Don't Panic Geocast

By John Leeman and Shannon Dulin

John Leeman and Shannon Dulin discuss geoscience and technology weekly for your enjoyment! Features include guests, fun paper Friday selections, product reviews, and banter about recent developments. ... more

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FAQs about Don't Panic Geocast:

How many episodes does Don't Panic Geocast have?

The podcast currently has 425 episodes available.

Don't Panic Geocast episodes:

February 05, 2016Episode 54 - "We use statistics"
We’ve already talked a little bit about the Earth’s magnetic field, but where does that fall in terms of geoscience? Lots of physicists look at the magnetic field, but so do geologists. Not just our current field, but the ancient magnetic field, which is called paleomagnetism.
Paleomagnetism
Continental Position Video
Butler’s Pmag Webpage
Apparent Polar Wander
True Polar Wander
Magnetism in rocks - Dunlop
Authigenic Mineralization
Pmag Chainsaw Drill
PmagPy (Python Software)
Super IAPD
Zijderveld, 1964
Mu Metal
Magnetic Field Shielded Room
SQUID Magnetometer
Fun Paper Friday
What can chopsticks tell us about earthquakes? Find out by reading this week’s fun paper!
Tsai, S.-T., Wang, L.-M., Huang, P., Yang, Z., Chang, C.-D., & Hong, T.-M. (2016). Acoustic Emission from Breaking a Bamboo Chopstick. Physical Review Letters, 116(3), 035501–5. http://doi.org/10.1103/PhysRevLett.116.035501
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
50min
January 29, 2016Episode 53 - "They call it the snowtron"
With the first winter storm of 2016 over with, we figured we would jump on the bandwagon and talk about some different types of winter precipitation.
Feedback
Bending Spacetime in the Basement (Thanks Mark!)
Cavendish Experiment
Winter Precipitation
Snowtron
John’s Drone Experiments
Pickle Juice and Cheese brine!
Atmospheric Temperature Profiles
Freezing Rain
Freezing Fog
Sleet
Ice Storms
Types of Frost
Hail
John’s Article “Highway to Hail"
Graupel
Inupiat Dictionary - Turn to page 104 in the pdf and you can see all the different words for snow!
Many Snow Crystals!
Snow Rollers (lots of photos!)
NWS Warnings and Watches - Definitions
Fun Paper Friday
This week we use seismology to find… a burglar?
Hinzen, K. G., Reamer, S. K., & Fleischer, C. (2016). Analysis of a Burglargram. Seismological Research Letters, 87(1), 193–195. http://doi.org/10.1785/0220150253
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
51min
January 22, 2016Episode 52 - "You pay for significant digits"
Last week we talked about glaciers, a basic staple of any geology education. That means it’s only fair to talk about a geophysics staple this week. We can measure gravity at different locations and use it to help figure out what’s under our feet. That and another great Fun Paper this week!
It’s All About Pentiums (Weird Al)
Gravity Basics
All geophysical methods are based on measuring some kind of physical property difference.
Gravity is sensitive to the density of the material below the measurement.
“Big G"
gal (unit)
Density for any rock varies widely.
Gravity from impact structures
Measuring gravity
Absolute gravimeter
Relative gravimeter
Zero-Length Springs
Differential GPS
Corrections
Examples of the more common corrections
Eötvös effect
John’s explanation of Coriolis Force and Toilets
Isostasy
Bouguer Anomaly
FORTRAN Talwani Example
Original Talwani Paper
Fun Paper Friday
Alarcón, Héctor, et al. “Self-Amplification of Solid Friction in Interleaved Assemblies.” Physical Review Letters 116.1 (2016): 015502.
Semis pulling on phone books
Mythbusters
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
1h 12min
January 15, 2016Episode 51 - "Regelation. I think I had that for lunch the other day" Glaciers
Last known survivor of the 1906 San Fran. EQ/Fire passes away
Ice is a mineral
National Snow and Ice Data Center
Great USGS informational publication on ice ages
Mendenhall Glacier
Video of 1 year of Mendenhall melting
Chasing Ice
Firn
Pressure melting point
Regelation
Video of Regelation Experiment
Weertman 1957 (Paper on ice movement)
Great Lakes
Glacial erratic
Ice age
Drumlin
Esker
Moraine
Kettle Lakes
Subglacial channels
Glacial striation
Fun Paper Friday
This week we learn about low frequency sound waves in the atmosphere and how we can use them to determine the winds at high altitudes and improve numerical weather prediction.
EOS Article
Arrowsmith, Stephen J., Omar Marcillo, and Douglas P. Drob. “A framework for estimating stratospheric wind speeds from unknown sources and application to the 2010 December 25 bolide.” Geophysical Journal International 195.1 (2013): 491–503.
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
1h 9min
January 08, 2016Episode 50 - "Some serious geometric voodoo" Projections Part 2
Last week we told you about many different map projections and talked about why they are all wrong. This week we’ll discuss a few of our favorites, why we like them, and when they fail us. We also have another Star Wars themed Fun Paper Friday!
How’s your 2016 so far? (PhD Comics)
Nuclear Test
John’s Particle Motion Movie
How To Detect A Secret Nuclear Test
Picking a Projection
Consider what you need
For dot density plots, equal area is important
Mercator projection
Gnomonic projection
Great circle distance
Great circle
Our Favorites
Compare landmasses to Africa.
Mercator puzzle
Wikipedia lists over 60 different projections!
Strangest: Hammer retroazimuthal projection or Waterman Butterfly Projection
Most boring/overused: Mercator Projection or Web Mercator
Pleasing whole-world: Robinson , Winkel tripel projection, or Armadillo
Polar Regions: Stereographic Projection or Pierce Quincuncial Projection
Fun Paper Friday
