Friday, December 30, 2011

Friday Roundup: 2011 top science lists, radium laced condoms, and the clitoris

A Double X Science grandma showed us this picture.
We thought it was the most ridiculously cute thing we'd seen all year.
As 2011 draws to a close, media outlets and science bloggers have busily collated their top-10 (or 12 or 20) lists of science-related cool/interesting/freaky/fantastic stuff this year. Here's a selection that should keep you busy for about the first half of 2012:


Health 'n' stuff
  • Do you know the clitoris? Not many people really do. Read this. It's important information, not to mention mindblowingly cool.
  • Put the toilet seat lid down when you flush. Please.
  • Emily Willingham, Double X Science managing editor, is also an editor on a new book just out, The Thinking Person's Guide to Autism. Consider buying a copy to leave in your pediatrician's office or to donate to your local library.
  • Once upon a time, people made condoms that glowed in the dark, thanks to radium. Yikes.
Sciencey fun!

Thursday, December 29, 2011

Pregnancy 101: On the cervical mucus plug and why I’ve never been more happy to hold something so disgusting in my hand

Like the eye of Sauron drawn to the One Ring, one cannot resist looking at the mucus plug.
June 3rd, 2007 fell on a Sunday. I awoke that morning feeling disappointed that I was still pregnant. My due date had come and gone and, honestly, I was sick of being a human incubator. I had enough of the heartburn, involuntary peeing, and the overall beached-whale feeling. The baby in utero was resting comfortably on my sciatic nerve, and I could barely walk. And perhaps even more important was the fact that I just wanted to finally meet the child I had grown from just a few cells!

Feeling like it would never come to be, I slowly waddled into the bathroom and somehow negotiated the tall edge of the bathtub in order to take a shower. As I stood allowing the hot water to pour down my back, I looked down at the giant watermelon growing from my abdomen and literally began to beg. “Little baby, please please PLEASE make your way out today!” Right at that moment, and I kid you not, my cervix released my mucus plug and deposited it into the palm of my hand.

Video of a mucus plug being poked and prodded with tweezers. Watch at your own risk.
Suddenly, I saw the light at the end of the pregnancy tunnel. I excitedly called for my husband. “Jim! You have to come see this!!” He came running in as he was already on edge, given the circumstances. “My mucus plug came out! Do you want to see it?” As much as he tried to resist looking at something that was potentially grotesque (and it was), instinct overrode logic. His actions did not match the words coming out of his mouth, which were along the lines of “hell no!” and, like Sauron responding to the wearing of the ring, his eyes were slowly drawn down to what was gently wobbling in the palm of my hand.   
The human eye is poised for setting its gaze upon things that are aesthetically pleasing and the mere mention of the word “mucus” could potentially elicit a queasy feeling in one’s gut. However, mucus plays a significant biological role in our bodies. In general, the mucus serves as a physical barrier against microbial invaders (bacteria, fungi, viruses) and small particulate matter (dust, pollen, allergens of all kinds). Protective mucus membranes line a multitude of surfaces in our bodies, including the digestive tract, the respiratory pathway, and, of course, the female reproductive cavity.
But when it comes to matters of ladybusiness, the function of mucus goes beyond that of a microbial defense system. Produced by specialized cells lining the cervix, which is the neck of the uterus and where the uterus and vagina meet, mucus also plays a role in either facilitating or preventing sperm from traveling beyond the vagina and into the upper reproductive tract.
For instance, cervical mucus becomes thinner around the time of ovulation, providing a more suitable conduit for sperm movement and swimming (presumably toward the egg). Furthermore, some components from this so-called “fertile” cervical mucus actually help prolong the life of sperm cells. Conversely, after the ovulation phase, normal hormonal fluctuations cause cervical mucus to become thicker and more gel-like, acting as a barrier to sperm. This response helps to prepare the uterus for pregnancy if  fertilization happens.
During pregnancy, a sustained elevation of a hormone called progesterone causes the mucus-secreting cells in the cervix to produce a much more viscous and elastic mucus, known as the cervical mucus plug. In non-scientific terms, the mucus plug is like the cork that keeps all of the bubbly baby goodness safe from harmful bacteria. It is quite large, often weighing in around 10 g (0.35 oz) and consists mostly of water (>90%) that contains several hundred types of proteins. These proteins do many jobs, including immunological gatekeepers, structural maintenance, regulation of fluid balance, and even cholesterol metabolism (cholesterol is an ever important component of healthy fetal development).
As a woman nears the end of a pregnancy, the cervix releases the mucus plug as it thins out in preparation for birth. Often, the thinning of the cervix can release some blood into the mucus plug, which is why some describe the loss of the mucus plug as a “bloody show.” However, losing the mucus plug is not necessarily an indication that labor is starting. Activities like sex or an internal cervical examination can cause the mucus plug to dislodge. It can fall out hours, days, or even weeks before labor begins. In my case, the loss of my mucus plug was associated with the onset of labor, which is why I have never been so happy to hold something so disgusting in my hand. 

