SIZE - TIME EXPLORER

In science, we encounter a huge range of scales both in space and time, and this interactive has been designed to deepen your appreciation of these scales. An oak tree is a central feature in the size-time explorer and you will see references to this tree throughout the various level of scale presented.

The explorer is an interactive graph, with time (in seconds) on the x-axis and size (in metres) on the y-axis. The numbers on each axis are presented as powers of ten on a log scale, which means that each tick mark is 10 times bigger (or smaller) than the previous one. For example, three consecutive tick marks size axis are 10¹, 10², 10³ metres, which is the same as 10, 100 and 1000 metres, respectively.

The full extents of the space and time scales are not visible at the same time, but you can choose what is shown in the graph by moving the sliders on each axis. There are words on the time axis and images on the size axis to help you put the very large and small numbers of metres and seconds into context.

On the graph there are 13 levels, shown as cream-coloured bars, which each represent a process occurring at a different size and time scale. You will need to scroll up and down the axes to see all of the bars. There are also a series of questions associated with each level that will help to increase your knowledge and understanding of events at that scale.

Use the buttons on these bars to explore the processes as follows:

	Read more information about what the bar represents.
	Play the video or slide show about the process represented by the bar.
	Go to the interactive questions about the process.
	Record which levels you have completed (toggle to green = done).

Some of the associated questions will ask you to place additional processes (represented by bars) on the space-time explorer, using information you have calculated to work out where they should go. To find the available bars you need to access the 'activity panel' by:

selecting 'Open activity panel' from this menu button at the top right of the screen

selecting the arrow on the right-hand side of the screen.

Opening this panel will reveal some new blue bars in the graph area, which you can use to place the additional processes. To add a process to the graph, select it from the activity panel and then select the blue bar in the graph area that you think represents the appropriate time and size values. You may need to scroll along the time and scale axes to find the right location. If you have chosen the correct placement, the bar in the graph will now show the processes name.

You can choose whether or not to show the additional processes at all times by checking the 'Always show activity items' box within the activity panel, and you can hide the panel list using the menu button or the arrow on the right again.

Also, using the menu button in the top right of the screen, you can select 'Reset activity' to remove all of the added bars, and 'Reset progress' to return all progress ticks marked green back to grey.

Using a keyboard

Use the W, A, S and D keys to control the size and time sliders.

Use the Tab key to cycle through the menus. Also, use the Tab key to access the icons of each visible process, and then press the space or enter key to action it. To access the icons for a process that is not currently visible, first move the size slider to make the process visible and then tab to it with the Tab key.

New processes can be placed on the graph with the keyboard. Move to a process in the slide-out panel with the Tab key, and select it with the space or enter key. Move the size scale slider to find the matching process and tab to it, then select it with the space or enter key.

Happy exploring!