Lichtenberger Engineering Library

Creating Citations with EndNote – Learn & Create Xpress Class!

We have joined with the Engineering Technology Centers to present a new series of classes!! The Learn & Create Xpress Classes will cover a variety of topics and are scheduled for Thursday afternoons at 2:00 p.m. in the Engineering Library Creative Space. The classes are half an hour long and are limited to 20 participants. Click on the link to register!

This Thursday, Feb. 8, 2018, Marina Zhang, Engineering & Informatics Librarian, will be presenting Creating Citations with EndNote. EndNote is a bibliographic management tool for collecting, organizing, sharing, and formatting citations. It is citation management software which allows you to import, organize, and format citations for your papers and articles! Sign up now – registration is limited and you don’t want to miss this class! This is information you will use throughout your academic career!

Each Learn & Create class is limited to 20 participants – and they fill up fast! To register for each class head to the Learn & Create Xpress Classes webpage! Each class has a registration link and the option of being put on a wait list if the class is already full!

Future Learn & Create Xpress Classes:

2/15/2018: Oscilloscope Basics. An oscilloscope allows for the observation of varying signal voltages. We have one available to check out in our Tool Library. Diem Nguyen and John Kostman from the Engineering Electronic Shop will be the presenters.

2/22/2018: Patents & Standards: The University of Iowa Libraries provides electronic access to several sources of patents and standards from around the world. Kari Kozak, Lichtenberger Engineering Library, will present the various resources that can be accessed on and off campus.

3/1/2018: Multimeter Basics: The multimeter is a tool used for measuring voltage, current, and resistance. We have one here in the Tool Library and it is available for you to check out. Diem Nguyen, Engineering Electronic Shop, will help you learn to troubleshoot electrical problems!

3/8/2018: Collect & Analyze Data Using LabQuest Devices. The Tool Library includes LabQuest Devices and a wide range of sensors to use with the LabQuest. These LabQuest devices allow for collecting and analyzing data – with a nearly endless number of possibilities! This course, presented by John Kostman, Engineering Electronic Shop, will provide an overview of what the Tool Library has and instruction on how to use it.

3/22/2018: MATLAB. MATLAB combines a desktop environment tuned for iterative analysis and design processes with a programming language that expresses matrix and array mathematics directly. Learn what is possible with this software! This class will be presented by Mitchell Moeller.

3/29/2018: Creating a Poster for Presentation. Presenter: Scott Coffel, Hanson Center for Technical Communication.

4/5/2018: Camtasia & Video Creation. Create and edit video tutorials and presentations via screencast using the Camtasia software suite! John Kostman & Diem Nguyen, Engineering Electronic Shop, will help you learn about the software PC World calls “a full-featured education/information video tool.”

4/12/2018: Managing Data with OpenRefine. Presenter: Brian Westra, Hardin Library for the Health Sciences.

4/19/2018: 2D & Vector Design with CorelDRAW. CorelDRAW is a vector graphics editor and image-editing software package. Learn about power that CorelDRAW gives you to create digital art! Presenters: John Kostman & Diem Nguyen, Engineering Electronic Shop.

Each of these classes are limited to 20 participants – and they are filling up! To register for each class head to the Learn & Create Xpress Classes webpage! Each class has a registration link and the option of being put on a wait list if the class is already full!

Don’t miss out on these free and informative classes – sign up now!

New Learn & Create Xpress Classes!!!

This week, 2/1/2018, Cliff Curry from the Engineering Electronic Shop will be presenting Printing Circuit Boards: Testing (Part 2). This session is a follow-up to last week’s session and will go into detail about special problems and challenges for circuit boards, including testing.

Check out the schedule for the rest of the Learn & Create Xpress Classes:

2/8/2018: Creating Citations with EndNote. Marina Zhang from the Lichtenberger Engineering Library will be presenting on how you can use EndNote in your next paper or project. EndNote is a bibliographic management tool for collecting, organizing, sharing, and formatting citations.

3/29/2018: Creating a Poster for Presentation. Presenter: Scott Coffel, Hanson Center for Technical Communication.

4/12/2018: Managing Data with OpenRefine. Presenter: Brian Westra, Hardin Library for the Health Sciences.

Don’t miss out on these free and informative classes – sign up now!

It’s National Puzzle Day!!

Are you addicted to Sudoku? Rubik’s Cube^© ? Logic puzzles?

Well, you are in luck, because —

January 29th is National Puzzle Day!!

Nothing is a difficult as it seems

Nothing is as easy as it looks

Puzzles always have one, several, or no solutions

^{(Gianni A. Sarcone in the introduction to Impossible Folding Puzzles and Other Mathematical Paradoxes)}

SO many puzzles! Where does one even begin!?