Last week, I told the story of my two births, including the loss of my mucus plug, at an event called The Story Collider. I described the mucus plug as “a big hot gelatinous mess.” I pushed it a bit further by providing the following graphic imagery: “Picture a Jell-O jiggler, but instead of brightly colored sugar, it’s made up of bloody snot.” I was pleased with the audience response, which mostly consisted of animated face smooshing accompanied by grossed-out groans and sighs. For the rest of the evening, I heard people call to me from all over the bar by screaming “MUCUS PLUG!!!” Given the importance of the mucus plug during pregnancy (and mucus in general) combined with its comedic potential, its no wonder that it was a hit. Go mucus!

Jeanne Garbarino, Double X Science biology editor

Kamran Moghissi, Otto W. Neuhaus, and Charles S. Stevenson. Composition and properties of human cervical mucus. I. Electrophoretic separation and identification of proteins.. J Clin Invest. 1960 September; 39(9): 1358–1363.
Lee DC, Hassan SS, Romero R, Tarca AL, Bhatti G, Gervasi MT, Caruso JA, Stemmer PM, Kim CJ, Hansen LK, Becher N, Uldbjerg N. Protein profiling underscores immunological functions of uterine cervical mucus plug in human pregnancy. J Proteomics. 2011 May 16;74(6):817-28. Epub 2011 Mar 23.
Ilene K. Gipso. Mucins of the human endocervix. Frontiers in Bioscience 2001 October; 6, d1245-1255.
Merete Hein MD, Erika V. Valore MS, Rikke Bek Helmig MD, PhD, Niels Uldbjerg MD, PhD, Tomas Ganz PhD, MD. Antimicrobial factors in the cervical mucus plug. American Journal of Obstetrics and Gynecology 2002 July Volume 187, Issue 1, 137-144
Naja Becher, Kristina Adams Waldorf, Merete Hein & Niels Uldbjerg. The cervical mucus plug: Structured review of the literature. Acta Obstetricia et Gynecologica. 2009; 88: 502_513

Wednesday, December 28, 2011

Wordless Wednesday: Non-human animals that use tools

Image in U.S. public domain. Via Wikimedia Commons.
In addition to the tool-making crow in the video below, many other non-human animals make tools. See this photo series from MSNBC's LiveScience for more. It even includes an invertebrate, although certainly not the only spineless species to use a tool.

Tuesday, December 27, 2011

Everyday Science: Why Can You Hear Around Corners But Not See?

As I sit and type this in my study, I can hear my cats crashing around the living room, which is around the corner from me. There's a wall between us, so I can't see them or shoot them with my water pistol (which I would be tempted to do if they were in the same room, before they knock over something fragile). So, just like in my earlier post on mirrors, we'll start with a question: why can I hear my cats around the corner, but not see them?

Both sound and light are waves, but the way we perceive those waves are very different. I don't just mean the organs we use - eyes and ears do have major biological differences - but how the characteristics of those waves differ. We perceive differences in light through color, and differences in sound through pitch, but in the end these characteristics mean the same thing: they're a measure of how big the wave is. The technical term for this is its wavelength: the distance it takes for a wave to start repeating itself.

For visible light, red has the longest wavelength, while violet has the shortest. In between you get the other colors of the rainbow, and if you mix them all together you get white light. Visible light wavelengths are between 400 and 700 nanometers, which is smaller than bacteria (which themselves are smaller than cells in our bodies)! Wavelengths smaller than 400 nanometers get into ultraviolet, X-ray, and gamma-ray territory; wavelengths greater than 700 nanometers comprise infrared, microwaves, and radio waves.

