I was just reading on someone else's flashlight blog that had a bunch of flashy pictures that explained a lot about the components in a flashlight and very little about flashlights. The writer explained that a good flashlight will always light and should never need to banged against your hand to work. Total Bullocks.
Once again all flashlights are about electrical connections. Any flashlight that depends on spring loaded contact will have corrosion issues and banging it against your hand can help it work.
WTF does that mean?
Most, not all flashlights, depend on wire springs that provide pressure to improve electrical contact between the various parts of the flashlight. The tension of the spring is important. The stronger the spring the more likely there is to be contact between the various components.
Lets look at a typical 2D cell flashlight, cheap, expensive, whatever. The vast majority have a wire wound, helical spring, at the "bottom", two batteries, a switch, a bulb holder with a metal plate on the bottom and a bulb.
Everything made of metal corrodes, slowly for some things, very slowly in the case of gold and iridium. The spring, the tops and bottoms of batteries, the metal piece on the bulb holder and even the body of the bulb. That corrosion creates resistance. The resistance causes the flashlight to stop working. People used to carry steel wool or a scrap of leather to clean flashlight connections. The corrosion resistance is better these days so people don't do that as much.
When you bang a flashlight against your hand, any kind or brand or expense of flashlight, the rubbing between the various components can scrap away corrosion and make the flashlight work.
Here is the funny part, corrosion depends on the materials used, the amount of humidity and if the moisture can reach the surface. A cheap flashlight with cheap batteries and a cheap bulb can end up having nearly "perfect" connections which prevent the corrosion from forming. An expensive flashlight with good batteries and a bulb can end up having poor connections. The issue is manufacturing variables.
Realistically the probability have having excellent connections is better with a well made flashlight, like a Maglite, good batteries like Duracells and Maglite bulbs is better than a cheap flashlight.
Lets toss in a way for you to build a really bright, long lasting LED flashlight fairly cheaply.
First thing you need is a decent AA flashlight with a standard PR style bulb. There are lots of these, buy one you like the looks of, that looks like it has a good switch.
The next thing you need is 2 14500 Li-ion batteries. These are 3.6 or 3.7 volts. These can run some money, I get mine on e-bay fairly cheaply. Get 4 and a charger if you use your flashlight a lot.
The last thing you need is a really good "3 watt" LED bulb. You can buy these on Amazon, SuperBrightLEDS.com or even at your local Walmart. The bulb will run you 15-20 bucks. Make sure you buy the bulb that handles up to 9 volts. Some are made for 3.6 volts max.
The 14500 batteries are the same size, about, as AA batteries but they put out twice as much voltage. Two 14500 will put out as much voltage, about, as five normal batteries 1.5v batteries. You could use a bulb from a 5 cell Maglite in your new flashlight and the plastic reflector would last minutes. The plastic reflector will melt. I'm told the Garrity G-Tech cheap AA flashlight has a metal reflector and if so that would be a good thing to have. I have not found one yet.
Put the "3 watt" led in the flashlight you purchased and then put the 2 14500 batteries in the flashlight.
My experience is that when using 7.2v or 7.4v the LED bulb will not melt a plastic reflector as long as you don't use the light more than about 30 minutes at a time and you let it cool between uses.
Saturday, January 19, 2013
Thursday, January 17, 2013
Archaeology and Abandonded Cities
I'm taking a class in basic archeology right now and I am throughly disgusted with all the theories about why archaeological sites were abandoned.
I can you why they were abandoned. There was a problem. Why problem? Essentially there are two reasons cities are abandoned, economics and disaster.
Economics means that previously available resources that provided for support of the city have declined or failed. Abandoned "boom" towns are created when, silver mines, coal mines, niter mines running out or the market for the resource disappears.
A disaster means earthquake, plague, volcanic eruption, anything which makes people feel as if they can no longer live in the area.
Political problems lead to revolutions, not abandonment. Detroit is not abandoned as much as some white supremacists like to pretend it is. Is Detroit thriving? No, but it isn't dead either.
To figure out why people abandon cities we need to look at why people abandon cities. Look at the ghost towns, the abandoned cities of today and we can learn why cities are abandoned. Once we understand the reasons why people abandon cities today we can systematically eliminate the various possibilities until only one remains.
