LASER: Materials Science Podcast

In this episode Cameron interviews Dr. Sarah Truebe, the cave resource manager at Kartchner Caverns State Park in Arizona. This episode was recorded underground at the end of a day we spent cleaning graffiti out of this popular wild cave.

We discuss how Dr. Truebe got started caving, how some cave research is performed, and some ethics of destructive testing methods in sensitive cave environments.

Show Notes:
3:00 Sarah talks about her experience on her first caving trip (right in the cave where we were sitting!) and a bit about cave safety
5:00 White nose syndrome is discussed, a fungal disease killing bats across North America.
10:20 How Sarah got interested studying the monsoon at a young age, and how that turned into studying paleo climate in grad school.
20:20 What are the ethics of paleo climate studies in caves? How can we study delicate and irreplaceable features?
35:50 After a cave (like Kartchner) been studied for 50 years, what is left to do and monitor long-term?
40:00 CO2 variations in caves
45:20 How people can submit a proposal for a cave study that could potentially be approved in a cave like Kartchner.

Links:

• To learn more about or visit Kartchner Caverns, visit https://azstateparks.com/kartchner and follow them on Facebook
• To find a local caving club (grotto) or learn about the National Speleological Society, visit https://caves.org/
  • If you are totally new, maybe start with the “Guide to Responsible Caving” brochure

As always, if you are doing interesting research you want to talk about, or have any interesting topic ideas, please get in touch and we may be able to do a show about it.

Thanks to Ray Keeler for organizing the Peppersauce Cave Cleanup Project event that this interview was recorded during.

questionable data in χ, pointed out by Brian Skinner [arXiv:1808.02929]

You may have heard about some controversy surrounding a recent pre-print published on the arxiv about room temperature superconductivity.  This would be an extremely exciting result if it weren’t for some issues.  The authors won’t share their samples and have not yet fully described how to make it–they say that will come in a future publication, and there is some question about the veracity of two plots in one of their very important figures.

for some background information and citations for things I talked about:

While I was taking notes, I ended up writing them like a blog post instead of just my normal index card podcast notes, so here is an approximate transcript of the entire episode:

I wanted to share a recent paper that has been making some waves among the scientific community and on twitter about a claim of room temperature superconductivity. I’ll probably regret speaking out about this so early, so I’ll maybe treat this like a paper review and we’ll see how the data work out with peer review and reproducibility. A group from the respectable Indian Institute of Science, graduate student Dev Kumar Thapa and associate professor Anshu Pandey, have posted a pre-print paper on the arxiv called Evidence for Superconductivity at Ambient Temperature and Pressure in Nanostructures. Since this is the arxiv, this is an unfinished pre-print of a paper, not a peer-reviewed manuscript in final form, but it is a fast way to get it out and free to read. There will of course be links in the show notes. The most important part is they claim to have measured superconductivity at 236 K in silver nanoparticles embedded in a gold matrix. This claim is really remarkable when you look at other superconductors. A regular metal superconductor has a Tc less than 9.2 K, which is the highest Tc metal, Niobium. After this, the high temperature binary alloys go up a little bit toward 30 K, and the high temperature cuprates are all very complex structures like YBCO, BSSCO, and HBCCO are 92, 110, and 133 K respectively. Im going to start off ignoring the current controversy and saying that overall this paper is not bad, the claim is extraordinary but they characterized their material extensively, and documented all the things that I would have asked for. Assuming the data are correct and independently reproducible, this could be a very serious discovery.