For sound, the situation is a little messier, since our ears respond to frequency, not wavelength. The specific wavelength of sound depends on the temperature and humidity of the air, but if we assume dry room-temperature air, a low-pitched sound has a wavelength of about 17 meters and high-pitched sounds have wavelengths around 2 centimeters. That's a big range, and not all those sounds will travel around corners. Shorter wavelengths are ultrasound, which are probably most familiar for tracking the health of fetuses: these sound waves can penetrate or reflect off tissue, and by measuring the waves that bounce back, doctors can track blood flow and other developmental processes inside your body. (X-rays go right through soft tissues, so they're better for looking at bones.) Longer wavelengths are infrasound; animals like elephants use these very low-pitched sounds for communication across long distances.

When a wave meets an opening like a door, it can experience something known as diffraction: the wave passing through the opening spreads out on the other side. However, the wave doesn't just come through the center of the door: it makes a bunch of waves along the length of the opening, and those waves actually interfere with each other. The wider the door, the more of these new waves are made.

The image to the right shows the interference pattern from a red laser shining through a very narrow opening (smaller than a millimeter). The central maximum is where most of the light coming through the opening ends up, but you also have dark spots where the light interferes and cancels out. The secondary spots on either side of the maximum are much less bright, and you also get tertiary and smaller spots that are fainter still. You get the same pattern for sound, though for obvious reasons I can't show you a picture of it! The only difference is you exchange brightness for loudness, and dark spots for places where the sound is silenced.

The width and intensity (brightness or loudness) of the spots depend on the ratio of the wavelength to the size of the opening. If the wavelength is bigger than the opening, there isn't diffraction; if the wavelength is about the size of the opening, then you get strong diffraction, and the central maximum is a lot wider than the opening. If the wavelength is much smaller than the opening, then the central maximum is quite small, and since the secondaries, tertiaries, and so forth are fainter still, the pattern may be hard to detect.

So there's our answer! A typical doorway is around a meter wide (a little less, usually), so sound with its relatively large wavelengths will create a big central maximum and sufficiently-loud secondaries. That can be enough to hear even if you aren't in a straight line with the hooligan cats in the other room. A corner is just a very wide doorway, so everything I've said about doorways carries over to them too.

Visible light has very small wavelengths, so while you do get light diffraction through doorways, you'd need a microscope to see the pattern! If you have a strong light shining through the door, you'll get a nice rectangular blaze of light on the opposite wall, but it's not much bigger than the door, and doesn't go around corners. However, if you have a cell phone or a cordless phone, the signal from those definitely can go around corners: those are based on microwaves or radio waves, which have much larger wavelengths than visible light.

Similarly, elephants communicate via infrasound over huge distances because rocks, trees, and other obstacles are smaller than the wavelengths they use, so the sound just diffracts right around them. Very handy! Tigers use roars to establish territories, and since they live in dense forests, again infrasound lets their growls travel around the trees easily. (We humans may not hear the infrasound part of the roar, but we can definitely feel it. The lowest notes from large pipe organs or tubas are below our normal hearing range, but they still can contribute to the overall sensation of a musical piece.)

There is one place where diffraction does play a role in our vision: our eyes themselves. Doorways are too big for diffraction, but the pupil in a human eye is about 2 millimeters across, varying depending on whether we're in a bright or dark place. The size of the central maximum of light cast on our retina is part of what determines how well we see. Diffraction also is why radio telescopes need to be very large, but why an ordinary visible light telescope you might have doesn't need to be huge - yet the larger it is, the more clearly you'll be able to see distant planets and galaxies. The telescope is like a big window, so you want to match the size of the window to the wavelength of the light you're viewing.

Now if you'll excuse me, I need to go make sure my cats haven't wrecked the living room.

Wednesday, December 21, 2011

Wordless Wednesday: The secret life of scientists and engineers

NOVA put together a web series that gives viewers a peek into the real work of scientists and engineers. Forget about lab coats and beards and beakers. The look and life of science these days may not be what you think. Series tagline: "Where the lab coat comes off." Know a charismatic scientist who lives outside the stereotypical scientist box? NOVA's taking suggestions!

[Note: there have been technical difficulties with the promo video, so click here if it won't play for you in this window.]


Link courtesy of Annie Murphy Paul, from her Time piece, "America needs more geeks: How to make science cool."