There is another kind of disaster that I think probably caused the desertion of some major cities of the past, although, it would be difficult to prove. Population pressure causes pollution. I believe that the water supply of some ancient cities became polluted and caused what seemed to be a plague on the city. People left because they could no longer stay. Overtime the ecology cleaned up the problems.
Now that the basic inductive logic is over we can address some speculations.:-)
I'm not sure it would have taken very many people to die for people to leave. How many deaths does it take for a group to migrate?
Rome was all but abandoned because the water supply was destroyed. If population pressure polluted the water supply it could have driven people out of cities.
Population pressure also creates the potential for an actual plague.
Recently archaeologists have begun blaming a volcano for the abandoning of the Mayan population centers. I think it is possible that smoke or volcanic ash was the source of pollution that made required resources unavailable.
I can you why they were abandoned. There was a problem. Why problem? Essentially there are two reasons cities are abandoned, economics and disaster.
Economics means that previously available resources that provided for support of the city have declined or failed. Abandoned "boom" towns are created when, silver mines, coal mines, niter mines running out or the market for the resource disappears.
A disaster means earthquake, plague, volcanic eruption, anything which makes people feel as if they can no longer live in the area.
Political problems lead to revolutions, not abandonment. Detroit is not abandoned as much as some white supremacists like to pretend it is. Is Detroit thriving? No, but it isn't dead either.
To figure out why people abandon cities we need to look at why people abandon cities. Look at the ghost towns, the abandoned cities of today and we can learn why cities are abandoned. Once we understand the reasons why people abandon cities today we can systematically eliminate the various possibilities until only one remains.
There is another kind of disaster that I think probably caused the desertion of some major cities of the past, although, it would be difficult to prove. Population pressure causes pollution. I believe that the water supply of some ancient cities became polluted and caused what seemed to be a plague on the city. People left because they could no longer stay. Overtime the ecology cleaned up the problems.
Now that the basic inductive logic is over we can address some speculations.:-)
I'm not sure it would have taken very many people to die for people to leave. How many deaths does it take for a group to migrate?
Rome was all but abandoned because the water supply was destroyed. If population pressure polluted the water supply it could have driven people out of cities.
Population pressure also creates the potential for an actual plague.
Recently archaeologists have begun blaming a volcano for the abandoning of the Mayan population centers. I think it is possible that smoke or volcanic ash was the source of pollution that made required resources unavailable.
Designing the "perfect" flashlight
My perfect flashlight would have an aluminum body.
The battery holder would be attached to a sealed switch switch and the LED bulb using a slide in connector with contacts made of iridium. The battery holder could be a simple flat plastic rectangle like many battery holders are. It would hold a single battery. The end of the batter holder would have two short prongs hidden inside a protective hood. The battery box would slide into the flashlight from the bottom. I would think a 26650 or an 18650 Li-ion rechargeable. The battery box could slide into a charger. A second battery box that held two AA or AAA could be included.
The battery would drop in between two flat spring steel made from iridium. Nothing to do about the battery contacts except include a piece of scotchbrite in the body of the flashlight. The AA or AAA battery box could use cheap wire springs, but, flat iridium springs would work :-)
The LED would be able to use the body of the flashlight to dissipate any heat.
The bottom of the flashlight would be a slip on rubber end cap that would make the flashlight water resistant. The end cap could be something like the slip on tips for a cane or a walker, although it could be rectangular rather than round. Round is easier There would be a grove for an o-ring near the bottom of the body of the light. The water resistant seal would be between both the rubber of the end cap and the o-ring.
The switch would be in the body of the light near the bulb. It would have a cover of some kind so it could not be turned on automatically. If the flashlight were round it could have a friction twist cover that used o-rings to provide the friction.
That should make a ridiculously expensive flashlight that no one would buy because they wouldn't understand how cool it really is.
The battery holder would be attached to a sealed switch switch and the LED bulb using a slide in connector with contacts made of iridium. The battery holder could be a simple flat plastic rectangle like many battery holders are. It would hold a single battery. The end of the batter holder would have two short prongs hidden inside a protective hood. The battery box would slide into the flashlight from the bottom. I would think a 26650 or an 18650 Li-ion rechargeable. The battery box could slide into a charger. A second battery box that held two AA or AAA could be included.
