Friday, November 23, 2007
During the last post, we talked a lot about the psychology of bicycle lighting. At the end of the day, you want the brightest light that you can possibly get. This is to not only allow drivers to see you, but also gauge your distance to them.
We'll work through this together by first talking about the various technologies that are on the market today for your lighting needs. In the later part of this post, I'll then give you some specific ideas of what systems you should buy.
There are four primary technologies used for white lighting:
1. Incandescent (with subset Halogen and argon)
3. High Intensity
In general, the efficiency is in rank order above. Fluorescent are the most efficient for general lighting and are certainly the best for a home environment, but because of other challenges it does not work well for bicycles.
However, the gap is closing on all the top three. Let's look at some numbers.
In general, you should think about brightness in terms of lumens. If something is brighter, it should have a higher lumens rating. However, this is only part of the battle, to get an idea of efficiency you want to know how many lumens per watt is created.
Now, like most specifications, lumens can be manipulated and don't completely describe the brightness of a light. With all these shortfalls, lumens is still the best measurement.
Since most bicyclist want small light batteries, higher efficiency lights are preferred. What your really want to know is how many lumens per watt of input are created.
In general, here is the following ranges:
Incandescent bulbs: 10-15 lumens per watt
Compact Fluorescents: 40-50 lumens per watt
T8 (Standard Fluorescents): 70 lumens per watt
T12 (1" Fluorescents): 90 lumens per watt
Incandescent bulbs have been around forever, and the best of this technology "halogen," really isn't very efficiency. Not compared to the rest of the technologies, as we can see above.
Now, if you are familiar with those funny yellow colored low pressure sodium lights, they can generate 180 lumens per watt! This is a type of High Intensity Discharge lamp. They are the winners of the lighting wars, but nobody would want to do a bicycle light around them.
The two best technologies for bicycle lighting is a normal HID light or Light Emitting Diode (LED) based light.
A good HID will produce about 50-60 lumens per watt. A little better than a compact fluorescent bulb, but not as good as a T12.
Some of the best LEDs out today will produce about the same amount of light as an HID, or 50-60 lumens per watt.
Now, a HID light is any light that uses high voltage to arc across a gap to make light. As a matter of fact, the low pressure sodium light above is a HID light. LED lights are different from normal lighting. They rely on electricity being generated by electrons cross a semiconductor barrier (called a p-n junction), and part of that electricity being converted into light. The LED light is a miracle of the semiconductor age, and it has only been around in a practical form since 1962.
However, as we write this post today, you can bin the LEDs and get as much as 70 lumens per watt. For example, the Cree 7090 XR-E LED can theoretically be over 70 lumens per watt. I have read that Cree has a roadmap to get to 100 lumens per watt.
The new high technology LEDs are expensive, but they are pretty fool proof. All that you need with these new LEDs is a good heat sink. The HID lights are simply more complicated from an integration standpoint as mentioned before.
A good Cree LED will last around 50,000 hours (less if you over volt it), which is going to be a lot longer than most of use want to be in the saddle. LED lights are extremely rugged as mount the LED so that it stays cool in operation.
So, now that you have some ideas of the technology, I am simply going to tell your what to buy:
1. The Home Brewed Path
If you enjoy experimentation, I would buy the Trailtech SCMR16, and blow people off the trail or street. However, it is very home brewed, as we like to call it in lighting circles, and therefore, you need to do a lot of elbow grease to get it running and keep it running.
So what do you need to do with the home brew system. First you will need to buy the bulb. As of this writing it is around $130-140 USD. However, just having the bulb doesn't solve the problem because you also need to drive it some how.
Probably the best way of doing this is to purchase a battery or a battery pack to drive the bulb. One of the best places to start is on batteryspace.com. Of course, it doesn't stop with just picking up the battery. After the battery, pick up a charger. Then you'll need to figure out how to fuse protect your system. Then you make up a switch. The list goes on.