How about Tic-Tac-Toe!

How much time did you spend playing tick-tac-toe when you were a kid? Did you realize the person who had the first go was at a disadvantage? The first player actually has to draw one connecting line longer than the opponent. So, if you are the first to go and still win, that’s impressive! If you add more squares – say 18 – there are 153 connecting lines. Which means there are 3¹⁵³ game situations – roughly equivalent to the number of particles in the universe. Searching for a winning strategy is quite impossible and sometimes referred to as “computational chaos.” I had trouble winning with just 9 squares….

Another popular grid puzzle is Sudoku. The most common version of the puzzle consists of 9 squares by 9 squares – a grid of 81 squares. The grid is divided into 9 blocks, each containing 9 squares. The rules: each of the 9 blocks must contain all the numbers 1 – 9 within the squares. Each number can only appear once in a row, column or box. The tricky part is that each vertical 9-square column or horizontal 9-square line – within the larger square – must also contain each of the numbers 1 – 9, with no repeats… Each puzzle has only one solution…

If that isn’t challenging enough, there are also circular Sudoku puzzles!

Each of the 4 rings and 8 quarter circles have the numbers 1 through 8 (unlike the square version which has 9). Of course, you can always have 3-ring puzzles, or 5 and 6 ring puzzles. Variants and puzzles can be found in Nets, Puzzles, and Postmen.

How many of us have tried to solve the Rubik’s Cube^© ?

The classic Rubik’s Cube^© consists of 26 cubelets on 3 levels. Each level of cubelets can be twisted by 90 or 180 degrees. If you twist the layers independently the cube can be brought into approximately 43 million, trillion possible states of the cube (yes, really 43 million trillion!) … The goal? Make each side of nine cubelets the same color. Tomas Rokicki, a Stanford trained mathematician, ran a program on the supercomputer at Sony Pictures Imageworks. The computing time required the equivalent of 50 years of computing – and with solving more than 25 million billion configurations none were recorded that required fewer than 22 moves. Are you able to do it in 22 moves? Are you able to do it in fewer than 22 moves?

Are you able to solve it in a minute and a half? This robot made with Legos^© and Raspberry Pi (we have the Raspberry Pi 2 in our Tool Library!) can!

Ready for the grown-up version of the baby donut stacker?

The Tower of Hanoi is a much more complicated form of the donut stacker. It was invented by the French mathematician, Edouard Lucas, and was first sold as a toy in 1883. The goal is to transfer the tower of 8 disks to one of the 2 vacant pegs in the fewest moves possible…without putting a larger disk on a smaller one…. For 8 disks that will take 255 moves… If you haven’t figured it out for yourself, the complete mathematical formulas are on pages 196-200 in Famous Puzzles of Great Mathematicians.

Logic puzzles more your style? Try to solve these – good luck!!

Wine & Water:
- A dishonest servant takes 3 pints of wine from a barrel and replaces those pints with the same amount of water. He repeats his theft twice, removing a total of 9 pints, replacing those pints with water. As a result, the diluted wine remaining in the barrel lost half of its former strength. How much wine did the barrel originally hold?
Animals in a field:
- A cow, a goat, and a goose graze on grass in a field. The cow eats the same quantity of grass as the goat and the goose together. the cow and the goat eat all of the grass in the field in 45 days, the cow and the goose in 60 days, and the goat and the goose in 90 days. How many days will it take the cow, the goat, and the goose together to eat all of the grass, assuming that the grass grows at the same daily rate?
Compose plane figures/Fibonacci’s numbers:
- Make a rectangle without any gaps by using small squares whoe sides are the Fibonacci numbers 1, 1, 2, 3, 5, 8, 13, and 21.

^{(answers to these puzzles can be found in Famous Puzzles of Great Mathematicians.)}

Want more logic puzzles? Origami, Eleusis, and the Soma Cube, by Martin Gardner presents (among others) a puzzle called The Monkey and the Coconuts…

Ever heard of the “pea and the sun paradox?” A solid of any size (a small pea for example), can be partitioned into a finite number of pieces and then reassembled to form another solid of any specified shape and volume, (the sun, for example). Is that even possible? Author Leonard Wapner explores this (and many more) puzzles in The Pea & the Sun : A Mathematical Paradox.

Or perhaps you would rather eat the puzzle? Try the chocolate puzzle with real chocolate bars and enjoy them once you have solved the puzzle!

The solution may found on page 67 of Impossible Folding Puzzles and Other Mathematical Paradoxes.

