We humans have 5 senses. Five "inputs." Five ways of sensing the environment. Five ways of understanding where you are: Sight, Sound, Touch, Smell, Taste. We sometimes refer to sight and sound as "distal" senses and touch-smell-taste as "proximal" senses.
In many ways the distal senses, Vision and Audition, are the most complex. In every waking moment our brains perform monumental analysis projects of contrast mapping, edge finding, noise masking, geometric rectification, pattern recognition, and the search for meaning. Opening your eyes in the monring and "seeing" your loved one or your cat or the tree out the window is a vastly more complex task than winning a presidential election or discovering a new element or a new planet.
It's also worth noting that the human eye and ear are, quite literally, "quantum particle detectors." Under ideal conditions the human eye is capable of detecting a single photon and under ideal conditions the undamaged ear can hear the impact of a single air molecule on the eardrum. Give or take a couple orders of magnitude, human vision and human audition both have dynamic ranges in the neighborhood of 100 million : 1.
Then again, what we loosly call the sense of "touch" (encompassing ideas of haptic, proprioception, interoception, and exteroception) seems almost limitlessly varied as it encompasses so many aspects of "what it feels like to be me."
If, for a moment, we consider one aspect of touch as the sensing of windspeed / windchill, then it's interesting to note that 3 of our senses, Audition, Touch, Smell are all concerned with air molecules. Audition is the detection of rythmic patterns in the vibration of air molecules. Touch-windspeed is the sensing of the locomotion of air molecules. And olfaction is the chemical analysis of air molecules.
For this project I would like to sense the ambient, passive environment at a given location. By ambient, passive, I mean qualities like windspeed, rather than "the caress of a loved one." I believe that it is possible to measure abient light, sound, and air (movement, temperature, pressure, saturation, chemical composition) but that there is no such thing as "ambient taste." Yes, you could lick the ground, but that seems a bit off. Friends have told me that they do experience ambient taste, such as a gritty Long Beach oil refinery having a particular taste. They may be right. Or they may be having a synaesthetic experience. I think if we define smell as the chemical analysis of gasses and taste as the chemical analysis of liquids and solids, then without quibbling about the sizes of airborne particulates, I'm going to say that there's no such thing as abient taste.
Which brings us to:
Ambient Light, which I'll call FOOTCANDLES
Ambient Sound, which I'll call DECIBELS
Ambient Touch, which I'll call KNOTS and DEGREES
Ambient Smell, which I'll call PPM / CO2
FOOTCANDLES
The lumen is the absolute amount of light, a lightbulb, for example, emits. The foot candle is a measure of how much light falls on a given area. One lumen shining on one square-foot equals one foot candle. Ten lumens shining on one square-foot equals ten foot candles. (a "lux" is one lumen per square-meter. One fc equals 10.76 lux) (as you can imagine, the footcandle originates from one candela or standard candle at one foot)
10,000 foot-candles - Direct outdoor daylight in the summertime
1,000 foot-candles - Overcast daylight
300 foot-candles - Open shade
100 foot-candles - Deep shade
5,000 - 100 foot-candles - Light near a window (depending on orientation, season, latitude)
10 foot-candles - Lit Room
.02 foot-candles - Full Moonlight
.00011 foot-candles - Starlight
So, the human eye has a dynamic range of something like 90 million : 1. It can cover much of that range in a fraction of a second, and can cover the whole range within about 20 minutes of dark adapting.
DECIBELS
Unlike the footcandle, the deciBel is logarithmic and therefore allows very large or small ratios to be represented with a conveniently small number. The boys at Bell labs defined the TU (transmission unit) as the reduction in audio level over 1 mile of standard telephone cable. Around 1924 they changed the name of the unit to the "bel" ("B") in honor of Alexander Graham. Also, since the unit was enormous, the decibel ("dB") or .1 bel became more commonly used. (a difference of 120 dB represents a ratio of a trillion : 1)
A 0 dB Sound Pressure Level (SPL)(the threshold of human hearing) is equal to 20 micropascals in a gas which is roughly the sound of a mosquito flying at a distance of 10 feet. (and, if you really want to know, XdB = 20log10(X/X0) where X is the sound and X0 is a specified reference with the same units as X, this is often 1 and is ignored)
194 dB SPL - loudest sound possible
(limit for a sound wave at 1 atm. environmental pressure)
(pressure waves of greater intensity behave as "shock waves")
180 dB SPL - Death of hearing tissue / liquification of eardrum
180 dB SPL - Krakatoa volcano explosion at 1 mile in air
180 dB SPL - Space shuttle at lanuch pad
150 dB SPL - Jet engine at 100 feet
150 dB SPL - Rock music peak
(rock musicians - 13-30% incidence of hearing loss)
140 dB SPL - Bleeding / burst eardrum / separation from membrane
140 dB SPL - Low caliber rifle at 3 feet
140 dB SPL - Formula One car at 3 feet
137 dB SPL - Symphonic music peak
(classical musicians - 4-43% incidence of hearing loss)
130 dB SPL - Civil defense siren at 100 feet
120 dB SPL - Threshold of pain
(or 130 or 140 depending on who you ask)
120 dB SPL - Train horn at 3 feet, perforation of eardrums
110 dB SPL - Football stadium at kickoff at 50 yard line
110 dB SPL - Chainsaw at 3 feet
110 dB SPL - Rock music average
110 dB SPL - Average iPod volume in NYC
100 dB SPL - Jackhammer at 7 feet
100 dB SPL - Discotheque
94 dB SPL - Walkman on 5/10
90 dB SPL - and above: sustained exposure results in hearing loss
90 dB SPL - Loud factory / heavy truck at 3 feet
85 dB SPL - Magic sound mixing volume
80 dB SPL - Vacuum cleaner at 3 feet
70 dB SPL - Busy traffic at 16 feet
65 dB SPL - normal conversation at 4 feet
60 dB SPL - Office or restaurant inside
50 dB SPL - Quiet restaurant inside
40 dB SPL - Residential area at night
30 dB SPL - Theater, no talking
20 dB SPL - Whispering
10 dB SPL - Human breathing at 10 feet
0 dB SPL - Mosquito flying at 10 feet
0 dB SPL - Threshold of (healthy) human hearing
Note that the SPL of a Jet Engine or a Jackhammer or anything else is meaningless without distance information. In the case of this project, Location:Sensation, SPL numbers won't be defining the loudness of OBJECTS, but the ambient sound levels at the various PLACES that I find myself.