Feinstein, Zachary. “It’s a Trap: Emperor Palpatine’s Poison Pill.” arXiv preprint arXiv:1511.09054 (2015).
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
54min
January 01, 2016Episode 49 - "Would it blow your mind if I told you Africa is 14x larger than Greenland?"
Maps are useful things, but it turns out that projecting a 3D object on a 2D map can cause a lot of unexpected problems. They even inspired an XKCD comic. This week we explore maps and map projections. We also chat about machine learning as part of #FunPaperFriday.
What’s the big problem?
The Earth is a sphere, actually it’s an ellipsoid, actually it’s really bumpy and messy
Taking 3D information and pushing in onto a 2D medium means that you must sacrifice something, you are losing a dimension with which you can express information.
Projections are a well thought out as researched problem, even in pure mathematics.
You have to pick a projection that will tell you want you need to know accurately, and know that you lose some other information.
There is even a West Wing clip about this
A few examples of projection problems
There are geographical properties that we care about: area, shape, direction, conformality, distance, scale… and you can’t get them all at once. In fact, some it’s hard to get more than approximately the right answer.
Area: Maps that preserve area relationships between things on the globe are called equal area maps.
Distance: Some maps (equidistant maps) show an accurate distance from the center of the projection to all points.
Scale: The same scaling relation applied across the map will give accurate values for scale relations on the globe.
Conformality: Scale in any direction at any point is identical. This means that parallels and meridians are at right angles. (Local shape preserved)
http://www.colorado.edu/geography/gcraft/notes/mapproj/mapproj_f.html
A few projections
Projections can be generally classified as cylindrical, conic, azimuthal, or other. These are as you would think, projections onto cylinders, cones, planes, or with rules of “rectangular meridians” or something else. There are lots of sub-classes, you can view them here.
Wikipedia lists over 60 different projections!
Fun Paper Friday
That’s what she said. Can we teach computers to better understand human speech patterns? This paper takes a humorous problem as a test case.
Kiddon, C., & Brun, Y. (2011). That’s What She Said: Double Entendre Identification (pp. 89–94). Presented at the Annual Meeting of the Association for Computational Linguistics.
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
46min
December 25, 2015Episode 48 - "You know you're going to be inspired" AGU
We want to wish you happy holidays and invite you to join us while John was at AGU. This show should have been released a week ago, but John got very ill at AGU and took several days to recover. Thank you for the well wishes and sticking with us!
AGU Fall Meeting
5 Tips for Surviving your First Conference
John didn’t get to see the Elon Musk lecture.
He did get to sit in a car from Tesla Motors though.
ObsPy
Orbital Mechanics - Check them out!
Fun Paper Friday
Can plants remember and learn? The answer may surprise you, it did us!
National Geographic Article
Gagliano, Monica, et al. “Experience teaches plants to learn faster and forget slower in environments where it matters.” Oecologia 175.1 (2014): 63–72.
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
43min
December 11, 2015Episode 47 - "That's nerd points" Holiday Gift Guide
The holiday season is approaching and you may be wondering what to get that geoscientist or science nerd in your life. Look no further as we discuss our recommendations on the Don’t Panic gift guide!
John’s Picks
Gear
Pedco UltraPod II
AmScope SE400-Z Microscope
Shower Mate Speaker
MakerBeam
Lowepro Extreme Padded Sport Backpack
Books
Thing Explainer
What If?
The Annotate Build-It-Yourself Science Laboratory, checkout author interview here
Seveneves
The Three-Body Problem
Misc
Geology Bed Sheets
Audible Membership
Dropbox Membership
Soft Earth Pottery
Geology Tricorder
Shannon’s Picks
Gear
Garmin Monterra GPS
Plateau Designs Field Pouch
Rite in the Rain pouch and books
UV/LED handlens
Books and Movies
Annals of a Former World
Storm Kings
Hyperbole and a half
Jurassic World!
DamNation
Misc
REI
Chacos!
Patagonia Messenger Bag
Nikon AW110
Field Notes - snowblind!
Fun Paper Friday
Star Wars! Need we say more? Learn about Dunes and Tatooine with this week’s fun paper!
Dunes on planet Tatooine: Observation of barchan migration at the Star Wars film set in Tunisia Lorenz, Ralph D., et al. “Dunes on planet Tatooine: Observation of barchan migration at the Star Wars film set in Tunisia.” Geomorphology 201 (2013): 264–271.
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
1h 1min
December 04, 2015Episode 46 - "The sweet sounds of square wheels rolling" Posters Continued
This week we continue our discussion of posters, presentation, and talk about splashing around with our fun paper Friday!
Graphing Software
Igor Pro
KaleidaGraph
Matplotlib
Bokeh
Veusz
Poster Tools
Inkscape
Adobe Illustrator
Adobe InDesign
Adobe Color (Formerly Kuler)
John’s AGU Talk
Fun Paper Friday
This week we talk about urine splashing and industrial uses of carbon nanotubes.
Abstract: M32.00010 : Creating a urine black hole
Phys.org with Videos
Vantablack Article
Vantablack Video
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
49min
November 28, 2015Episode 45 - Revisit "What if you calibrated your candles differently?"
This week we re-visit one of our favorite shows while everyone is outside or in their turkey food-coma here in the US. We also read some listener mail about last week's episode on earthquake magnitudes!

