Investigation: UV radiation

UVA, UVB, UV Index, and SPF.  Here are some things I kind of knew about - UVA and UVB are bad, and SPF is good - but I didn't really understand.  What started me thinking about this was a set of eclipse glasses I bought from Amazon that was later removed, maybe because they were fake.  But why does that matter?  How would I know?

And can I buy a tool to help investigate this?

What is all this stuff

Ultraviolet light is light with wavelengths slightly shorter than that of visible light, with the following ranges:

    UVB: 280-314nm

    UVA: 315-400nm

UVA and UVB cause different kinds of damages to the human body.   As a broad generalization, UVB causes short term issues like sunburn and UVA causes long term issues like skin cancer.  Remember that UVB light at 314nm will affect you approximately the same as UVA light at 315nm, so the effects are not as clear cut as the broad generalization.

The nice thing about sunburn (and UVB), so to speak, is that it helps you and your body know that something bad is happening so that you both can protect yourselves.  You get out of the sun.  Your body builds melanin to protect against UVA and UVB.  Let's remember this for later.

UV Index and SPF

It's probably clear that people learned about sunburns earlier than skin cancer and when we designed our products to prevent the harmful effects of the sun, we designed products to block UVB (sunburns).

Then we, as a society, created the UV Index to measure UVB radiation.  And we created an SPF rating for products that measure how much UVB radiation it blocks.

Here is how the UV Index is calculated: https://www.epa.gov/sunsafety/calculating-uv-index-0

Wavelength		Weight
290nm		15
320nm		5
400nm		3

From the above grid, you can see that the UV Index weights UVB higher than UVA because UVB causes more sunburn.  This indicates that the UV Index is not suitable for determining the long term effects of sun exposure (UVA).  What I find most interesting about the way the UV Index is calculated in the United State is that it uses elevation, cloud cover, and ozone measurements to estimate ground level exposure, instead of actually measuring it.

So if we are relying on high-SPF rated sunscreen to protect us from the sun, what are we doing?  We are preventing our skin from being burned which encourages us to stay outside longer, exposed to cancer-causing UVA rays, all while blocking our natural melanin creation which is supposed to protect us from UVA.  This sounds a lot like a recipe for greater long-term skin damage, which is probably what happened.

Broad Spectrum

What about broad spectrum SPF sunscreen?  That must block UVA and UVB.  According to thesunscreendoc.blogspot.com/2015/08/, which I did not verify, most broad spectrum sunscreens just block a small amount of UVA.  The only ingredients that protect against both are zinc oxide, Tinosorb M, and Tinosorb S.

The writer of this blog has created a sunscreen company, selling the Sun Whip brand sunscreens, so it can't be taken as unbiased, but everyone does seem to agree that zinc oxide blocks UVA and UVB.  But zinc oxide is super white and looks pretty bad.  However, that's "old" zinc oxide; now we have encapsulated zinc oxide, which is supposed to go on clear. 

Excited, I decided to test that claim with derma-e, which the EWG seems to like.  Unfortunately, it's "clear zinc oxide" is still white and difficult to spread on my hairy skin.

This blog seems to like the Sun Whip brand sunscreens from the blog-doctor above, among others: https://beautyeditor.ca/2017/06/19/zinc-sunscreen-for-face.

And, for good measure, here is a list of bad sunscreens for kids, also from the EWG.

The sunscreen doc also says that windshields do not block UVA.  Let's check that out later.

Tools

I found a handful of tools that could measure UV light, ranging from $25 to $250.  Unfortunately, the only brand that published the spectral response graph of their sensors was Solarmeter, the one that costs $250.

The Solarmeter Model 5.0 UV Meter measures UVA and UVB: https://www.amazon.com/dp/B01GT4EID0

This graph is nice, because it covers UVA and UVB, with an emphasis on UVA (the high response at the right-hand side of the graph).

Solarmeter also has a Model 6.5 UV Index Meter that tries to calculate the UV Index.  However, it appears to be the same device as above with an added filter that blocks UVA light, further indication that UV Index ignores UVA exposure.

The $250 price tag is unfortunate because all Solarmeters cost $250, even the visible light meter, which is simply a $2 sensor, a chip, a cheap screen, and a button.  So, I did a little search for UV sensors to see if I could build my own meter.  Adafruit has two UV sensors, about $6 each:

GUVA 1918 (Analog): https://www.adafruit.com/product/1918

VEML 6070 (I2C): https://www.adafruit.com/product/2899

Again, unfortunately, the spectral graph of the Solarmeter is much nicer than these two, so that's the one I bought.

