Tag Archives: experiment

Writing prompt: World Laboratory Day

Time: 10 minutes. Click here to go to my list of prompts.

“World Laboratory” (Inspired by this list of silly holidays.)

 

The capsule docked at the World Laboratory station. Dr. Trinner pushed gingerly from weightlessness into the gentle rotational gravity. The door slipped closed.

“Your laboratory is a ways from the dock. It’s all allotted by need, the labs with heavier shipping duties are near here, the vacuum labs are surface labs, the gravity labs rotate faster, the zero g labs are on the axis.”

“It’s all right, I wouldn’t mind stretching out,” Trinner assured the nervous guide. Her reputation obviously preceded her. But it had been years since the Erlenmeyer Incident…

Strictly speaking, her research didn’t benefit at all from work in space. But as a child, she had dreamt of being an astronaut. Doing science on a space station was damned near the next best thing. The station had jumped at the opportunity to have a Nobel winner onboard.

The light gravity was disorienting, harder on her stomach than zero g somehow.“How many are onboard now?” She braced against the walls of the corridor.

“30%, about,” the guide responded. “Some of the laboratories require special work and will take longer to complete. It will be pretty peaceful for a while here!”

“Other than the construction,” Trinner said.

“Yes, other than that.”

#

Trinner was alone in the lab. Some colleagues would follow in a couple of days. Her quarters were in the cluster near that lab section. It felt like science camp, living and breathing science, away from the cares of the world.

The construction echoed through the bulkheads from time to time. But there were other noises that Trinner couldn’t explain—voices. Voices came from the walls, in languages she didn’t know. She wondered if it were recordings of radio or television, but she couldn’t find a source.

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Writing prompt: National Stress Awareness Day

Time: 10 minutes. Click here to go to my list of prompts.

“National Stress Awareness Day” (Inspired by this list of silly holidays.)

 

Lisa pressed the start button on the tester. The arm slowly pulled harder and harder on the cylindrical sample, and recorded the resistance of the rod. Lisa watched while holding her breath. This was what she had been working toward for the last six years. This either spelled the ticket out of school to a prominent job and good paycheck or back to god-knows-how-much-more grad school with an advisor that would view her as more of a liability than an asset. It had taken three years full of setbacks to build the casting machine. And three more of broken parts and materials choices and whatnot. If she’d known that she would wait six years for a meaningful result, she would never have gone to grad school.

But she had. And she waited. The machine plotted the relationship. The slow grinding sound filled the room. Scritch, scritch, scritch, and another data point.

Crack! A fracture shot through the sample, spider-webbing as it went. It reached from the top to the bottom of the rod. The machine beeped “I’m done!” and stopped pulling on the rod. The chart of the stress-strain filled the air. Lisa’s eyes shot to the stress axis. How far had it gotten?

“Only that far?” Lisa shouted. “That far?” She stood and threw her chair against the ground.

Six years. Six years down the drain. What would she do now? Find a new project? Give up? Her mind buzzed and reeled. The hallway seemed to lurch as she lumbered down it.

“Lisa!” the undergrad accosted her at a time she was least prepared to coddle him. “Lisa, about your test!”

She snarled and moved past him. She needed to be outside. It pulled at her.

“Lisa, you didn’t just do the stress test, did you?” the undergrad pursued.

She looked over her shoulder and kept moving. He seemed to understand.

“Um, which… which sample did you use?”

She stopped.

“It wasn’t in the blue case, was it?”

“It was.” She should be relieved at this line of questioning. She wasn’t. The tension built in her.

“I might have switched the samples. I dropped several of them and had trouble sorting them back out. It might not be the final sample.”

#

Their advisor found the undergrad later, with “stress test” written on his face. He had been bludgeoned with a fractured cylindrical rod.

The professor found Lisa with the stress machine, cradling her printout and another fractured cylindrical rod. She smiled serenely and extended the plot to the advisor.