So before I get too deep into the paper here’s a really quick summary of superconductors for anyone who might not know what they are. A superconductor is a material that conducts electrons with no resistance, they are important for high tech devices and scientific research, and especially in wireless communications and extremely sensitive sensor applications. The primary goal here is to build these high tech devices that require the unique properties of superconductors, not to get zero-loss power lines (although there is a group trying that). The two types of superconductor are those that screen or block magnetic fields completely (these are Type I superconductors) and those that allow magnetic fields to pass through tiny pinholes of normal material called fluxons or flux vorticies (these are Type II). The easy way to guess which type a superconductor is is just to remember that for the most part, pure metal superconductors are all type I (as in they exclude magnetic fields completely until the field gets so strung it shuts off the superconductivity completely, this is called the Meisner effect), while compounds are mostly type II (as in they allow magnetic fields through little flux vorticies up to a point where the field destroys superconductivity completely). These magnetic fields are referred to as Hc1 and Hc2 (as in H, the magnetic field, c for critical, 1 where flux vorticies are formed and 2 for where superconductivity is destroyed completely).

Okay, that should be enough background for what I’m going to say, so on to the publication. Like I said earlier, their remarkable claim is to have measured superconductivity at 236 K in nanostructures of silver nanoparticles (about 10 nm) embedded in a gold matrix. An easy thing to point out is that neither gold nor silver are superconducting on their own, and based on their chemical and structural analysis this is not an alloy, so these support the authors’ claim that the property has something to do with the nano structure.

1) aphelion 2) perihelion 3) sun (Not to scale) source: WIkipedia on Apsis

Welcome to 2015! This year’s perihelion edition was recorded on the day which the earth is closest to the sun.  We cover a diverse list of important scientific and engineering happenings from 2014, and even talk about a little biology and genomics research! (but don’t worry, its mostly cool physics, space, and engineering stuff.)

4:00  Many of these stories came from this big summary graphic that was posted on /r/futurology.  Don’t worry, we looked up real sources for everything!

7:30 the big bang BICEP 2 discovery (and controversy and final dismissal)

11:09 There was also controversy with a fraudulent report of a way to make induced pluripotent stem cells (IPC) by dipping them in a light acid.

14:08 artificial white blood cells (used as an injectable “cancer vaccine”)

15:00 Gene therapy used in eyes to help treat macular degeneration

18:00 There were a pair of genetically engineered monkeys born this year! and we have a bunch of discussion about ethics

25:30  we finally move on from Biology back to physics!

26:40 removing hydrocarbons from seawater. (like we talked about in Episode 16)

29:00  “Visual microphone” reconstructing audio from tiny vibrations in videos.

33:50 space and disasters (Virgin Galactic’s SpaceShipTwo & Orbital Sciences Antares Rocket)

36:00 space is hard. but really important for the future of humanity and science!

41:00 The Curiosity rover might have detected methane on Mars!

44:00 computers and data security were kind of bad this year. We discussed this in detail on our Heartbleed show (our most popular episode ever!) but things have continued and are very bad both in terms of security, and internet freedom.

47:30 Cosmos was pretty cool, except chase doesn’t like NGT because chase hates everything other people love.

Can’t really tell which is the 3-d printer and which is the espresso machine… Images from Lavazza and Made In Space

We’re finally back from our long hiatus!  Sorry about the wait, both Cameron and Emily were busy getting their masters degrees, and right after he submitted his thesis, Cameron’s laptop got fried!

This week we discuss Space X and Boeing contracts to transport NASA astronauts to the International Space Station by 2018, and some new luxuries that will soon be available on the ISS; a 3-D printer, and an espresso machine!

2:00 First story today is about the recent announcement that NASA will have contracts with SpaceX and Boeing to deliver astronauts to the international space station by 2018! http://www.space.com/27169-nasa-picks-spacex-boeing-spaceships.html

15:00 we wonder about the nomenclature for spaceships/vehicles/shuttles/capsules

24:00 we start our discussion on coffee with a unrelated mention that Starbucks is working on a coffee drink that is supposed to taste like beer?

26:00 the ISS-Presso is an espresso machine planned to go to the space station at the end of 2014.

40:00 on to 3-D printing in space!!! The company “Made In Space” is working with NASA to send one of their fillament-extrusion 3-D printers onto the ISS for an experiment to show that the additive manufacturing technique works in space without modification. http://www.madeinspace.us/

44:00  technology readiness levels, whatever those are.

