Changes With Scale

Scale |
| As you increase and decrease the size of a variable, we say that the scale of that variable changes. This is especially true if this change in size is in powers of ten or in orders of magnitude. One of the reasons that the concept of scale is so important is that, as the scale of a variable changes, how that variable behaves often also changes. So an experiment run with objects that are around 1m in size might give totally different results than if the experiment was run with objects that are around 1mm in size. The diagram below indicates the many ways that the universe changes with scale. Certainly, different objects exist at different scales. Viruses are much smaller than human beings. But scale effects the tools we use to obsever objects, the scientific models we use to describe how objects behave, and even which forces apply to those objects. |

Taken from: Nanosense: the basic sense behind nanoscience
Cups & Water Exercise
| Let's compare how water behaves when poured from cups of very different sizes (or scale). Fill a large cup with water and pour it out. Then do the same with a very small cup. The large cup should be the size of a regular coffee cup (diameter around 8 cm), while the small cup should have a diameter of around 0.7 cm.
| Predict what will happen and explain why.
| This is one example of how things behave diffeently when the scale changes.
| A video of the cups & water exercise is available below in mpg format. To watch it, you can click on the link below and play it using Quicktime Player. Or, you can right click and choose, Save Target As. Then you can double click on the file, cups_scale.mpg, to run it in Windows Media Player or your default media player.
| Cups & Water Video
| A complete nanotechnology lesson based on the two cups idea, called Shrinking Cups: Changes in the Behavior of Materials at the Nanoscale, is avaialble in Nanoscale Science, published by NSTApress.

The Promise of Nanotechnology
| One of the reasons that nanotechnology might lead to many new useful applications is due to the fact that variables change with scale. It has only been recently that we have been able to see and build materials at this small of a scale. And the properties that materials exhibit at the scale are often quite unusual and useful.
| Exercise: Come up with examples where how something changes its behavior when the scale of a variable is changed.

Other Examples of the Effects of Scale
| As heat is added, the temperature of a liquid subsance increases at a regular rate until, at a certain temperature, it begins to boil. A force will keep accelerating an object to greater and greater speeds until it reaches the speed of light at which point it canot go any faster. A force will keep stretching a spring more and more until the spring breaks. A plane can keep increasing it's velocity smoothly until it reaches the speed of sound. Quantum (subatomic) particles act very differently than real world size objects.