Thursday, May 3, 2007

Dr. J's Tech Talk - Time and Power, Part 1

In the “real” world (read: non-cycling related) I have recently become involved with a scientific organization that uses Femtoseconds as a primary element of time measurement (for reference, a femtosecond is to a second, what a second is to 100,000,000 years). During this period, it was pointed out to me that I hadn’t written anything about cycling in quite some time. TIME. I thought about that for a moment and decided that it was only true depending on how one views “Time,” although I do admit that many femtoseconds have passed since my last entry.

Note to Readers: By the way, the world of Physics can create a plethora of wonderful rationalizations and excuses...seriously. Actually, so can Anthropology…did you know that the Hopi culture had no verbal or written reference for time – past, present or future?

Anyway, I got to thinking about how many cyclists judge themselves and others by a number of (seemingly) concrete orders of magnitude, primarily those relating to elements of “time” and “power.” Speed is another factor that I may get into in the future but I’ll stick with time and power for now. While these units, or measuring systems, are not truly stable in an academic sense (don’t make me go Einstein on you), base values and meanings can be used to differentiate performance on a “human” scale. After all, the theory of relativity is not meaningfully applicable for cyclists travelling at different speeds until Litespeed or Cervelo actually make a bike that can go about 186,282 miles per second. Although, there probably is a psychological equation involved. But that’s another topic for another time…Psychology can be even trickier than Physics.

Where was I? Oh yeah, Time and Power. I’ll start off with the notion of Time because more people probably understand the basic elements of how we typically view time intervals than those of power or output. As such, most people probably think they have a fairly strong concept of time…but unless they have a PhD in Physics, most of those people are wrong. Time can actually be quite difficult to wrap the old melon around when looked at critically. With this in mind (leaving Kant, Leibniz and Existentialism out of the picture), let’s look at the basic framework by which human beings view the concept of “Time.”

Most of us probably know that Greg LeMond won the closest Tour de France of all time by a mere 8 seconds over Frenchman Laurent Fignon. Considering that the race took place over 2,000 miles and three weeks, that 8 second differential seems incredibly small. And when compared to most Tours, it is a tiny margin of victory. But when viewed in the context of a larger timescale, these 8 seconds take on a whole new meaning. First, let’s take a look at what a “second” really is and then we can try to grasp some non-standard units of measurement so that the “second” becomes a much more relative term.

Second [Traditionally understood as the 60th part of the 60th part of the 24th part of the day]


1/60 of a Minute
1/3,600 of an Hour
1/86,400 of a Day
1/31,557,600 of a Year


1s – approximate time of a single heartbeat
1s – the time required for light to travel 186,282 miles
1.26s – approximate time for light to travel between the Earth and the Moon
8s – the time by which Greg LeMond defeated Laurent Fignon in the 1989 Tour de France
9.77s – world record for men’s 100m sprint event

Millisecond [one thousandth of a second]


1ms – cycle time for frequency 1kHz
2ms – single flap of housefly wing
5ms – single flap of honeybee wing
8ms – standard camera shutter speed
100ms – the blink of an eye

Microsecond [one millionth of a second]


1μs – cycle time for a frequency 1MHz radio wavelength at 300m (AM mediumwave band)
1μs – the time required for a sound wave at sea level to travel 1/3 of a millimeter
5.4μs – the time required for light to travel one mile in a vacuum

Nanosecond [one billionth of a second]


1.02ns – the time required for light to travel 1 foot
2-4ns – time for typical pc microprocessor to complete a single instruction

Picosecond [a millionth of a millionth of a second]


1ps – half-life of a bottom quark
3ps – average lifetime of a hydrogen bond between water molecules at room temperature
3.3ps – the time required for light to travel 1 millimeter

Femtosecond [a millionth of a billionth of a second]

Context: A femtosecond is to a second, what a second is to 100,000,000 years. Or…a femtosecond is to a second, what a minute is to the known lifetime of the Universe.


10 to 100fs – single vibration time of an atom in a typical molecule
100fs – the time required for light to travel the distance across a human hair
200fs – the reaction time of eye pigments to light

Other References

32 years – yours truly
75 years – average lifespan of humans in First World countries
231 years – age of United States on July 4, 2007
40,000 years – time since Cro-Magnon colonization of Europe (Upper Paleolithic)
200,000 years – approximate age of Homo sapiens
40 million years – estimated period of time until Australia will collide with Asia
250 million years – Galactic Year – a revolution around the center of the Milky Way of our Sun and the Solar system
100 billion years – estimated total lifetime of the Universe (if the Universe is “closed”…big if)

Hopefully, these examples and definitions help put the concept of time into greater focus. And until someone proves otherwise, I will continue to claim that I have the world “Femtosecond” record for cycling. People can talk about the “Hour” record and discuss the merits of Merckx, Boardman and everyone else but I’m pretty sure that no one has posted the “Femtosecond” record yet. And I didn’t even need a specially made TT bike or a disc wheel. Take that O’Bree.

Coming soon…Part 2: A “Real” analysis of Power. Hint: You don’t have much.


Olaf Vanderhoot said...


my brain hurts now, but


Anonymous said...

Well, duh...

velogirl said...

power schmower! real cyclists judge themselves by how white their shoes are, silly boy!

Anonymous said...

I have never been a bike computer/Power tap type of guy, but I liked the time-numbers. I'm looking forward to the "Power" installment! Maybe I'll learn something new...

Anonymous said...

Glad you're back!

Jeremy T. Arnold said...

Thanks folks. So in response...

Brain Hurt is good.

Can anyone recommend a way to clean and pimp-up my white Sidi's? Velogirl?

Shark - glad to hear from you bro. Remember, whenever you learn something new it pushes old stuff out. Say hello to V.

Glad to be back...thanks again.