The battery would drop in between two flat spring steel made from iridium. Nothing to do about the battery contacts except include a piece of scotchbrite in the body of the flashlight. The AA or AAA battery box could use cheap wire springs, but, flat iridium springs would work :-)
The LED would be able to use the body of the flashlight to dissipate any heat.
The bottom of the flashlight would be a slip on rubber end cap that would make the flashlight water resistant. The end cap could be something like the slip on tips for a cane or a walker, although it could be rectangular rather than round. Round is easier There would be a grove for an o-ring near the bottom of the body of the light. The water resistant seal would be between both the rubber of the end cap and the o-ring.
The switch would be in the body of the light near the bulb. It would have a cover of some kind so it could not be turned on automatically. If the flashlight were round it could have a friction twist cover that used o-rings to provide the friction.
That should make a ridiculously expensive flashlight that no one would buy because they wouldn't understand how cool it really is.
Batteries, Flashlights, Ignorance and Capital Investment
A while back I wrote a blog discussing flashlights and how flashlights are all about the connection between the battery, the switch and the bulb. I went into detail in that blog, but, I can sum it up easily. Battery connection surfaces, springs, bulb connection surfaces and switch connection surfaces are all subject to corrosion. The cheaper the flashlight, the more batteries involved, the more problematic the corrosion issues.
Sealed rechargeable flashlights with solid state lighting such as LEDs are hands down the most reliable flashlights.
The next most reliable flashlight has a sealed solid state bulb, a sealed switch and one battery.
Next comes just the sealed switch, a standard bulb and a single battery
Then comes a sealed switch, standard bulb and multiple batteries
Finally comes the unsealed switch, standard bulb and multiple batteries.
Batteries are all about connections, the more unsealed connections the less reliable the flashlight.
That is pretty simple electronics and logic.
When a flashlight is dim or goes out, someone bangs it in their hand and it comes on because the contacts in the flashlight changed, the motion made surfaces rub and the contact improved. Sometimes doing this will break the filament in an incandescent bulb and the light is toast.
Think about springs for a second. Who hasn't seen a rusty spring somewhere? Springs move, plating or paint flakes off and the spring corrodes or rusts. Ever try cleaning rust off a wire spring?
I like flat spring steel springs in flashlights. They are very rare, but, they can be found.
Eveready used to make a cheap, flat 2XAA flashlight that was nice because it used flat steel springs which could be cleaned. The switch sucked and it was hard to reach the springs in the bottom of the battery compartment.
Another company used to make a 2XAA flashlight that required a screw driver to take apart. The switch was not great, people would lose the screw changing the batteries.
I had a sliding side flashlight that had wire springs.
Sometimes I think the people building flashlights are really clueless. The reality is building a custom flat spring for the end cap of a Maglite would be expensive and the vast majority of people out there are ignorant of the benefits so the investment in such a spring would not have any return.
Maglite could replace the little foam bulb holder in the endcap with a scotchbrite pad that people could use to clean the contact surfaces when they needed to.
Would replacing the springs and the foam have any return on the investment? Would it help sell flashlights? No. People wouldn't understand. Using the scotchbrite pad would make it lose the springy protection for the bulb and people would be annoyed so they would never use it. How about putting a simple, small round hunk of scotchbrite on top of the bulb, inside the spring? I already do that, I'm sure others do too.
Look at the flashlights at any store. Think about all those connections that could corrode and screw up the flashlight.
Sometimes I ask people about flashlights. My brother for example. What is a good flashlight?
People describe brands but no one tells me what to look for in a flashlight, except "quality".
So go to a store and look at the flashlights. Does the $20 flashlight have better springs than the $5 flashlight? Is the switch sealed or is it cheap and crappy?
Ever think about holding a flashlight while you are walking or working? I hold flashlights with my mouth quite often. Can I hold the flashlight in my mouth?
How bright is the flashlight going to be? How long will the batteries last?
Do you know why the stats on how long batteries will last in a flashlight are not published? Because corrosion on the connection surfaces of batteries (and springs) is a variable that manufacturers cannot control.