Perceptions of increases in dB levels
1 dB - imperceptible change
3 dB - barely perceptible change
5 dB - clearly noticible change
10 dB - about twice as loud
20 dB - about four times as loud
On a vinyl record, the signal can be 55 dB above the noise... so if you listen at 85dB SPL the noise is at 30 dB SPL. S/N for tape can be 75dB and for CD 90dB. So a CD played at 85 dB SPL could have its noise at -5 dB SPL. (exceptional human hearing can hear -10 dB SPL)
OSHA Daily Permissible Noise Level Exposure
90 dB SPL - 8 hours / day
95 dB SPL - 4 hours / day
100 dB SPL - 2 hours / day
105 dB SPL - 1 hour / day
110 dB SPL - 30 minutes / day
115 dB SPL - 15 minutes or less / day
CARBON DIOXIDE - PARTS PER MILLION
For sight, sound, and touch, I have chosen measurements that are reductive to the point of absurdity. To abstract a complex visual scene to "7,600 footcandles" is to abstract away almost all the content. In addition to providing for highly reductive comparisions of the qualities of locations, this act underscores the extraordinary power and range of human sensation. For smell I take an opposite approach. Although the Carbon Dioxide content of the atmosphere is of monumental importance, Carbon Dioxide is, for us, a colorless, odorless gas. With all of our extraordinary senses there are qualities and expereinces that lie outside of their abilities to percieve and so it is with Carbon Dioxide. Carbon Dioxide and Oxygen are fundamental to life. In grammer school we learned that we breathe in oxygen and expel Carbon Dioxide in a dance with plantlife.
Because CO2 is a colorless, odorless gas it is easy and convenient for politicians not to see it. Scientists, Al Gore, and many others have noted that this is a devastatingly short-sighted vision. James Lovelock predicts that global warming is now so dire that by 2050 the entirety of the United States will be uninhabitable and that the surviving 20% of earth's population will be joined by "aligators swimming in the artic circle."
So, for this project's "sense of smell" I will mesure the "odorless" levels of atmospheric Carbon Dioxide in Parts / Million.
CARBON DIOXIDE - PARTS PER MILLION
280 ppm - Atmospheric CO2 in 1850
381 ppm - Atmospheric CO2 in 2006
350 - 400 ppm - fresh air
500 - 600 ppm - NYC/LA on a muggy day
<600 ppm - few indoor air complaints
1,000 ppm - Inadequate indoor ventillation
>1,000 ppm - discomfort in 20% of occupants
2,000 ppm - significant discomfort in >50% of occupants: Headache, Nausea, Reduced activity level
4,000 ppm - cigar bar
5,000 ppm - OSHA limit for adult 8-hr work day
30,000 ppm - 10 minute exposure limit
40,000 ppm - immediate danger to life
45,000 ppm - human exhallation
80,000 ppm - unconsciousness in a few minutes
960,000 ppm - Atmospheric CO2 on Mars
BEAUFORT WIND SCALE -- DESCRIPTION -- KNOTS
0 -- Calm -- 0
1 -- Light Air -- 1
2 -- Light Breeze -- 4
3 -- Gentle Breeze -- 7
4 -- Moderate Breeze -- 11
5 -- Fresh Breeze -- 17
6 -- Strong Breeze -- 22
7 -- Near Gale -- 28
8 -- Gale -- 34
9 -- Strong Gale -- 41
10 -- Storm -- 48
11 -- Violent Storm -- 56
12 -- Hurricane -- 64
1 Knot = 1 nautical mile / hour = 1.852 km/h = 101 feet/minute
The circumference of the earth can be divided into 360 degrees or 360 x 60 = 21,600 minutes. The circumference of the earth at the equator is about 21,600 nautical miles. 1 nautical mile is 1.852 km or 1.15 (statute) mile or 6076 feet. 1 nautical mile is 1 meridian arc minute at sea-level. (so when your GPS unit ticks off .001 minute, that's about 6 feet (latitude anywhere, or longitude at the equator)
WINDCHILL
Note that Windchill is only defined for temperatures below 50°F
