Day 36: Is Plastic the New Oxygen?

Imagine that it was possible for you to observe the primordial Earth, a little over 2 billion years ago, when plant life first began to emerge. Up until then, all life depended on chemicals in the environment, such as hydrogen sulfide from volcanic vents, or simple hydrocarbons such as methane. Along comes this new form of life that can get its energy from the sun using photosynthesis. No longer tied to certain locations where they could find food, they could spread to any location that received sunlight, and populations of photosynthetic life forms explode.

This new life form came with a price, though: these creatures emitted a highly corrosive chemical as a waste product of photosynthesis: oxygen.

That’s right: before photosynthesis, there was little oxygen in the atmosphere. What little there was reacted with metals such iron, corroding it to oxides like rust.

By any definition of the word, plants were polluting the atmosphere. From that definition:

The presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects.

To early Earth, oxygen was a pollutant. In fact, geologists use the sudden increase of oxidized metals in the Earth’s crust to determine when the emergence of photosynthetic life occurred. But it was exactly this sort of “pollution” that enabled the rise of a different kind of life: animals that breathed oxygen to “burn” carbohydrates and fat for energy.

Fast-forward to the present day. Human life has left its mark on the planet, and have created two materials that will likely be part of the geologic record: concrete and plastic. Concrete is relatively inert, but plastic is made from hydrocarbons, and could be a source of energy. Amazingly, scientists have already found a bacterium that can digest plastic for energy. That’s pretty amazing, considering that plastic has only existed for a century or so, which is infinitesimal on an evolutionary timescale.

So if it were possible to be present when it was happening, who would have ever thought at that time that the emergence of highly-corrosive oxygen pollution in primordial times would ever be a good thing? Yet today we certainly feel that it was, as it enabled the rise of new life forms (such as us!).

So I have to wonder: is it possible that the emergence of plastic as a nearly ubiquitous presence in the environment might result in amazing new forms of life, as happened with the addition of oxygen to the environment? It seems just as far-fetched as considering the introduction of a corrosive element would be a positive change.

Of course, we’re talking millions and millions of years, but nature has done stranger things in that kind of time frame.Such evolution would require that humans would continue to crank out plastic and dump it into the ocean for millions of years, or life that depends on consuming plastics would quickly hit a dead end.

Don’t get me wrong: I’m not advocating for plastic waste in the hope of some wonderful new life form. I feel very strongly that we should reduce out plastic usage, and recycle/reuse as much as possible. And we should be doing everything we can to limit the spread of waste plastic into the environment.

But it’s something to think about.

Day 35: Chopped Candidate

Have you ever watched the TV show Chopped? If you haven’t, it’s a competition among 4 chefs. There are 3 rounds, and after each round, one of them is chopped (eliminated), until one remains. The winner gets a cash prize. This would seem like a good way to determine who is the best of the group, right?

The problem is how the competition is run: each round the chefs are given a basket of “mystery” ingredients that they can’t see until the round begins. And more often than not, the basket contains, shall we say, “odd” combinations. One such basket contained blood orange syrup, the African spice blend ras el hanout, hot cross buns, and lamb testicles. The chefs can add other staple ingredients, but those four flavors have to be featured prominently in the result.

And if that isn’t difficult enough, there is a time limit that is always ridiculously short. The chefs had 20 minutes to create an appetizer from the basket I described above: 20 minutes to create a recipe, determine what other ingredients to add, prepare and cook the food, and then plate it for a beautiful presentation.

I must confess that I find the show very entertaining, and have watched countless episodes. And I’m not alone: the show has been running for 44 seasons over the past 11 years. But let me ask you: if you were opening a restaurant, would this be the way you would select your head chef? I would hope not! Any restaurant that would spring surprises on their chefs and expect them to deliver first-rate food in impossibly short time limits wouldn’t last very long.

Which brings me to the point of all this: if you are interviewing for a programmer, do your interviews actually determine how well they would be able to work in your team? How positive their contribution will be?

Making a candidate live code a solution to a problem they’ve never seen before in a short period of time with people watching their every keystroke is the software development equivalent to being on Chopped. I certainly hope that your work environment isn’t anything like that. So why would you think that a live coding session in an interview tells you anything about their potential?