Friday, December 16, 2011

Friday Roundup: Sex, math, sugar bombs, and vocal fry

Via Wikimedia Commons. This is a picture of a whole lot of sugar.
Women and men and science
  • Vocal fry: I (Emily) am a biologist. This phrase makes me think of tiny, loudmouthed fish. But it's really about a vocal tic. Do you do this when you speak? It’s all the rage among young XXers these days.
  • Decaying hoods, premature birth: living in among dilapidated buildings linked to higher risk of premature childbirth. 
  • Do you know when you want it? Yes, that It
  • Women can do math. Yep, as well as men. Or maybe we should write that as, Men can do math. Yep, as well as women.
  • Male circumcision: the controversy continues. Does it or doesn't it stem the transmission of AIDS?
Cool, cute, crazy sci stuff
Baby sloths.Cuuuute baby sloths.
Science education

Science and health

Thursday, December 15, 2011

From alchemist to chemist: What kind of chemistry is that?

Figure 1: The Alchemist Discovering Phosphorus

What does the word chemistry  mean to you? For many, it was a class in high school or college to get through. In these introductory courses, called general chemistry, one gets a mix of all the flavors of chemistry – but the flavors are very different. To those who hear the calling of chemistry, it isn’t just any chemistry that will do. Some courses are more interesting to them than others. 
Many instructors start their general chemistry course with a history, introducing alchemy. Alchemy is considered to be the process by which to turn [name item of your choice] into gold. Alchemists were chemists by accident in that they performed many chemical reactions in their quests, discovering a number of elements in the process - embodied by Hennig Brandt’s discovery of phosphorus from the refinement of urine.
Alchemy relates to all the fields of chemistry. In perhaps the most famous of alchemy pictures, that by Joseph Wright of Derby entitled “The Alchemist Discovering Phosphorus,” the alchemist is kneeling by a very large round bottom flask. For many in modern chemistry, the round bottom flask signifies hours in the organic chemistry laboratory mixing chemicals together to create something new.

Organic chemistry is the “branch of chemistry that deals with the structure, properties, and reactions of compounds that contain carbon” according to the American Chemical Association (ACS). Organic chemistry is the largest of chemistry fields in terms of number of people working in it. Organic chemists strive to make new compounds, usually to improve upon an existing one for a purpose and the field is often thought of in terms of synthesis applications.

The actual process of converting urine to phosphorus generally falls along the lines of inorganic chemical reactions. The form of phosphorus in urine is in the chemical sodium phosphate (Na3PO43-). Heating phosphates along with the organic products also in urine will form carbon monoxide (CO) and elemental phosphorus (P). The sodium phosphate, carbon monoxide, and elemental phosphate are all inorganic chemicals, falling under the field of inorganic chemistry.

Inorganic chemistry is “concerned with the properties and reactivity of all chemical elements,” according to UC-Davis chemwiki. While organic chemistry requires the presence of carbon in a specific type of bond, inorganic chemistry involves all the elements present in the periodic table. Inorganic chemistry delves into theories surrounding the bonding of metals to molecules and the shapes of molecules themselves.

Figure 2: Components of Urine
While the process of collecting phosphorus from urine requires organic and inorganic chemical reactions, the process of making the products in urine is biochemistry. Note in figure 2 that the primary product in urine is urea.

For students of biochemistry, images of the urea cycle (aka the Krebs cycle) are well known. According to the ACS, biochemistry is “the study of the structure, composition, and chemical reactions of substances in living systems.” Besides the chemical cycles to produce and use up necessary chemicals in biology, biochemistry encompasses protein structure and function (including enzymes), nucleic acids such as DNA, and biosynthesis.

As the alchemist turned urine to phosphorus, he added heat. The addition of heat to a reaction involves thermodynamics, a subsection of physical chemistry. If heat hadn’t been added, the reaction products would have been kinetic, which is another subsection of physical chemistry.

In a suite of physical chemistry courses, a student would also take quantum mechanics, rounding out the aim of physical chemists, which is to “develop a fundamental understanding at the molecular and atomic level of how materials behave and how chemical reactions occur,” according to the ACS. Physical chemists work by applying physics and math to the problems that chemists, biologists, and engineers study.

The alchemists who took exact measurements of their reactants and products, using quantitative methods, employed analytical chemistry. Presumably, the alchemists did this because every ounce of gold was precious, and they wanted to know how much substance they started with to produce the coveted metal.