Resources:

Smullyan, Raymond M. 2009. Satan, Cantor and infinity : mind-boggling puzzles. Mineola, NY : Dover Publications. Engineering Library QA 95 .S5 2009

Szpior, George. 2010. A mathematical medley : fifty easy pieces on mathematics. Providence, R.I. : American Mathematical Society. Engineering Library QA93 .S973 2010

Gardner, Martin. Hexaflexagons, probability paradoxes, and the tower of Hanoi. 2008. Cambridge ; New York : Cambridge University Press. Engineering Library QA95 .G247 2008

Higgins, Peter M. Nets, puzzles, and postmen. 2007. Oxford ; New York : Oxford University Press. Engineering Library QA95 .H54 2007

Clarke, Barry R. 2013. Mathematical puzzles & curiosities. Mineola, N.Y. : Dover Publications. Engineering Library QA95 .C53 2013

Petkovic, Miodrag S. Famous puzzles of great mathematicians.Providence, R.I. : American Mathematical Society. Engineering Library QA95 .P4358 2009 2009

Sarcone, Gianni A. 2013. Impossible folding puzzles and other mathematical paradoxes. Mineola, New York : Dover Publications. Engineering Library QA95 .S315 2013

Gardner, Martin. 2008. Origami, Eleusis, and the Soma cube: Martin Garnder’s mathematical diversions. Cambridge ; New York : Cambridge University Press. Engineering Library AQ95 .G2975 2008

Wapner, Leonard M. 2005. The pea & the sun : a mathematical paradox. Wellesley, MA : A.K. Peters. Engineering Library QA248 .W29 2005

Count on Sudoku. 2005. counton.org

Lego Rubik’s Cube Solver.youtube . Date accessed January 31, 2017

Raspberry Pi-powered Lego robot can solve a Rubik’s cube.The Next Web B.V. January 31, 2017. TNW.

Rockbolting

If you are like me and are driving through a rock tunnel (like the one below in Custer State Park, South Dakota), you might be amazed at how sturdy it is and a little afraid of the “Falling Rock” sign. But, again, if you are like me, you’ve probably not given more than a passing thought to how the tunnel was created and what keeps it from collapsing…

Part of the answer is “rock bolting.” According to dictionary.com, the term “rock bolt” was first recorded between 1955 and 1960 and is the “steel or fiberglass bolt inserted and anchored in a hole drilled in rock to prevent caving of the roof of a tunnel or subterranean chamber.” The use of rock bolts goes back much further than 1955, however. The use of rockbolts was documented at the end of the 1800s, and in the 1900s, it was introduced in coal mines.

And, in November 1930, the Detroit-Windsor Tunnel was dedicated. It is a 5,160-foot-long tunnel between the cities of Detroit, Michigan, and the Canadian city of Windsor, Ontario. The first passenger car to drive through it was a 1929 Studebaker. The first Michigan-to-Canada tunnel opened in 1891 – the 6,000-foot-long Grand Trunk Railway Tunnel. During the first 9 weeks the Detroit-Windsor Tunnel was open nearly 200,000 cars passed through it. Today, around 9 million vehicles use it each year!

On December 1st, 1990 workers – 132 feet below the English Channel – drilled a car-sized opening through a wall of rock! The “Chunnel” (Channel Tunnel) connects Great Britain with the European mainland. It took nearly 13,000 workers four years to dig 95 miles of tunnel. The average depth of which is 150 feet below sea level. The cost? $15 billion….

As one might expect, the process of rockbolting is complicated and there are different types of rock bolts for different situations. The reinforcement function of a rockbolt depends on the load carried on the bearing plate. That loading pattern is dependent on rock mass quality, rock joint pattern, rock stresses, and the anchoring mechanisms of the bolt.

Rockbolts are generally made of steel and their design is based on how they are used. Some typical rockbolts include the mechanical rockbolt, slot-and-wedge rockbolt, and a grouted rockbolt. There is even an inflatable rockbolt! For more information on these, and many more, refer to the chart (left) and our resource Rockbolting: Principles and Applications.

Rockbolts do fail – especially during dynamic load shifts, often after a rockburst (a sudden, violent, rock fracture). For a quick look at a rockburst check out this video! Needless to say, there is a lot of quality control and testing which must happen with rockbolts. The quality and composition of the steel used in rockbolts is obviously critically important. There are also design proof tests, and viscosity tests of the cementitious grout. Along with the quality control on the mechanical properties of the rockbolt, there are many tests that are done on-site. These include pull tests, proof tests, and the inspection of boreholes.