Measurements

So now that I have this tool, what science can I do?

First, the noon-day sun where I live measures 4.5 mW/cm2.

Through my car windshield: 0

Through my car windows: 0

Through my car sunroof: 0.2

Through my wife's car windshield: 0

Through my wife's car windows: 2.0  (that's pretty high)

My car has a darkening film, which is probably why my car has higher UV protection.  After taking these measurements, we will likely put film on my wife's car too.

My wife's rather high reading is consistent with the idea that car side windows block UVB but not UVA.  I would like to test this with UVA and UVB band pass filters, but sometimes science is just too expensive and it'll be cheaper to just put film on the car.

My sunglasses: 0

Real eclipse glasses: 0

Possibly-fake eclipse glasses: 0

House windows: 0.4 (but more measurements are needed for different days and sun positions)

Investigation: Jews

I have heard a few things said of the Jews at my Christian church that, when coupled with the messages of the Old Testament, prevent me from forming a cohesive story in my head of what is a Jew.  I get the impression that many pastors have a very narrow and biased view of Jews, so I thought I'd test this view.

Luckily, a friend of mine happens to be a Jew, rather intelligent, and the son of a professor of Jewish studies.

Roughly, here is the portrait of Jews as painted in the sermons I have attended.  Jews are roughly the same as Christians except:

• They believe in the Old Testament and not New Testaments
• They follow (or should follow) all the rules in the Old Testament

So I asked him two questions.  Or, as it turns out, three.

Question 0

"Can I ask you some questions regarding what Jews believe?"

Aaron immediately responded with "What do Christian's believe?"  I responded with something that roughly encapsulated Catholics and Protestants, but he reminded me of the other Christians I might be implicitly ignoring - Lutheran's, whom I know nothing about, and Mormon's, who non-Mormon's generally ignore. 

And then he asked a more specific question, "How many Christians are pagans?"  I had to admit that I don't know what a pagan is, which was apparently the correct answer.  There are Christians who believe that Jesus was born a man and became divine sometime during his life.  This is Adoptionism, which my have been practiced in the early church before the doctrine of the Trinity was created (in the 2nd century, with refinements through arguments into the 4th century).  His implication is that if someone worships a man, born mortal and made divine, than that person follows a pagan religion.

To top it off, some Christians don't believe in the Trinity.

So what do Christians believe?  Each sub-group has specific beliefs, and believes that the other sub-groups, who have differing beliefs, are wrong.  And if you were to graph all these beliefs, for all Christians, the centroid of those beliefs may not represent any group.

The same is true of the Jews.  There is no simple description of what Jews believe because the individual beliefs vary widely.  Also, the traditions of the Jews have changed over time, perhaps as a result of wars, raids, etc.  There is a tribe of Jews recently discovered in Africa that did not experience persecution by Christians and Muslims and their traditions may hint at what the old traditions were.  In particular, they open their doors at the beginning of some particular ceremony instead of the end; Jews in the rest of the world open their doors at the end, after the meal has been consumed, because during Islamic occupation any house visibly having a feast would be raided.

From a much earlier conversation, I was taught about the current establishment of Jewish matrilineal descent (children of Jewish mothers are born Jewish) was a change from the traditional patrilineal descent (children of Jewish fathers are born Jewish), based on war casualties.  So many men were dying in wars that the culture would die if women could not pass on the culture.

Question 1

"I haven't seen much mention of Heaven and Hell in the Old Testament.  Do Jews believe in Heaven and Hell?" 

In many Christians' belief systems, the concept of Heaven and Hell is vitally important, perhaps of paramount importance.  If it is of such great importance, why did God not tell his chosen people about it?

Again, Aaron wasn't going to tell me what all Jews believe, or even what most Jews believe, and he wouldn't guess at what percentages believed what.  However, he would answer what, from his necessarily limited perspective, the Jews that he knows or heard about believe.

You can map the spread of Judaism with a tree, the root planted somewhere around Israel and reaching out to all the continents.  Every Jew is somewhere on the tree, and groups of Jews who live closer to each other are closer on the tree and more likely to believe similar things and have similar cultures.  On top of this, there are major cultural forces, like the various movements such as Orthodox Judaism, which catch on and homogenize the Jewish beliefs across cultures.

