Paper Cuts Hurt so Much Because Our Fingers Are Really Sensitive

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Originally posted here: https://mcgill.ca/oss/article/did-you-know/paper-cuts-hurt-so-much-because-our-fingers-are-really-sensitive

You’re reading the morning paper,or turning the page on your recipe, when suddenly you notice a little line of blood, and feel a disproportionate amount of pain.

Paper cuts are tiny, barely cuts at all, more like deep scratches. So why do they hurt somuch?

Some areas of our bodies have more nerve cells than others, meaning that those areas are more sensitive to touch. A visual representation of this is seen in the cortical homunculus, a humanoid figure whose most sensitive body parts are the largest.

https://lh5.googleusercontent.com/-j4I0ok7lP_4Z1JebopsSogmBErvKvoCbGXzJIzl-rHPE84OFn0yOWBPvcKqi3qzNhuG9_1LBGgqMTQYts0-DaCrwPwKTqPG1LUvwugikH3wcITez5mZriXERhkX4Adre96CeR-D

As you can see, his hands are huge! That’s because our hands are one of our most sensitive body parts, able to detect microscopic differences in surfaces.

With that many nervesit’s no surprise that any cuts on our fingers, even those done by paper, hurt like heck. It certainly doesn’t help that we use our hands all day long, so areprone to reopening the healing cut, or getting foreign substances into it.

Curious what parts of your body are the most sensitive? Try the two-point discrimination test!Have a friend take two pencils (dull ones!) and touch them to your back in different, far apart, places. Slowly bring those pencils closer together, and note the point at which you can only feel one pencil. Then repeat the experiment on other body parts.

Everyone is different, but the image below shows the approximate distances you begin to distinguish between the two pencils at ondifferent body parts. Generallythe lips, tongue and hands are the most sensitive, and the back and shinsthe least.

https://lh3.googleusercontent.com/-YIRG0HJwdhZxyncxXtPkCHMFENiFqqxE-7GENjxgcJK8YlCTIyfR7PwHBfKaCd3m1Rao63OTf1bXli04wl6RqLrPOOsFKDgahDPmMULfar_8z79hGAll_3NAwm6QWCVcyiEUWnS

It’s Not the Smoke from a Joint That Makes Your Eyes Red

Originally published here: https://mcgill.ca/oss/article/did-you-know/its-not-smoke-joint-makes-your-eyes-red

The familiar red and glassy-eyed stare of someone who’s high was thought to be due to the irritation of eyes by pot smoke. Now we know that weed makes your eyes red for the same reason it makes you dizzy- vasodilation.

Marijuana’s has a lot of active ingredients. Tetrahydrocannabinol (THC) is only one of the many (>113) cannabinoids present in cannabis. These compounds interact with cannabinoid receptors, which are part of the endocannabinoid system. They’re found throughout your body, notably, in your eyes.

Cannabinoids bind to cannabinoid receptors and induce the dilation, or widening, of the blood vessels. This increases the blood flow to these areas,and causes an overall decrease in blood pressure. The increased blood flow to your eyeball causes the red appearance, and the lowered blood pressure causes the dizziness.

You can test it yourself, by consuming marijuana through a non-smoked method,and looking for reddening of your eyes.

The Luminescent Chemistry of Lava Lamps

Originally posted here: https://mcgill.ca/oss/article/did-you-know/luminescent-chemistry-lava-lamps

If you think back to the 60’sand 70’s your memories are probably illuminated by a lamp filled with swirling globs of colourful goop that really didn’t shed much light at all.

Lava lamps were invented in 1963 by a British accountant, Edward Craven-Walker, and marketed under the name Astro Lamps. The name might have changed since then, but the chemistry largely hasn’t.

The whirling globs we remember are made mainly of paraffin wax, with compounds like carbon tetrachloride added to increase its density. The liquid the wax floats incan be water or mineral oil, with dyes and sparkles added for whimsy.