What artificial scenarios like Chopped or live coding interviews do is test a candidate’s ability to handle stress. Personally, I’ve never had a problem with live coding, but then again I’ve never had test anxiety in school, either. I’ve seen many talented developers choke under those circumstances, but that doesn’t mean that I wouldn’t want to have them on my team.

What does it say about your company as a place to work if the bar they have to clear is how well they can handle high levels of stress?

When I first started interviewing candidates when I was at Rackspace, the standard was to have one interviewer do a live coding challenge, and another ask one of those bizarre, abstract brainteasers (“Walk us through your thoughts…”). Once again, these practices just show how nervous someone is in what is already an inherently stressful situation. That link includes a juicy quote:

These types of questions are likely to frustrate some interviewees so watch out for those who aren’t willing to play the game. It’s an interview after all and you make the rules.

Mark Wilkinson, head of recruitment, Coburg Banks

It’s all a game to him, and if asking questions with no right answers eliminates potentially good candidates, tough. It sounds like he is more interested in seeing who can tolerate being bullied than finding the best people for his company.

After sitting through some of these types of interviews at Rackspace, I campaigned internally to change these practices, because I saw some intelligent and capable candidates get flustered and end up looking dumb. I found that there are better ways to determine if someone is a good addition to your team. Perhaps I’ll elaborate more about these in a future post…

Day 34: They Grow Up So Fast

Remember that large collection of butterfly eggs that I found almost 2 weeks ago? They’ve been eating, pooping, and growing non-stop ever since.

For some reason it seems that some grow faster than others. I generally keep the very little ones in a small plastic container with their food, as it helps to keep them from wandering off. But once they get big enough (third instar if we’re being technical), I transfer them to a larger mesh enclosure where I can provide more food, and where they can eventually pupate.

About half of the growing caterpillars outpaced their siblings, and so I transferred them to the larger enclosure first. The rest went into a second enclosure a few days later. Now that first group has grown to the point where they are ready to pupate.

When they’re ready, they stop eating, purge any undigested food from their stomachs, and search for a place to attach themselves to transition to a chrysalis. In the wild they can travel pretty far – when I used to let them grow outdoors, I’ve found their chrysalises attached to plants over 25 feet away. To get to those plants they would have had to crawl down the pot they were in, up a two-foot tall stone wall, and then across the garden to the plant.

Being in an enclosure limits their ability to find an attachment site. Sometimes they climb the enclosure itself and attach to either the sides or the top (as Lazarus did), but that’s not ideal, as it makes it hard for me to attend to the others without disturbing them. So I create what I call a Pupation Station.

The new Pupation Station

They are pretty simple: I find a branch with a Y-shape to provide a stable base, cut sections of branch at a slight angle, and then glue them to the base. Most of the time the wandering caterpillars find it, and choose to transition there. Here is a photo from last year’s crop of caterpillars, where 5 of them attached themselves to the branches:

5 Swallowtail chrysalises

So as I mentioned, the first group has already begun the pupation process. Two of them have purged, and have attached themselves to the ceiling of the enclosure. The rest are looking pretty pudgy, and I suspect that they will soon join them.

2- week-old big fat caterpillars

I took the above photo during a feeding/cleaning session. I remove the bundle of parsley and/or rue from the container of water, and separate the stalks with caterpillars from the rest, which is discarded. I take a bunch of fresh parsley, add the stalks with the caterpillars to it, and tie the base with a rubber band. Meanwhile I empty the glass that holds the water, as it is pretty gross from all the caterpillar poop that drops into it. I’ve started adding some round glass pieces to help prevent the caterpillars from drowning, so those have to be washed too. Then everything is carefully re-assembled and placed back into the enclosure.

Speaking of not drowning, I noticed this morning in the enclosure for the slower-growing caterpillars that one of them was partly submerged.

Saved by the glass pieces!

It looks like it had fallen down from the parsley leaves into the water, but since the glass pieces are there, it was able to crawl back up the stems to continue feeding. It made me very happy to know that I had learned from the bad experience of the past, and that adding those pieces saved a caterpillar from drowning.

