How do Traffic Lights Know When to Change?

*IMPORTANT: Some of the facts shown in this post are only accurate in Missouri and/or the city of Springfield, MO*

Last week I waited on my bicycle as the light before me stayed red though no cars passed before me.  I waited what felt to be an unreasonable amount of time (about 2 0r 3 minutes) before running through the light (its legal).  This lead to an obvious question in my mind; how do traffic lights know when to change?

First I decided to learn about the electric traffic light.  It was invented by William Potts, a police officer in Detroit Michigan.  His light worked with three lights (red, amber, green) and less then 40 dollars worth in wiring.  This device was set up in 1920 at one cross traffic location.  At the end of its first year in use there were 14 more around Detroit.  I am unaware by what system these lights were controlled by, but in the 1970′s traffic lights were controlled by a timing mechanism and heavy taffic flow areas timed traffic lights are still used.

This leads to an obvious question;  if timers are used at some intersections, what device is used at the rest?

The answer can be found in the cracks of the road.  Before you come to a stop at a red light you will drive over large patches of asphalt which show a black square.*  In the grooves of this square is laid a metal wire.  This wire is designed as a metal detector which senses when car drives over it.  If you are on a cycle (of the bi- or motor- variety) then you will probably not have enough metal in your vehicle to set off the sensor and will have to weight the “unreasonable amount” of time until you are allowed to legally go through a red light.

In short, the only way to trip the sensor for a traffic light is to have a large amount of metal on your vehicle and to have gone over to have actually gone over the sensory.

-Warning, about to step on soap box-

Drivers who pull forward in traffic to set off the laser sensor on traffic light when you have waited a while, stop doing that.  The light is either set off by the metal detector (which is behind you and which you have already set off) or a timer system.  Pulling forward in traffic will not help and will make it more likely that you will be in a side collision (even if only slightly)

Cyclist; stop running red lights when vehicles are right next to you and have already set off the sensor.  The light will change and there is no reason to go proceed through the red.

-Steps down from soap box-

So the technology for the traffic lights is relatively simple.  Large amount of metal; change.  Small or no amount of metal; don’t change.  But, even in its simplicity, it is always fascinating to see how our urban world functions.

Sources

Source 1

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Source 4

Source 5

*Sometimes the black square will be lightly paved over and while the detector still works, it will not be visible.

What is an Ice Cream Headache?

At least thirty percent of the population knows what painful sensations an ice cream headache invokes and most know that such a headache is caused by eating cold food.  The real question is, why does the cold food do this.  I heard a person once say it is because, “When the cold food reaches your stomach your body draws all its heat, including heat form your head, into the stomach to digest it.”  This explanation did not sound quite right to me because when ever I had an ice cream headache it only really hurt in the back of my mouth and I did not feel any kind of chill in my arms or chest or anywhere really.

So I did research and I found that the cause of ice cream headaches has a more simple answer than heat transfer.

When you eat a cold substance quickly (like ice cream or slushy) the material does not have an opportunity to warm up in the front of your mouth so when it reaches the center or back of your mouth it will often touch the center or back of your palate (the roof of your mouth).  When it does this the blood vessels in the palate painful swell adding pressure to the inside of your head.

Such a painful sensation will last only 30 seconds to a minute (though the pain time has also been quoted as 20-30 and, rarely, 2 to five minutes).

An easy way to avoid such pain is to simply it your frozen treats slower and let them warm up in the front of your mouth before you let them touch the sensitive center and back part of your palate.

Sources:

http://www.mayoclinic.com/health/ice-cream-headaches/ds00640

http://kidshealth.org/kid/talk/qa/ice_cream_headache.html

http://www.hopkinsmedicine.org/neurology_neurosurgery/conditions_main/ice_cream_headache.html

http://www.coolquiz.com/trivia/explain/docs/ice_headache.asp

http://www.howstuffworks.com/framed.htm?parent=question96.htm&url=http://www.bmj.com/cgi/content/full/314/7091/1364

Do Hebrew’s Believe in Hell?

HellThis question has been in my mind for a while.  I think it was as I was listening to Stephen Colbert and his Report that I heard him mention that “no hell” would be a good draw for people searching for religion; but I cannot remember for sure.  I cannot recall exactly when the thought occurred to me because, for a while, I assumed that the notions of a Christian afterlife would be the same as the Jewish (aka Hebrew) afterlife.