So what causes the wax to float and fall? When the lamp is turned on, the incandescent light bulb in the base begins to heat the interior of the lamp. The wax expands when heated, and since density is equal to mass divided by volume, when the volume increases, the density of the wax decreases, and it floats. 

When the ball of goop reaches the top of the lamp it cools down, decreases in volume and thus density, and falls back to the bottom to begin its journey again. A veritable Sisyphus of home decoration.

The exact composition of the wax and liquid are trade secrets, but they’re constantly being improved on. You can make a basic lava lamp at home with just oil, water and aspirin.

The newest innovation in the lava lamp legacy was the addition of ferrofluid. These liquids have microscopic magnetic particles suspended in them that allow you to interact with your lava globs with a magnet!

Besides mood lighting, lava lamps have also been used as random number generators. Programs were made to change the motion of lava blobs into truly random numbers, for use in cryptography. Whatever you use them for though, don’t drink them. Multiple people have been hospitalized for consuming the insides of these psychedelic accessories.

Can Nike’s New Shoes Really Make You Run Faster?

Photo make by Ada McVean
Originally posted here: https://mcgill.ca/oss/article/did-you-know-technology/can-nikes-new-shoes-really-make-you-run-faster

A New York Times’ study of 500,000 race times, set wearing Vaporflys and other shoes, confirmed Nike’s claims. They found that Vaporflys allowed a runner to run 1% faster than the next-fastest shoe, and 3-4% faster than a similarly skilled runner running in different shoes.

These results, taken from race entries on the app Strava, show that runners were more likely to set a personal record when wearing Vaporflys (though not quite as likely as those wearing Nike Streak shoes). Runners were also more likely to run faster when switching to Vaporflys and complained of less leg fatigue.

So, what’s so great about these shoes? Carbon fibres. Each sneaker features a carbon fibre plate in the midsole which absorbs and releases energy, throwing the runner forward with every step.

Since the shoes don’t contain any springs or elastics, they’re not likely to be banned from future sports competitions. But given their $250 price tag, don’t expect to see me wearing them anytime soon.

Queen Ants Don’t Have a Divine Right to Their Thrones, Just the Right Genetics

Originally posted here: https://mcgill.ca/oss/article/did-you-know/queen-ants-dont-have-divine-right-their-thrones-just-right-genetics

Humans have classified more than 12,500 species of ants, and there are an estimated 10,000 more waiting to be discovered. Besides their incredible strength, almost all of these species have something in common: queens. 

Ants adhere to a caste system, and at the top is the queen. She’s born with wings and referred to as a princess until she takes part in the nuptial flight, mates with a male ant, and flies off to start her own colony. Since she retains the sperm from this first mating for her entire life, she never needs to mate again,and can digest her wings to nourish herself until her colony is established.

Queens selectively fertilizethe eggs they lay. Fertilized eggs become infertile female worker ants (the larger of whom are referred to as soldiers) and unfertilized eggs become fertile males, called drones. The males exist just to mate with the queen ants and die soon after.

How new princesses are made though has always been somewhat of a mystery. It’s been well established that, when fertilized eggs and the resulting pupae are better nourished, they develop into princesses, but how ants can develop into the two hugely different groups of workers and queens just by being fed more was a conundrum. Until now.

American researchers have found that some pupae are born with a particular gene, insulin-like peptide 2 (ILP2), expressed a lot, while others are born with it barely expressed at all. This causes some pupae to have more of the insulin-like protein in their bodies (which functions much like normal insulin, to allow glucose to be absorbed from the blood), and thus absorb more nutrients.

While in their larval form, all pupae are actually sent signals to suppress ILP2. This way, it’s only the ants born with naturally high ILP2 expression that areable to reproduce. These reproduction-destined ants will be better fed by the workers and will eventually develop into queens. In times of stress, like droughts or when food supplies are low, ants will choose not to feed fertilized eggs better, thus stopping the queen-development process and saving resources for the colony.

