History is full of Quirky Stories

How do they build tunnels underwater?

I was driving to Baltimore, through the Harbor Tunnel, when I wondered this: how in the world do they build tunnels, with electricity, underwater? So I did a little research.

It turns out tunnels beat out bridges for maintenance, security, weight capacity and distance capacity.

Many older tunnels were built by boring into the rock and earth underneath the water, but the Turkish Marmaray Tunnel, opened in 2013, was assembled underwater, piece by piece. It cost $3.3 billion to build. The engineers chose this method because it better suited the seismic activity in the region, but it’s an increasingly popular method for building underwater tunnels.

When engineers bore into the earth underneath the water to build tunnels, they have to worry about water breaking in to the tunnel they are building. They use a tunneling shield, which slowly moves forward as the people dig through the earth. Yes, people – as in, manual labor. There is a tool called a tunnel boring machine, but it’s immensely expensive and prone to breaking. The shield was inspired by a shipworm, which is in the saltwater clam species.

Tunneling shield, copyright HowStuffWorks.com.

The tunneling shield was inspired by the shipworm, drawn above. Image copyright treehugger.com

But when building immersion tunnels like the Marmaray, engineers don’t have to bore into the rock at all. HowStuffWorks explains it so well that I’m just going to quote them here:

To make each tunnel segment, workers assemble 30,000 tons of steel and concrete — enough for a 10-story apartment building — in a massive mold, then allow the concrete to cure for nearly a month. The molds contain the tunnel’s floor, walls and ceiling, and are initially capped at the ends to keep them watertight as they are transported out to sea.Once over the pre-dug sea trench, each tunnel section is flooded enough to allow it to sink. A crane slowly lowers the section into position while divers guide it precisely to its GPS coordinates. As each new section connects to its predecessor, a massive rubber piece on its end squeezes and distends to establish a seal. Crews then remove the bulkhead seals and pump out the remaining water. Once the entire tunnel is built, it is buried under backfill and possibly covered with rock armor.

Still, I was curious exactly how the Baltimore Harbor Tunnel came to be, so I did a little more research. In the 1940s, a federal official reportedly called Baltimore the WORST city in the entire USA, as far as traffic was concerned (take that, Manhattan!). So the Tunnel’s opening in 1957 was a major event, because Baltimore was the only route to get from Philadelphia to destinations south. The Tunnel eliminated 51 traffic signals in downtown Baltimore, and reduced a 45-minute drive through the city to 20 minutes. The Baltimore Sun excitedly reported that locals could look forward to not longer getting abused by, “battalions of outlanders whose only acquaintance with the city has been in its capacity as a bottleneck.”

(Incidentally, did you ever imagine that a publication called Toll Road News, to disseminate “news from and about the world of surface transportation tolling” existed??).

It took over two years to build the Harbor Tunnel, and supposedly it cost $130 million to build, with a $14 million financing cost. It was built using the immersion method – they pre-dug a trench underwater and sunk each piece of the tunnel. Each of the 21 sections is 300 feet long! When it opened, the tolls cost 40 cents for cars and 80 cents for trucks. According to the Bureau of Labor Statistics, 40 cents in 1950 is the equivalent of $3.93 today, Since it costs about $4 for cars to go through the Tunnel, the cost hasn’t really risen in the past 65 years!

Another big issue the engineers faced in designing the Tunnel was how to keep the carbon monoxide from building up inside of it, and how to pump in fresh air. So they designed ventilation systems at each end where the Tunnel meets land, and the CO2 levels inside the Tunnel are monitored 24/7.

So there’s a bit of history and some random interesting facts.


June, 1837

I badly miss regularly writing on this blog – I started it as an outlet, to encourage myself to be intellectually creative, and now I find that I really miss having time to delve into a topic and logic out things for fun. So in the interest of re-connecting, despite something of a time crunch in my life lately, I’ve started digging up some history I have from various projects I did primary source research for. Bit by bit I will carve out more time to explore things in depth, but in the meantime I can amuse myself and others with primary sources and the occasional random science.