If it sound a little complicated....it is. Batteryspace sell a whole kit here. However, many people have complained that the mount normally breaks, and you'll need to replace some of the screws from Home Depot. Oh well, this is the normal case with home brewed systems.
Most of the others, will want to basically buy something off the shelf.
2. The Cheap Route
The cheap route still requires some work, and some money. However, a few dollars more on a light scheme is better than being killed.
First buy the Fenix double AA flashlight from the Fenix Store. By using "cpf8" they will take off 8% on the price.
For a little under $60, after discount, this puts out an amazing 175 lumens. Most of us know the old Maglight 6D cell flashlight. This thing blows that flashlight away. I showed my sister one time, and she instantaneously said "where can I get that thing."
Without getting into the details don't run this flashlight from anything but rechargeable NiMH batteries. This this thing chews through batteries (it'll last a little over an hour with a good set of rechargeable batteries), so you want to get a good charger.
Now, I could write a whole posting on battery chargers, but to cut to the short, get the one right here. The LaCrosse charger is extremely cool, plus it comes with enough batteries to get you started. For $40, you'll have a world class battery charger.
How to mount it? We'll Fenix has seen a lot of popularity in there lights for bicycles, and they have just announced a new mount. You can find it here.
However, while this bicycle mount looks great an is recommended by the maker of the flashlight that you'll be using, I have have been using a no-name Chinese flashlight mounter. You can order it here or probably a better and cheaper way is ordering it here.
Although it is completely plastic, it have been working fine for thousands of miles. To make the flashlight grip, I've wrapped my Fenix light with a compressible wrap of rubber, otherwise the holder doesn't grip the flashlight that well.
Finally, for the tail light, the Planet Light Super Flash rear light is the best. Now, this rear light almost has a cult following, but it is a bit hard to find. What is worse is that the name of the light is not very specific.
However, here is the image. You should be able to order it through REI or Bike Nashbar. If you get the charger above, it will come with two AAA batteries that will power the tail light very nicely. The run time for rechargeable batteries in the tail light should be 10 hours on steady mode. The tail light is very eye catching compared to the competitor LED models.
So, for around $140-150, you will get a very workable system. There will be a couple of issues, like a shorter burn time, but the great thing is that you can stop and change your batteries
3. The All In One Expensive Route
If you have around $500, the best thing to buy is a Dinotte combo system. If the tail light in the cheap system is good, then the tail light here is blinding. The lumens in the cheap system is about 175. The lumens here are 600.
If you have enough time to research it, the best spot for this type of activity is either The Candlepower Forums or Lactic Acid Threshold.
The best thing about the Latic Acid Threshold is the great reviews plus a lot of shots of bicycle lights in action. Here are a couple of pictures of the Dinotte in action. The best thing that I like about the Dinotte is that it is an integrated system. You get the headlight and the tail light all in one package with a common battery charger. This makes for simplistic operation.
In the first picture we have the street without a headlight.
Now lit by the Dinotte:
The second one looks a lot better.
Monday, November 19, 2007
It's not that they challenge my faith. It that their assumptions are so flawed to be laughable. I am not saying that ALL atheists are hackneyed in their approach, and I have written before how Scotty Atran is one of my favorite atheists that can actually challenge my faith.
However, two of my biggest and most popular atheists, Richard Dawkins and Sam Harris, are often quoted and often admired by the lay person. Unfortunately, the core logic of both are fatally flawed.
Now, of the two, Sam Harris can and should simply be ignored. Sam is the type of person that dropped out of Stanford because of a big dose of ecstasy (I kid you not), and spent 11 years trying to find himself before he returned to Stanford to finish a degree in philosophy. He is trying to get a PhD in the neural sciences. Good luck Sam. Give us a call once you've actually done something other than be given a book award by a liberal institution.
Richard Dawkins can not and should not be dismissed. For all of logical faults, Dawkins is extremely bright and has added much to the world of science. Dawkins, for example, has coined ideas like the Blind Watch Maker and the idea of memes. Most of his work centers around the idea of the gene as the central focal point of Darwinist evolution. Many of his ideas may be wrong, but many may be right. He is truly very creative and smart. It is well worth reading many of his concepts and works.