Analytical chemistry focuses on obtaining and processing information about the composition and structure of matter. There are so-called wet lab ways to determine these quantities that often been employed. However, most analytical labs consist of the precision instrumentation that you may have seen on forensic crime shows, such as a mass spec, short for mass spectrometer, a frequent player on CSI.

While the alchemists were only trying to produce a substance to enrich pockets, they ultimately led to a rich science with several subfields, each with a trail leading from the practice of alchemy.

Adrienne M Roehrich, Double X Science Chemistry Editor

(1734-1797), Joseph Wright of Derby. "English: The Alchemist Discovering Phosphorus or the Alchemist in Search of the Philosophers Stone." Derby Museum and Art Gallery, Derby, U.K., 1771.
Lawton, Graham. "Pee-Cycling." New Scientist, 20 December 2006 2006.
Weeks, Mary Elvira. "The Discovery of the Elements. Xxi. Supplementary Note on the Discovery of Phosphorus." Journal of Chemical Education 10, no. 5 (1933/05/01 1933): 302.

Wednesday, December 14, 2011

Wordless Wednesday: Best video from space--EVAR

This is a time-lapse video of images captured from the International Space Station from August to October 2011. You'll see the auroras (borealis for the north, australis for the south) and, well, the entire island Earth. Bora Zivkovic, blog editor at Scientific American posted this last month. According to Bora, we owe thanks to Ron Garan, the photographer and astronaut who took the pictures and to Michael K├Ânig for editing them into this lovely visual voyage. Enjoy!

Tuesday, December 13, 2011

Freezing Point: Science never tasted so good!

Learning about freezing point can lead to a tasty reward!

When trying to devise cool activities for my kids, I generally stick with either a culinary or a scientific theme.  This is mostly because cooking and science are what I know best.  But when the opportunity arises to combine the two in a fun-filled, hands-on, and awesomely secret educational activity, I do my best to keep from micturating in my undergarments. 

In my experience, the best example of culinary science fusion involves a lesson on the concept of freezing point, mainly because the end product of this stealth lesson can be topped with whipped cream and a cherry.  That’s right, I’m talking about teaching science while making ice cream.

To fully appreciate the culinary chemistry behind this frozen delight, it’s important to understand the concept of freezing point and melting point.  Simply put, the freezing point is the temperature at which a liquid freezes and the melting point is the temperature at which a solid melts.  For most substances, the melting point and the freezing point are the same. 

Let’s use water as an example.  If water is cooled below 0°C (32°F), it will transform into ice.  Therefore, the freezing point of water is 0°C.  However, if the temperature of ice is raised above 0°C, it will melt.  Therefore, the melting point of water is also 0°C. 

HOWEVER, these points can be manipulated.  For anyone who lives in an area where winter happens, you’ve probably seen the massive seasonal salt inventory at The Home Depot.  The idea is that by putting salt on walkways, usually in the form of either rock salt (NaCl) or calcium chloride (CaCl2), you will prevent the build up of ice and snow and thus prevent any nasty slips.  This is because salt will lower the freezing point of water, thereby helping to keep it from turning into an icy mess, even when temperatures are below freezing.  But, it will only work if the walkway is warmer than -9°C (or 15°F). 

How does this relate back to ice cream?  Well, we can use the same idea of lowering the freezing point of water and apply it to making cream freeze.  The set-up involves two resealable plastic bags (one quart-sized and one gallon-sized), ice, lots of salt, cream, milk, sugar, vanilla, and your flavoring of choice. 

Into the quart-sized resealable plastic bag, combine the cream, milk, sugar, vanilla, and flavoring (follow the recipe below and ensure that the bag is fully sealed).  Fill the second resealable plastic bag about halfway with crushed ice and all of the salt.  Place the cream-filled bag into the ice-filled bag and seal.  Then…shake! 

When salt is added to the ice water, the temperature of the mixture drops.  Because the temperature of the ice-salt mixture is lower than the cream mixture, a temperature gradient is created and the cream mixture easily freezes.  After about five to ten minutes of shaking, you will have yourself some fresh-churned sciencey deliciousness!  Enjoy!

Science Experiment Ice Cream:
½ Cup Heavy Cream
½ Cup Milk
¼ Cup Sugar
¼ Tsp. Real Vanilla Extract
Crushed or Shaved Ice
1 Cup of Table Salt or Sea Salt
1 Quart-Sized Ziploc Bag
1 Gallon-Sized Ziploc Bag

Here is a video of my and a few of my pals doing this experiment with my daughter.  We did this last year and my daughter STILL talks about it!  

