Old Wives’ Tale: Dim Reading

If you are anything like me, you love to read. I used to wear cargo pants and carry a book around in one of the pockets; I was especially fond of Tolkien’s works. And since I loved reading so much, I would read whenever I found a few minutes of time, regardless of the light. Many of my family told me that I would hurt my eyes and need glasses if I kept reading in the dark, and now I need corrective lenses. Were they right, or was that just coincidence?

Coincidence. A quick google search will lead you to an article by the ever-helpful website WebMD that reassures us that there is no scientific evidence that  reading in dim light results in any long lasting effects; it only gives the reader eye fatigue or strain. Harvard also points out some other myths about eyesight, such as eating carrots to improve vision.

“No scientific evidence” could mean that it could actually contribute to poor eye health in the long run but no one has proved this yet, but that is a stretch. It is far more likely that those who have spent years studying the eye know what is harmful to the eye and what is not. I could not find any peer-reviewed journal articles supporting or rejecting the claim that dim light reading leads to worse vision, although I did find a study that you may find interesting. According to this study in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), the use of light-emitting eReaders versus a printed book before bed can make it more difficult for you to sleep and impacts your circadian system as the light increases alertness when used immediately before attempting sleep.

So if you want super vision, put down the carrots and stop worrying about the light levels; the best thing for you is probably some form of exposure to massive levels of radiation. I kid! I kid!

Fare thee well, and thanks for reading!

Featured image from Unsplash.com’s Kate Williams.

An Experiment in Heat Treating 3D Printed PLA

Ever since I’ve started 3D printing solutions for mechanical integration of payloads into unmanned aerial vehicles, I’ve wanted to experiment with heat guns and soldering irons to see how I could affect PLA parts, which is one reason I decided to not stay around such things for extended periods of time. But someone recently mentioned to me soaking parts in boiling water as a method of strengthening them, and I thought that sounded like something not as dangerous that I could do and not go overboard on. And so I bought an old pot at a second hand store, some wire from a hardware store, and a thermometer from Walmart, then confiscated a hot plate from my university.

I wrapped the wire around the part and set it up in the pot so that the piece was not touching the bottom nor any of the edges. It wouldn’t do to have it melt, now would it? With the part in place, I filled the pot with room temperature water until the part was fully submerged with about an inch of water above it, and then I turned on the hot plate and waited. This is the closest thing to cooking that I’ve done in a long time, I thought with a small grin.

And waited.


. . . and waited. . .

Finally, I decided to check on the part outside of the pot and to possibly flip it, even though the water hadn’t reached boiling yet.


. . . Oops. . . So, to anyone experimenting with 3D printed parts in this manner, here are some things I would change in my method: 1) Make a better harness that holds the part evenly and not at an angle with respect to the heat source. 2) Add the part to already boiling water for a shorter duration (20-40 minutes, shorter on the side of caution). My part was in there for well over an hour before my impatience won over; it takes a long time to make that much water reach boiling.


It changed color, as well, though that did not surprise me. I might try something like this again, although I’m leaning more toward baking it instead. In the end, the layers were not noticeably any more merged than before and all that really happened was the obvious, undesirable warping and color change.

This PLA was extruded at 230 deg C on a build platform held at 100 deg C, so the fact that it warped so much at temps below 80 deg C was a little surprising to me. But I suppose it should not have been, seeing as water’s heat capacity is so high. Welp, lessons learned, I guess.

Old Wives’ Tale: Swallowed Gum

I have an irrational fear of swallowing gum, so much so that I’ve had a nightmare about it. This fear was brought about by the belief that the gum would sit in my stomach for about 7 years, and it would clog up the whole system. This sounds like another old wives’ tale to me now that I’m an adult. . . well, at least now that I have more years under my belt. So, does swallowed gum stay in your stomach for an absurd amount of time?

No. According to WebMD’s source, Robynne Chutkan, MD, a gastroenterologist and assistant professor of medicine at Georgetown University [1], the gum leaves your system in a matter of days. A lot of the gum’s substance cannot be digested, but it will still go through the intestine into the colon and mix with the rest of the waste.

That isn’t to say that swallowing gum is perfectly fine. It might even be logical to scare children, for instance, with these fictitious tales of everlasting gut gum just so they won’t swallow it. This article [2] took 3 cases in which kids swallowing gum resulted in extreme adverse effects. Too much swallowed gum can lead to the inability to pass waste, especially when constipation is already an issue.

But this article doesn’t just stop at the adverse effects of swallowing gum; it’s plainly against even chewing gum. There are many benefits to chewing gum, however, and it shouldn’t be disregarded completely. While the article mentions the disadvantages of chewing gum depending on the ingredients, it fails to mention the advantages, such as increased saliva production. If you chew sugarless gum, you might experience diarrhea, flatulence, or borborygmi (fancy word for tummy rumblies as fluid moves around in your digestive tract). If you chew gum with sugar, you might develop cavities. But what increased saliva production means is that less bacteria will build up and create plaque [3]. So in my mind, sugarless gum is more beneficial than not.