So, why do I lump the drop-out and the professor into the same category? It is simply that they both defend an idea that is outrageous in its structure. Interestingly enough, because they both support the same logic, the two are in a mutual admiration society.
Both Harris and Dawkins have a very simple proposition:
a. There are problems in this world
b. There is faith in this world
c. Therefore, if we remove faith, then we will remove the problems
If you have a book on logic, look up fallacies. You will find a picture of Dawkins and Harris.
Let us, for a moment, say that all religion is absolutely false. Let us take two societies:
1. The religious society (which has an absolutely wrong belief)
2. The non-religions society (which has an absolutely right belief)
Which society do you think is going to be happier, healthier, and more forward progressive. To Dawkins and Harris, the answer is obvious. The non-religious society.
And my question to this is "what proof do you have of this?"
Scotty Atran, one of my favorite atheists, recently pointed this out at a conference specifically with Dawkins and Harris. In the 20th century, there has arisen at least two experiments where God was stricken from the page. Atran addresses these examples.
To quote Atran:
Two of these "isms" - communism and fascism - were explicitly based on what were once seriously thought to be scientific theories and philosophies. These particular variants led to the greatest mass murders in human history. Although, this is only a N of 2, and a poor base of evidence for generalizing to the role of science in politics in general, it is still 100% more informed than most other views heard at the conference
Atran further reflected on the words of his peers:
I find it fascinating that brilliant scientists and philosophers have no clue how to deal with the basic irrationality of human life and society other than to insist against all reason and evidence that things ought to be rational and evidence based. It makes me embarrassed to be a scientist and atheist.
In other words, it is very unclear if society without religious thought is a society that can survive long term. This is even if religion is proven as false.
I have heard Dawkins and Harris talk. They believe that the reason that certain people groups are so violent is because of their religion. Obviously they don't understand the godless communist systems under Stalin or Mao.
Now, the closest we have to a non-religious society in Europe. However, they are not anti-religious. They are pro-tolerant. This is a very big difference to what Dawkins and Harris are suggesting.
The problem with both Dawkins and Harris is that they simply have never studied the social sciences. I'm not talking about pop psychology. I am talking about the hard core sociology science work that has been done. There is no debate that man has a God-Shaped hole in their psyche. Now this God-Shape hole may be a left over structure of the way we are cognitively wired (coined as a spandrel by the brilliant Scientist Stephen Jay Gould). It doesn't matter how religion got into our society.
What matters is that it is here, and it seems to be irreplaceable.
You don't have to look hard at the data to determine several things:
1. Religious people have less stress
2. Religious people have more financial success
3. Religious people have more children
Sounds like a pretty good evolutionary advantage. To any atheists that stumble across this blog, maybe you should believe in something also if you want your genes to live on.
Saturday, November 17, 2007
There is nothing more important that the proper selection of lights because this is the primary way of cars seeing you.
Now, many people will say that cars seeing you is a secondary importance, since you'll need a light for seeing the street.
Once you start biking in the dark, for the most part, in both the city and the county, lights are not necessarily to see the road. When you are on a bike, you naturally go slower than a car, your eyes adjust to the local lighting, and often times street lights will be more than enough light for you to bike. The primary purpose of bicycle lights is to be seen. Because of this, it is easy enough to think that you really don't need a bright light. You need just a light to "be seen."
However, we will examine our human perceptions. In reality, a light "good enough to be seen" is really a light "good enough to get hit by."
To understand why a bright light is so necessary, we must take a detour into the world of vision.
The most important thing, for a car to see you, is to understand how far you are away.
The #1 reason for cars hitting bicycles is either a car pulling out from a side street or a car pulling across a street. Both of these are problems of the driver not adequately seeing or judging distance to the bicyclist.
