Archive for How Things Work

Science of electronic cigarettes, as seen on the Tourist

// January 2nd, 2011 // 1 Comment » // How Things Work, Science in the Movies

Happy New Year! On the first of January, I went to see The Tourist. It promised to be an excessively attractive movie starring Angelina Jolie and Johnny Depp, the two best heartthrobs on screen. I won’t spoil the plot, but I will say that one cool gadget graces the scene. The electronic cigarette.

As described in the movie, the electronic cigarette does not emit smoke, just vapour. The one in the move was shaped like a cigarette, complete with a red LED light on the end for a burning ember. He tapped the end to put it out, but I don’t think that’s necessary. The automatic versions just turn on when you breathe in, a sensor recognizes the airflow, and I’d say it turns off afterward.

Electronic cigarettes, designed by Chinese company Ruyan “to resemble smoking”, come in a variety of designs. From classic cigarettes to cigars to pipes. Even a ballpoint pen, so you can look like you’re intelligently thinking witty thoughts while taking a sneaky huff.

All the designs have the same basic features. A cylindrical battery, a heating element, and a mouthpiece. When the sensor picks up air flow, it switches on the battery which heats up the element, vapourising the nicotine mixture absorbed on material in the mouthpiece. Manual versions lack a sensor, and you have to press a button to get them started. The nicotine can be replenished by dripping fluid refills onto the absorbant material, or buying a new prefilled mouthpiece.

An electonic cigarette

An electonic cigarette

But it’s the mixture itself that’s really cool. It comes in a variety of nicotine levels and a variety of FLAVOURS. Some are designed to taste like certain brands (such as Malboro), some taste like regular ciggies, some are menthol, and others come in tastes of caramel, coffee or vanilla. One recipe listed on Wikipedia contains hardly any nicotine, but 8% alcohol. That’s a 16 proof cigarette delivered straight to your lungs! Wow. Seems dangerous.

What I wanted to know was how do electronic ciggies compare to the real thing when it comes to health. It seems like we’re still unsure. Electronic cigarettes only hit the market in 2004, so they’re pretty new still. Most countries are taking a conservative stance. In England they can be bought in pubs and smoked indoors. In New Zealand they are only available in pharmacies. In Australia it is illegal to sell them, but they can be purchased over the internet for personal use, and I believe there are no laws against it. Please correct me if I’m wrong.

The debate seems to center around the fact that these electronic cigarettes are KIND OF tobacco products and KIND OF smoking cessation aids… but kind of not. No studies have been done to show that they could help people quit smoking and become nicotine free. To me it seems more like you would quit smoking cigarettes, and start smoking the electronic version instead.

And what’s the harm in that? Most of the damage caused by smoking is not due to nicotine itself. It’s all the other crazy chemicals that come with it which cause the cancer and lung damage and so forth. Nicotine is just the stuff that keeps people coming back. It’s highly addictive, working on the reward system of the brain and our favourite neurotransmitter, dopamine. Smokeless cigarettes are a way to enjoy nicotine without getting a hefty dose of dangerous chemical cocktails. Plus the secondhand smoke is safer. So it’s an example of harm reduction. Plus your teeth would get whiter.

Of course, nicotine is not exactly a friendly chemical. It might not cause cancer, but it IS highly toxic. 60 mg can be toxic to an adult. Nicotine is made by the tobacco plant as an insecticide, need I say more? In fact, it’s also made by other members of the Solanaceae (nightshade) family, such as tomatoes. That explains why my basil plant is getting torn to pieces by insects while the tomato plant right next to it is still intact. So maybe we don’t want to encourage people to smoke anything.

But gun to my head, I think the electronic cigarette is a good thing. I don’t think young kids are going to be swayed by sexy marketing into becoming the next generation of smokers. I don’t think we’d allow such sexy marketing in the first place. I don’t even know why the government allows cigarettes to be sold at all; the health problems must cost the economy millions every year. But what do you think? Do you think electronic cigarettes would be the lesser of two evils, or a new evil all on its own, ready to pounce on hapless youths and struggling smokers and catch them forever with nicotine claws.

