One of the conversations that is starting to develop here at the blog relates to the concept of scale. In a recent comment, Michelle wrote about an application that aids with the visualisation of time-scales (although the application's designers see it as more of an interactive teaching tool).
Seeing as "Scale of the Universe" is so popular on the internet, I expect that this application, ChronoZoom, should become equally popular one day soon. Scale of the Universe allows you to zoom in and out of distance scales and it shows you the relevant physics, chemistry or biology at each scale. ChronoZoom kind of does the same for time. However it is quite a bit more detailed and much, much more ambitious as a project. Watch the video above, read a recent article on the project, and play with the application itself.
Michelle wrote in her comment that she finds visualising time-scales through this application more difficult than the equivalent for spatial-scales. This is not surprising. We encounter space with our eyes every day, so visualising space is already second nature. Zooming in and out is also something we do naturally every day. Extending this to a need to zoom in and out on a greater range of scales shouldn't be too hard. However, no matter what happens in life, we always proceed forwards in time at a rate of one second per second and we definitely don't "see" time. Despite all of that I think it is also true that the Scale of the Universe application was specifically designed with the aim to give a sense of perspective. Whereas, ChronoZoom has been designed more as a way of organising information. The sense of perspective it can give seems to be much more of a bonus than a feature.
One interesting observation I can make (and have already to a certain degree in this comment) is how in the early stages of the universe, time scales and length scales were intricately related. This relationship arises from two different mechanisms. The first, and more obvious, is the expansion of space with time. As time progresses, things in the universe get further apart. Therefore the relevant distance scales get larger and larger as well. The second mechanism is the growth of structures in the universe. Structures grow hierarchically. This means small things grow first, then larger, then larger. This is actually a distinct effect from the expansion of the universe, but it's aesthetic implication is the same; earlier times mean smaller scales.
Of course most of the ChronoZoom application is devoted to later times. Something that struck me quite a bit when I first realised it is that the Earth is about a third of the age of the universe. Whether this means that the Earth is very old, or the universe is very young depends on your perspective, but whichever perspective you hold, when it comes to time, the universe and the Earth exist on similar scales. You can see this really clearly in ChronoZoom. What is also quite striking, but already appreciated by many people is just how young humankind is. If you go to ChronoZoom and click on "humanity" right at the top of the page you are given quite a sense of perspective regarding how young we are as you watch it take forever to zoom in on our relevant time.
For both those old dudes, Earth and universe, we humans really are just a flicker.