Random Musings on the Stuff of Science and the Science of Stuff

CERN, The Higgs, ATLAS, CMS and the Ultimate Experiment in the Science of Stuff

By Cheryl R Stewart
January 19th, 2012

Before the holidays, the world was mesmerized by a scientific result and millions of people listened in as it was discussed. The subject was the possible discovery of something called the “Higgs Boson” or simply the “Higgs”. (You know you have really made it when you become a one word name such as Cher, Gaga, Adele, ARod, Tebow, DaveB*…) The Higgs is a particle that ties up our understanding of the subatomic world and the host of particles that we have seen over the last half century. As an example, imagine what you would think about the periodic table of the elements if you only knew about electrons and protons, not neutrons. While the overall structure would make sense to you, there would be a gap in your understanding that required a new particle to exist, the neutron. You could look at the entire framework and say either we understand it and we have yet to discover this new particle (the neutron) or if we could prove it didn't exist, we would then be forced to conclude that we don’t understand the entire structure. The Higgs is like this for the zoo of subatomic particles. More

A “Thank You” to our Founding Head

By Cheryl R Stewart
January 12th, 2012

This term Uday Pal, the founding Head of the BU Division of Materials Science and Engineering, is stepping down from the leadership team. It is time for us to thank him for his leadership and all his efforts on behalf of the materials science community at BU. Starting the Division was a lot of work given that almost nothing about the organization existed when he began. He developed a strategic plan across multiple departments and colleges, helped put the staff together, created the processes and got everything up and running. My work as the second Head is immeasurably easier because of all his efforts. As we grow and evolve the Division, we owe a real debt of gratitude to Uday for his vision as the founding Head. We wish him a hearty thanks. All the best, Dave B.

Phase Transitions at BU, Looking at Stuff in a Whole New Way

By Cheryl R Stewart
January 5th, 2012

Traditionally the study of condensed matter physics focused on the nature of the ordered phases. This means the study of solids and liquids, their structures and properties. Some of the most impactful work leveraged the periodic nature of crystalline solids to gain an understanding of metals and semiconductors. The computer and the internet are the direct result of that work. However, as research in condensed matter physics matured, the focus shifted from how these systems behaved and their properties to much more subtle questions beyond what they do to questions of why they exist at all. This is sort of like the difference between studying medicine and evolution. One field studies “how” the other studies “why”. If you look at all the stuff in the universe, one way to think about it all is how disordered it is. Think about water for a minute. You can have crystalline solid phases, a liquid or a gas. These different phases all have very different properties and a unifying way to think about them is elusive but one useful approach is to think about disorder. The crystalline solids are well-ordered (the molecules are all lined up like good... More

Standing Tall at Boston University

By Cheryl R Stewart
December 1st, 2011

Bone is pretty amazing stuff.  It is light, strong, alternatively hard or flexible when or where it needs to be, self-healing and it does all of this having been made using only room temperature processing.  With all of our technology today, we can’t come even close in terms of making anything this amazing. Most of bone is not alive but the cells that manufacture it live within its structure and therefore need to stay connected to their source of nutrients, the blood vessels of the body.  Unlike a piece of concrete, the structure of bone is quite complex with two different types of bone. There is hard, dense bone called cortical bone which is on the outside providing most of the strength and impact resistance we usually think of when we consider our skeletons.  Inside of this is a type of spongy (or cancellous) bone which has a lower density (and strength) but which is incredibly tough.  The detailed structure consists of rings on the outside (like a tree) with internals structures inside (like the re-bars in a concrete building) allowing for great strength with low weight. If our bones were solid and dense throughout their volume, they would be strong... More

The Sublime World of the Sub-Miniature

By Cheryl R Stewart
November 23rd, 2011

At Boston University we have a large and active group of researchers working in MEMS and NEMS.  MEMS are Micro-Electro-Mechanical-Systems and NEMS are Nano-Electro-Mechanical-Systems.  These are devices built at the micrometer and nanometer scale using Silicon VLSI processing with parts and structures that can either move (dynamic systems) or have other functionality enabled by their small sizes.  Basically, in the jargon of today, they are micromachines. Why is this kind of work interesting and important?  It turns out that, generally speaking, there are two broad categories of scientists who are rushing towards the nano-world.  There are chemists who traditionally worked with atoms and molecules that entered the nano-world by creating ever larger molecular complexes such as carbon nanotubes and proteins.  They developed the techniques to create, control and understand larger and more complicated molecules and now much of chemistry does this.  Physicists and Electrical Engineers have gotten to the nano-world by following Moore’s law, using the techniques of Silicon VLSI processing to make increasingly smaller structures, down to the nanoscale.  Characterizing chemistry and physics/EE this way is a gross generalization but the high level trends are these. The reason for this assault on the nano-world is that is where much of the interesting... More