For love of the pancreas

// December 13th, 2010 // Comments Off on For love of the pancreas // How Things Work

Pancreas toy from Organbank on Etsy (click through)

Ahoy! Today’s Request a Post comes from Devil’s Snare, a Potter fan I’d wager.

Devil’s Snare asks “what features will a person show if his pancreas is removed?”

Ahh… woke up in a bathtub full of ice, did you? That’s embarrassing.

But hey, we’ve all been there. I’ll answer your question.

The pancreas is a noble organ with two functions. It makes hormones which regulate blood sugar (insulin, glucagon etc.), and makes lovely pancreatic juices with enzymes for breaking down food.

Damage to the pancreas is cause for distress, as enzymes which chow down food also nom the body. Type 1 diabetes starts with an autoimmune disorder that destroys the insulin producing cells found in the mystical islets of Langerhans.

Black market organ trade aside, the pancreas IS sometimes removed. Mostly it’s because of cancer or chronic pancreatitis.

A total pancreatectomy often involves taking out the spleen, the duodenum, the gall bladder and part of the stomach, then attaching the remaining stomach directly to the bowel.

Symptoms from removal are pretty clear given what the pancreas does: Without insulin producing cells you get severe diabetes. Without the enzymes, your food is poorly digested and you might get diarrhea or worse. If the spleen is also removed, you are more at risk of infections.

However it can be the only option, and the symptoms can be treated. Plenty of people out there live with diabetes. Enzyme supplements can help with the digestion department. Vaccinations or antibiotics can help control infections.

Interestingly, in 2005 a surgery taking 12 hours successfully removed a patients pancreas, collected and purified some insulin producing cells, and infused them into the patient’s liver where they started producing insulin. Full report here.

So essentially, my dear Devil’s Snare, if you think you MAY have misplaced your pancreas I suggest you would be feeling rather sick. I think you should go see a doctor.

If you love your pancreas, here’s a song by Weird Al Yankovic which just might blow your mind.

I’m always thinkin’ ’bout it
I don’t know what I’d do without it
I love, I really love
My pancreas

My spleen just doesn’t matter
Don’t really care about my bladder
But I don’t leave home without
My pancreas

Science that’s only skin deep

// December 3rd, 2010 // 2 Comments » // How Things Work, Recent Research, Science Communication, Sex and Reproduction

I’m a guest blogger for the RiAus, and this post also appeared on their fancy website. To tell the truth, I really wanted to call this post “Hormonally Yours” in homage to the Shakespeare Sisters (anyone?) but I’ll save it for another post.

Recently I was in Arnhem Land, visiting some Indigenous communities with a couple of friends. While I was there, I got pretty jealous of everybody’s darker skin. “It’s so well suited for Australia,” one of my friends lamented. “I should be in Norway or something.”

Pale skin like mine is not great for Australia. I tan pretty easily, but only after being burned bright red. While I was in the NT I slathered sunscreen religiously, but still managed to get a highly embarrassing burn on my lower back when I was building a sandcastle (an epic sand turtle, actually. Totally worth it.)

Anyway, enough about me and my weirdly tanned lower back (it’s been months! Why won’t it go away?) Let’s talk about Nina Jablonski, an anthropologist. In 2000 she suggested a new reason why skin colour varies so much. It’s not an adaptation to protect against skin cancer and sunburn, like I always thought it was.

It’s real job is to keep us highly fertile by maintaining a delicate balance between two key vitamins: Vitamin D and Folic acid.

Pica's skin tone matched her UVB exposure like her scarf matched her dress. Image by Monja Con Patines

Vitamin D is obtained through some foods, but mostly from drinking in sunshine. UV light turns cholesterol into Vitamin D, which then goes to either your liver or kidneys to be converted to an active form.