So what does "quality" mean to the person who is giving someone else advice about a flashlight?
We could replace the springs and battery contact surfaces with iridium. Iridium does not corrode and would be great in flashlights. It runs about $1,000 to $1,200 bucks an ounce right now. Would you pay an extra $50 bucks for a flashlight with springs that can't corrode? Would advertising that issue mean anything to the vast majority of people?
The military uses a lot of gold contacts to reduce corrosion but contacts still get dirty, causing increased resistance and decreased battery life.
Flashlights are a good metaphor for most things in life. They are really simple, yet interestingly and infinitely variable. Most people don't think of spring tension or contact corrosion resistance when they buy a flashlight. Consumer quality is usually a subjective perspective.
People are ignorant about most things and we make decisions in ignorance. People criticize our decisions, and I have typically found that the people criticizing don't know any more than the I did when I made the decision. They just think they do. Occasionally, like me, they know what they are talking about. But! Does it matter?
Suppose ten million people read this blog and start looking at flashlights critically? How long will it take flashlight manufacturers to build better flashlights?
Never. A couple manufacturers, Maglite and Scotchbrite, might incorporate some changes in design or marketing, BUT, 10 million is a drop in the bucket when we are talking about a world wide market of between 6 and 7 billion. Capital Investment will still follow the majority of subjective consumers and we are still going to have to look at flashlights in the store and make guesses about which one will be "best".
Sealed rechargeable flashlights with solid state lighting such as LEDs are hands down the most reliable flashlights.
The next most reliable flashlight has a sealed solid state bulb, a sealed switch and one battery.
Next comes just the sealed switch, a standard bulb and a single battery
Then comes a sealed switch, standard bulb and multiple batteries
Finally comes the unsealed switch, standard bulb and multiple batteries.
Batteries are all about connections, the more unsealed connections the less reliable the flashlight.
That is pretty simple electronics and logic.
When a flashlight is dim or goes out, someone bangs it in their hand and it comes on because the contacts in the flashlight changed, the motion made surfaces rub and the contact improved. Sometimes doing this will break the filament in an incandescent bulb and the light is toast.
Think about springs for a second. Who hasn't seen a rusty spring somewhere? Springs move, plating or paint flakes off and the spring corrodes or rusts. Ever try cleaning rust off a wire spring?
I like flat spring steel springs in flashlights. They are very rare, but, they can be found.
Eveready used to make a cheap, flat 2XAA flashlight that was nice because it used flat steel springs which could be cleaned. The switch sucked and it was hard to reach the springs in the bottom of the battery compartment.
Another company used to make a 2XAA flashlight that required a screw driver to take apart. The switch was not great, people would lose the screw changing the batteries.
I had a sliding side flashlight that had wire springs.
Sometimes I think the people building flashlights are really clueless. The reality is building a custom flat spring for the end cap of a Maglite would be expensive and the vast majority of people out there are ignorant of the benefits so the investment in such a spring would not have any return.
Maglite could replace the little foam bulb holder in the endcap with a scotchbrite pad that people could use to clean the contact surfaces when they needed to.
Would replacing the springs and the foam have any return on the investment? Would it help sell flashlights? No. People wouldn't understand. Using the scotchbrite pad would make it lose the springy protection for the bulb and people would be annoyed so they would never use it. How about putting a simple, small round hunk of scotchbrite on top of the bulb, inside the spring? I already do that, I'm sure others do too.
Look at the flashlights at any store. Think about all those connections that could corrode and screw up the flashlight.
Sometimes I ask people about flashlights. My brother for example. What is a good flashlight?
People describe brands but no one tells me what to look for in a flashlight, except "quality".
So go to a store and look at the flashlights. Does the $20 flashlight have better springs than the $5 flashlight? Is the switch sealed or is it cheap and crappy?
Ever think about holding a flashlight while you are walking or working? I hold flashlights with my mouth quite often. Can I hold the flashlight in my mouth?
How bright is the flashlight going to be? How long will the batteries last?
Do you know why the stats on how long batteries will last in a flashlight are not published? Because corrosion on the connection surfaces of batteries (and springs) is a variable that manufacturers cannot control.