Links to the music used in this week’s episode:

Image from Wikipedia with slight modifications

Most coffee-particular people already know that the quality of the water you use is important for good coffee, but a recent paper describes how affecting the specific hard mineral content can have important changes in the relative extraction of specific flavor and strength affecting chemicals in your brew. We discuss the basics of coffee preparation, and the conclusions of the paper.

1:15  Greg throws out a Leeroy Jenkins reference right off the bat. (I guess wait for episode 32.33?)

2:00 the article that prompted this show was “A Chemist Has Uncovered A Secret To Brewing Delicious Coffee At Home” published in Business Insider on Jun 5th, 2014.

2:45 The paper is called “The Role of Dissolved Cations in Coffee Extraction”, by Christopher H. Hendon, Lesley Colonna-Dashwood, and Maxwell Colonna-Dashwood, published in the Journal of Agricultural and Food Chemistry.

3:50 The researcher identified seven chemicals important to the flavor and strength of coffee,  and used density functional theory to calculate the bonding energy between these chemicals and common ions in water that contribute to water hardness.

6:45 one of the chemicals present in Coffee, eugenol, is also present in whisky and other barrel-aged liquors.

18:10  The paper only talks about water with Total Dissolved Solids (TDS) of <300 ppm, which is standard for municipal water supplies, but well or ground water in areas (like our own Phoenix area) can have much more calcium hardness than that.

Links to the music used in this week’s episode:

This week on LASER we discuss a realistic computer simulation of a universe, a proposed mechanism for why tin whiskers are destroying our most sensitive computers, and GaInSn liquid metal used to reconnect severed nerves in frogs.

5:00 Our first story is about the story “Astronomers create first realistic virtual universe”   from the Illustris Project.

16:40  One of the most important thing about this simulation is being able to “see” how galaxies evolve and form and interact with each other, and since it is a computer simulation we are able to look into the past and future.

22:05 maybe eventually we’ll be able to look for distribution of M-class planets.

25:00 after talking about videogames, reddit, minority report, and cutting a five minute discussion on the history of neckbeards (https://en.wikipedia.org/wiki/Neckbeard#Neckbeard) we finally move onto the second topic…

25:30  Whiskers!!! ( http://news.sciencemag.org/physics/2014/05/scienceshot-how-shave-metal-whiskers)

26:45 Whiskers are when a thin single-crystal piece of metal grows (very quickly) out of a metal (most often something used in solder or semiconductor packaging).  This causes problems for electronic devices, where it can short out devices, and has been attributed to taking offline three satellites and one nuclear power plant (specifically places where you can’t go in and fix a part.  This also has taken out many computers that just stopped working for seemingly no reason).

28:15 Lead-free solders are especially prone to this problem, because they often contain Tin.  We would prefer to use lead-free because of the environmental and health effects, but it is–so far–the most reliable available solder, based on whiskers and microcracking.

34:50  The paper is  V. G. Karpov, “Electrostatic Theory of Metal Whiskers” Phys. Rev. Applied 1, 044001 – Published 15 May 2014. doi:10.1103/PhysRevApplied.1.044001

37:00 the proposed mechanism for whisker buildup is charge differences on the surface, that are centered around defects.  This extra energy might give the metal the energy it needs to grow directly out.

44:40 Now we’re talking about Liquid Metal nerve grafts in frogs! http://www.newscientist.com/article/dn25510-terminatorstyle-liquid-metal-connects-severed-nerves.html#.U5DWzzk2pHT

The researchers have used a GaInSn liquid metal to connect severed nerves in frogs, and it resulted in connectivity similar to a healthy nerve, allows for the nerves to grow back, and is easily removed once it is no longer necessary.

55:00 fun prank for dinner parties: cast spoons out of low-temperature melting metals, and give them to your friends to stir their coffee. The spoon will melt in their drink, likely poisoning them! (not a fun prank.)