The set-up:

Shakin' it up:

The big reveal: 

For more information check these out:

General Chemistry Online Why does salt melt ice?

Jeanne Garbarino, Double X Science Editor

Sunday, December 11, 2011

Mirror Mirror On the Wall, Mirrors Don't Switch Hands at All

Nearly every kid has asked some variation on the question, "Why do mirrors switch left and right, but not up and down?" Maybe you still ask yourself that question too - it doesn't seem to make sense. After all, there's nothing special about "left and right" vs. "up and down" as far as a mirror goes. If you lean sideways, it still looks like your left and right are being switched, leaving your up and down the same.

That's the clue to solve the mystery: mirrors actually don't reverse left and right, however it may look. It's a common misconception - I've even seen science museum displays say it. If you really want to see what mirrors do, hold your hand up between your face and the mirror with your palm toward the mirror, so that you can see both your hand and its reflection at the same time. You see the back of your hand, but the reflection shows the palm of your hand, a view you aren't able to see without the mirror. The mirror is actually reversing front and back! The front of your hand (the side you see without the mirror) is the back of your hand in the reflection.

We can see why mirrors fool us into thinking left and right are swapped, though: it looks like a second person is standing in the mirror, looking back at us. When you raise your right hand, the mirror person appears to raise her left hand. However, what's really happening is that the mirror person is still raising her right hand, just that the front of your hand is the back of hers, the front of your head is the back of hers, and so forth. If the mirror really flipped left and right, the mirror person would be facing the same way you are: you'd be seeing the back of her head instead of her face!

Concave Mirrors for Makeup and Telescopes

Ordinary bathroom mirrors are flat, but there a kind of mirror that flips left and right as well as front-to-back - but it also reverses up and down, too. This type of mirror is a concave mirror: one like the inside of a polished metal bowl or the cupped part of a soup spoon. Again, you've probably played with making faces into a shiny metal spoon: one side gives you an upside-down reflection. (I'll talk about the other side of the spoon in a little bit - that's a third kind of mirror.) A spoon is kind of an odd shape, since reflecting your image isn't their main purpose, but many makeup and shaving mirrors are closer to being ideal concave mirrors.

The upside-down and backward image you see will always appear smaller than you are, but it will also seem to be closer to the mirror than you are. Unless the mirror is nearly flat, your face will appear to be distorted: a big protruding nose and smaller ears fading in the distance. If you sway left, your image will sway right; if you duck down, your image will bob up. That's how we know the image is truly reversed, unlike the flat mirror! A big concave mirror can be a bit headache-inducing (at least if you're like me): the image looks very strange compared to the image in your bathroom mirror. That's because it's what is known as a real image: it's on the same side of the mirror as your face, so your eyes have a lot of trouble focusing on it. In fact, if you put a piece of paper at the right location, you can actually project the image from a concave mirror onto it.
There's a special distance from the mirror known as the focal length, where the light focuses. A very curved mirror has a small focal length, while one that is nearly flat has a large focal length.(Also, the flatter the mirror, the less distortion you see in the image.) If you stand close to the mirror than its focal length, your image will be right-side up and magnified. That's the real reason many makeup and shaving mirrors are concave: they have large focal lengths, so that your image in the mirror is slightly larger than your actual face - and appears closer to the mirror than your face really is. You can guess the advantage of that: you can see your eyelashes or the contours of your face more clearly.

Let's go beyond the everyday for a bit: if you want to build a really big telescope, a concave mirror is the way to go. Unlike lenses, you don't have to make a telescope out of a single flawless piece of glass: you can make a huge metal dish, or make one big mirror out of a bunch of smaller mirrors in a tile pattern. The Keck telescopes in Hawaii are about 30 feet in diameter (actually 10 meters, to be precise): the width of a large classroom or a substantial house! These mirrors focus light onto a detector, creating the wonderful and often beautiful images astronomers use in their work. The huge size of the mirrors allow observatories to see both farther and with higher resolution than smaller telescopes. (If you're shopping for telescopes, look for words like Newtonian or Cassegrain: those tell you you're looking at a 'scope with a mirror rather than lenses.)

You might have a satellite dish; that's another type of concave mirror, but for radio waves or
microwaves instead of visible light, which is why they don't look like mirrors at first glance. Again, the purpose is to focus the signal from the satellite. Big radio telescopes are also mirrors: the biggest mirror in the world is the Arecibo radio telescope in Puerto Rico: that one is 1000 feet (305 meters) across!