The below is an excerpt I found while developing curriculum materials several years back. I should probably save it for Valentine’s Day, but hey, the author didn’t wait for February to express these ideas. And surely we could all use a hopeless romantic sigh during this week of almost-Spring, non-stop rains.

June (no day given), 1837. Pg. 144 of James Bryce’s personal journal
(copied from Curator’s transcription)

“Two weeks ago last Thursday my wife left here on a visit to her parents in Ohio. the first time we have been parted for many days since I first called her my own. and though I was willing. and anxious. she should go from a principle of duty. and from love to her. and to them. still I miss her much. the time hangs so heavy on my hands. at work it is least irksome. for there is employment. and that always gives at least comparative peace. under any circumstances– but when idle I feel her absence most sensibly. then memory is busy and the longing desire to see her again. become almost a painful feeling.

Mysterious (tie??) that gives being and blessedness to married life. a few short years ago. we were nothing to each other. then gradually more and more interested in. and knit to each other by trusting love. until now after more than a year of the most intimate acquaintance with each others characters. I can realize the force of the truth of the Divine ordinance that twain shall become one flesh…other relations of life are near and dear.. but in this. the fountains of hope and happiness of life itself are intermingled. the very being. the views and feelings. the hopes and prospects. the whole character in short. are blended and merged in one–and so must be to enjoy happiness for there is no greater mistake. than to suppose the mere ceremonial of marriage sufficient. or even tolerable. without the union of the heart.”

Epsom Salts

I started CrossFit training this week. It’s amazing and fun and I had difficulty walking for a few days afterwards! So I walked – slowly – to CVS mid-week to buy Epsom salts. My friend asked me if they really work, which made me curious to research how they work. I suspected the salt was just a carrier for some other chemical that gets dissolved in the bathwater.

I thought this would be a quick project, but I got really into the history research! Here’s what I learned.

For those of you inclined to scroll, here’s the layout of this post:

  • What are Epsom salts?
  • How are Epsom salts made?
  • A Brief-ish History of Epsom Salts
  • The Research on Epsom Salts
  • My Conclusions

What are Epsom salts?

Epsom salt is a compound of two naturally occurring chemicals – magnesium and sulfate. Magnesium and sulfate are both chemicals that help your body run smoothly – especially your bones and joints. The idea is that you absorb the magnesium and sulfate through your skin during an Epsom salts bath.

How are Epsom salts made?

The information I found online was really vague, but here is what I was able to figure out/find:

Magnesium and sulfate can both occur in water. The original “epsom spring” is/was in Epsom, England (more on this below). Originally, people used the waters as is; later, they dissolved the spring water to obtain epsom crystals.

According to the EPA, sulfate occurs naturally in our drinking water, but at small doses (high levels of sulfate can be associated with diarrhea. About 3% of US drinking water has the max recommended level of sulfate [the level at which it affects the taste and smell of the water], but sulfate levels are not regulated by the US government).

Magnesium also naturally occurs in drinking water, but at low levels. In fact, there is concern that many or most Americans may be deficient in magnesium, and there’s some push for magnesium to be added in to our drinking water.

So unless you have a naturally occurring spring with high levels of magnesium sulfate, I would venture to guess that most manufacturers today are producing magnesium sulfate in the laboratory and then infusing salts with it. I saw a few references to using Dolomite crystals, which are made up of magnesium and calcium.

If you’re interested in crystal-growing, the easiest thing is to buy some Epsom salts to start with. Dissolve the salt in the hot water and pour it over a rock in a bowl (that’s the surface for your crystals to grow on). As the water evaporates, the salt will re-crystallize. (source)  Alternatively, you can buy a Dolomite rock for crystal growing.

Dolomite crystals. Image courtesy of geology.com

Dolomite crystals. Image courtesy of geology.com

A Brief History of Epsom Salts

“… medicine sent from Heaven.”
– Nehemiah Grew, “On the Bitter Cathertic Salt in the Epsom Water” (1695)

The original “epsom spring” was in Epsom, England. In the early 1600s, the story goes, some cows refused to drink from the spring. The local people decided that the waters must be medicinal and began using it for open sores, and in 1645 Lord Dudley North published a book promoting the benefits of Epsom waters for open sores, skin conditions and “melancholy”.