Corrosion of rock bolts from direct contact with acidic groundwater. Photo credit: *Practical Guide to Rock Tunneling*,

If you are thinking of building a rock tunnel, there is, not surprisingly, lots of pre-planning, site investigations and testing that must be done before the actual building can begin. Practical Guide to Rock Tunneling is just that, a guide explaining the planning process and what needs to be taken care of – including the design, drainage requirements, rock strength, and practical considerations (among many others!). It is full of photos – many in color – of the various stages of tunneling and the equipment used. There are also a number of tables and graphs detailing everything from historical failures of hydraulic pressure tunnels (figure 6.3) to a critical path construction schedule example (figure 14.1) to a risk matrix for quantitative assessment (16.3).

Links between rockbolts, mesh, mesh strap, and mesh square. Rockbolting: Principles and Applications.

Whether you are planning a career in tunnel building – or thinking ahead to tunneling out of a snow fort this winter – be sure to check our resources. We’ll help you dig through . . .

Resources:

Brox, Dean. 2017. Practical guide to rock tunneling. Leiden, The Netherlands : CRC Press/Balkema. Engineering Library TA805 .B75 2017

Li, Charlie Chunlin. 2017. Rockbolting : principles and applications. Oxford Buttenworth-Heinemann. Engineering Library TA772 .L5 2017

International Symposium on rock Fragmentation by Blasting. A.T. Spathis. 2013. Tunnelling in rock by drilling and blasting : workshop hosted by Fragblast 10 : the 10th International Symposium on Rock Fragmentation by Blasting, New Delhi, India, 24-25 November, 2012. Boca Raton : CRC Press. Engineering Library TA800 .I58 2012.

1930, Detroit-Windsor Tunnel is Dedicated. This Day in History. November 1. History. A&E Networks. Date Accessed: January 2018

Kaiser, Peter, K.; Ming Cai. 2015. Design of rock support system under rockburst condition. Journal of Rock Mechanics and Geotechnical Engineering. vol. 4, issue3, 25 Sept. 2012, pgs 215-227. Science Direct .

rock bolt: Word origin: 1st recorded in 1955-60. noun, Mining, Civil Engineering. 1. a steel or fiberglass bolt inserted and anchored in a hole drilled in rock to prevent caving of the roof of a tunnel or subterranean chamber. — dictionary.com

Chunnel makes breakthrough. This Day in History, Dec 01. History. A&E Networks.

Build Your Own Igloo!

So, it’s winter. You are tired of being cooped up inside. You need exercise (and not on a treadmill). You need fresh air. Got snow? Why not build an igloo?

A great way to spend some time in the great outdoors – fresh air, exercise – fun with your family and friends! So, let’s get started!

According to Norbert E. Yankielun, author of How to Build An Igloo and Other Snow Shelters, the first thing to do is “make friends with winter.” Which makes sense since you’ll be outside working with snow – it’s cold out there and you don’t want frostbite, dehydration, or hypothermia. To protect yourself, you’ll want to be sure to have the right clothing, nutrition, and water. You may already know that several layers of clothing are the best way to insulate yourself from losing body heat. But, you do want to avoid wearing cotton clothing because it absorbs and holds water and moisture. Similarly, you’ll want to wear mittens (which are warmer than gloves) that have a waterproof shell to keep your hands dry. And, don’t forget the sunscreen and UV-blocking sunglasses or goggles – the sun glaring off white snow intensifies the damage to skin and eyes.

So, what else do you need to know to make your own backyard igloo? It is possible to build an igloo by yourself – but what fun would that be? It is also much safer to build with another person. If you are building in an urban setting there are some “don’ts” about which you should know. Avoid the piles of snow near parking lots, streets, driveways, etc., a plow driver could easily mistake an igloo for another pile of snow. You also don’t want to build too close to parking lots, roadways, or driveways to avoid the possibility of car exhaust and carbon monoxide poisoning.

So, you have a safe spot picked out and a group of your friends/family. What else do you need?

Snow. You have to have snow to build an igloo (obviously). There are lots of different types of snow – which are beyond the scope of this blog. What you want for a good, strong igloo is sintered snow. Sintering is what happens when you compress snow into a snowball – it squashes the flakes, briefly melting the edges and then re-freezing into a snow mass. It also occurs when snow goes through melt and freeze cycles. Don’t have sintered snow in your yard? Stomping the snow underfoot is one of the easiest ways to create the snow blocks you’ll need for your igloo.

Now, what tools do you need? For the recreational igloo builder, ordinary tools will suffice. A carpenter’s saw will work nicely to cut blocks of snow – but cutting snow will ruin the blade for much of anything else. Buy an old blade at a garage sale! A flat-handled show shovel – the kind used for clearing sidewalks and drives – works great (avoid the “pusher” type shovels). The ideal shovel is a grain scoop…

You are with your family and friends, have snow, are dressed in layers and have assembled your equipment. What’s next?