In any case, the question came to mind and I did some research and the answer was: “No…sort of.”

The afterlife that Hebrews believe in is called Olam Haba and there are two different areas of this afterlife.  There is Gan Eden which literally means the Garden of Eden. It is the Paradise or Heaven of the afterlife in the Hebrew religion.  The second is called Gehenom which is close to, but is not the same as, the idea of hell.  Hell is an eternal place of punishment, while Gehenom is a temporary place for painful atonement.

It is described as a place where your whole life story is shown to you and it is also shown to you how you could have done better in life (mostly toward your relationship with God -random fact: the name of God is so sacred that Hebrew do not speak and even when they use the title of God, they spell it G~d).  At the end process the soul has been cleansed and may now ready to enter Gan Eden.

Although Olam Haba has also been described as an arena theatre where the best seats go to the most faithful so they may bask in God’s glory while the less faithful the worst the seats and the worst the show.  Some who attend will simply not like the show and find it quite painful and irritating.

The most interesting thing about it though is the way the soul is presented.  Some souls which go through Gehenom are purified to the point that they simply disappear.  The soul has been described as being part of God; that when he breatherd life into man he breathed pat of himself.

Warning: Opinion About to Expressed

To me that idea makes since.  After your soul is purified you return to God.  If you were so wicked in life that you simply disappear then perhaps you had no soul to begin with or you reject your soul in your path of life.

Opinion Stated

So in the Hebrew belief system it appears that there is no Hell, only Gehenom and as long as you are not to wicked (I am looking at you Hitler) then your sins may be atoned for.

Resources:

Source1

Source2

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Source4

What is the Difference Between Cheap and Expensive Sunglasses?

The other day one of my eyes was swollen and hard to open.  This was due to a bad case of poison ivy (no I was not rolling around in it, I am just highly allergic  so even a small bit can give me a bad month) and despite a steroid inject at Jordan Valley to reduce the swelling and spread of the rash my eye was still looking deformed.  I went to work and was allowed to replace me glasses with a pair of Terminator shades (pictured to the left) I picked up (but had not really worn) last year so the customers would be spared the sight of my eye.  A work friend decided to “support me” and wear his sunglasses.

His shades were Blues Brothers like and cost 150 dollars while my own Terminators had been 1.75 (without tax).  I told him I thought it was silly to spend so much when I purchased mine so cheaply (especially since 1984 also sells the Blues Brothers shades for 1.25)  He retorted by saying his would las t a lot longer than mine or the any other cheap sunglasses.

Some part of me was not satisfied by the idea that more expensive sunglasses were more durable than cheap sunglasses.  My line of thinking was the plastic in his sunglass frames could not be too different than those in the cheaper kind.

I went on HowStuffworks.com (http://science.howstuffworks.com/sunglass1.htm) and lasikanswers.com (http://www.lasikanswer.com/optical-lasik/eye-7-1-6528.html) and I found out the expense of the glasses is not the durability but the lens quality.

The UV protection of 10 and 100 dollar sunglasses are the same but the the 10 dollar lenses are not as clear as 100 dollar lenses.  If your lenses are too distorted  then they will be hard to wear and can cause head aches if you wear them too long.  If you wear the more expensive lenses it will be like wearing clear glasses with a darkened tint (so no head aches or strained vision).  If that worth 100 dollars (sometimes more) then I suggest you do it.

Oddly enough, I went through the whole day in my Terminators head ache free while my co-worker had to take his off claiming he had a bad headache.

Personally though, I cannot say for certain how good the Terminators were in their lens quality because I wear prescription glasses.  The day I wore the shades I had to take off more normal prescription and I could not see more than five feet in front of me.  In the future, ideally, I hope I can pick up a pair of transcendent lenses and not have to worry about needing sunglasses again; cheap of or expensive.

What is this Blog

Hi, I am Daniel Emmitt Harrington (or Emmitt19 on this blog sight)

I have never really blogged for so this will be an interesting activity for me.  My plan on this site is not to discuss anything but just post something new i learned that day (answers to all my questions).  This site, I hope, will give people succinct access to information I have gathered.  But, I cannot promise that I will not post some opinions on this blog and if you dislike those possible opinions feel free to express your feelings about them.  Not much else to say, so if you like what I write, read on.