A Misuse of HDR in LA

I have been playing with Pro HDR Camera – an app that lets you take HDR images…

Which are High Dynamic Range images. The technique uses several images (usually three) with different exposures and combines them to maximize the dynamic range of your photos. For example, taking a picture of your friend sitting in the shade on a sunny day with one exposure may result in good detail of the bright scenery around them but a too-dark subject, or a well-defined subject but a washed out background. HDR let’s you take both of those images and intelligently splice the best parts together.

That is the intended use at least.

In LA I abused the HDR app to try and capture fast-moving scenes. The result is ghostly scenes of semi-transparent objects and blended backgrounds. Hard to control, but very fun!

I tried some fairly extreme post-processing as well. The first two in the sequences are the processed images, the third is the original. The idea of the first was to make it “pop”, and the second was to emphasize the spookiness of the technique.


The Official APS March Meeting Coffee Ranking

Coffee is to a physics conference as beer is to a hockey game. While some patrons want quantity over quality, I would prefer to relish my coffee. I want to fall in love with my coffee. I want a coffee I could bring home to Mom. But hey, you do you. I just want to help. I will rate and review as many coffees as possible and report my findings daily.

apscoffee2018 day2


8) Verve Coffee – pour over – $4.00

Taste: 10/10

Price: 4/10

This is the only true specialty coffee shop I’ve found so far. With that in mind, the coffee was incredible, and they had many beans available for sale. But with that, comes a greater price. This is exactly what I wanted, but it may not be for the average coffee drinker. I would highly recommend for the specialty coffee enthusiast but if you just like a good cup and don’t want to think too much about it, don’t bother.


7) Impresso – Americano – $3.00

Taste: 9/10

Price: 7/10

Ding ding ding! We have a winner. The first coffee I was truly impresso’d with. Another shop that doesn’t seem too concerned with bean specifics, but I can tell you their Americano was appropriately dark and chocolatey. If anything, maybe it was a bit dilute for my tastes, but at this point I’m splitting hairs. Worth the trip.


4) Philz Coffee – pour over – $3.50
Taste: 8/10
Price: 6/10

I have to thank the March Meeting staff for this recommendation. Philz is a 5-10 minute walk from the conference center and is worth the trip. They offer a large selection of coffees sorted into “dark, medium, light, and decaf” designations. It appears all coffees are pour-over, made to order which is fine by me. Flavor notes of all varieties are listed, but place of origin or bean varietal is not. I ordered the “New Manhattan”, a light roast that was marketed as having notes of cherry and citrus. I disagree with the citrus, but as the cup cooled the cherry flavor become more obvious. I would predominantly call this a floral coffee – one of those light roasts that more resembles tea than a deep, bold Americano. If I were guessing origin, I would say likely a blend, but maybe Ethiopian? A generous small will run you $3.50 which seems to be approximately the sweet spot of prices in LA. I would highly recommend the trip.

Philz wasn’t the prettiest shop I’d ever seen, but the graffiti on the other side of the road was nice.

5) Cow Cafe – drip coffee – $3

Taste: 8/10

Price: 7/10

Wow, APS Meeting staff know their stuff. Cow Cafe was a 5 minute walk from the center and had some nice fresh food as well (grilled halloumi sandwich anyone?) As for the coffee… In short, very satisfied. Unfortunately their espresso machine was broken which meant they only had drip. Luckily, they really nailed their drip! Another blend, this time two South American varietals. The end result was a smooth, sweet, slightly chocolatey medium roast. Very easy drinking, no bitterness at all. I highly recommend going for lunch. My only criticism is not calling it a Calfe.

6) Kaffebaren – Americano – $3.00

Taste: 7/10

Price: 7/10

Another completely fine Americano… What I’m starting to find is that the “third wave” gourmet coffee culture I’m used to in Hamilton might not be as big here. I’m still getting fairly confused looks when I ask what kind of coffee they’re brewing. All have been blends, none could tell me much about the roasters they buy from. Don’t get me wrong, there is no problem with this, but it certainly makes for a dull adventure. Kaffebaren was a very cool looking cafe/bar (who woulda guessed?) in the fashion district. In fact, on my walk there I saw three independent photo shoots happening. As for the cafe itself – they boasted 63 beers on tap, which seems hard to believe. No taps were visible, so I assume they are in the back or something. I would not make the trip again for the coffee (it was very average, nothing about it stood out) but I would come back for the beer.


