Thursday, February 28, 2013

Experiments with light.

This week I stumbled upon Veritasium, a video blog featuring experiments and explanations about various topics in science and nature. The host and creator Derek Muller, who has a Ph.D. in Engineering Physics, aims to communicate sometimes abstract scientific concepts to the public in an interactive and easy to understand way.

This is a GREAT video he put together demonstrating Thomas Young's double-slit experiment. When Young first presented his results of his experiments to the Royal Society of London in 1803, he explained: "...(it) may be repeated with great ease, whenever the sun shines, and without any other apparatus than is at hand to every one."

The property of light that this experiment so elegantly demonstrates is it's distinctly wave-like. It has properties of waves, such as a wavelength (or color) and it can constructively and destructively interfere with itself, like ripples in a pond.  In the early 1800's, this idea was very revolutionary, as it was commonly believed that light behaved more like individual particles, thanks to pioneering work by Isaac Newton in the 1600's.

Double slit experiment showing small particles, such as individual electrons or photons, passing through two slits will cause an interference pattern, a property of waves. Isn't that crazy? Yes. It is. Because quantum mechanics is totally bonkers, but that's why it's so interesting.

Turns out Young and Newton were both right. As Albert Einstein discovered 100 years later in the early 1900's, light can behave both like a wave and a particle, and this particle can only have only a discrete set of energies, or quantized energies.  Today, we call these discrete quanta of energies photons. Einstein's work describing the photoelectric effect -- in which you can shine light at a metal and get it to conduct electricity -- won him the Nobel prize in 1921.

The photoelectric effect: If you shine light, made up of photons of specific energies, at a metal material, the light will excite the electrons in the metal and cause them to eject from the surface.  The idea of photon-electron interaction is an important piece of the quantum mechanics puzzle. 

The so-called wave-particle duality is one of the main concepts of quantum mechanics and is essential in understanding how semiconductors and solid-state light emitters work. Of course, quantum mechanics gets very dense and abstract very quickly, and details of it are still being discovered to this day. Still, it's fascinating to think about how simple experiments like sunlight passing through a double-slit were so influential in developing our understanding of light and matter.

Saturday, February 23, 2013

Oh, the sometimes mindless drudgeries of experimental research

My research has taken on several interesting developments lately. As exciting as this is, the downside is it requires generating a lot of samples, and painstaking measurements on a lot of samples, which has been very time and energy consuming. On top of paper writing and all my other postdoctoral responsibilities, I'm swamped with work. I've recently recruited a graduate student to help me out on the measurement side, thankfully, as I'm not sure how I would manage otherwise.

As tough as it is, I know my project is (finally) building up to something interesting (and publishable). I remind myself that many scientific discoveries are likely not serendipitous eureka moments, but probably required a lot of planning, time and effort. And measurements. Long, slow, mind-numbingly boring measurements...

In experimental research, sometimes you can't avoid what feels like mindless drudgeries. This is why patience and dedication is such an important skill in graduate school. Also coffee. Also lab computers with internet access.

(Thank you, When In Academia)

Thursday, February 7, 2013

Productivity & email

One of my tips for grad school is to come up with a systematic way to stay organized and consistant. I'm not at ALL tidy or organized in real life, but at work I NEED a good system to keep my research and sanity in line.

Something I quickly learned to get under control as a grad student was my email. Between coworkers, campus-related announcements, department-related announcements, lab-related announcements, as well as personal emails, bacn, spam, etc., it can get overwhelming pretty quick.

Colleen Wainwright of Communicatrix changed my life when I saw this video on how to use the filters function of Gmail to automatically sort incoming mail. This is a few years old, but still super useful.

Show me yer rig! (Gmail filters edition) from communicatrix on Vimeo.

I now have all my email accounts get routed directly to my Gmail account which then auto-filters them into folders. The best part of this system is they are accessibly from anywhere, and if I go off-line for several hours or days, I don't have so many new messages in my inbox demanding attention when I return. Instead, I can easily find where the most important messages are, and then skim over the rest when I have time.

I also love Gmail's advanced search functions to quickly look up an old messages. For example, if I'm trying to find an old email I sent that had an attachment, I search "from:me has:attachement" and it will narrow down to find it easily.

I know Gmail isn't the only service that has these functions (and is likely not the best). Still, when I hear people use Gmail and don't auto-filter their incoming email, I'm just like: "WHAT?? HOW DO YOU LIVE??" And then I punch them in the face. 

The end.