Once you find a nice, flat area for your igloo, you’ll need to size your igloo and flatten the floor. An igloo large enough for 2-3 people should have a diameter of at least 6 feet. Have ski poles? Plant one to use as the center and use the other to draw the circle around it. Or for more fun, have the tallest person in your group make a snow angel – that will give you approximately the right sized igloo for two people! Then if you all get together and stomp around inside the circle, you’ll tromp down the snow into a nice foundation!

If you have sintered snow, take your saw and start cutting your blocks! Blocks need to be the same size and it is suggested they be about 18 to 24 inches long, 9 to 12 inches thick, and 12 to 18 inches tall.

Don’t have sintered snow? No worries, you can also use a clean bucket, or storage tub and pack the snow in that. When you turn it upside down you have your snow block! Got those ice blocks made? Time to start building that igloo! Place them, edge-to-edge, on your circle. Once you have the first layer made, you’ll want to cut the blocks into a ramp which should go at least halfway around the block circle. Now you can begin stacking the blocks on the ramp base. You’ll probably have to cut the edges of the blocks so they will fit tightly together. In order to form a stronger structure, you’ll want to be sure the block bridges the seam of the two blocks beneath it. It is helpful to have one person inside the igloo to help place and shape the blocks and to help place the cap block (or King Block) on the top of the igloo! The cap block has to be carefully shaped so it will support the inward leaning of the walls.

Yes, you have now enclosed one of your party inside the igloo with no way out! Making the entrance before the dome is complete weakens the entire structure, so that part of the construction must wait. (Might be a good idea to make sure the person on the inside isn’t claustrophobic!) There are a couple of options to consider when planning your entrance. One option is the “gopher hole.” A gopher hole is basically building a tunnel under the wall of the igloo – an advantage is it helps keep the heat inside the igloo! The other option is a surface entry, which I suspect, is what we think of when we visualize an igloo. It is an arch-shaped entry cut into the side of the igloo. Using an arch shape helps reduce the stress on the shell of the igloo when creating a hole in the wall. It shouldn’t be larger than 2’x2′ – just large enough to crawl through.

These are the basics of igloo building – be sure to check our resources before you start your own! Learn from the experts!

There are other types of snow shelters: quinzees (a hollowed out, dome-shaped mound of well sintered snow); slab shelters (looks like a pup-tent or A-frame); drift caves (similar to a quinzee – only in a hollowed snow drift); and spruce traps (using the umbrella of a spruce, pine, or other evergreen tree as a shelter). How to Build an Igloo and Other Show Shelters is a great source of information about these shelters and how to build them!

Be sure to check out Igloo : Contemporary Vernacular Architecture – it is an absolutely fascinating look at modern architecture and the influence the igloo has played!

Want to see the Guinness World Record holder for largest snow dome igloo ever built? Check this out!

Get outside! Get some fresh air! Get some great exercise! Build an igloo!

(I don’t think you’ll need to worry about a polar bear checking in on you!)

ENJOY!!

References:

Yankielun, Norbert E. 2007. How to build an igloo : and other snow shelters. New York : W.W. Norton. Engineering Library TH4890 .Y36 2007

Bahamon, Alejandro, Ana Canizares, editors. 2012. Igloo : contemporary vernacular architecture. Atglen, PA : Schiffer Publishing, Ltd. Engineering Library TH4890 .I35 2012

Other Resources:

Hewings-Martin, Yella. Jasmin Colllier, Fact Checker. Nov. 7, 2017. Why am I cold when nobody else is? MedicalNewsToday. Healthline Media UK Ltd.

National Film Board of Canada. Jan. 6, 2015. How to Build an Igloo. youtube.

How to Build An Igloo. NOVA. PBS.

Igloo 101. arcticPassage. NOVA Science Programming on Air and Online. Date assessed 12/06/17

Heid, Matt. March 1, 2012. Snow Sintering: How to Get Cohesive Snow for Building Snow Walls and Snow Shelters. Appalachian Mountain Club; AMC.

Photo Credit: How to Build An Igloo. NOVA. PBS.

How Much Coffee? Make a Guess – Win a Mug!

How many cups of coffee will be made in the Engineering Library during Finals Week?

Make a guess & win an official Lichtenberger Engineering Library Travel Mug!!

Don’t forget we have extended hours!

Sunday, December 10^th, from 2:00 p.m. to midnight

Monday through Thursday, December 11^th through 14^th, 8:30 a.m. to midnight

Friday, December 15^th, 8:30 a.m. to 5:00 p.m.

Post your guess on Facebook or Twitter by 6:00 p.m. on December 13^th! Use #uienglibcoffee to post your guess! If your guess is the closest to how much we actually serve, you will win a new Lichtenberger Engineering Library travel mug! You don’t want to miss out on winning this amazing travel mug – be the envy of all your classmates!