Epsom, England is now known for women cheering at the local Derby. Image courtesy of Zimbio.

Epsom, England is now known for women cheering at the local Derby. Image courtesy of Zimbio.

Epsom quickly became a major tourist draw as hundreds – or even thousands, by some accounts – traveled to use the medicinal waters. In 1695, Nehemiah Grew, a physician and member of the Royal Society, published a treatise on Epsom salts. Dr. Grew may have been the first to extract Epsom salts from the water, and he recommended it for a wide array of maladies, including heartburn, poor appetite, colic, diabetes, jaundice, vertigo and many other conditions. He would flavor it with mace, which is still used today as an anesthetic.

By the early 1700s, the external use of epsom salts and waters was established in the “regular” medical profession. (“Regular medicine” was the term for what we now think of as “Western medicine”.) Retailers would boil Epsom water to get the salt crystals. Physicians would prescribe the salts along with instructions for how much water to dissolve them in. Gauze would be soaked in this solution of dissolved Epsom salts and would be applied for twenty-four hours to the affected skin, or patients would drink the solution. Around 1715, subcutaneous – meaning injected under the skin – application of Epsom salts was slowly came into popularity. Applied subcutaneously, Epsom salts were meant to be an anesthetic, relieving pain.

Still in the early 1700s, a Dr. Hoy figured out how to use sea salt to manufacture Epsom salt crystals, driving down prices and raising accusations of bogus imitation medicine.

The Epsom spring remained popular until the mid-1700s, when sea bathing became the newest health fad. Obviously, Epsom salts survived the ages despite the incoming trends.

Sources: Colonel R. D. Rudolf, “The Use of Epsom Salts, Historically Considered” Canadian Medical Association Journal (1917); A. C. Wootton, Chronicles of pharmacy, Volume 1 (1910).

The Research: Do Epsom Salts Really Work?

At first, this question seemed to lead to a lot of dead ends. I couldn’t find any published studies – I found one study that has never been published where the researchers did find increased blood and urine levels of magnesium and sulfate in subjects who took Epsom baths. But I couldn’t find any research on whether absorbing magnesium sulfate is beneficial, or if it needs to be ingested for our bodies to use it.

Since I’ve been seeing a lot in the blogosphere recently about our bodies absorbing chemicals through skin (ie, from using deodorant), I was really bothered by this. Someone had to have looked into it! So I kept looking, and I found a study published in the European Journal for Neutraceutical Research that looked at cellular increases of magnesium using some “magnesium products” (not Epsom salts, but still based on skin absorption). Not only did this study find increased levels of magnesium, but the researchers claim that skin absorpotion might be better than digesting a supplement because the digestion process destroys some of the supplement. The study looked at a really, really small group of people, so it’s hard to say whether the results are really valid. I also can’t be sure that the results apply to Epsom salts.

My Conclusions: Do Epsom Salts Really Work?

The answer is, unfortunately, that I really don’t know. Obviously I’m not a doctor and you shouldn’t take my advice anyway!

It’s honestly hard to say whether we can go on “historical precedent” or anecdotal evidence here. Yes, a lot of people have used Epsom salts for a long time. Hypothetically, if they did nothing for us, we’d have dropped it completely long ago. But human history doesn’t seem to go that way. It’s not so much that we’re good at tricking ourselves as that our bodies do respond to what we expect to feel.

Do Epsom salt baths hurt you? No (unless you use way too much Epsom salts in your bath – follow the package instructions!).

Has it been scientifically proven that they help you? Not really.

So – my conclusion? We need more research. And I would make the argument that it’s worthwhile research. Anything that people are using as a medical therapy should be seriously researched and understood, and it seems that we would additionally benefit from better understanding the ways that our bodies absorb chemicals and nutrients.

Short: Ways to Recognize You’re a History Geek

I actually started this when I worked at a history museum. I’m much more involved with science now, but they still hold true for me!