Another benefit from chewing gum is increased swallowing frequency. Now, you may be asking how is that a benefit since the whole point of the previous article was how bad swallowing gum is. But encouraging swallowing (heh heh) is important for people who suffer from Parkinson’s disease [4].

For those of us who have been fortunate enough to not be familiar with the symptoms of this disease, “Parkinson’s involves the malfunction and death of vital nerve cells in the brain,” according to the Parkinson’s Disease Foundation [5]. This results in less and less control of movement in the patient. So increasing the frequency of swallowing is a big deal, in this case.

Not only that, but chewing gum can help those with laryngopharyngeal reflux (LPR), which is when acid from the stomach travels up to the throat. This study [6] shows that chewing gum actually results in an increase of pH in the esophagus and pharynx, which can be used for antireflux therapy.

Continue chewing gum, ye gum chewers, and fear ye not the odd ingested parcel. Just don’t swallow the whole pack.

Fare thee well, and thanks for reading!

[1] Smith, M.W., 2008, “Swallowing Gum,” WebMD,
[2] Milov, D.E., Andres, J.M., Erhart, N.A., and Bailey, D.J., 1998, “Chewing Gum Bezoars of the Gastrointestinal Tract,” Pediatrics, 102(2)
[3] Yankell, S.L., and Emling, R.C., 1989, “Clinical Study to Evaluate the Effects of Three Marketed Sugarless Chewing Gum Products on Plaque pH, pCa, and Swallowing Rates,” J. of Clinical Dentistry, 1(3), pp. 70-74
[4] South, A.R., Somers, S.M., and Jog, M.S., 2010, “Gum Chewing Improves Swallow Frequency and Latency in Parkinson Patients,” Neurology, 74(15), pp. 1198-1202
[5] Parkinson’s Disease Foundation, http://www.pdf.org/about_pd
[6] Smoak, B.R., and Koufman, J.A., 2001, “Effects of Gum Chewing on Pharyngeal and Esophageal pH,” Ann Otol Rhinol Laryngol, 110(12), pp. 1117-1119

Picture from Ryan McGuire’s www.gratisography.com

Old Wives’ Tale: Hair Growth

A common belief that has been passed down generation to generation is that cutting hair actually encourages hair growth. I myself believed this to be true but found myself wondering if this wasn’t just another old wives’ tale that I was tricked into placing unwitting faith into something so silly. Time and time again, I find that I’ve been taught and indoctrinated to believe in things that turn out to be false. [INSERT DERIDING COMMENT ABOUT RELIGION HERE] And so I thought I’d do a little digging to get to the root of all this.

Starting off without looking up any sources, it conceptually made sense to me. We prune bushes for the good of it growing, right? So why wouldn’t it be similar for hair? And the second justification for why hair might grow faster would be because you are reducing the weight put on the follicles which would then, I reasoned, allow the follicles to push more hair out, encouraging production.

But I’m no biologist nor physician, and so that is where my train of thought paused until I could gather more information. I assume plant biology is different from human biology since I breathe in oxygen and don’t usually jizz out eggs that fly around in the air and up people’s noses, so the pruning analogy might not be valid. Hair also consists mainly of dead cells, yet another flaw. The physics viewpoint is tenuous at best. And so, to the internet I delved.

According to the Huffington Post [1] and a butt-load of other such sites, no, cutting hair does not do anything for hair growth. It gets rid of things such as split ends or weaknesses in the hair that would result in it breaking and thus partially staying shorter, but the actual rate your hair grows does not change due to the trim. Which, if you think about it, is basically only one aspect of pruning bushes (again, not a biologist). So what does affect the rate of growth? Anything?

Before I go any further, I should probably mention some of the basics about hair growth. You can check out WebMD’s article about the “science” of hair [2]. Here, you can find information about how hair grows. Hair grows in cycles which consists of a growing period (anagen), a resting period (telogen), and a transitional phase between the two (catagen). The anagen phase lasts for about 2 to 6 years, and the catagen phase lasts for 2 to 3 weeks. The telogen period lasts for about 100 days and is when the hair stops growing and falls out, about 25 to 100 resting hairs a day. There are also three different types of hair: Lanugo (fetus hair), vellus (soft, unpigmented hair), and terminal (long, thick, and pigmented) [3]. Here, I’m only talking about the terminal hair that can be found on the scalp. And with that, I’m moving on.

It’s really easy to notice a difference in the hair growth rate in animals; many animals have seasonal coats, thicker for winter and then we all get to enjoy the change of coats as they shed all over the place for the warmer seasons. Those of us with allergies get to doubly enjoy it. The length of the photoperiod affects animals’ follicles; the longer the day, the more at rest the follicles are and thus the shorter or thinner the hair [4], at least with some animals such as the cashmere goat.