In vision, why we get hit is often a problem with depth perception. Everybody knows that we see in 3D. The reason that humans see in 3D is that they have stereopsis. If you have two cameras or two eyes, which act just like cameras, there is a parallax between your two cameras or eyes.
Parallex simply means that one eye will have a sightly different image from the other eye due to the fact that they are set apart in our heads. Most of us enjoyed, as a child, closing one eye then the other eye and watching the image just just back and forth. When I was a child, and bored in church, I could make the pastor jump around a bit with this trick, even through we weren't pentecostal. (Yes, that is a joke.)
Because our eyes are set apart, each eye sees something slightly different. If our brain wasn't morphing the data from our eyes, we would be seeing two images from either eye like two images on the TV screen that didn't line up.
However, our brain magically puts those two images together, and the slight differences in the images register at different depths in our vision. When you start to think about how our brain works, it is a miracle. What should be a problem with our vision design turns into a benefit. If we had to try and create it, I don't think that it would be easy. However, God using his skills to create something clever.
By this gift, we can judge if an object is 100 ft away or 1000 feet away automatically. However, some people don't have two eyes. For instance, my sister lost one of her eyes at a very young age, and her stereopsis does not exist. However, she can drive, although her depth perception simply does not exist.
If we lose an eye, how do we judge depth?
Again, the magic of the brain is that a secondary system cuts in. The brain, with just one eye, can calculate distance by an object's size. If you see a stop sign in the distance, your brain says "Stop Signs are 7 feet high, and they have a 18 inch sign." If the stop sign is a small object in your field of vision, it simply says "well it must be far away."
However, this depends on the mind having a previous reference frame for size for any given object. What happens if you stumble across a stop sign that is really small? Without other objects in you field of vision, you'd simply misjudge the stop sign and say "that stop sign is really far away."
Now, we are all familiar with this type of work. In movies, small miniatures are made to deceive us. This works very well, as long as the miniature is detailed, because we only use one camera (or eye) to judge distance.
So how does this impact night vision? Our eyes have an iris, which lets in light. When it is bright, the iris shrinks making our pupils (the black thing in the center of your eye) small. When the pupils are small, it is easier to judge distance because it helps to focus the image. However, at night, the iris gets bigger to let in more light, and it becomes harder to judge distance via stereopsis. Just like my sister, the brain switches to the secondary system of judging distance. By previously stored reference frames.
Most car headlights are similar in brightness at a given distance. So if a light looks dim, it must be far away. If a light is bright, it is close.
The other thing that helps the driver to judge distance is the distance between the front two headlights of roughly 6 or so feet. So the problem becomes obvious.
1. Bicycles don't have two headlights with a spacing of 6 feet
2. Many bicyclists have dull lights that will look like a car really far away
Even if you are close to a car, the driver will have part of his or her brain saying "don't worry, that dull light is really far away." Compounding this problem, you only have 1 light vs the 2 required to help judge the distance on the car.
So if becomes very obvious why you shouldn't have a dull headlight. You will be really challenging the driver of cars to figure out how far away you are.
This is beyond just theory. I have been nighttime biking for many years. The difference in how cars react to a bright and dull light is absolutely amazing. The brighter the light, the less that I would be cut off. To the opposite, if you can't judge depth well, you can't judge speed. So guess what happens when you have a really bright light, and a car sees you coming?
It waits. And waits. And waits. It waits because the driver can't tell how fast you are closing on it. They only see a bright light, and they expect it to be closing quickly.
As a rule, cars always wait much longer for me at night than day time. However, if you have a dull light, they will not wait at all, and often cut you off. It is clear as "day and night" for the difference.
In the next section, we will examine the different technologies of headlights on the market today.
Saturday, November 03, 2007
Recently, I was reading my nephew-in-law blog, and he was describing and complaining about a book written by a Professor out of Penn State, Richard Doyle, trying to wring out the philosophical implication of science.
Having my curiosity piqued, I went to Google Books to get an idea of how this person wrote.