Good Luck!!

Twitter: @UIEngLib

FB: UI Lichtenberger Engineering Library

Contest open to University of Iowa students, faculty and staff. Only one guess per person.

Extended Finals Week Hours!

It’s that time again – FINALS WEEK!

Are you finding that you are having trouble concentrating when you try and study in your room? Too many distractions? The couch and TV or gaming system just too close? Or that nice, soft, comfy bed? Let us help!

Extended Hours

Sunday, December 10^th: 2:00 p.m. to Midnight

Monday, December 11^th through Thursday, December 14^th: 8:30 a.m. to Midnight

Friday, December 15^th: 8:30 a.m. to 6:00 p.m.

Saturday and Sunday, December 16^th and 17^th: Closed

And, to help you stay awake and focused – we’ll be providing FREE coffee, hot chocolate, and hot cider throughout the week (while supplies last!!)

Please bring your own mug – Mother Earth will thank you!

We have plenty of space for both individual and group study. We have 2 group study pods with white boards, and pod 1 has MediaScape^®. Instructions for reserving the study pods are here on our webpage.

The Creative Space is also available for group or individual study! We have two 4-person collaboration tables with 43 inch (4K) quad monitors, 4 modeling stations, and 5 dry erase boards! There is room to spread out and work collaboratively on that final project!

And, don’t forget the lower level of the library is a dedicated quiet space! We have study carrels (with lights & electrical outlets), easy chairs, bean bag chairs, and gamer chairs. You’ll be able to find the perfect spot to focus and concentrate.

We also have tools and cables in the Tool Library. Need a calculator? You can check one out! And we have cables and chargers in case your laptop battery runs low!

Stress getting to you? Need a break to help clear your mind? We’ve got you covered there, too! We have Color by Number – Engineering Style grids, LEGOs^®, and this year we have an augmented reality sand table! Perfect for giving your mind a break!

Come study with us – and GOOD LUCK!

SKYWARN® Recognition Day!

Tomorrow – December 2^nd – is National SKYWARN^® Recognition Day!!

So, just what is SKYWARN^® ?

SKYWARN^® is a National Weather Service (NWS) volunteer program with between 350,000 and 400,000 trained severe weather spotters. The main responsibility of a SKYWARN^® spotter is to identify and describe severe local weather and storms. Unlike storm chasers, they generally stay in one place until it is necessary for them to move. The spotter is the “eyes and ears in the field” for the NWS.

In 1999, the NWS and the American Radio Relay League (ARRL) created SKYWARN^® Recognition Day to recognize and honor “. . . the contributions that SKYWARN^® volunteers make to the NWS mission, the protection of life and property. . .”

If you are interested in learning more about the weather, we can help! We’ve had several blogs over the last couple of years that have covered weather – from hurricanes and tornadoes to snow and ice. Catch up with our weather blogs here! If you are interested in hurricanes and tornadoes check out our resources, including Weather and Climate : Notable Research and Discoveries, Extreme Weather : Understanding the Science of Hurricanes, Tornadoes, Floods, Heat Waves, Snow Storms, Global Warming and Other Atmospheric Disturbances, and Big Weather : Chasing Tornadoes in the Heart of America.

Think you would be interested in becoming a SKYWARN^®volunteer? Training includes learning about basic severe weather structure and development, how to report, and basic severe weather safety. Training is free and typically lasts about 2 hours. Volunteers include police, EMTs, dispatchers, fire fighters, individuals affiliated with hospitals, schools, nursing homes – and concerned private citizens! You can attend training at any NWS office facility, no matter where you live! Check SKYWARN training for information and find the SKYWARN^® program in your area! Attend a training course near you, register as a spotter, and help keep your community safe!

Thank you to all the spotters out there who volunteer their time to help the NWS with the updated, real-time weather information!

Resources:

Skywarn Recognition Day : First Saturday in December. National Day Calendar. Date accessed Nov. 20, 2017.

Skywarn Recognition Day : December 2, 2017 from 0000z to 2400z. National Weather Service. Date accessed Nov. 20, 2017.

NWS SKYWARN Storm Spotter Program. National Weather Service. Date accessed Nov. 20, 2017

Find Local Training Classes. SKYWARN. Date accessed Nov. 20, 2017

Kirkland, Kyle. 2010. Weather and climate : notable research and discoveries. New York : Facts on File. Engineering Library QC861.3 .K57 2010

Mogil, H. Michael. 2007. Extreme weather :understanding the science of hurricanes, tornadoes, floods, heat waves, snow storms, global warming and other atmospheric disturbances. New York, N.Y. : black Dog & Leventhal Publishers. Engineering Library QC981 .M65 2007

Svenvold, Mark. 2005. Big weather : chasing tornadoes in the heart of America. New York : Henry Holt. Engineering Library QC955.5 .U6 S75 2005

Leonid Meteor Shower This Weekend!