Objects In Mirror Are
Closer Than They Appear

If you still have your spoon from the previous section (and I hope you do - the author is not responsible for lost utensils), turn it around so that your image appears right-side up. This type of mirror is convex: like the flat mirror, it flips back and front, but not left and right. Like the concave mirror, it distorts your image, but makes your face appear farther away than it really is.

As a quick aside: if you have trouble remembering the difference between "convex" and "concave", here's a mnemonic. Concave includes the word "cave": that's a
mirror that bows inward. Convex rhymes with "flex": that's a mirror that bows outward. At least that's how I remember which is which!

The passenger-side mirror of a car bears the message "Objects in mirror are closer than they appear". (Hopefully the object is not a tyrannosaurus.) That mirror is convex, and it's designed to give a wider view of the side and rear of the car than can be done with a flat mirror. The price of the wider field of vision is that objects do end up looking farther away than they really are. You also see convex mirrors in shops, so that the staff can look down aisles out of their direct vision, and in a famous self-portrait by M.C. Escher.


We've come a long way in a short time from a basic flat bathroom mirror: we've seen why normal mirrors don't flip left and right, but why concave mirrors do. We connected
makeup mirrors to the biggest telescopes in the world, and shop mirrors to cars. Even better, you probably have all these types of mirror easily accessible, especially if you're willing to goof around with spoons. Try them out, see how they work, and the next time someone tells you that mirrors reverse left-to-right, you can help get them facing back the correct way.

Matthew Francis, Double X Science Physics Editor

Saturday, December 10, 2011

Real science vs. fake science: How can you tell them apart?

Phrenology is a famous pseudoscience that involved determining
a person's personality based on bumps on the skull.

Pseudoscience is the shaky foundation of practices--often medically related--that lack a basis in evidence. It's "fake" science dressed up, sometimes quite carefully, to look like the real thing. If you're alive, you've encountered it, whether it was the guy at the mall trying to sell you Power Balance bracelets, the shampoo commercial promising you that "amino acids" will make your hair shiny, or the peddlers of "natural remedies" or fad diet plans, who in a classic expansion of a basic tenet of advertising, make you think you have a problem so they can sell you something to solve it. 

Pseudosciences are usually pretty easily identified by their emphasis on confirmation over refutation, on physically impossible claims, and on terms charged with emotion or false "sciencey-ness," which is kind of like "truthiness" minus Stephen Colbert. Sometimes, what peddlers of pseudoscience say may have a kernel of real truth that makes it seem plausible. But even that kernel is typically at most a half truth, and often, it's that other half they're leaving out that makes what they're selling pointless and ineffectual.

If we could hand out cheat sheets for people of sound mind to use when considering a product, book, therapy, or remedy, the following would constitute the top-10 questions you should always ask yourself--and answer--before shelling out the benjamins for anything, whether it's anti-aging cream, a diet fad program, books purporting to tell you secrets your doctor won't, or jewelry items containing magnets:

1. What is the source? Is the person or entity making the claims someone with genuine expertise in what they're claiming? Are they hawking on behalf of someone else? Are they part of a distributed marketing scam? Do they use, for example, a Website or magazine or newspaper ad that's made to look sciencey or newsy when it's really one giant advertisement meant to make you think it's journalism?

2. What is the agenda? You must know this to consider any information in context. In a scientific paper, look at the funding sources. If you're reading a non-scientific anything, remain extremely skeptical. What does the person or entity making the claim get out of it? Does it look like they're telling you you have something wrong with you that you didn't even realize existed...and then offering to sell you something to fix it? I'm reminded of the douche solution commercials of my youth in which a young woman confides in her mother that sometimes, she "just doesn't feel fresh." Suddenly, millions of women watching that commercial were mentally analyzing their level of freshness "down there" and pondering whether or not to purchase Summer's Eve.

3. What kind of language does it use? Does it use emotion words or a lot of exclamation points or language that sounds highly technical (amino acids! enzymes! nucleic acids!) or jargon-y but that is really meaningless in the therapeutic or scientific sense? If you're not sure, take a term and google it, or ask a scientist--like one of us (seriously--feel free to ask). Sometimes, an amino acid is just an amino acid. Be on the lookout for sciencey-ness. As Albert Einstein once pointed out, if you can't explain something simply, you don't understand it well. If peddlers feel that they have to toss in a bunch of jargony science terms to make you think they're the real thing, they probably don't know what they're talking about, either.