I think that’s all I can handle today. This afternoon became quite warm. If this keeps up I may have to switch to iced coffee…


1) InterContinental hotel, downtown LA – Americano – $4.75

Taste: 6/10

Price: 2/10

A totally reasonable coffee at a fairly unreasonable price. No real discernable flavor notes, just a standard dark roast you would expect from a chain, but without the burnt taste. Good coffee to water ratio. Very poor for the cost. Skip it.

2) APS Limited Edition 9:30-10:00 – batch brew – free

Taste: 4/10

Price: 10/10

It’s free, and it’s right outside the session you’re in. I would never accuse it of being “good”, but strong and it’s free. However, it’s only available for 30 minutes a day. How’s that for a “micro-lot” coffee?

3) COFFEE (Taste of LA, main lobby of conference center) – Americano – $3.00

Taste: 7.5/10

Price: 6.5/10

The first coffee I can honestly recommend. The price is what one would expect to pay in Canadian dollars, which suggests to me it is slightly inflated. Regardless, a solid dark roast, minimal burnt taste. Well extracted shot, not particularly bitter. No real “sweetness” or interesting flavor notes, but a solid, classic “espresso”.

All right, I’m jittery and feel a little sick. Back tomorrow with more data.

Math Papers by Ekaterina Lukasheva

Ekaterina Lukasheva is a mathematician and programmer  from Moscow who has taken to creating incredible origami and kusudama.

“Origami tessellations are complex geometrical 3-d structures. These surfaces are made using origami technique, which means only one sheet of paper is folded without stretching, cutting or gluing. These 3-d structures are indeed developable surfaces. This also means that those pieces represent the result of continuous isometric mapping of the flat surface to a 3-dimensional surface. It’s hard to believe, but they can be stretched back to a flat sheet at any time. Moreover the collapse/stretch process would be smooth. ”

Bridges Math Art Gallery

She has published three books on the art, all available on amazon.

I was particularly drawn to her recent post on Instagram where one of her designs exhibits interesting behavior…

Typically, if you compress a material in one direction, it will expand in the other, and vice-versa. This is essentially a conservation of volume effect, and is described by its Poisson Ratio. Things like rubber and most liquids are “incompressible” and will have a Poission Ratio value of 0.5, meaning a compression of a certain magnitude in one direction will turn into an extension of the exact same magnitude in the other (in 2D). Materials like metal can undergo some amount of compression in one direction before expanding in the other.

However, Lukasheva’s tessellated origami sheet above has a negative Poisson Ratio. An extension in one direction actually turns into an extension in the other. Materials that exhibit this behavior are known as auxetic materials and are quite rare (interesting fact: your tendons – in their normal operating range – are auxetic). In the case of the origami sheet, it takes advantage of the third dimension to allow for this novel behavior.

Auxetic material research is part of the larger field of metamaterials, and has applications in body armor, packing material, and high-tech shock absorbers, and beautiful paper art.

Smart People Recommend Podcasts

In our busy, dog-eat-dog, work-a-day world of fake news, snapstreaks , and avocado toast, we don’t always have time to read books. Podcasts are great but there are so many out there, it can be hard to know where to start. So I asked some smart people what podcasts they listen to. Our cast of characters include three physicists, one computer scientist, a mathematician, medical doctor, paramedic and a social scientist.

If you are new to the podcast game, there are many apps for keeping yourself on top of new episodes. iTunes is the go-to on Apple products, but Google Play and Spotify allow you to subscribe to your favorites as well. However, I have found that some of the more obscure podcasts can be hard to find on Google Play and Spotify. For this reason I use Podcast Republic. It seems like you can find pretty much anything on there.