What we see is that many Jews are influenced by the major movements and also by their local environments.  Jews in North America are more likely to believe in Heaven and Hell than those in Israel because of the pervasive Christian culture in North America.

As for the Old Testament, there is no concept of Hell.  The word Sheol which is translated to Hell means either grave, or "that stinking pit outside the city," signifying an unpleasant place, but not one of eternal torment.

Incidentally, The New Testament does not support the current Christian idea of Hell as a place of eternal damnation either.

Heaven is slightly different.  There is no concept of the Christian Heaven in the Old Testament, but there are hints that something exists.  In particular, the thummim and seraphim are non-worldly artifacts, and if they are not of this world, and they are from somewhere, then there must be another place not in this world.  This is a far cry from a place of eternal bliss.

Aaron also had a comment concerning the carrot and stick approach to Heaven and Hell often used today to entice people to follow church teachings.  In Judaism there is not a concept of "if you don't follow these rules, bad things will happen to you."  Instead, they have "you will follow these rules."  There is no option if you want to live God's way.

Question 2

"Do Jews believe that all the books of the Old Testament are true?

It is taught in my church that Christians are expected to believe that all the books of the bible at true.  However, there seems to be a hierarchy in the Old Testament, with the Torah being more important than the rest.  What's up with that?

Aaron said that some Jews believe that all books in the Old Testament are true, just as some Christians believe that all books in the Bible are true.  However, most believe that some are stories.

In particular, the Old Testament, known as the Tanakh, is broken into three sections, the Torah (the first five books of Moses), the Nevi'im (the works of the Prophets), and the Ketuvim (the Writings).  The word TaNaKh, is formed of the first three consonants of Torah, Nevi'im, and Writings.  Here is a talk about the Dead Sea Scrolls, given by a Jewish scholar to Jews, where he describes "the Torah being big divine inspiration, the Prophets being a little less, and the Writings being, again, even less - a descending order of inspiration."  This description states that the books of the Ketuvim "do not present themselves as the fruits of direct divine inspiration."

In particular, Chronicles is currently part of the Bible, but the author is interpreting other books and we don't know if he thought he was writing a book or the Bible or we took his interpretive book and added it to the Bible.

My thought goes something like this.  The Jews have a very powerful pattern of passing information from one generation to the next, an extremely solid oral and written tradition and a history of unbroken ceremonies and lessons.  They are much, much better than Christians at preserving knowledge through the centuries.  So why is it that Christians do not use this amazing resource to help understand the Jewish Bible?  If Christians generally believe that the books of the Old Testament are true and Jews generally believe some are not-so-much, then it is highly likely that this particular Christian belief is a result of recent changes in mindset and thinking.

Missing Question 3

It was also my intent to ask him about the many laws the Jews are purported to follow, with The Old Testament often being referred to as "The Law."  This guy, describes the Torah as instruction and calling it Law is unfounded in scripture and against the general intention of forming a relationship with God.

In another conversation, it was explained to me that some of the Jewish laws are meant to protect the people from breaking the commandments.  For example, from Deuteronomy 14:21, "You shall not boil a young goat in its mother's milk," becomes "do not eat milk and meat together."  In order to guarantee that you never boil a young goat in its mother's milk, keep the two foods separate.  What if you have cows milk and lamb meat?  It should be okay, but how sure are you that your cow's milk is really cow's milk?  How sure are you that what you think of as lamb's meat is really lamb's meat?  The truth is that you cannot be sure, so better be safe than break a commandment.

Commentary

I have often been in situations where someone makes a claim about another group of people, not necessarily in a religions context.  In church, it is often a sweeping generalization of another religion and what people in those religions believe, be it Judaism, Buddhism, or any other.  I often wonder, why don't we just ask an intelligent Jew, Buddhist, or other?  I think we will often find that our simplistic notions are flawed.

A new barbell

It's been exactly one year since my last weight training update.  I was stuck at a 212 lbs until a few months ago when I finally bought a new Olympic barbell.  It's black metal oxide and pretty sexy.  I also picked up some great steal Troy and IGX weights from Craigslist.  I've got about 600 lbs, which should last me a while.

You'll notice in my picture above that I covered the grips in electrical tape and scotch tape.  I added the electrical tape because the grip was far too aggressive, and even at 100 lbs it ripped into the fleshy bits of my hand; it was unusable.  Here's what it looked like up close:

The electrical tape is a bit too smooth so my grip doesn't feel very secure, but I haven't had the time to try anything else yet.  I might fill the grooves with something later.