“This is excellent data,” the advisor said. He nodded, turned around, and left the room in a good mood.

Fun Science: Two metals in contact do fun stuff

Have you ever made lasagna, and later discovered black spots or holes on the tin foil you used to cover it? Those spots are due to bimetallic or galvanic corrosion. Galvanic corrosion is an electrochemical process that occurs when two different metals contact through an electrolyte. Any two metals or alloys can experience galvanic corrosion, but pairs with dissimilar potentials will experience more. The potential of a metal is an inherent property of that metal, like density or hardness. Galvanic corrosion can be a very destructive force, or it can be exploited to make electrical current in a battery. In the case of the lasagna, the lasagna functions as the electrolyte, the pan as one metal, and the tin foil as the second metal.

How to make a simple battery at home

The first battery was invented in 1800 by Alessandro Volta. It was called the voltaic pile, and it was composed of a stack of zinc and copper disks.

A voltaic pile, the earliest kind of battery. Voltaic piles were used to discover many elements and to study electricity (credit: wikimedia commons)

If you have coins, you can make a battery. US pennies are zinc coated with pure copper and US nickels are 75% copper.

Battery 1 (weak, but easy): You can make a weak battery by stacking pennies alternated with nickels. Just separate the coins with paper towels soaked in vinegar, which will serve as the electrolyte. Here’s a great summary of some experiments you can do with this system. If you have a multimeter, you can measure the voltage of your system; the more alternating sets of coins, the higher the voltage. This battery won’t be powerful enough to light an LED, but if you keep it wet for a few days, you will be able to see the effects of the corrosion on the coins.

Battery 2 (strong, but more work): If you’re more ambitious, you can sand the copper off one side of the pennies, and create a battery from just pennies. A few pennies like this can easily light LEDs.The video below shows how to make battery 2.

Battery 2 is much more powerful because the metals in battery 2 (the zinc of the penny’s core and the copper of the penny’s surface) have a higher difference in potential than those in battery 1 (the 75% copper of the 5 cent coin and the pure copper of the penny surface). The farther apart two substances are on the galvanic series, the more voltage there will be.

Galvanic corrosion and the Statue of Liberty

The Statue of Liberty has an iron skeleton covered by a thin layer of copper. It was built with insulators between the copper and iron to prevent corrosion, but these insulators broke down. The Statue of Liberty was extensively renovated in the 1980s to repair damage from this corrosion.

Galvanic corrosion occurs in a lot of systems. If you use washers that are a different kind of metal than your screw, galvanic corrosion will occur. Galvanic corrosion can get even trickier: alloys that contain more than one kind of metal are composed of crystal grains that may vary slightly in composition. Galvanic corrosion can occur in an alloy between grain boundaries!

The bolts are a different kind of stainless steel, which has led to corrosion (credit: wikimedia commons)

Fortunately, we have methods for combatting corrosion. Corrosion only eats away at the lower potential metal. So engineers often design less critical pieces out of lower potential metals, so that they are sacrificial. Galvanic and other kinds of corrosion are major topics of research, relevant to boat construction, bridges, high temperature processing, and more. And thanks to galvanic corrosion, you can power a light with just pennies.

The Beautiful Lab

Across the country, thousands of labs study thousands of topics. In my lab, we study nonlinear dynamics in electrochemical oscillators. The dynamics of these oscillators can be used to make math models for other oscillators we might be very interested in, like heart cells, breathing, and neurons in the brain. Oscillators and their dynamics show up in many places. In a previous post on synchrony, I discuss some of these dynamics.

My experiments aren’t particularly much to look at. The beauty in mostly in the data. But here are a few of my better snaps over the years. There can also be science in the photographic technique. The bottom two photos were taken using reverse lens macro, a cheap way to do great zoom shots.

From top to bottom the photos below show: the electrochemical 3 electrode cell, the variable resistance resistors for each electrode, and a capacitor. The featured image is of some resistors.

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SONY DSC SONY DSC