4. Does it involve testimonials? If all the person or entity making the claims has to offer is testimonials without any real evidence of effectiveness or need, be very, very suspicious. Anyone--anyone--can write a testimonial and put it on a Website. Example: "I felt that I knew nothing about science until Double X Science came along! Now, my brain is packed with science facts, and I'm earning my PhD in aerospace engineering this year! If they could do it for me, Double X Science can do it for you, too! THANKS, DOUBLE X SCIENCE! --xoxo, Julie C., North Carolina"

5. Are there claims of exclusivity? People have been practicing science and medicine for thousands of years. Millions of people are currently doing it. Typically, new findings arise out of existing knowledge and involve the contributions of many, many people. It's quite rare--in fact, I can't think of an example--that a new therapy or intervention is something completely novel without a solid existing scientific background to explain how it works, or that only one person figures it out. Also, watch for words like "proprietary" and "secret." These terms signal that the intervention on offer has likely not been exposed to the light of scientific critique.

6. Is there mention of a conspiracy of any kind? Claims such as, "Doctors don't want you to know" or "the government has been hiding this information for years," are extremely dubious. Why wouldn't the millions of doctors in the world want you to know about something that might improve your health? Doctors aren't a monolithic entity in an enormous white coat making collective decisions about you any more than the government is some detached nonliving institution making robotic collective decisions. They're all individuals, and in general, they do want you to know. 

7. Does the claim involve multiple unassociated disorders? Does it involve assertions of widespread damage to many body systems (in the case of things like vaccines) or assertions of widespread therapeutic benefit to many body systems or a spectrum of unrelated disorders? Claims, for example, that a specific intervention will cure cancer, allergies, ADHD, and autism (and I am not making that up) are frankly irrational.

8. Is there a money trail? The least likely candidates to benefit from conclusions about any health issue or intervention are the researchers in the trenches working on the underpinnings of disease (genes, environmental triggers, etc.), doing the basic science. The likeliest candidates to benefit are those who (1) have something patentable on their hands; (2) market "cures" or "therapies"; (3) write books or give paid talks or "consult"; or (4) work as "consultants" who "cure." That's not to say that people who benefit fiscally from research or drug development aren't trustworthy. Should they do it for free? No. But it's always, always important to follow the money.

9. Were real scientific processes involved? Evidence-based interventions generally go through many steps of a scientific process before they come into common use. Going through these steps includes performing basic research using tests in cells and in animals, clinical research with patients/volunteers in several heavily regulated phases, peer-review at each step of the way, and a trail of published research papers. Is there evidence that the product or intervention on offer has been tested scientifically, with results published in scientific journals? Or is it just sciencey-ness espoused by people without benefit of expert review of any kind?

10. Is there expertise? Finally, no matter how much you dislike "experts" or disbelieve the "establishment," the fact remains that people who have an MD or a science PhD or both after their names have gone to school for 24 years or longer, receiving an in-depth, daily, hourly education in the issues they're discussing. It they're specialists in their fields, tack on about five more years. If they're researchers in their fields, tack on more. They're not universally blind or stupid or venal or uncaring or in it for the money; in fact, many of them are exactly the opposite. If they're doing research, usually they're not Rockefellers. Note that having "PhD" or even "MD" after a name or "Dr" before it doesn't automatically mean that the degree or the honorific relates to expertise in the subject at hand. I have a PhD in biology. If I wrote a book about chemical engineering and slapped the term PhD on there, that still doesn't make me an expert in chemical engineering. 

There is nothing wrong with healthy skepticism, but there is also nothing wrong in acknowledging that a little knowledge can be a very dangerous thing, that there are really people out there whose in-depth educations and experience better qualify them to address certain issues. However, caveat emptor, as always. Given that even MDs and PhDs can be disposed to acquisitiveness just like those snake-oil salesmen, never forget to look for the money. Always, always follow the money.

Emily Willingham, Double X Science Editor

Here is a handy short version, too!

ETA: I've also blogged about pseudoscience before here and here; the latter formed the basis for this post. There's also a much longer and very good primer on what the signs of a pseudoscience are here; it's now 10 years old, but it's all still applicable, which just goes to show that some things don't change.