It is November and that not only means Thanksgiving, it also means it is time for the Leonid Meteor Shower!

Modra Observatory of the 1998 Leonid meteor shower.

The meteor shower begins on November 5^th and will continue through November 30^th. But, the peak – ah, the peak – will be THIS WEEKEND – November 17^th and 18^th!

Other meteor showers may be more popular, but “. . . the Leonids of November are the most famous.” (Meteors and How to Observe Them). The Leonids can be seen from nearly everywhere on Earth and has produced some of the most impressive meteor storms on record. The meteors seem to emanate from the constellation Leo, hence the name “Leonids.” They are formed when the earth moves through the orbit of the comet 55P/Tempel-Tuttle, which is a a small comet, roughly 2.2 miles across (It takes Tempel-Tuttle 33 years to orbit the sun once!). The rates at which meteors fall can range from around 15 meteors per hour to hundreds or thousands per hour (which happens every 33 years or so). And, they are fast. They travel at 44 miles per second. The Leonids are also known for their fireballs and earthgrazer meteors. Fireballs are large explosions of light and color which can persist longer than an average meteor streak. A fireball comes from larger particles of the comet debris and are also brighter the average meteor streak. An earthgrazer is a meteor that streaks close to the horizon – they are known for their long and colorful tails. (Interesting fact: Tempel-Tuttle comet was discovered twice – independently – by Ernst Tempel in 1865 and Horace Tuttle in 1866.)

Confused about terminology? A meteor is a piece of stone or metallic material which burns up when it enters the Earth’s atmosphere. A meteoroid is a piece of stone or metallic material which is traveling through space. And, a meteorite is a meteor which doesn’t burn up before impacting Earth’s surface. A meteor shower is when dust or particles from asteroids or comets enter Earth’s atmosphere at a high rate of speed. When they hit the atmosphere, they heat up – which vaporizes most meteors – producing what we call shooting stars. Those particles of dust may be a small as a grain of sand or as large as a boulder! A meteor storm contains at least 1,000 meteors per hour. The term “meteor shower” was coined after astronomers’ observed an impressive Leonids meteors in 1833.

Want the best viewing experience? You won’t need those binoculars or telescope – the Leonids can be seen with the naked eye. The point from which the meteors originate (the constellation Leo) is called the radiant. NASA recommends looking outside the constellation – the meteors will appear longer and “more spectacular.”

Here are some other viewing tips: Try and find an area away from city lights – and come prepared with blankets or sleeping bags (November nights can be pretty cold!). Lie flat on your back, with your feet to the east and look up! It may take about 30 minutes for your eyes to adjust to the darkness and then you’ll begin to see the meteors! The best time for viewing is late evening tonight, Friday, November 17 until dawn tomorrow – the 18th.

Cross your fingers for clear skies, grab your sleeping bag, a thermos of something hot, and get ready for a star-studded light show!!

Catch a falling star and put it in your pocket
Never let it fade away
Catch a falling star and put it in your pocket
Save it for a rainy day

— written by Paul Vance & Lee Pockriss

Resources:

Lunsford, Robert. 2009. Meteors and how to observe them. New York ; London : Springer. Engineering Library QB743 .L86 2009

Meteors & Meteorites: Leonids. NASA. Date Accessed 11/16/17

Adams, Dallon. November 15, 2017. Sky watchers, get your popcorn ready: A guide to the Leonid meteor shower. Digital Trends.

And the answer is… StarChild. High Energy Astrophysics Science Archive Research Center. Astrophysics Science Division at NASA.

Meteor Showers and Shooting Stars: Formation, Facts and Discovery. June 9, 2017. space.com > Skywatching.

Photo Credit:

Leonids Meteor Shower | 2017. Photo via ranker.com. Fun HeapSF

Engineering Time – A New Exhibit

Guest Blogger: James M. Cox

The phrase “(Insert item here) makes the world go around” is used frequently to express the importance of an idea or concept. Time does not make the world go around. The tools used to measure the time it takes the world takes to go around is one of the most important tools in human history.

Stop in and see our new exhibit “Engineering Time”

As the human race and cultures shifted from a hunter-gatherer society to an agrarian society, the measurement of time became more important. “Once [time] caught humankind’s attention, savants never stopped inventing and building tools to improve the measurement of time. ‘Controlling’ time allowed ways to improve survival as well as structure society.”[1]

The Gishodo Suwako Watch and Clock Museum has a full-sized working replica of Su Song’s Clock.