Radiolab: An award-winner, this show focuses on broad scientific and moral topics. Radiolab has some of the highest production quality I’ve ever heard in a podcast and can sometimes turn very heavy and dramatic.

Hidden Brain: Host Shankar Vedantam dips into psychology, economics, sociology and anthropology to illuminate the hidden biases that drive human behavior.

Gastropod: Not a podcast about snails. Cynthia Graber and Nicola Twilley explore the science and history of various foodstuffs like saffron (Why is it so expensive? Did you know it was used as an anti-depressant?) and sourdough.

Stuff You Should Know: One of the “originals”. Josh and Chuck give an entertaining intro to – at this point – probably every topic imaginable. They are not experts by any means, but they do a good job researching and presenting material. They really seem like guys I’d like to hang out with.

Freakonomics:  Socioeconomic issues for a general audience. My favorite episodes focus on quirky and interesting applications of economic analysis on things like parenting, “the upside of quitting” and the dangers of “drunk walking”. This podcast also features high profile interviews.


Dissect: A serialized music podcast, each season takes one influential album and studies it track by track over the course of each episode. Season one looks at Kendrick Lamar’s “To Pimp a Butterfly” while season two is on Kanye’s “My Beautiful, Dark, Twisted Fantasy”.

Song Exploder: Each episode focuses on one song with artists explaining their creative process, step-by-step.

History, News and Current Events

The Daily: 20-minutes a day, 5-days a week, a quick morning briefing at 6:00 am courtesy of the New York Times.

Revisionist History: Malcolm Gladwell of “Outliers” fame reinterprets overlooked, or misunderstood people and events from the past.

More Perfect: From the people that brought you RadioLab, a podcast about “how the Supreme Court got so supreme”. Oyez, oyez.


“S”-Town: John hates his hick Alabama town so decides to do something about it. What begins as a crime drama turns into a heartbreaking character study.

Lore: Campfire-style stories of historical events showing the dark side of human nature.

Something True: Short, bizarre, hard-to-believe… and apparently true stories. For example – ever hear of the giant pie an English village made in celebration of the fiftieth anniversary of Queen Victoria’s coronation? “It was the largest pie ever made. Larger than reason. Larger than dreams. Large enough to hide a secret.”

LeVar Burton Reads LeVar Burton of Reading Rainbow, Star Trek: Next Generation and Roots reads short stories from various authors.

The Hilarious World of Depression: “The Hilarious World of Depression is a series of frank, moving, and, yes, funny conversations with top comedians who have dealt with this disease, hosted by veteran humorist and public radio host John Moe… It is a chance to gain some insight, have a few laughs, and realize that people with depression are not alone and that together, we can all feel a bit better.”

Serial: A non-fiction story told by producer and host Sarah Koenig about the murder of an 18 year old high school student Hae Min Lee . The story is told over the course of several podcasts and covers the trial and ___________ of her ex-boyfriend. The podcast renewed interest in the case and lead to a successful appeal for a retrial.

Business and Design

How I Built This: This podcast tells the stories of inspiring, enterprising individuals who are building the world we live in.

99% Invisible: A podcast about the ingenuity and design of the things we don’t often think about. Where did the small-medium-large sizing convention come from? Why do used car lots love that inflatable waving arm guy? What about the speech bubble in comics?


Tell Me Something I Don’t Know: Journalism wrapped in a game show by the guy who brought you Freakanomics. Contestants are invited on stage and challenged to “tell us something we don’t know”. Hosts grill the contestants on their facts and stories.

Welcome to Night Vale: “Community updates for the small desert town of Night Vale, featuring local weather, news, announcements from the Sheriff’s Secret Police, mysterious lights in the night sky, dark hooded figures with unknowable powers, and cultural events.” I don’t think it’s real, but I’m not sure…

’til Death Do Us Blart: Friends decide to watch and review Paul Blart, Mall Cop 2 every Thanksgiving until they die.


Any recommendations of your own? Let me know in the comments.