Could we be affected similarly to the seasons? I didn’t look this up directly, but my answer based on the material I found is that no, our hair won’t grow more during the colder seasons, at least not significantly. And here is why I think this: we don’t shed. Not in the same sense, anyway. We don’t lose hair on an annually or semi-annually basis; instead, we lose it daily after our hair goes into the telogen phase, which 6 to 8% of our hair is at any given time [2]. We also have different hair types (vellus and terminal, as mentioned earlier), and our hair has different properties than most animals’. 

That said, there are other trends that occur during summer that could have more impact, though still imperceptively. Hair is made up of proteins, so it stands to reason that if you have a change in diet that vastly increases or reduces your protein intake, your hair growth will be affected, which WebMD also mentions [5]. Other substances that you consume will also affect your hair growth. From what I’ve found, your diet is the biggest thing that you can control that contributes the most to your hair health and growth. Well, besides hormones, but I’ll touch on that later.

However, the same woman interviewed for the Huffington Post’s trim myth article was interviewed for another article two months later on this subject [6]. I know, two Huffington Post (and two WebMD) references in one article. Ugh. But the appeal to authority is strong with this one! Their trichologist interviewee mentions in this article that whatever changes in our diet that comes of typical summer trends is minimal and probably not even noticeable, in essence. Whether or not this expert meant the same about the effects of diet minimally contributing to one’s hair is hard to discern from the short article. Perhaps she meant that compared to your genetics, any other change will likely not affect your hair in any significant manner. Or perhaps she meant just eating a lot of fruit compared to winter does not make a noticeable difference.

But what about drugs? The one drug most of us take, in many cases daily, is caffeine. Those of us concerned about growing hair can relax, though, because according to this study [7], caffeine actually helps hair shafts elongate and prolongs the anagen phase, resulting in more growth. Steroids would have a significant impact, however, as they typically contain hormones. See [3] (PO. . . had to) for speculation on how androgen could affect hair growth.

There are many other factors that contribute to the health and growth of your hair. Here’s a questionably reliable list of things that might aid or hinder you in your path to righteously awesome long, lovely locks [8]. This last reference is unfortunately the least reliable as it does not have the author’s name nor references the author might have pulled information from, so read with the realization that this person could be making up whatever they wished and just feeding it to you as absolute truth. We wouldn’t want any more myths going around now, would we?

Here’s the skinny of it: trimming your hair does not affect the growing rate which is mainly determined by your genes. You can affect your hair’s health and growth in small ways, through your diet mostly, but for the most part, your hair’s growth will not change significantly without the use of hormones, intentionally or not.

EDIT: I should have mentioned this before, but perhaps the reason we might think a hair cut results in quicker growth is due to perception. The percentage growth is easier to witness, and so when we take a look at, say, 1 inch length hair, when it grows 1 more inch, that’s 100% growth. But if we look at 10 inches of hair, 1 inch growth is only 10% growth; it’s far less noticeable. Perception is a funny thing!

Fare thee well, and thanks for reading!

[1] The Huffington Post, 2012, “Hair Growth Tips: Do Regular Trims Really Make It Grow Faster?” Huff. Post,
[2] WebMD, 2010, “Hair Loss: The Science of Hair,” WebMD,
[3] Alwaleedi, S., 2015, “The Involvement of Androgens in Human Hair Growth,” Amer. J. of Biomed. Sciences, 7(2), pp. 105-124.
[4] Lin, B., Gao, F., Guo, J., Wu, D., Hao, B., Li, Y., and Zhao, C., 2016, “A Microarray-Based Analysis Reveals that a Short Photoperiod Promotes Hair Growth in the Arbas Cashmere Goat,” PLoS ONE, 11(1), doi:10.1371/journal.pone.0147124B
[5] Saling, J. and Martin, L., 2011, “Eat Right for Your Hair Type,” WebMD,
[6] The Huffington Post, 2012, “Does Hair Grow Faster in the Summer? A Pro Gives us the Real Answer,” Huff. Post.,
[7] Fischer, T., Herczeg-Lisztes, E., Funk, W., Zilikens, D., Biro, T., and Paus, R., 2014, “Differential Effects of Caffeine on Hair Shaft Elongation, Matrix and Outer Root Sheath Keratinocyte Proliferation, and Transforming Growth Factor-Beta2/Insulin-Like Growth Factor-1-Mediated Regulation of the Hair Cycle in Male and Female Human Hair Follicles in Vitro,” Brit. J. of Derm., 171(5), pp. 1031-1043.
[8] Author, G., “Factors Affecting Hair Growth,”

Picture from unsplash.com‘s Hannah Morgan