So with antsit seems the key to the kingdom isn’t as easy as marrying a prince. You’ve got to be born at the right time, with the right gene expression, in the right place.

Before the Breathalyzer There Was the Drunkometer

Originally posted here: https://mcgill.ca/oss/article/did-you-know-history/breathalyzer-there-was-drunkometer

The idea of a mechanism to measure the alcohol a person has consumed dates back quite far. A 1927 issue of Popular Science speaks of a device to ‘test a Tippler’s breath’, suggesting that housewives use W.D McNally’s new invention to see if their ‘errant’ husbands had been out drinking. The device is said to use chemicals that change colour, but what chemicals they were is unknown. This is howeverthe same mechanism behind the first portable breathalyzer just years later.

The first stable breathalyzer for out-of-lab use was developed by Rolla N. Harger in 1931 and named, hilariously, the drunkometer. This early breathalyzer functioned very differently from modern ones: it relied on a colour change due to a reaction between alcohol in the breath and acidified potassium permanganate. Lacking a quantitative scale it simply relied on the idea that more purple colour equaledmore alcohol.

The first breathalyzer as we currently know it was developed by Robert Frank Borkenstein in 1958. Borkenstein coupled a photometer with a reaction between the alcohol in a subject’s breath and potassium dichromate. 

This method allowed quantitative measurements of blood alcohol content, and let us move away from simply declaring people “50% drunk.”

His breathalyzer was a tremendous leap forward for law enforcement and road safety, as it gave police a non-invasive, quantitative and rapid method to confirm that somebody was too drunk to drive. 

Since Borkenstein’s breathalyzer, the technology hasn’t changed that much (read about it here). Except that breathalyzers are now less than $20 and small enough to fit on keychains.

Science Says Scotch Tastes Better Watered Down

Originally posted here: https://mcgill.ca/oss/article/did-you-know/science-says-scotch-rocks-tastes-better-straight

Everyone knows that oil floats on water. That’s because oil is nonpolar, and water is polar. These terms describe the arrangement of charges in their structure: nonpolar means a molecule has no net charge, polar means it does. The polarity of a molecule influences the way it interacts with other molecules.  We tend to think of two ‘like’ substances, be they nonpolar like two different oils, or polar like water and vinegar, as mixing completely, but that’s not entirely true in all cases.

When water and ethanol mix, they do so partially, dispersing in a way that depends on their concentration. Add some small molecules into the mix, and where we’d normally expect them to diffuse evenly throughout the solution (like tea diffuses out of a tea bag when brewing) we get instead certain clusters of the molecule. 

Most flavour molecules are small and hydrophobic,and prefer to hang out with ethanol rather than water,since its bigger surface allows more interaction. 

Since water and ethanol are not uniformly distributed throughout the glass, this leads to hot spots of flavour and aroma. Studies have found that ethanol and its associated flavour molecules are found evenly distributed when the concentration of your beverage is above 59%.

But at concentrations lower than 45% (like the 40% of most commercial whiskeys) ethanol is preferentially found at the liquid-air interface, or the top of your cup. Flavour molecules found here are more easily inhaled and immediately tasted upon sipping, leading to an overall better whiskey experience!

This effect is heightened if the whiskey is further diluted with water (down to about 27% in most cases). The flavour molecules are found even more preferentially at the liquid-air interface,and become more likely to evaporate and contribute to that pleasant smokey smell you love.

With this in mind, I think I’ll pass along some science next time someone gives me a judgemental look for ordering a scotch on the rocks. Though, since coldness can decrease taste, we really should be adding room temperature water. Maybe I can get used to that.

Cheers! To the science of sipping!

Measles: The Plague That Ruined Rome

Originally posted here: https://mcgill.ca/oss/article/did-you-know-history/measles-plague-ruined-rome

Rome wasn’t built in a day, but from 165-180 CE, up to 2,000 of its citizens were killed per day.