Coffee with an Aeropress Champion

Coffee is the lifeblood of academia. When global warming wipes out the coffee belt (google it, it’s happening), I wouldn’t be surprised if, as a direct consequence, institutions of higher learning ceased to exist and law and order became determined via the Thunderdome. Being a scientist and casual coffee enthusiast, I am very interested in what goes into making the perfect cup of coffee. With this in mind I decided to attend the Toronto Aeropress Coffee Championships hosted at Hale Coffee.

This is Aeropress. It’s a very elegant way of brewing coffee at home. At its most basic, you simply drop some coffee grounds in the tube, add water, then push it through the filter. The process makes for a very good cup of coffee, and it’s extremely easy. But the competitors don’t want good, they want to brew something that sets them apart.

The Toronto competition saw 27 competitors attempt to take the title. Competitors were broken up into heats of 3 people, each of which brewed their cup and submitted it to tasting by the judges. The winner of the heat then progresses to the next round. Luckily 27 is divisible by 3, so the first 9 heats paired down into 3 semi-final heats, which paired down to the final 3 competitors.

Competitors are challenged to make their best cup of coffee from the same batch of beans within a limited amount of time. Other than that, most other variables are up to you: How much ground coffee do you add? How fine should the grind be? When do you add the water? How hot should the water be? Do you stir? How long do you let the brewed coffee sit? When do you press the coffee? How hard do you press it? At what temperature should you consume the coffee?

At its core, coffee is a solution of “coffee stuff” dissolved in water. The “coffee stuff” is,  generally speaking, caffeine, volatile oils, organic acids, proteins and sugars. A typical cup of coffee will be about 1-2 percent “coffee stuff” by mass, while an espresso shot will be closer to 8 percent by mass. It therefore stands to reason that one of the most important variables is water taste. As for the “coffee stuff”, well, it gets complicated.

All of the molecules that make up coffee have different sizes and solubility, meaning they will dissolve at different rates and saturate at different levels. Caffeine is tiny and very soluble, so it is typically pulled from the bean fastest. In general, the oils are where the good flavors are and luckily they are usually the second easiest to extract. Somewhere in the mix then, are the organic acids. These – you guessed it, add a certain sourness to the brew. As for the proteins, well, some proteins react with the natural sugars in the bean to make caramel-y flavors, some are also extracted on their own and make for bitterness. In extremely broad strokes, we can say that the sour flavors are extracted quicker than the bitter ones. Of course this is going to be highly dependent on the type of bean, where it was grown, how it was processed and how it was roasted. While these things are all determined before you buy the beans, there are a lot of variables one can play with during the brewing process to control extraction. As competitor, you want to understanding how these variables affect extraction and what you can do to control them.

Being the skeptic that I am, I went into this wondering “how different could these brews be? Can the judges even discern a difference between the cups?” Interestingly, I observed that the frequency with which a competitor won a heat by a unanimous decision was anomalously high. If one were to be cynical and claim that all the cups taste identical and the judges pick at random, there are only 3 ways a cup can be unanimously chosen. Now, 3 judges all have 3 cups that can choose from, so the total number of ways judges can pick cups is 3^3 = 27. That means if judges choose cups randomly we would expect a unanimous decision once out of every 9 heats (3/27). There were a total of 14 heats over the evening, so naively we would expect a heat to be decided unanimously once or twice. While I didn’t see every round, I did witness 4 unanimous decisions.

One of those 4 times was in the finals, and the cup belonged to Yadi. By winning the Toronto Competition, qualified for the National Competition at Dogwood Coffee in Winnipeg.

Yadi has been brewing coffee for about 5 years and is the owner of FIKA Cafe in Kensington Market in Toronto, Ontario. I met with Yadi at his shop to talk coffee and get a few tips on home brewing.


Before we talk about the competition, I have to know. Where do you go for coffee?

I have a few favorite spots: Arvo, Neo Coffee Bar, Boxcar Riverside, Smalls Coffee… I like visiting different cafes to meet different people. I feel coffee tastes better when someone else is making it for you.

What’s the best cup of coffee you’ve ever had? You can say your own, you are a champion.