Time is a very complex subject that you can devote your entire life to. Today we’ll cover a few of the basics and enough to get your interest up! We’ll see that it’s difficult to know what a second is and how long relative times are, but absolute time is even messier! We also discuss dried coffee and tetris!
Importance of Time (and why it’s on a geology show)
It synchronizes the world and our human interactions (need minutes - hours accuracy generally)
It allows us to talk about events in a common coordinate system
Allows synchronization of scientific measurements and comparison of data sources. This is really important for seismometers for EQ location!
Let’s us use GPS! 1 billionth of a second (nano second) error in 1 GPS satellite, GPS receiver is +/- 1 ft to satellite, which is 2–3 feet on Earth.
Early Timekeeping
Burning candles in marked cases
Hourglass
Water powered clocks
Pendulum clocks Galileo and Huygens (fancy temperature compensation as well)
Video on Galileo
Modern Time Keeping (Atomic Clocks)
First clock was ammonia maser at National Bureau of Standards in 1949, but it really wasn’t all that accurate. It was more of a proof on concept device
First cesium clock was in 1955 at the National Physical Laboratory (UK)
Leads us to the definition of the SI second he duration of 9,192,631,770 cycles of radiation corresponding to the transition between two energy levels of the caesium–133 atom
The NIST-F2, a cesium atomic fountain clock, is good to one second in 300 million years. How F2 works is a combination of feedback control loops, lasers, and really cold atoms.
Remember, atomic clocks tick away seconds, they say nothing about the hours, minutes, seconds notation we use to write time. We just define a frequency
Leap seconds
Can’t predict them far into the future because of irregularities in Earth’s rotation
Announced ahead of time in a bulletin by the International Earth Rotation and Reference Systems Service
25 leap seconds since 1972
Next leap second is this year! June 30, 2015
Real problem in computing, has caused software and GPS hardware crashes/issues before
Google smears the second out over a period prior to the leap
Time Standards
There are TONS of time standards, we’re only going to touch on a few. Most are known with highest precision in retrospect!
Solar time
Exactly what you would think, it’s about using the sun’s position as a time source. There is the sundial time (apparent solar time) that changes throughout the year, and the mean solar time which is like a clock time.
The equation of time represents the difference between the mean and apparent solar day
Star clock
International Atomic Time (TAI)
A measurement of proper time (it’s a relativity thing)
Weighted average of over 400 atomic clocks
If there is an error, it isn’t corrected. This makes it into terrestrial time.
Universal Time (UT)
This is what we used to call GMT!
Based on Earth’s rotation w.r.t different bodies (why there is UT0,UT1,UT1R,UT2,UTC)
UT1 is really mean solar time at the equator
Coordinated Universal Time (UTC)
Formalized in 1960
Adjustments were accommodated by leap seconds starting in 1972
Generally considered to be GMT, but GMT isn’t defined/recognized by the scientific community
This comes from TAI by accounting for leap seconds!
Epoch time (Unix Time)
Epoch time is the number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970
No leap seconds by definition, but implementation is actually messy
Stored is an integer (32-bits) meaning that it will run out and roll over on Tuesday 2038–01–19 One second after 03:14:07 UTC, it’s the year 2038 problem.
The Timekeeper Video
Audio after the outro is David Allen
FunPaperFriday
Coffee rings and coffee disks: Physics on the edge
Particle shape controls movement during drying
The can be applied to surface design, paints, and more
Contact us:
Show - www.dontpanicgeocast.com - @dontpanicgeo - [email protected]
John Leeman - www.johnrleeman.com - @geo_leeman
Shannon Dulin - @ShannonDulin
...more
1h 1min

FAQs about Don't Panic Geocast:

How many episodes does Don't Panic Geocast have?

The podcast currently has 425 episodes available.

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