Once active it helps white blood cells like macrophages kill bacteria, and helps control levels of calcium and phosphate – important for building healthy bones.

Deficiency in Vitamin D causes rickets, a disease resulting in soft, easily broken bones and deformity which can lead to early death.

So getting enough UV (specifically UVB light) is important to not dying, and therefore having reproductive success later in life. It’s been backed up by Yuen, A. (Vitamin D: In the evolution of human skin colour DOI: 10.1016/j.mehy.2009.08.007)

Natural selection favours soaking up UV.

Penny stayed under foliage at noon to protect her folic acid. Image by Monja Con Patines

Folic acid is obtained in leafy vegetables and fortified cereals. Rather than being made by UV, the light can destroy folic acid by literally breaking it apart. (Jablonski, N. The evolution of human skin coloration DOI: 10.1006/jhev.2000.0403)

Critical for DNA synthesis, folic acid is essential during pregnancy when a lot of new cells are being made.

Folic acid prevents against 70% of neural tube defects in embryos. Its destruction by UV is bad news.

Natural selection favours avoiding UV.

So there’s an ideal amount of UV light that needs to get through the skin – enough to produce Vitamin D, but not too much to destroy all the folic acid. Getting the balance right for the environment you’re in means higher fertility, which drives natural selection

This is what Nina Jablonski thinks caused the evolution of skin colour through the sepia spectrum we see today. Dark skin, with high melanin, stops more UV light. That’s exactly what you want if you live in a place with a lot of sun, like places near the equator. Light skin lets more UV in, which is great if you live somewhere overcast and not very high on UV.

Understanding how your skin colour (NOT your race) influences these two vitamins is important in being healthy. It’s more important now than ever, because we humans travel a LOT.

Sadly, Australia is pretty high in UV and I am pretty white. Thank god for sunscreen.

Things are rarely that simple though, and I imagine there’s a few different things going on that connect UV light to skin colour.

On Tuesday the RiAus is holding an event called Skin Deep: Exploring human ancestry. They’ll be showing a preview of a new SBS documentary about skin colour scientific research, as well as results from the Genographic Project. Basically they took DNA samples from a lot of volunteers and some national identities, and now they’re giving us the goss on who’s related to who’s secret love child.

I’ll be there, I’d love to see you (though seats are limited.) I’ll be the one tweeting in the corner. Follow me @CaptainSkellett

Would love to hear from anyone who took part in the Genographic Project, and anyone who didn’t. Who would you most like to be related to? For me it’s David Attenborough, then I can dream of inheriting his voice.

What is a light cone?

// November 28th, 2010 // 1 Comment » // How Things Work

Simultaneous is not simultaneous. Space and time do not exist. These, and other strange and wonderful things, are the hallmarks of Einsteins Theory of Relativity and what we’re talking about today.

A few days ago I got Request a Post which read:
ahoy there, cap’tun! a prawn from beneath your deck speakin’. could you do a post on Light Cones? yeh know, the stuff Stephen Hawking talks about in the second chapter of his ‘Brief History of Time’? i’d love to read a simplified version. i simply can’t wrap the wiki article around my head! danke!

Ahoy there Prawn! Danke for requesting and here be yer post.

Something can’t move through space without moving through time as well. The Theory of Relativity dispenses with time and space, and instead describes a new thing called Spacetime.

Imagine a train moving in a straight line to the Eastward. We can map its movement through Space, Time or best of all, Spacetime! Notice how much more epically cool Spacetime looks. This will be important later.

With our Spacetime graph, we map space horizontally and time vertically.

In the realz world, there are three dimensions of space – length, width and height. Thankfully there is only one dimension of time, and this runs from past to future (unless you’re looking backwards.) To graph something using all four dimensions is hard, so instead we just take two dimensions of space and make a horizontal plane, then map time vertically. This will make sense in a second.