Links to the music used in this week’s episode:

Source: The Wikipedia

For our first episode of the summer on LASER: Let’s Agree Science & Engineering are Rad, we discuss our own Chris’ recently-accepted paper about inorganic ZnS window layers on organic solar cells.  These increase the efficiency, and help protect the cell from environmental damage.   We then talk about the NRL Press release describing long-chain hydrocarbon fuel (jet fuel) they have made by extracting CO2 and Hydrogen from seawater!

4:00 We’re all back from traveling for work and conferences, finals are done, and Chris just finished his qualifying exams, so we’re back to podcasting, even if we are a little rusty.

6:00 Our first paper is somewhing Chris just got accepted into Journal of Applied Physics, and it is titled “Efficient ZnS cathode layers for orgnaic photovoltaic applications via n-type doping.”

They are using an inorganic material, ZnS to replace the very sensitive organic cathode (top) layer in organic photovoltaics.  Since the organic components are very sensitive to temperature and air, an inorganic cathode can protect the bottom layers.

At the time we’re putting this episode out, the paper isn’t available online yet, but it will eventually be available at http://dx.doi.org/10.1063/1.4878155

32:30 We discuss the recent press release from NRL (http://www.nrl.navy.mil/media/news-releases/2014/scale-model-wwii-craft-takes-flight-with-fuel-from-the-sea-concept)  describing fuel made from CO2 and Hydrogen that was extracted from seawater.  There are a number of press articles about this: Discovery (http://news.discovery.com/tech/alternative-power-sources/us-navy-game-changer-seawater-turned-into-fuel-140408.htm) Business Insider (http://www.businessinsider.com/christopher-harress-us-navy-technology-to-turn-seawater-into-fuel-2014-4) and Inhabitat (http://inhabitat.com/u-s-navy-converts-seawater-into-jet-fuel-using-game-changing-technology/) are a few.

38:00 Removing Co2 from ocean water *might* have a small local effect reducing ocean acidification, but because the end result is burning a hydrocarbon fuel, it will end up just going back into the atmosphere and back into the oceans.

Links to the music used in this week’s episode:

Source

This week’s LASER Pulse! is about the Heartbleed computer vulnerability.   We cover the basics of the heartbleed bug, why its important, and mention that you really need to CHANGE YOUR PASSWORDS.  Because this is a Pulse episode, there are little to no edits (just the intro and outro really), and the whole show is only about 20 minutes.

No real show notes, just a list of a bunch of links if you want to know more.

Here are links to Sam’s Blog and her Twitter.

Be safe online!

Image from Paper.

The cast of the Technically Speaking Podcast join us to talk with  about the future of super rad airships for scientific use similar to satellites! We also talk about a company planning a new method for extracting Lithium from geothermal vents, to meet the needs of the Tesla Giga-Factory.

3:00 Our guests today are Jacob and Joe from the Technically Speaking podcast! Check out their show if you like technology, engineering, or other rad stuff.

4:15 Our first story is about AIRSHIPS! The Keck Institute for Space Studies has released a report titled “Airships: A New Horizon for Science” a FREE paper published on the arXiv   where they explain the scientific merit of using rigid airships for scientific applications, and potentially to replace satellites.   There are also articles about this on motherboard.vice and in the MIT Technology Review.

5:50 what is an airship?

8:00 The Hydrogen vs Helium debate

14:10 the ISIS project (canceled) had neat “suction cup” tethers to keep the airship down on the ground.

16:00 the scientific applications the Keck Institute found as useful were Earth sciences such as atmospheric and environmental monitoring, and for planetary/astronomical sciences a telescope could be mounted with “Hubble comparable imaging”.

