbox 360 sales data for October and November in the years 2009 through 2012.  2013 is an outlier because the XBO launched that month which almost certainly had an effect on Xbox 360 sales.

As expected if November sales ramp up as people shop for Christmas, the Xbox 360 sold more units in November than in October every year from 2009 through 2012.  The percentage increases in the number of Xbox 360s sold in November compared to October reported in the Forbes article are as follows.

  • 2009 – 328%
  • 2010 – 422%
  • 2011 – 433%
  • 2012 – 467%

sad bag headThis is information that is important for understanding Mehdi’s announcement that XBO sales had tripled and Forbes deserves praise for providing it.  The article in Forbes is dismissive of the importance of Mehdi’s announcement based on the argument that sales tripling in November is just business as usual. Unfortunately, Forbes’ argument is beside the point. Mehdi wasn’t comparing November to October when he wrote that XBO sales had tripled, he was comparing the first week in November to the last week in October, and he explicitly made this clear in his blog post. Forbes ignored this.  Given that one can expect consoles to increase throughout November as we get closer and closer to Christmas and that there is the further expectation of a large increase in sales at the end of November when Black Friday and Cyber Monday take place, you can’t legitimately drawn any conclusions about November sales based on sales during the first week of the month.

When all is said and done what can be said about Mehdi’s announcement regarding XBO sales?  XBO sales tripled in the first week of November as compared to the last week in October.  This doesn’t give us any useful information about the success of the XBO console in general because sales in the last week of October were likely to have been artificially depressed as people waited for the announced price cut and sales during the first week in November were likely to have been artificially inflated because of people who had been waiting and bought an XBO as soon as it went on sale.

What can be said about the online gaming and digital media’s coverage of Mehdi’s announcement?  They did not address the basic and fundamental question of what was the original number of units sold in the last week of October that tripled in the first week of November. They didn’t point out that a week-to-week comparison of sales is too small to be meaningful. They didn’t point out that a sales comparison over these two weeks is especially meaningless because of the price reduction that separated one week from the other. One article provided important data about typical Xbox sales in October and November and then misused these data by using them to dismiss a sales announcement that compared one week to the next. The media failed miserably.

Boy_raising_handIt’s not really very surprising that a spokesperson for a major corporation like Microsoft would present information about the company and its products in the best possible light (speaking kindly) or in ways that are knowingly and purposefully  designed to be deceptive and then vetted by corporate lawyers to avoid claims of fraud (speaking unkindly).  It’s disturbing, however, that, for the most part, the online media that covers gaming and digital technology didn’t ask the basic and obvious questions that have to be answered if “sales have tripled” is going to be anything more than empty and meaningless marketing blather. You don’t need advanced degrees in economics or mathematics to either think of or try to answer these questions.  The math involved is taught in grade school. You just need to think about what you’re told and then ask what should be the first questions that come to mind.

Posted in Critical Thinking, Gaming, Numbers Game | Tagged , , , , , , , , | 1 Comment

Make a Dragon Wanna Retire

Like that big band funk? Check out Uptown Funk by Mark Ronson with Bruno Mars.

When I first put this post in the que for The Info Monkey, Uptown Funk was just another track among many.  While the post was waiting in the que a video was released, the band did the song on Saturday Night Live, and buzz happened.  Because it got popular don’t mean it ain’t good.

Don’t believe me? Just watch.

Or, if you prefer, on Spotify.

Uptown funk you up.

Posted in Music | Tagged , , , , , , | 1 Comment

Linking College Degrees and Occupations

degree_job graphic

Philosophy jobsSuppose you wanted to create an infographic that showed the occupations of people with a particular college degree.  One simple and clear way to do this is with a pie chart like the one to the right which shows the occupations of people who received a degree in philosophy from Cambridge University.  This is an example of a one-to-many mapping where one factor (a philosophy degree) is mapped or linked to many possible other factors (the occupations).  Pie charts are especially good at depicting one-to-many mappings.

Suppose, however, that you wanted to create an infographic that showed how a variety of different college degrees are linked to a variety of different occupations.  This is called a many-to-many mapping.  Pie charts don’t work as well for this because you need a separate pie chart for each different college degree. If you want to present information about a lot of different college degrees, the number of pie charts you’d need would become tedious and possibly confusing for your audience.

The people at the US Census Bureau came up with an elegant solution to this problem with the interactive infographic pictured at the top of this post. The infographic maps 15 categories of college degrees into 20 occupations.  For each degree it gives a graphical representation of the proportion of people with that degree that move into each one of the occupations.

The infographic is focused on Science, Technology, Engineering and Math (STEM) majors and occupations.  There are three basic variants of the core infographic: one for all majors, one for STEM majors, and one for non-STEM majors. Majors and occupations are listed around the outside of the circle and mousing over the name of the major shows where those majors are employed while mousing over the occupation shows which degrees feed employees into the occupation. Tabs along the top of the graphic allow you to break the data down by gender or ethnicity.

Follow this link to play with the infographic. It can be a bit confusing at first but all it takes is a minute of playing around with it for it to become clear how it works.