The scotch tape is my fault.  I bought a power lifting bar instead of an Olympic bar, not knowing there was a difference, and the longer knurling cuts into my knees on the squat.  I use the tape to make it smoother.  However, I think this was the only 5 foot long Olympic-weight bar I could find, so I didn't really have a choice.

Before finding the nice weights on Craigstlist (which took a few months), I purchased some cast iron Weider weights from Big 5 Sports.  The first one I put on my bar immediately scratched it.  Always up for some experimentation, I decided to try and fix it, by:

1. Removing the [excessively thick] paint using a chemical peal and a wire brush attached to my hand drill.
2. Smoothing the inner circle using a grinding stone attached to my hand drill.
3. Painting it black with canned spray paint.

Here is the result after the peal and grinding, beside the original.


In the end, it worked okay.  I didn't scratch my bar immediately, but wasn't even close to the smoothness of steal.  And the diameter of the inner holes were still about 2mm too large so the weights rattled.  I only used them once and it was not at all worth the effort.

And here's where I'm at in all my barbell exercises.
Deadlift: 239 lbs
Squat: 199 lbs
Standing Press: 99 lbs

A heavier barbell

I have run out of weight plates and reached the limit of my barbell in the deadlift.

My deadlift is now at 212 lbs and I'll need new equipment to increase it!  While not super impressive, it's 50 lbs heavier than when I started.

And here's where I'm at in all my barbell exercises.
Deadlift: 212 lbs
Squat: 145 lbs
Standing Press: 82 lbs

A better barbell

Let's start with the obvious: I'm cheap.  Or perhaps frugal.  And lazy; we shouldn't forget that.  I want to build some strength and don't want to bother driving to or paying for a gym, let alone waiting for equipment or listening to the awful music.  However, my standard weights and barbell pose a few problems:

1. The weight plates are too small to do deadlifts, about 8 inches in diameter less than Olympic weights, so the bar lays too close to the floor. 
2. It takes forever to change weight plates with the screw locking mechanism.

I have a history of hurting my back with squats and deadlifts at the gym.  The last time I tried them I was out of the gym for 3 months.  This time I'm following Starting Strength by Mark Rippetoe and, surprisingly, his advice and instructions are more cohesive and useful than the "training" I got at my last gym.  I highly recommend this if you plan to gain strength with free weights.

But my weights aren't the greatest.

To fix the height-off-the-ground problem, I built a simple platform using a single 4x4 (cut to 1 foot sections at Home Depot), a cheap rubber mat, a 3/4" x 1.5" piece of wood, and some scrap MDF:

 

This was a pretty simple project.  My only mistake was gluing the 4x4's together before screwing them to the MDF.  The glue seeped out and pooled on my workbench.  I made two of these:



These platforms work great and also help keep my deadlifts honest.  I can see if the bar inches forward during my lifts by their placement on the blocks.  If you read Starting Strength, Mark will tell you many times that there is a tendency to move the bar forward before, during, and after your lift, and I can see easily when this happens, prevent it, and learn to lift correctly.

In the picture above you'll also notice how I modified my bar.  First, I got Lock Jaw collars to replace the barbell screw locks.  These save me many valuable seconds in a workout set since I can take the lock off in about 1 second instead of 10.  While this is good, when changing weights they kept getting caught on the spiraling screw mechanism.  My solution, again too cheap to buy a better bar, was to cover it up with duct tape.  Now my weights move fairly smoothly and the bar looks bad ass.  As a bonus, there is less space between the bar and weights so there's less slop in their connection.  I'll soon be adding one or two more layers of duct tape to make this even smoother and create a better fit between the bars and the weights.

That's it.  A simple project, but it made a huge difference in my happiness working out with these weights.

The War on Education

We'll get to the war in a moment; first some background.

Introduction
I had a conversation with a high school student this week about logarithms and the cost of college tuition.  She asked her math teacher for some uses of logarithms, a question he could not answer. That's a shame, since they are so useful.  One way that everyone uses them without being consciously aware of it is when dealing with large sums of money.

Think of millionaires.  They have a lot of money.  When you think of billionaires, how do you think of them?  I think "they are one step beyond millionaires."  And if there were trillionaires, they'd be one step beyond billionaires.  You may also think "a trillion has 3 more zeros than a billion, which has 3 more zeros than a million."  But this hides the real scale.  A single billionaire has as much money as a town full of millionaires, and a trillion dollars is unfathomably large.  However, counting the "number of steps" in an exponentially growing value (like the number of decimal places in a number) is a logarithm.