The Antonine Plague, also known as the Plague of Galen (after the doctor who described it), decimated the Roman Empire. It was brought to Rome by armies returning from western Asia, causing fevers, skin sores, diarrhea and sore throats.

This plague, and the Plague of Cyprian that occurred about 70 years later,are generally thought to be due to smallpox and measles. The Roman citizens at this time would not hadbeen exposed to either virus and thus would have had no immunity, which could explain the mass casualties seen (the first plague had a mortality rate of 25%).

While smallpox has not been seen clinically since 1977, measles still kills upwards of 85,000 people every year, despite being vaccine preventable. While the measles virus is most famous for causing the red rash that begins at the hairline and slowly spreads over the entire body, it can also cause fevers, sore throats, nausea and diarrhea. Perhaps just as distinctive, if not as noticeable, are the tiny white Koplik spots that may appear inside a victim’s mouth. The good news is that the rash actually signals the end of the viral infection, and the skin usually flakes off as the rash goes away.

Most of our readers are safe from the Romans’ fate, as measles was officially eliminated from the Americas in 2016. However, this elimination is conditional on travellers not bringing the virus back from their vacations and causing an outbreak. That’s why the MMR vaccine, which provides immunity against measles, mumps, and rubella, is recommended for all, travellers and home bodies alike. 

In 2014 a group of unvaccinated Amish missionaries brought measles back from the Philippines. It rapidly spread through their largely unvaccinated communities, resulting in 383 cases of measles across 9 countries. Luckily, thanks to modern medicine, no one died. We’ve come a long way from the plague that wiped out one third of the Roman Empire, and thanks to vaccines, we’ve got no plans for a measles plague of our own.

Beavers Have Metal Teeth

Originally posted here: https://mcgill.ca/oss/article/did-you-know/beavers-have-metal-teeth

I once broke my tooth on some toffee my mom made. Every time I see a beaver, I think of that day and wonder how they can gnaw on trees all day without chipping an incisor when I couldn’t even conquer candy. 

Since beavers are rodentsit’s not too surprising that their teeth constantly grow. This allows them to chew away on their sticks while keeping their teeth, but my guinea pigs are also rodents and I wouldn’t put them up against a log.

Beavers have another trick up their pelts though: their enamel. If you’ve ever seen a beaver’s teeth you’ll know that they appear pretty orange. This is because, whereas other rodents have magnesium in their tooth enamel, beavers have iron. So beavers have orange teeth for the same reason we have red blood.

The iron causes the orange colouring in beavers’ teeth, makes the teeth stronger against mechanical stress,and makes them more resistant to acid. Researchers are using these new findings to look at ways of strengthening human teeth, which gives my dreams of candy-conquering new hope.

Spaceships recycle everything… except astronaut’s poop

Originally posted here: https://mcgill.ca/oss/article/did-you-know-technology/spaceships-recycle-everything-except-astronauts-poop

Astronauts inhale oxygen and exhale carbon dioxide, just like you and me. On Earth, where exhaled air warmed by our bodies naturally rises away from us, the possibility of inhaling too much carbon dioxide isn’t usually a worry. But for astronauts, it’s a major one. Without the ventilator fans installed in shuttles and stations, carbon dioxide would accumulate around an astronaut. This is especially a concern at night,since we tend to stay still while sleeping. This would allow CO2 to collect and starve astronauts of oxygen.

So what happens to the carbon dioxide once it’s suckedaway by the fans? Like almost everything on a spacecraft, it’s recycled.

Carbon dioxide removed from the air by the aptly named ‘carbon dioxide removal system’ is combined with hydrogen (a byproduct of the oxygen generator system) to produce methane (which is vented into space) and water, which re-enters the oxygen generating system. This cycle allows astronauts to keep breathing, drinking and flying for long periods of time without having to lug to space all the oxygen they will need for the trip.

So what isn’t recycled onthe International Space Station? Human feces. But Mark Watney seems to have inspired a potential use for that