So what does "quality" mean to the person who is giving someone else advice about a flashlight?
We could replace the springs and battery contact surfaces with iridium. Iridium does not corrode and would be great in flashlights. It runs about $1,000 to $1,200 bucks an ounce right now. Would you pay an extra $50 bucks for a flashlight with springs that can't corrode? Would advertising that issue mean anything to the vast majority of people?
The military uses a lot of gold contacts to reduce corrosion but contacts still get dirty, causing increased resistance and decreased battery life.
Flashlights are a good metaphor for most things in life. They are really simple, yet interestingly and infinitely variable. Most people don't think of spring tension or contact corrosion resistance when they buy a flashlight. Consumer quality is usually a subjective perspective.
People are ignorant about most things and we make decisions in ignorance. People criticize our decisions, and I have typically found that the people criticizing don't know any more than the I did when I made the decision. They just think they do. Occasionally, like me, they know what they are talking about. But! Does it matter?
Suppose ten million people read this blog and start looking at flashlights critically? How long will it take flashlight manufacturers to build better flashlights?
Never. A couple manufacturers, Maglite and Scotchbrite, might incorporate some changes in design or marketing, BUT, 10 million is a drop in the bucket when we are talking about a world wide market of between 6 and 7 billion. Capital Investment will still follow the majority of subjective consumers and we are still going to have to look at flashlights in the store and make guesses about which one will be "best".
Monday, January 14, 2013
Hypocrisy and Anonymous
You have to love people who are openly hypocritical.
Anonymous removed the published content from MIT's website and posted several things, most of which I agree with, including:
"We call for this tragedy to be a basis for a renewed and unwavering commitment to a free and unfettered internet, spared from censorship with equality of access and franchise for all."
The tragedy here is the suicide of a man who made "secret" government data public. Truthfully, that specific situation is something else I agree with.
Does it occur to Anonymous that by censoring what MIT had published they are doing exactly what they want to stop?
Do they think that by being censors they can somehow stamp out censorship? If that isn't hypocritical I don't know what is.
Here is another good one:
"We call for this tragedy to be a basis for greater recognition of the oppression and injustices heaped daily by certain persons and institutions of au"thority upon anyone who dares to stand up and be counted for their beliefs, and for greater solidarity and mutual aid in response"
I believe that what this actually is saying is that people should be able to stand up for their beliefs without being afraid of ridicule or retribution.
Isn't MIT and many others standing up for their beliefs by publishing what they believe and along comes Anonymous to censor in retribution.
Here is another one:
"We call for this tragedy to be a basis for reform of copyright and intellectual property law, returning it to the proper principles of common good to the many, rather than private gain to the few"
Can't say anything bad about this. Copyright laws should be twenty years, the same as patent laws.
"We call for this tragedy to be a basis for reform of computer crime laws, and the overzealous prosecutors who use them."
Computer crime does need to be reformed, and people who attack, censor, invade privacy and destroy peoples lives should go to jail.
In the end Anonymous is just as hypocritical and ignorant as everyone else. What bothers me is not when someone is hypocritical, all of us are.
I believe it was wrong of Anonymous to invade the privacy of the assholes who raped the girl in Ohio and publish the video bragging about the rape. I am also damn glad they did it.
Hypocritical? You bet. I know I'm being hypocritical. I aspire to things I do not always achieve and I am constantly working on becoming a better person. People are not perfect, get over it.
To do become better we have to know when we screw up. We have to be consistent in our words and actions. Anonymous isn't. I don't think most people know or even want to know how ignorant and hypocritical they themselves are and Anonymous isn't any better.
Is some of what they are doing going to make the world a better place? Probably, I think the the Ohio rape video is an example.
I can justify torture the same way. It's okay to censor someone if they participated in a "greater wrong" and we can use the same logic for torture, its okay to torture someone if they participated in a "greater wrong".
That takes an awful lot of judgment and an awful lot of ego to enforce that judgment on others.
Talking is useful, negotiating is useful. There comes a time when talking has to stop and people have to act.
Is doing that which must be stopped a useful action? History will tell us. I don't believe so.
Personally I think Anonymous could have gotten their message across without censoring the original content of the publication and I think that would have communicated their message much more effectively.
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