Unit, as defined by the dictionary, is "a determined quantity adopted as a standard of measurement. When one use a unit to measure with the sole purpose of measuring, any unit may be adopted as a standard, as long as one is familiar with the standard and has a way to reference to the standard. When one intends to communicate with others using a unit, everyone who uses the unit must be on the same page--that they must all be familiar with the standard, and they must all have a common way to reference to the standard--in order for the unit to be useful. In other words, when one attempts to solve the unit of measurement problem in a social context, it is crucial for one to find a unit that everyone finds reasonably easy to use.

Most people in the United States are familiar with distance and speed units such as feet, yards, miles, miles per hour, etc. They take for granted these units as their "default" unit for measurement, often without critically examining whether such units are proper for the particular kind of measurement. There are times when using some units are more effective and convenient than other units. For example, in nautical navigation, nautical mile (1 nautical miles = 6076.115 feet) is used rather than a mile (1 mile = 5280 feet). This is because 1 nautical mile is the angular distance of 1 minute of arc on the earth's surface, which is more coherent with the units used on sailing maps. For the same reason, knot (1 nautical mile per hour) is used instead of miles per hour as the measurement unit for speed.

Let us consider a possible origin of feet as a unit: an apprentice was ordered by a British king to make a bed for the queen, and was thrown into jail because the bed he made was too small. In order to communicate clearly with the king on the exact measure that the king looks for, the apprentice suggested to use the king's feet as the unit of measurement and successfully solved the problem. In this case, all the figures in the social context, namely the king and the apprentice, agreed on a unit that they both found reasonable. The unit is also convenient to use in this social context: using his own body as a tool, the king measured by walking feet-to-feet and counting the number of steps he took, which is simple enough for the king to do, and not too tedious for the king to do when all he wanted was one bed.

This story suggests that it is convenient for people to use feet as they can get a measurement of distance using only their body as the measuring tool. However, one has to bear in mind that such a measuring method works well only in limited-size social context on a limited-scale (i.e. making one bed). When more people are involved in the social context, this method of measurement becomes inconvenient--everyone would have to wait for the "king" to walk for them to get a measurement; or, if they measure using their own feet, they would get inconsistent measurement simply because every person's feet is likely to be of different length. Therefore, feet (as measured by a person's feet) is only useful for individual use and cannot be used among multiple individuals with expectation of accuracy.

With further consideration, feet as measured by a person's feet may not even be accurate when used by the same individual. Human feet do not have flat edges. Both the heel and toe of human feet has round edge, which makes it hard to align the feet perfectly every time the person takes a step. In order to achieve higher uniformity and accuracy, it is agreed among the people in the states to use a set distance as the measurement unit (i.e. 1 feet = 12 inches) instead. This raised a question in my mind: if most people cannot get this 12 inches measurement with their own feet, why do we still name the unit feet? Just the fact that human walk with their feet and can use their feet to measure distance (without uniformity and accuracy) does not justify this--if it does, doesn't it mean that a person walking with one's hand should use hands to measure distance and hands per hour to measure speed?

My project seeks to investigate and to question the use of units to represent distance and speed for navigation. The project is a performance that takes place in the Death Valley Racetrack playa as the playa has a large flat surface with minimal traffic flow, which minimizes other distractions for the performance viewers. The performance begins with me walking with my hands on the surface of the playa. For each hand-step I take, my assistant places a plastic glove on where my hand was placed, which signifies a "hand print". A trial ends when I reach the farthest distance that I can walk with my hands. A second assistant records the time it took me to complete the trial. After a trail of hands (gloves) is made, the number of gloves placed is counted. A speed in the unit of hands per minute is calculated using the number of gloves placed and the time recorded. Three trials were completed in the performance. The performance is documented with photography and video-photography.

In the first trial, I left 7 handprints in 8.88 seconds; this yields to an approximate speed of 47 hands per minute. In the second trial, I left 19 handprints in 19.61 seconds; this yields to an approximate speed of 58 hands per minute. In the third trial, I left 24 handprints in 18.91 seconds; this yields to an approximate speed of 76 hands per minute. The actual distance traveled varies in all three trials.

The performance has a number of sources of error. First of all, the gloves were not placed directly under the location where hand-step took place. This is due to the physical limitation of the performer. Instead, an assistant helps placing gloves next to the performers' hand-step, which introduces another source of error: the assistant was not able to catch up with the performer's moving speed. Hence some of the gloves placed were not accurate. Second of all, the way that the gloves were placed varies. This is due to the physical limitation of the assistant and the performer--the assistant cannot place the glove in perfect position in the time that the performer can stay still in one location. Another source of error is the direction of travel; the trails left by the performer are not uniform in direction. This increases the difficulty for measuring the actual distance traveled (and thus the distance are not recorded). Yet another source of error is that the assistant would skip a few actual hand-steps, and this is also due to the physical limitation of the assistant. Overall, the measurements taken provide no accurate result, despite the level of difficulty involved in actually taking the measurements.

Measuring distance using a feet-to-feet methodology cannot be any more accurate than the measurements taken in the performance. The use of a standardize feet unit (i.e. 12 inches in 1 foot) does not provide the same convenience as the feet-to-feet measuring method, where one can use their body part to take a measurement. In addition, the standardize feet unit is difficult to perceive when one attempts to covert it to other units in the same system (i.e. miles, inches, etc.) as there is no consistent scaling factor as in the metric system (10 mm = 1 cm, 100 cm = 1 m, 1000 m = 1 km, etc.). Therefore, any unit system using feet should be replaced with systems such as the metric system, which as least provides some convenience for having a consistent scaling factor, because using a unit system that employs feet as a unit to take measurements is simply as ridiculous as the performance.