The Question
But what if we stopped thinking of large numbers in terms of logarithms?  How large is a trillion dollars?

Let's start small.  Most people believe that a college education is expensive, that it's a lot of money, that it is expensive to send your kid to college.  Let's see if that's true.

The Math
And now for the war.  It doesn't matter if you are for the American wars or against them, the math is agnostic.  And we can compare war costs with college tuition.  I read recently that the US cost of the Iraqi and Afghan wars total 4.4 trillion dollars (http://costsofwar.org/article/economic-cost-summary).

Here are the statistics:

• 3.3 million US high school grads per year (http://nces.ed.gov/fastfacts/display.asp?id=372)
• $4.4 trillion: US cost of Iraqi and Afghan wars (http://costsofwar.org/article/economic-cost-summary)
• $10 thousand / year: average in-state tuition for US public colleges (https://bigfuture.collegeboard.org/pay-for-college/college-costs/college-costs-faqs#)
• 3.25% prime interest rate (http://data.worldbank.org/indicator/FR.INR.LEND)
• 4 years: length of college degree

The US spends $4.4 trillion * 3.25% = $143 billion per year on interest for the previous two wars.
And $143 billion per year / $10 thousand tuition = 14 million college tuitions per year.
And 14 million per year / 4 years = 3.3 million four year college tuitions.
And there are 3.3 million high school graduates per year.

That is, we can pay the tuition cost of a four year in-state college degree for every high school graduate in the US (for the rest of time!) with the interest on our war debt (assuming a stable population, interest rate, and tuition cost, and that the US does not pay down its national debt).

Note that tuition cost might not rise like it does now if it were prepaid by the government.  This can be verified by looking at the cost of public school in the US or the cost of post-secondary school in countries that pay for every child to get a college education.

And said another way, because 1 / 3.25% = 30, the US citizens, as a whole, believe that it is 30 times more important to fight people in Iraq and Afghanistan than giving every child in the country a college degree.

Addendum
We use logarithms every time we measure an exponential function in terms of steps.  Here are some examples:

1. Number of digits in a number.
2. Scientific notation.
3. Number of years before the word population hits 8 billion.
4. Number of years before the rain forests are cut down.
5. Number of years before your investment reaches $100,000.
6. Half-life of a radioactive isotope.
7. How loud your stereo is (in Decibels).
8. How strong an earthquake is (in Richters).
9. Notes on the musical scale (frequency increases exponentially).
10. The height of a binary search tree.
11. Whatever you're talking about when you say "order of magnitude".

What babies know

I've been postponing this post for a long time since I was expecting the list to grow.

There are many things a baby doesn't know, like how to walk, sing, and do long division.  Here is the list of things that my baby didn't know how to do which I wasn't expecting:

1. Sleep.  I kinda knew this one.  But my kid had to be taught how to sleep.  I suspect he would of learned on his own given more time, however.

2. See moving object.  When my son started to be able to see me, he could recognize faces.  If I was in front of him, he'd pay attention.  However, if I moved my head by a few inches, his eyes stayed affixed to my previous location for at least a second.  Once I stopped moving, he would notice out of the corner of his eye a face and then turn to my direction and look again.  It's like I didn't exist when moving, but once stopped a new me materialized.

3. Binocular vision.  This one was cool and it was exciting to see him change.  Even when my son could see me, he often only looked with one eye, or perhaps one eye first and then the other.  While one eye looked at me, the other was free to wander and see other things.  Over time, he learned to move both at the same time and converge on the me he wanted to see.  I don't know if he can see in stereo yet, but he can certainly judge distance.  And I suspect that he could have learned to use both eyes independently like a chameleon, but the advantages of stereopsis and binocular summation are too enticing.

4. Left/right independence.  When my son could first grab things, he used his right arm.  Then he tried his left.  I could see him intently trying to acquire the toy but every time he tried to move his left arm, the right one would go instead.  If his left hand was in the right position, his right hand would make a grasping motion.  It's like his brain had learned how to do a "grasp" but didn't know there was a "left grasp" vs. "right grasp" yet.  The little guy got it eventually; he did try really hard.

And that's it.  Everything else you'd expect.

My son never really cried until last week when he saw a baby cry and get lots of attention; now he does it frequently.  So I guess learning to cry is another one.