  1. When you start thinking things like “$15,000?! 200 years ago I could have bought 90 acres of farmland in New York for that!”
  2. When you have preferences for what denomination dollar bills you get in your change based on what person is pictured on the bill. I smile every time I get Andrew Hamilton, and frown every time I get Andrew Jackson.
  3. When you immediately connect pretty much every current political situation back to the Constitutional Convention – because we’re pretty much still stuck on the exact same struggles.
  4. When you look for your “favorites” every time you’re around lists or artwork of important historical figures – and they are almost never included because most people don’t know about them.

I’m sure there are many others I just haven’t noticed about myself. Any suggestions?

PS – I decided, as an experiment, to start including some posts that are more personal rather than research-y, like adventures I have (glassblowing class, paragliding, etc) and projects (photo, cooking, fitness). Like or dislike the idea? Let me know in the comments. Thanks!

Ten Things I Learned About Galileo This Week (that I may or may not have known before)

I’ve been snatching moments to read Galileo’s Daughter by Dava Sobel – a biography of Galileo and his family. I only knew the elementary school basics before, and I’m finding that he was a fascinating man. It’s especially interesting to draw comparisons to today – when our models and ideas of how the world works continue to be upended by new research and calculations.

Below are some of the things I found especially fascinating about Galileo – call it a book report, if you will.

1) Galileo was his first name. I did technically know this before, but it never occurred to me to be curious about it. Why is Galileo known for his first name like Madonna or Cher, instead of his last name like Mozart or Shakespeare or Einstein?

At first I thought that maybe it was a trend of the times. But when I looked up Galileo’s contemporaries, we know them all by their last names: Shakespeare, born the same year as Galileo; Descartes, born about 30 years after Galileo was born (who held off publishing a book of his own on the Copernican system when he heard the verdict of Galileo’s trial); etc, etc. It doesn’t seem to be an Italian thing, either: Machiavelli, for example (incidentally, I learned that both Botticelli and Donatello weren’t the artists’ real names while researching this).

Fortunately, others have wondered this same question and I found a Slate article on the topic. The simple answer is: we call Galileo Galileo because that’s what he chose to be called.

2) Galileo really didn’t mean to be a rebel.

Galileo sincerely believed in Catholicism. He sincerely believed in science. And he believed that because science could never contradict religion, then any discoveries he made only served to illuminate misinterpretations of the Bible. He went out of his way to demonstrate that his theories actually helped to support the Biblical text, in particular the story of Moses asking that the sun hold still. He pointed out that many things in the Bible were not taken literally, and that it would be blasphemous to do so.

It’s worth noting here that many people in the church really thought that Galileo was a wonderful person and scientist.

3) He learned how to be a rebel from his father, as illustrated by this wonderful quote:

“It appears to me, that they who in proof of any assertion rely simply on the weight of authority, without adducing any argument in support of it, act very absurdly. I, on the contrary, wish to be allowed freely to question and freely to answer you without any sort of adulation, as well becomes those who are in search of truth.”

– Vincenzio Galilei, father to Galileo Galilei

To re-state: Galileo believed in the pursuit of knowledge. He believed that this knowledge could only enhance his appreciation of a God-made world, and that to stifle the exploration of science could only support blasphemy.

4) At the same time, Galileo was great at flattery. It helped when you had something he wanted … like the ability to give him an appointment as the Chief Mathematician of the University of Pisa and Philosopher and Mathematician to the Grand Duke:

“Your highness … scarcely have the immortal graces of your soul begun to shine forth on Earth than bright stars offer themselves in the heavens which, like tongues, will speak of and celebrate your most excellent virtues for all time…”

Incidentally, Galileo’s dedication of the moons of Jupiter (as described in the quote above) to the Grand Duke also helped his business, because when other scientists questioned whether these celestial bodies existed at all, Galileo naturally had to supply them with his superior, homemade telescopes – to protect the Grand Duke’s honor.

5) Art and science were far more entwined in Galileo’s time than in the modern day. Part of what fascinates me about Galileo is that all of his great discoveries were simply the result of him following tangents that interested him. His interests led him to invent a compass, improve the telescope, discover the moons of Jupiter, study poetry, develop a compound microscope, design an early thermometer, study how things could float in water, develop a prototype for pendulum clocks and much more.

6) At the same time, Galileo had an uphill battle to use mathematics – his true love – in the world of science.