Here's a nice little quote from his book Wetwares:
"Uploading,' the desire to be wetware, makes possible a new technology of the self, one fractured by the exteriority of the future....Uploading seems to install discursive, material, and social mechanism for the anticipation of an externalized self, a techno-social mutation that is perhaps best characterized as a new capacity to be affected by, addicted to, the future."
Now mind you, I am a bit interested in the subject Doyle wrote about, and I even touch on an attribute of uploading intelligence when I discussed Penrose in an earlier post. I am not turned off on any talk on Wetware per se, but I profoundly turned off on poor rambling and incoherent writing on wetware. There seems to be a wide spread belief in the humanities (and now stretching into science) that you express your education thought by making it incomprehensible.
This leads us to the "Alan Sokal Affair," which is often shortened to simply "The Sokal Affair."
Dr. Sokal is the stereotypical physics geek. He currently teaches at NYU and you can visit his page there. He evidentially was a bit of a rebel, having taught in Nicaragua during the Sandinista regime.
In 1996, he submitted a paper to Social Text, out of Duke University, one of the non-peer reviewed journals popping up at the time. The paper was called "Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity." The paper, in summary, said that quantum mechanics had a implication on the idea that science is actually just a made up reality, signifying that science is a belief structure. The editors at Social Text probably said, "Well of course this must be correct. It makes science more social scientific."
They published Sokal's paper. Once published, Sokal revealed that the paper was a hoax.
Sokal's paper, in function, was a loose knit chunks of hyperbole, crazy graphs, and unintelligible statements with a few political quotes thrown in. The author had carefully constructed it to be tripe and nonsense.
Social Text immediately did the proper thing: it vilified Sokal as being dishonest. One of the publishers told the New York Times, "he's ill-read and half-educated." Obviously, and this is why the editors could spot the fake right away. (My sarcasm is hopefully evident.)
After all, they were duped by a clever professor into publishing something that made no sense. They immediately claimed that Sokal did a grave injustice. To me, the problem never with Sokal. The problem is with a paper so corrupt that they couldn't admit their mistakes. When he offered to explain his hoax in a follow-up, the journal refused to publish it. However, other journals did.
So, what did Sokal have to say about his paper? Let's look at one section:
"...but the most hilarious parts of my article were not written by me. Rather, they're direct quotes from the postmodern Masters, whom I shower with mock praise. In fact, the article is structured around the silliest quotations I could find about mathematics and physics....
This involved, of course, advocating an incoherent mishmash of trendy ideas -- deconstructive literary theory, New Age ecology, so-called ``feminist epistemology'', extreme social-constructivist philosophy of science, even Lacanian psychoanalysis -- but that just made the parody all the more fun....
Now, what precisely do I mean by "silliness''? Here's a very rough categorization: First of all, one has meaningless or absurd statements, name-dropping, and the display of false erudition. Secondly, one has sloppy thinking and poor philosophy, which come together notably (though not always) in the form of glib relativism.The first of these categories wouldn't be so important, perhaps, if we were dealing with a few assistant professors of literature making fools of themselves holding forth on quantum mechanics or Gödel's theorem. It becomes more relevant because we're dealing with important intellectuals, at least as measured by shelf space in the cultural-studies section of university bookstores."
Sokal is one of heroes of the modern age. Within 6 months, he demonstrated powerfully, more than any academic article or study, how a diseases of false thinking has climbed into our academic environment.
However, if you are a Christian, you should also be able to see bridges back to our own faith. The problem, in this case, is that the left tried to grab science and use it to support something more than it does. In the same way, often in the Church, we do the same thing. In some sense, you need to approach both Christianity, and scripture, and science in the same way.
To be successful, don't read into the data. If you find out that science says "the earth is 6 billion years old" and you read "God created the earth in 6 days," don't immediately warp the science to suit scripture. On the other hand, don't warp scripture to suit scripture.
The objective, if you are a Christian, is to approach every problem with an open heart and an inquisitive mind. In all my years, I have never found where I couldn't reconcile scripture to science.
And I never needed to check my brain at the door or hide behind incomprehensibility.