Saint Frank Coffee in San Francisco. Great ambiance and great beans from Honduras (can’t remember the farm). Executed properly as an espresso, tasted it on its own, then I mixed it with tonic water, blew my mind.  You can have the best beans but if the person behind the bar does not care enough to execute the drink properly then you will be disappointed!

Aside: What in the heck, how come I never heard of this tonic water thing!?! 

So you are an Aeropress champion. How do you feel the Aeropress design compares to other coffee making devices (typical espresso machines, French press, etc…)?

The Aeropress is so accessible, you don’t need any fancy equipment, just an interest to learn and brew good tasting coffee. Definitely each device has its own merits. I had been using the Hario V60 for my daily morning routine….. but the recent competition forced me to take out my Aeropress from the cabinet and start pressing! Which is great as it forces me to learn and appreciate its versatility once more.

I am impressed with the attention to detail and exactness with which you and your competitors executed, but at the end of the day the coffee is ranked qualitatively by judges. Do you have any special strategies when you compete? How variable is the finished cup? 

Yes, just a loose strategy…with Aeropress there are so many variables that are beyond your control…missing a few seconds [of brew time] or grams [of coffee or water] here and there doesn’t really matter. Temperature is important, but as long as it is not too hot during tasting then it is ok.

How did you get to your current recipe? 

It is a long tedious process. I deal with the variables one by one (water, temp, grind size, agitation, filter medium, time) until I get what I like. Took me a few days. Every morning before work I just brewed 2-3 times, and keep tasting and take notes. The first few days were frustrating as the coffee is a very complex blend! That’s why they chose it.

So are you going to change anything in your recipe before your next competition?

We are going to receive a new coffee from Winnipeg so the recipe will definitely change!

So… can I have the recipe you used in Toronto? 

Yes! Sharing is important, plus a recipe is just that, a recipe. Everyone will still brew it differently.

Yadi’s Toronto Aeropress Championship Winning Recipe

Begin with aeropress inverted (plunger on table, chamber filter-side up)

Add 17 g medium-fine ground coffee

Add 80 g water, stir gentley, bloom for 30 seconds (water at 82 o C)

At 1 minute, add water until you hit 240 g, stir 15 times

Press with even pressure, finishing at 2:30

Aerate and cool as needed – a cooler temperature allows more tasting.

Note on blooming: Essentially, roasting a bean will cause the bean to degrade, creating carbon dioxide – a particularly unappealing molecule. It’s what gives carbonated water its taste. The carbon dioxide will be slowly released from the beans as they age, but adding heat (brewing) will make this happen very quickly. By blooming, we add a little bit of water to begin the release of carbon dioxide, and after we are satisfied that enough carbon dioxide has been release, we add the rest of the water. Here is an article on coffee bloom.  

It looked like you didn’t pay too much attention to temperature (I have uploaded a video of Yadi making his winning cup on Instagram) – do you just have a good sense of temperature from experience? I noticed other competitors seemed very concerned with temperature, measuring it all throughout the brewing process.

For this competition I just try not to stress out myself, so I kept the routine as simple as possible. But the Nationals may be a different scenario. Temperature is important.

Another guy brought his own water. ‘sup with that?

I brought my own water too! Basically, use what’s familiar. Water’s mineral content differs everywhere, and it’ll affect how the coffee tastes. So I am still trying to figure out my water strategy for Winnipeg.

Ok, final and most important question. Do you like Tim Horton’s new dark roast? 

I still prefer the original blend. I drink my Timmy’s in a medium with one cream.


After our chat, Yadi and I got together at FIKA for some hands-on brewing. We tried several varieties of beans and he gave me some more tips throughout the night. We spent about 3 hours after the shop was closed brewing and tasting. While I learned a lot, I I haven’t even scratched the surface. If I want to brew the best cup of coffee, I have a lot more to learn.

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Thanks again to Yadi for talking to me. If you want to try a coffee from the champ, check out FIKA coffee in Kensington in Toronto. You can also follow Yadi on Instagram. Say hi, tell him I sent you.