“I hear my adversaries shouting in my ears that … geometers [mathematicians] should stick to their fantasies and not get entangled in philosophical matters [physical sciences] … as if … anyone who knows geometry cannot know physics, and cannot reason about and deal with physical matters physically!” – Galileo

In Galileo’s time, science was driven by Aristotle’s observations hundreds of years before. To put it even more bluntly: science was driven by observations, period. The idea of using mathematics to support – or even derive – hypotheses was extremely iffy. Aristotelian science pretty much said that Nature was too chaotic to follow mathematical rules. One of the reasons that Galileo was able to gain some credence – and notoriety – advancing Copernicus’ theory of a Sun-centered universe was that Copernicus had only used mathematics. Galileo waited for years after learning Copernicus’s theory that the Earth moved around the Sun so that he could use observations, not just math. He was able to show how what you saw through his telescope paired with his mathematical logic to support his conclusions. This, along with the next item, were partial contributors to Galileo’s run-in with the Church. He also just had bad timing: Copernicus didn’t publish his theories until he was literally on his deathbed, and the Church passed edicts shortly thereafter that essentially outlawed any science that contradicted the Church’s interpretation of the Bible.

7) Galileo believed that education was for laypeople as well as high society.

This was another reason that he had the religious and scientific communities up in arms: he wrote some of his books in Italian instead of Latin – so that everyone could read it, not just scholars. He argued that it was unfair that only those who could afford to attend university had access to knowledge, arguing that laypeople had both, “Eyes with which to see her [Nature’s] works … also … brains capable of penetrating and understanding them.” As one of the Church scholars wrote, “He writes in Italian … to entice to that view common people in whom errors very easily take root.”

Further, Galileo published some of his arguments in the form of a play, poking fun at the opposition by demonstrating (through his characters) that even uneducated peasants could see that his opponents’ arguments were ridiculous.

8) Galileo wasn’t just a mind walking around on top of a body.

Galileo lived in a time when, similar to today, intellectualism was considered its own work if you could afford it. But Galileo enjoyed using his hands as much as his mind. A story goes that Galileo had unexpected visitors one day while he was gardening. Asked why he didn’t hire someone to do the manual labor, he replied, “No, no; I should lose the pleasure. If I thought it as much fun to have things done as it is to do them, I’d be glad to.” He also made sure to use real life applications in his writing. For instance, he explained how a 45-degree angle was optimal for shooting long-distance cannon fire, or how building boats in larger sizes impacted their structural integrity. This drastically changed the tone of physics; instead of trying to explain why things happened, he instead explored how they happened. This changed the focus of physics from 50,000-foot philosophy to on-the-ground, applied research that allowed the natural laws of the world to reveal themselves through their impacts.

He was also very much a family man; he and his daughter exchanged frequent letters and Galileo took on many of the finances for his brother, sisters, and children.

9) Galileo played by the rules. He really did (up until he was condemned by the Church). When the Church said that Copernicus’s theories were unmentionable, he desisted from mentioning them again in his writings until a new Pope was voted in who was more open to it. He carefully floated his ideas past this Pope before proceeding with his writing. When the Church said that he could publish about Copernicus’s theories so long as it was made clear that they were only hypotheses and not facts, he took care to do exactly that. His writing was proofread by the Church itself and approved.

So when Galileo ran into trouble – upon the publication of his Dialogue, which depicted three friends exploring the Ariostotelian and Copernican systems of the universe – it wasn’t because he’d gone behind Rome’s back or published anything without permission. It was simply that the Pope was having a bad month, had been accused of being too lax in enforcing the Catholic faith, and certain advisers counseled him that Galileo’s book was a personal insult.

Now …. did Galileo’s book basically argue that the Copernican approach was correct? Yes. But still – he had gone through all the correct channels to have his book approved and published. It would be inaccurate to say that the Church changed its mind – rather, those who were against Galileo gained the upper hand shortly after the publication of his Dialogue, which was most unfortunate timing.

There is an irony here: as soon as word spread from Rome that Galileo’s Dialogue had been banned, a fierce Black Market trade of the book sprung up. The book became more valuable, and gained both more readers and more “converts” to the Copernican system, inside of and outside of Italy.