Day 33: Discipline

Recently an online discussion about film vs. digital photography got me thinking. I absolutely love digital photography, and would never consider going back to film. Sure, it’s really tough to match the richness of color of Kodachrome 64, or the detail and subtle gradation of 4×5 black and white film, but to me, those are not the most important things when creating art. Those considerations are more like a measure of craftmanship than critical elements for conveying an idea.

However, I am so grateful that I grew up in the age of film photography because of the discipline it instilled in me. Every time you pressed the shutter button, you were spending money. Period. Contrast that to today, where images cost nothing: take a bunch of bad shots, who cares? Click the little trash can icon, and they’re gone. Doesn’t cost a cent.

If you were a poor, struggling student, as I was at the time, buying film was a good chunk of what was left of your money after paying for rent, food, and other essentials. So if I saw something interesting to photograph, I didn’t fire away, taking several exposures from a few different angles in the hope that one would be what I needed. Instead, I composed the image in the viewfinder, looking at it from various angles, and through this process learned to recognize what was important for the final image. Most of the time I walked away without taking the shot, because on further reflection, it didn’t seem worth it.

What if I had had lots of money to spend? I believe that I would not have developed the visual discipline that I have today, as there would never have been a need to limit what I shot. Without that discipline, I don’t believe that I would have become as good a photographer. Even today, with all my digital equipment, I still shoot as though every exposure means something.

In general, scarcity forces one to become disciplined. For example, when you grow up in an environment where food is in short supply, you learn not to waste anything, and to only eat enough to keep going. Back in the early days of computing, when both disk storage and RAM were expensive, you coded in a way to ensure that your program would fit into memory, and would require as little space as possible when written to disk. That parsimonious approach resulted in the “640K Ought to be Enough for Anyone” quote that Bill Gates never said, but keeps getting repeated anyway.

There’s something to be said for learning how to get through tough times. It’s a delicate balance, though – too much scarcity can damage you physically and/or psychologically. My mom grew up as one of six kids in a family during the Great Depression, and it definitely left its mark on her. She wasn’t a full-blown hoarder, but she definitely had a hard time throwing things away – “you never know when you might need it!” was her refrain. And we were not allowed to be fussy about the food we were served at mealtimes: you had to eat every bit on your plate before you could leave the table. That experience has had an effect on me, as I really hate to throw food out. Maybe it’s my mom’s voice still echoing in my mind.

Day 32: Caterpillar Update

Last week I wrote about the experience of finding over 30 caterpillar eggs at once, when typically I only find a few. So I thought I’d post an update on how they are doing.

A few days old

As far as I can tell, all of the eggs hatched. It’s hard to say for sure because in the two days after the initial finding, I found 5 more eggs, and then shortly after that, two baby caterpillars, like the ones in the photo above. So honestly I’ve lost count. Suffice to say that there are many, many caterpillars crawling around and eating like crazy!

Second Instar caterpillar among its smaller siblings.

When they’re this small, they are mostly black with a band of white around their middle. This is actually a form of camouflage, as it makes them look a bit like bird poop. Yes, bird poop mimicry is actually a thing! They keep eating and growing until they need to shed their skin to get larger. They look a little different in this next phase, or instar, besides the obvious part of being bigger.

I keep them in a plastic container until they reach the third instar, at which point I move them to a bigger enclosure where I can provide more food for them. It’s important to keep them contained, because they do like to wander!

Last night I moved a lot of them to the larger container, but there were a few that had wandered away from the food, and were just hanging out motionless. Usually if you place a bit of food in front of them, they crawl on top and start eating, but not these caterpillars – they weren’t interested.

In the morning, though, I checked in on these stragglers, and saw this:

Leaving the old skin behind

The dark, crumpled-up bit on the left is the old skin from its previous instar. The new, much bigger third instar caterpillar emerged by attaching the back section of its body to the surface with some silk, splitting the skin at the head, and then crawling forward, leaving the old skin behind. A short while later it definitely was interested in the sprig of parsley I placed in front of it, so once it was aboard, I transferred that sprig and its passenger to the larger enclosure. There they’ll continue to eat and poop for a few days, until an internal trigger tells them it’s time to move on…