Now imagine a flash of light. Say you were standing on a hill on a moonless night and turned on a torch for a second. The light would spread out in every direction, lighting first the bushes near by, then later the trees in the distance. If we think about it in just 2 dimensions we can draw it like this, kind of like ripples in a pond.

If we map time vertically, and stack these pictures up above each other, we get a cone. So a Spacetime graph looks like this. Notice again that it is epically cool.

So a light cone is a flash of light moving through Spacetime. Usually people draw it as two cones. The bottom one is light collapsing into a single event, and the top one is it exploding out again.

Image by Deibid

You might be thinking – why bother?

Because this is a more accurate way to imagine the world. It shows how the past can influence the present and the future. When light cones overlap, it means two objects or events interact with each other. Every event in the Universe has an associated light cone. It’s a mathematical way to represent the Universe, and the basis for lots of complex physics (such as curved Spacetime, and why simultaneous events are relative to the observer.)

The theory of relativity replaced the absoluteness of space and time with the absoluteness speed of light.

I hope this answers ye question Prawn. Find out more about awesome light cones here.

Physics of lapping lets cats drink without mess

// November 24th, 2010 // 2 Comments » // How Things Work, Recent Research, Science at Home

First up, apologies on the lateness of my post. A whole week has gone past! Oh me! I humbly do beseech you to forgive this old salt and do throw myself upon the deck in penance. Me only defense is that I have just moved from Canberra to Adelaide, and me Schooner does need an awful lot of bubble wrap. To distract you from me own slackness, I have scoured the nets for the cutest science story evah. I ply you with kittens thusly:

.

Cats are a more delicate and refined animal than messy, smelly and drooly dogs. I’ve always been a cat person. I think they have higher standards. Turns out they also drink better than dogs.

Both dogs and cats lack the complete cheeks that humans have, which means they can’t drink water by suction like we can. Dogs get around this by using their tongues as a ladle, cupping the water from bowl to throat.

Cat’s do it differently. They lap water briskly, but not like a ladle. Instead, they DEFY GRAVITY and make the water lift up into the air like a glorious floating blob of refreshment.

Sounds crazy, but it’s true. When they dip into the dish, water adheres to the dorsal (top) side of their tongue. The surface tension (sweet, sweet hydrogen bondage) of the water drags a column of water into the air. The cat can thus pull water into its mouth using inertia.

The competition between inertia moving water up and gravity pulling it down sets the lapping frequency of the cat. Smaller cats with smaller tongues lap faster to drink, large cats lap slower. Observation of lapping frequency in big cats like lions shows the same kind of trend, suggesting they use the same physics as the household feline.

Cats might do this because it’s a neater, cleaner way to drink and it keeps their whiskers nice and dry. Whiskers have an important sensory function, so it’s worth the effort to keep them tidy.

The research was published in Science, and began when a researcher was watching his own cat drink. A video of the researcher and cat is below, and shows in super slow mo exactly how water defies gravity when a cat enters the equation.

Did you hear that? Did you? Not only is it physics, hydrogen bonding and gravity defying, plus, PLUS, the tongue could have implications for robotics of the future. Yeah. Robot cat tongues. It’s going to happen.

Actually tongues are very interesting. They obviously have no bones for support, so instead they have a muscular hydrostat system where support comes from muscles. The same thing happens in octopus tentacles, where muscles stretch in one of three directions: Along the tentacle (longitudinal), across the tentacle (transverse) or wrapping around the tentacle (helical.) When an octopus moves, one muscle contracts to become shorter which forces the muscles around to stretch, supporting the movement like a skeleton.

Cats and octopus. You know this post was worth the wait.

ResearchBlogging.orgReis, P., Jung, S., Aristoff, J., & Stocker, R. (2010). How Cats Lap: Water Uptake by Felis catus Science DOI: 10.1126/science.1195421






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