The Church didn’t retract its ban on books teaching the Copernican theory until 1757, but the Dialogue remained banned until 1822.

10) Galileo inspired Newton’s laws of motion. Galileo was heartbroken after the Church pronounced him guilty of heresy, but his friends slowly drew him back into his projects. He refocused his energy on a project that he had allowed to lapse for most of his career: studying the laws of motion. The last book Galileo published, Discourses and Mathematical Demonstrations Concerning Two New Sciences, informed Newton’s later ideas on his laws of motion and universal gravitation. Interestingly, Galileo considered Two New Sciences to be his most important work. It nearly wasn’t published; after the Church condemned Galileo, it forbade the printing of any of his books. A Dutch publisher had to covertly visit Galileo to get his manuscript. Galileo later feigned surprise that his Two New Sciences had ever found its way to Holland, and claimed that he had not been informed of the printing until it was already underway.

On a related note, Einstein is quoted as having named Galileo the father of modern physics because of the way that he incorporated mathematics into his approach.

All in all – Galileo’s Daughter is a fascinating book, and I highly recommend it. I’m intrigued to find a book on Vincenzio Viviani when I have the opportunity. Viviani was Galileo’s student and fiercely loyal to him; we have him to thank for much of what we know of Galileo’s life and works, and his family is responsible for the eventual placement of Galileo’s body in its final, honored resting place.

I’ve been caffeinating my plants

I mentioned reading this book of tips from the 17- and 1800s recently. One tip in the book was that houseplants love food. Apparently they are partial to shrimp:

“Do remember that house plants enjoy many human foods. Leftover fish, coffee grounds, water from boiled eggs, crushed eggshells, water from cooked foods, watered milk, all give plants a lift. The effects of shrimp is best of any plant reviver.”

Anyways, one day at work I thought, “Well, why not? It’s essentially composting. And these leftover tea leaves after I drink my tea …. well, it’s just plant matter, right?” (leaving aside the scary theories about what’s really in your tea bag…)

So I started tearing open my used tea bags and putting the dregs into my plant soil.

So far my plants seem fine. I’ve noticed that the tea leaves seem to help the plant soil retain more water so I don’t need to water as frequently, which is nice (used to be my mint plant could barely make it a night without wilting, now it can go the weekend). And I might be mistaken, but my mint plant seems healthier – there was some spotting last week that implied a soil deficiency, and there seems to be less spotting today.

I really am curious if my plant is technically …. caffeinated now. I mean, when I put some of those mint leaves into my water …. will I be getting caffeine? Must research.

I wonder….

Did earlier generations ever deal with frozen cucumbers? Maybe frozen cukes were the “new popsicle” in some day and age? Or maybe cucumbers were eaten before they could freeze in the winter during pioneering days?

All I know is, I’ve got half a cucumber from the back of my fridge and I’m not quite sure what to do with it.

I just googled, but all the recipes involve salting the cucumbers first …. presumably to draw out the water and freezer-pickle them.

Ah, here we go. From The Complete Cook Book (Philadelphia, 1900), by Jennie Day Reese – reproduced here from The Old Foodie:

Take six large green cucumbers, cut a slice lengthwise from each one, and with a silver teaspoon or your fingers remove the seeds and pulp, and throw the hulls in cold water until ready to use. Peel and chop coarsely two whole cucumbers, add to them the seeds and pulp of the other six and let it stand in salted ice water one hour. Cucumbers should have a thick peeling taken off of them, as they are bitter near the skin.
Now drain the water from them, add two tablespoonfuls of chopped chives, one teaspoonful of grated onion, two tablespoonfuls of chopped celery, one tablespoonful of Durkee’s dressing, one cup of mayonnaise salt and tabasco sauce to taste. Color with spinach green and freeze. When frozen stuff the cucumber hulls with it, place them on fresh crisp lettuce leaves and serve at once. It should be a light green when frozen. This is new and beautiful as well as good.

From personal experience, I can attest to why they freeze the spinach but not the lettuce. Trust me, folks, don’t freeze your lettuce.

Frozen salad boats – quite a concept.