There is an extraordinary amount of information packed into this one infographic. Whether or not you’re interested in where people with different college degrees are employed, this type of infographic provides an elegant solution for graphically illustrating any kind of information that involves many-to-many mappings.

Posted in Information visualization | Tagged , , , , , , | Leave a comment

Making Charitable Donations Through Amazon

Chance-2_15pctLast February we were very fortunate to get a wonderful dog named Chance through an animal rescue outfit in the Washington DC area called PetConnect Rescue. They are a relatively small, mostly volunteer organization that was founded in 2005 to help the many animals that were left homeless and abandoned after Hurricane Katrina. They are also a registered 501(c)(3) non-profit organization which is where Amazon and charitable donations come into the picture.

You may already know about the Amazon Smile program but I just learned about it from a note at the bottom of a Happy Thanksgiving email we got from PetConnect. Smile is a simple and easy way to donate to the non-profit of your choice. You sign on to the program, enter the name of a non-profit, shop at the Amazon Smile website which is identical to the regular Amazon site, and Amazon donates 0.5% of the cost of what you buy to the non-profit of your choice.  Amazon says they have almost a million 501(c)(3) non-profits in the program and they range from large-scale heavy hitters like Doctors Without Borders to small, local non-profits like PetConnect.

Amazon Smile 2We rely heavily on Amazon for many things because it’s usually cheap, shipping is free (with a Prime membership), and they deliver to your door so we don’t have to spend time, energy and hassle going to the store. We buy things like pet food, cat litter, household cleaning products, toiletries, paper products and plastic bags, some bulk food, and often clothes and games through Amazon and all of it is eligible for donation through Smile. If a product is eligible, you will see an indicator in the product description on Amazon’s Smile website like the one marked with the arrow in the picture above.

Not everything is eligible, however. Nutrition for Cyclists which I published last spring through Amazon’s Kindle Direct Publishing is not eligible and I cannot change this.  Monkey Books, my out-of-print book business, has thousands of titles listed on Amazon and none of these books are eligible either.  A quick check of several titles from the large publishing companies shows that their titles are also not eligible for donations.

Smile looks like an easy and painless way to help non-profits large or small. Here’s a link to the Smile website and here’s another to Amazon’s Smile FAQ. Check it out if it looks interesting to you.

Posted in Charitable giving | Tagged , , , , | Leave a comment

What It Is

The Info Monkey aims to bring you posts that are interesting, informative, intriguing, exciting, or thought provoking without regard for genre or category. Thoughtful discussion is always welcome; ranting or vitriol are not. Follow on twitter (@TheInfoMonkey), tumblr (The Info Monkey), or Facebook (Kevin Murnane) for notification of new posts. I hope you find something of interest.

Posted in Uncategorized | Leave a comment

Amazing Greenhouse Gas Simulation from NASA

Take a look at this amazing simulation of how carbon dioxide and carbon monoxide gases change in volume and move through the atmosphere over time.

The swirling red/orange/yellow colors in the northern hemisphere represent carbon dioxide while the white/gray/black colors in the southern hemisphere represent carbon monoxide.  Over the course of the simulation you can see how atmospheric conditions affect the movement of greenhouse gases away from their source to other regions on the planet and how the volume of these gases in the atmosphere changes with the seasons.  Note the extraordinary reduction in carbon dioxide in the norther hemisphere as summer plant growth sucks the gas out of the atmosphere.

The computer model that produced this simulation was developed at NASA’s Goddard Space Flight Center in Greenbelt Maryland.  The model combines real-world data on man-made and natural greenhouse gas emissions with atmospheric conditions and then simulates changes over time.  The simulation in the video runs from May 2005 to June 2007.

As a personal aside, my normal daily cycling route takes me around part of the perimeter of NASA’s Goddard Center in Greenbelt.  Until a few years ago when they reworked the surrounding road grid for security purposes, my route took me right through Goddard.

The simulation model operates at an extraordinary resolution.  Typical global climate models are based on a horizontal grid of boxes that are 50 kilometers (a bit more than 31 miles) long.  The NASA simulation makes use of a grid of 7 kilometers (a bit more than 4.3 miles) boxes.  In other words, a 50k box that is represented by 1 data point in a typical global climate model is represented by approximately 49 separate data points in the NASA model.  The simulation you see in the video produced almost 4 petabytes of data (1 petabyte = 1 million X 1 billion bytes = 1,000,000,000,000,000 bytes). Completing the simulation took 75 days of runtime.

PDP 11-34 manualFor an illustration of how far Moore’s Law has taken us over the past 30 years, compare the NASA simulation model with the human memory models I was building in graduate school in the 1980s.  I was fortunate to be working in a lab that had, at the time, state-of-the-art computer resources in cognitive psychology – a pair of DEC PDP 11-34 computers.  People would regularly stop by our lab to marvel at our equipment.  I was writing code (in Fortran) for these beauties that ran computer-controlled experiments with human participants, and also ran simulations based on a variety of human memory models and early neural network models. The workspace we had available to us in the PDP 11-34s for the models, the simulation and experimental runs, the human and simulation data, and the data analysis programs was 64 kilobytes (approximately 64,000 bytes). We thought it was luxurious.

 

Posted in Information visualization | Tagged , , , , , , | Leave a comment