“Five thousand years ago, Sumerians had a calendar that divided the year into 30-day months, divided the day into 12 periods (each corresponding to 2 of our hours), and divided these periods into 30 parts (each like 4 of our minutes).”[2] The year began and ended around the harvest each year. The harvest began at different times each year, depending on how the crops had grown, resulting in an irregular year. Once the scribes began accounting and making records they shifted to a regular 12 month year with 30 days, or 360 total days. During the 8^th Century BCE, civilizations began to adopt the 365 day calendar.

For the smaller increments of time, early means of measurement were simple. A gnomon was a simply a stick, tree, or person standing upright and the shadow was measured. This would evolve into the sundial. Clepsydras, or water clocks, were developed during the 16^th-13^th century BCE. These were filled with water, which dripped out of the bottom and had markings in the upper portion to measure the passage of time by the decreasing water level. Yet another simple form of measuring time was the fire clock, which was a braided fuse that was tuned to burn for 4 hours.[3]

Fast-forward a few thousand years to around 1086 when Chinese engineer, astronomer, and calendrical scientist Su Song designed a hydro-mechanical astronomical clock tower. It was forty feet high and was completed by 1092. It used the same technique as the Clepsydras, but the draining water caused gears to turn which shifted displays of the lunar cycles.[4]

The Salisbury Clock is from the Salisbury Cathedral in England and was commissioned by Bishop Erghum.

The Salisbury Clock from 1386, is the oldest working mechanical clock in the world. By the 14^th Century “every” town had a clock with a striking mechanism. Having such a clock became a status symbol for towns.[5]

Christiaan Huygens was a Dutch mathematician and scientist known for his work as an astronomer and horologist, which is the study of time. He combined these two fields because accurate time measurement is a key to astronomy. He designed and had the first pendulum clock built, which he presented to the world in 1657.[6] Then he developed the balance spring clock in 1675.[7] This invention makes it possible to create pocket watches, since the balance spring clock was small, could be shaken, held in any direction, and remain accurate.

In 1754, Jean Romilly presented the first watch with a “dead seconds” system.[8] A “dead seconds” system is a watch, or timepiece, with discrete jumps between each second. This is complicated because the balance runs at about 5 times per second. Mechanical gears must be added to slow the balance down to 1 second in order to display the second hand.

US Patent 75463 “Escapement for Watches” March 10, 1868

The Industrial Revolution made numerous goods more affordable for the masses. Prior to the Industrial Revolution watches were only available to the wealthy, due to the expensive cost of the hand-craftsmanship of each timepiece. However, with the Industrial Revolution machinery lead to a decrease in the production time and specialization needed to create a watch. This advancement led to the creation of the Proletarian Watch, also known as the “One-Dollar Watch.”[9] George Roskopf wanted to lower the price even more by developing a watch that could be sold for 20 Francs – in the 1860s not counting for inflation. His work led to US Patent 75,463.

During the 20^th century the advances in technology allowed for a more precise measurement of time. The 13^th General Conference on Weights and Measures, in 1967, defined 1 second as “9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels (F=3 and F=4) of the ground state of the caesium-133 atom.”[10] This is the measure still in use today. The US Naval Observatory in Washington D.C. uses 57 high performance caesium atomic clocks to set the Master Time for the United States. These clocks, in conjunction with other countries’ master clocks, guide astronomy, aerospace, telecommunication, and all other forms of activities.

Watches and clocks represent the passage of time. How people mark the passage of time has evolved over the past several millennia. Humans have used to time to organize society and engineering time has been in constant development.

Resources:

[1] Dominque Fléchon, The Mastery of Time: A history of timekeeping, from the sundial to the wristwatch: discoveries, inventions and advances in master watchmaking (Paris: Flammarion, 2011).

[2] “Other Ancient Calendars,” Calendars through the Ages WebExhibits, accessed November 8, 2017. http://www.webexhibits.org/calendars/calendar-ancient.html

[3] Fléchon, The Mastery of Time, 53-55.

[4] John H. Lienhard, “Su-Sung’s Clock,” Engines of Our Ingenuity, accessed November 8, 2017. https://www.uh.edu/engines/epi1580.htm

[5] Fléchon, The Mastery of Time, 132.

[6] Fléchon, The Mastery of Time, 182.

[7] “Christiaan Huygens (1629-1695),” The Seiko Museum, accessed November 8, 2017. https://museum.seiko.co.jp/en/knowledge/episode/episode_01/index.html

[8] Fléchon, The Mastery of Time, 214.

[9] Fléchon, The Mastery of Time, 253.

[10] Fléchon, The Mastery of Time, 357.