21:00 Jacob brings up how well airships would work for something similar to Google’s Project Loon

24:33  CORRECTION: Scott Kelly is going to be on the ISS for a year, NOT Mark Kelly.  http://www.nasa.gov/home/hqnews/2012/nov/HQ_12-406_ISS_1-Year_Crew.html

30:00 we start on the engineering problems for building airships. Including the Hydrogen vs helium debate!

32:50 Joe points out that even though hydrogen is a dangerous gas, jet fuel is pretty dangerous too!

36:50 basically everyone would love to take an airship cruise

48:15 chase leaves early to go to dinner, but Joe and Jacob aren’t scared to talk about something outside their areas of expertise! (especially if it’s related to Elon Musk haha)

50:15 We start in on a story about a company, Simbol, that is trying to produce much more Lithium for batteries , specifically to meet the needs of the planned Tesla “Giga-battery factory”

55:15 the Tesla giga-factory’s object is to combine as much manufacturing as possible under one factory, but its the opposite with a lot of political things (like defense contracting) where things are built in a ridiculous number of factories.

61:05 How we produce lithium today (harvested from brine in salt flat areas)

63:00 The earth should run entirely out of Lithium around the year 2100!!!

64:00 it is VERY important to recycle your lithium batteries, because we are very close to running out completely!!!

65:00 THIS website says that lithium is 100% recyclable, but recycling it is just not economically feasible right now.   Someone should start a company storing all the lithium batteries for about 20 years until it becomes economically feasible to recycle.  Then you can donate an idea fee to our podcasts!.

76:20 Thanks to our guests today! If you need another link to Jacob and Joe’s Technically Speaking podcast, its available at http://technicalyspeakingpodcast.com

79:00 You can find them on twitter at @techspeakpod

We’ve changed our intro music to be something a little less obtrusive, you can buy the song or the album at the link below.  Thanks to Crying for letting us use their song.

Links to purchase the music used in this week’s episode:

As always, the LASER Podcast is released under a Creative Commons Attribution-ShareAlike 4.0 license.

The cast of the Technically Speaking Podcast

Image from Paper

On Episode 14 of LASER we discuss using tree branches as water filters, a new type of super-thin room temperature infrared light detector that uses graphene, and the $1 Origami Microscope.

4:05 The article in Popular Mechanics titled “A simple tree branch can become a backyard water filter”  and the FREE paper in PLOS One “Water Filtration Using Plant Xylem”

5:50  The idea is to help the developing world by testing a cheap water filter that only requires a tree branch and a tube

9:00 its really great when high school students get involved with university research projects and end up publishing papers! If you’re in high school you should talk to a university professor about helping out with a research project a couple of days after class.  Even if you don’t plan to study science! (why would you not plan to study science?!)

12:00 Alex joins the group for the discussion!  Unfortunately he hasn’t read any of the papers…

23:15 from Motherboard.vice.com we are talking about “infrared imaging may be coming to contact lens near you”   and the article “Graphene photodetectors with ultra-broadband and high responsivity at room temperature”

24:30 the article is fine, but I don’t like the headline, and I think that the author of the paper  somewhat misrepresented their results to the press.

25:45 a typical infrared detector is this Superconducting Edge Detector (or Transition Edge Bolometer)   https://en.wikipedia.org/wiki/Transition_edge_sensor

27:00 Alex asks a good question about the superconducting principle behind how a transition edge sensor works.

35:40 Alex thinks his eyes are bizarre

38:42  the story is found in the MIT Technology Review and is “The $1 Origami Microscope”

41:00 there was a TEDx talk about this a few years ago, when it was a $0.50 cent microscope! Since that time, it costs more because they have developed methods for brightfield and darkfield imaging, and that required a few additional parts.

45:40 We talk about roll-to-roll processing and calendaring of green ceramics.  These are manufacturing techniques for many materials.

48:05 Cameron said you can’t re-crystallize Al2O3 from amorphous to crystalline forms, but that is WRONG! http://link.springer.com/article/10.1007/BF00774113

Links to purchase the music used in this week’s episode: