Category Archives: science

Safer Table Saws Should Be Mandatory

14 Monday Aug 2017

Posted by in History, Safety, science, Telescope Making

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Three parts to this little essay:

  • What happened to me about a month into my retirement, with an old, nearly-free table saw that lacked SawStop safety features (and which I was using totally improperly, because I didn’t know better)
  • Table saws are one of the most commonly-used power tools both commercially and at home, and are responsible for an AMAZING number of injuries and amputations every DAY.
  • A fix for this exists — the technology included in every single SawStop table saw. The inventor tried, but failed to convince table saw manufacturers to incorporate this essential, and not-terribly-expensive feature, and they ALL turned it down, essentially saying that ‘safety doesn’t sell’. Congress has the power to make this feature mandatory and to save many a hand, finger, or eye.

Part One

These are not trick shots. It’s just my left hand, imaged poorly just now with my smart phone. I was really ashamed, embarrassed, and sad when this injury occurred, roughly a month after I retired from teaching, for several reasons:

(1) It turned out that I was using the table saw totally improperly, holding a very small piece of wood as I fed it into the blade

(2) I literally did not know that was an improper way of feeding wood into a table saw; I was treating it like a band saw

(3) I should have read up on safety rules for table saws, even though I had used them without incident quite a few times earlier, and thought that I was safe enough (and I wasn’t)

(4) While I am right-handed, losing part of one’s left-hand index finger and having the adjacent finger be mauled so that it lacks feeling on one side, and doesn’t bend properly, and is crooked, means that there are many things one can never do again – for example typing quickly and efficiently. The letters e, r, t, d, f, g, c, v, and b (look at your keyboard and if you ever learned touch typing, you’ll see why) are all now much harder for me to type. And unfortunately for me, E and T are the two most common letters in the alphabet. (I’m not asking for sympathy! Just don’t do this to yourself!! Wear safety equipment and read the fri&&14& manuals!)

 

On the good side, I am extremely grateful and amazed at the skill of Dr. Reisin, my hand surgeon. Without any warning that I could see, my hand got dragged into the blade by the tiny piece of wood. My two fingers looked like very fresh hamburger, and I thought I had lost them down to stumps. I was amazed that when I got my first view of the damage, I still had most of them! Yay Dr. Reisin! Really, amazing job!

In addition, we have Kaiser Permanente family high option insurance. It’s not cheap, something like $400 a month that I pay, plus I have a wonderful subsidy from the DC government, which pays something like $1000 a month. All of that adds up to just about 1/3 of my gross retirement pay, but at least I was never asked to liquidate my retirement savings or sell our house to pay for the astronomically huge bills for all of the doctors’ fees (think anaesthesiologist, primary care physician, ER physicians, surgeon, just to name a few) and the hospital stay and the several months of careful and skillful rehabilitation. It was tens of thousands of dollars, though I certainly don’t know the exact total. If we did not have medical insurance, it would have been very, very tough, but we had minimal co-pays for each visit and for the various antibiotics and painkillers. EVERYBODY SHOULD HAVE THAT!

Again, I was really embarrassed at my own stupidity. For the first few months, I labored under the misapprehension that the wood had been thrown INTO my hand by kickback. But a more knowledgeable friend (WHR) convinced me otherwise; plus I looked at the sawblade scars on the underside of the other pieces that I had fed through – in each case, the saw had started grabbing the wood and had left its marks on the pieces of plywood — and I was too stupid and ignorant to notice. This video shows how dangerous table saws can be – it’s pretty similar to what happened to me: the blade catches the wood, AND the author’s pushing block, AND just barely misses taking off his finger(s).

SECOND PART:

It took me a while to realize that I was far from the only person who had suffered this sort of injury. I was quite aware that the workers at my college (Dartmouth) were almost ALL missing a finger or two or five – but that was from industrial accidents in the textile mills that used to exist all over New England, but had moved on to other places, probably because the owners could get labor for even less and spend even less on safety than before… I wish now I had asked them more about those injuries… But I’m pretty sure that they were not operating table saws.

I did not know that anywhere from SCORES to HUNDREDS of Americans have some sort of an injury with a table saw not per year, not per month, not per week, but EVERY SINGLE DAY.

Let that sink in. Somewhere between 40 and 400 people in the USA have an accident with a table saw, EVERY SINGLE DAY. Some of these accidents were worse than mine, some were less so (two sources on numbers: here,  here and here, each with links pointing elsewhere. It seems to me reprehensible that Robert Lang, the author of the Popular Woodworking magazine (the second link), belittles the number of injuries, comparing them to the number of kids who are hurt by doors everyday.

‘Back in January 2005, the Consumer Product Safety Commission (CPSC) required that new tablesaw models include a riving knife and modular guard to prevent these injuries. Since that time injury rates have remained virtually unchanged, which begs the question: “Why are so many people hurt while using tablesaws, despite improvements in guards and splitters?”’ (source)

As soon as I could use my arm again, I supervised getting rid of that old table saw. I think we sold it for scrap iron. (It had been sold to us for a pittance by a friend — who passed away from a heart attack at a very early age, as it happened. I never had the chance to mention to him what happened to me.)

Fortunately, after this event, the same friend (WHB) got wind of someone who wanted to donate funds so that we at the NCA Amateur Telescope Making workshop could actually get a decent, SAFE table saw. We also used the monies to purchase a very nice H-Alpha solar telescope for the astronomy club under whose auspices we operate, as well as a nearly-unused Grizzly milling machine… And while it doesn’t have lots of fancy features, that SawStop table saw will immediately (in 0.003 seconds) if it senses anything like your finger touching the blade while in operation; if it does, it slams the blade down into an aluminum chunk and stops it immediately and OUT OF THE WAY. (Have you seen any of those hot-dog table-saw videos? or ) Sure, it kills the blade and the chunk of aluminum (roughly $60)  but that’s way better than cutting off your finger!

In fact, the inventor agrees to put HIS OWN finger into a SawStop table saw, under a high-speed camera and very bright lighting, here. He does so, and the sawblade stops instantly, you can see that no damage to his finger at all: no blood, no bruising, no nothing. The inventor says it felt a little like a buzzing insect or a tickle. Absolutely amazing!

Plus, the saws are really, really well made and easy to put together, and have a very good manual that comes with a spiral-bound notebook with laminated pages and very clear instuctions in English, that you can lay flat at any page you want.  In other words, not the incomprehensible hieroglyphics, printed on flimsy paper, that is so common with manuals today. (Think IKEA…) And the prices are well within range of the prices of other table saws with comparable features.

The original inventor has recently testified at the Consumer Product Safety Commission, and was interviewed by NPR. He could not get manufacturers to agree to put his device (or one just like it) into their saws, EVEN AS AN OPTION. So he set up his own company to make them.

It’s also reprehensible that something like the Power Tool Institute wants to prevent the government from making this electronic safety feature mandatory, as you can see here. 

It’s the usual crapload of hysterical propaganda: higher unemployment, making companies go bankrupt — the same lies that the Big Three carmakers said when they resisted putting in seat belts, antilock brakes, turn signals, doors that have hinges at the front and not the back, unleaded gas, airbags, and so on. But those inventions (and others) have saved untold millions of lives, despite the resistance of the rich and powerful. It’s disgraceful.

Yes, we ordinary humans do make mistakes, each and every single day. People are going to lose focus, or get distracted, or make stupid errors of judgement, like me. It doesn’t matter if you drive (or use a table saw) correctly 99.9% of the time: that still leaves that one time in a thousand where you don’t, AND IT CAN KILL YOU OR MAIM YOU FOR LIFE.

If the fix for that is simple — and even if it costs something — it should be done.

We are only human.

Rescheduled Open House at the Hopewell Observatory: Saturday, June 24, 2017

09 Friday Jun 2017

Posted by in astronomy, Hopewell Observatorry, science, Telescope Making

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We had to reschedule the public open house and star party from May to June 2017 because of bad weather last month. You are all invited, and it’s free. The directions and many other details can be found at a previous post on this blog. 

(Just ignore the date, because it’s no longer 2016! The directions are long, and I didn’t feel like copying and pasting them here.)

Looking at a planetarium app set for 6/24/2017, I see that Jupiter and Saturn will be well-placed for viewing at sunset, and the entire Summer Milky Way will be overhead, allowing you to look at lots of deep-sky objects like globular clusters, planetary and gaseous nebulae, open clusters, as well as distant galaxies. If you stick around until 4 AM, extremely bright Venus will rise in the east. The Moon will be too close to the Sun to be visible.

Caveat: we do not have running water, so no modern lavatory. We do have bottled water, an outhouse, electricity, and hand sanitizer. This place is really in the middle of the woods, which is where lots of insects and other arthropods live, so keep that in mind. We do have some bug juice you can use, but keep any spray far away from the telescopes!

If you have a telescope of your own, or binoculars, feel free to bring them. A flashlght or headlamp will be useful. We prefer red light at night, since white light makes you night-blind for about 10-20 minutes. If your flashlight(s) put(s) out white light, we have red plastic, tape, scissors, and rubber bands that you can use to shield your light.

Religions based on … well … myths, or alternative facts. Or lies.

14 Friday Apr 2017

Posted by in History, nature, science

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Every single religion that I can think of seems to be based on totally unreliable witnesses and stories that are mis-remembered (at best) or deliberately distorted.

Judaism just celebrated one of its most important rituals, the Passover seder, in which I have participated about six times. If you’ve forgotten, the story is supposedly recorded in the Old Testament (or Tanakh) and the event celebrates the freeing of a large group of Hebrew people from Egypt. They then wandered the Sinai desert (a very, very hot and dry place – I lived next to it for about 9 months).

The problem is, there is absolutely nothing in the historical record that corroborates any of this story. The Egyptians kept a lot of records, and much of it is still readable — no mention of any such tribe fleeing, no first-borns murdered, no special heavenly plagues, yadda, yadda. No archaeological evidence whatsoever of any tribe of Hebrews wandering in the Sinai desert for any such expedition.

(Stuff like that gets preserved there! In fact, at the famous fort and palace known as Masada, near the Dead Sea, you can clearly see the streets and walls of the camp built by the legions of the Roman Army that besieged and eventually captured the fort, from roughly 2000 years ago! Now THAT incident and war is definitely mentioned — in Josephus, among other places…)

That story of Abraham getting ready to slit his son’s throat and god providing a lamb instead? Really? Inscribed tablets from Mount Sinai – really? How do we know any of this? We don’t. And in any case, if God tells you to commit genocide (it’s spelled out in Genesis / BeReshit), is that a wonderful thing? I don’t think so.

If we get to Jesus, well, again, the evidence that he produced any miracles or was somehow resurrected and became one with God (or didn’t) is pretty darned thin. Today is supposedly the day that he got crucified (the Romans were NOT nice people!!!), which was a shame. The Romans killed and tortured and enslaved a LOT of people. I’m not so sure that they should be held in such high esteem…

But I can think of many ways that a body can be taken out of a tomb, and none of them involve miracles or angels. Then, if you read all of the various Gospels, canonical or not, you realize that their outlooks and details are all profoundly at odds with each other.

If you come to Mohammed, I can think of many ways that somebody could appear to be possessed and to recite various lines of poetry (see Mormons, below) — although that would certainly explain why he would have prophecies that justified what he wanted to do (such as marry little girls) or needed to be amended (see Satanic Verses…)

Now both Jesus and Mohammed said some stuff about equality and supporting the poor, nonetheless the leaders of both religions (Popes, Kings, Emperors, Califs and so on) ended up being wealthy beyond anybody’s dreams, while the majority of people lived in pretty base poverty….

If you go back to the founding of Buddhism, what does that mean that someone is ‘enlightened’? How do we know if someone is in fact in that state? Is it even a good thing to attempt to achieve it? It seems to me that it’s more worth while to try to be good to other people (without endangering your own welfare unless absolutely necessary) and to try to leave the entire planet (and solar system) a better place for your descendants — by not driving species to extinction, not raising the global temperature if at all possible, and by helping so many billions of our kin to avoid lives of infernal poverty and oppression.

Hinduism seems to blame the poor and lowest classes for having been wicked people in a past life, and therefore should be not permitted equality with the upper castes. Sounds great if you are a Brahmin, but what an oppressive religion, really! And how can anybody with an ounce of skepticism believe any of those stories?

Going back to 2000+ years ago — All those stories that the Romans, the Greeksm the Babylonians, Persians and Egyptians made up about their gods — are you serious? They actually believed that? Well, you may as well believe in the Tooth Fairy or the Easter Bunny or the Flying Spaghetti Monster!

Oh, can’t leave out the Mormons. Golden plates buried in upstate New York but only viewable and translatable by someone talking through his hat, writing pseudo-king-James-English and talking about lots of animals and plants and metals that supposedly were used by warring tribes of American Indians — and nobody has ever found figs, wheat, camels, sheep, goats, or horses, or the use of iron or wheeled vehicles of any sort anywhere in the Americas for the entire period of say 500 BC to 1491. So that’s all a lie, too.

Sorry if I offend you, but while I know I’m not perfect (far from it) I don’t need fairy tales to try to be a better human being. I prefer to know things that are true and verifiable. And I really don’t like it when people try to kill each other to support ideas that are really just hoaxes.

 

How Britain Became an Island

06 Thursday Apr 2017

Posted by in History, science

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Interesting report with pretty geological maps indicate that the Island we call Britain got cut off from what we know as France and Belgium by a catastrophic waterfall and flood that broke through what we now call the Straits of Dover as the ice that covered Northern Europe was beginning to melt, and sea levels were much lower than today.

Gupta_NCOMMS-16-16909A_Fig2_rev2

Here is the link. 

By the way, if the weather is fairly clear, it’s easy to see the famous White Cliffs of Dover from the French side (for example, at Cap Gris-Nez).

Telescope Fix, Scudding Clouds Over Moon, Tom Turkeys Hiding, and Successful Cloud Chamber!

12 Monday Dec 2016

Posted by in astronomy, astrophysics, science, Telescope Making, Uncategorized

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I had a productive 24 hours!

  • Night before last, I think I finally got Sky Wizard Digital Setting Circles installed on the 14″ alt-az telescope we were most generously donated by Alan Bromborsky. (That’s me, in the operations cabin  at Hopewell Observatory, taking a break and a picture, long before completion.)img_6169
  • So I went out to look at the sky at 1 AM. I saw no stars, but the 80% gibbous moon appeared to race dramatically through the clouds
  •  That afternoon, as I was driving out, I saw 5, maybe 6 tom turkeys playing hide-and-seek with me behind the trees. Believe me, they are REALLY GOOD at hiding behind little saplings, logs, and rocks! Or if you don’t believe me, ask anyone who’s tried to hunt them.
  •  Late that evening, I got a dry-ice-and-isopropanol particle detector working for the first time. (I had tried and failed, when I was a teenager, some 50 years ago, and failed several other times since then as well.) If you look at my little video, you can see the particles more easily than I could with your naked eye as I was filming it. Don’t ask me yet which ones are muons, which are alpha particles, and which are beta particles, because I don’t know yet. But you could look it up!

Productive 24 hours!

Sex and Math: The Zero to Two Percent of Our Actual Lives That Rules Our Lives

01 Thursday Sep 2016

Posted by in Math, science, Uncategorized

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Someone (probably Louis CK) pointed out that even though we all obsess about sex (and being attractive to the persons with whom we long to have sex), it’s actually a very, very tiny part of one’s actual (as opposed to our wishful) life.
[Of course, any species that survives needs to have a strong drive for procreation, or they won’t leave enough offspring behind to carry on. (Just ask pandas what happens when they seemingly couldn’t care less… They are, if you hadn’t noticed, nearly extinct in the wild. Rats, rabbits, ants and cockroaches survive by being unbelievably fertile — and sneaky.]
Let’s try to do some math on this.
Have you ever tried figuring out what percent of your entire life has consisted of you actually making love (having sex) with another person?
I am not counting masturbation here because
  • I don’t trust any data on this, even Masters and Johnson, so any guesses on my part would be just that
  • I’m only talking about having sex with another person, either Penis-In-Vagina or any other sort of sexual activity, which I am not about to list here —  use your own imagination if you want to. 
  • And no, I’m not going to tell you anything about my own habits or those of anybody else I know. However, if you want to tally up your OWN time doing ‘that’, feel free.
 
Let’s look at the high end of the spectrum of those having lots of sex first.
My guess is, based on observations of personal experience and what I’ve observed with people I knew well:  that only with the very horniest newly-weds or with a couple who have just entered a super-sensual, brand-new sexual relationship,  time would a couple be spending, say, as much as four hours a day actually’doing it’. Why? For one thing, sex is exhausting. Also, the tissues involved are delicate and can only take so much rubbing, no matter how well lubricated they might be. Plus the couple need to sleep, eat, wash, and most likely do something productive like going to school or work.
That very high figure for someone getting a HUGE amount of nookie is 4 hours  out of 24 hours in a day, or 1/6, which is about 17% of the time. Let me repeat: that’s extraordinarily high, and from my own observations (thin walls allow one to hear… and so on) only seems to last for the first few weeks, because then they get sore, exhausted, sated, and somewhat jaded.
After that, they’d be lucky to be ‘doing it’ for an hour or two a day, which is between about 4 and 8% of the time.
But let’s compare that to the rest of their lives for this remarkably horny and lucky couple… Let’s suppose that they are 20 years old, and let’s suppose that they each had sex a few times in high school and after (college, military, working, whatever, and I’m making no assumptions about whom they are doing this with). Maybe they got laid 2 – 3 times a week from age 16, at about an hour each time (girls, feel free to scoff at my suggestion that a typical male teenager can actually last that long) plus, now that they are not living at parents’ home any more, they have had several tumultuous, sexy relationships one after the next, each time spending an average of 2 hours actively ‘doing it’ each 24-hour period, for the last two full years.
So let’s make that say 6 hours a week for 2 years plus 28 hours a week for the last 2 years – and these people are those who are towards the very far right hand end of the frequency curve distribution. I don’t know whether the distribution of ‘nookie-hours’ if graphed, is ‘normal’ or ‘skewed’one way or the other. But in any case, most people ‘get’ a lot less sex than this. In fact, when I was in high school and college, the vast majority of my (male and female) friends my age or younger were virgins. No, I’m not going to tell you what age or to whom I lost my virginity. I will keep my fond memories to myself, and hope you will do likewise.
Here’s the arithmetic:
Denominator (total hours lived) for this very lucky pair of 20-year olds: 24 hours per day time 365. days per year times 20 years old equals 175,200 hours total that they have lived so far. (D)
 
Numerator ( total hours having sex with another person since they were born) Assuming this very sexually active couple who have sex 6 hours a week times 104 weeks (two years from ages 16 – 18) plus 28 hours a week times 104 weeks (two more years, aged 18 – 20) equals 3,536 hours having sex, grand total, (N)
 
I used a calculator to divide N by D and I get about .02, or two percent of their life so far. That’s tops.Two percent of their life.
I suppose it is theoretically possible that a married couple of 60 years, at age 75, has been actively having sex a full hour every single day of their married life (since age 15). Extremely rare, I know… But for this tiny handful of  extraordinarily horny, happy, healthy and lucky people, I get a grand total of 1/30 of their life, or a tad more than 3%. And I bet that you could probably hold a nice party for every single one of these lucky 75-year-old living couples — from all over the world — in the cafeteria of the elementary school nearest my house. Not sure how much standing room there would be, but this is out of our current world population of over 6 billion people. So they are outliers of outliers of outliers.
The vast majority of people would have much, much less sex than that, I predict with confidence.
Additionally: a good number of people die before losing their virginity. I have no idea what percentage do, but during the old days, it was probably well over half  of them, infant mortality rates being what they were — and I’m assuming that most of those babies and children who died at very early ages from disease, murder or accidents weren’t being sexually abused during their short, sad lives… Many soldiers die in combat having had sex perhaps 0 to 6 times in their entire lives, if I can trust various memoirs I’ve read by veterans of various wars…
So that’s the far left hand end of the ‘bell-shaped’ curve: 0%.
While there are a tiny handful or two-to-three percenters out there, I would bet (if we could test it somehow) that over 99.99% of the population has sex, on average, between ZERO and TWO percent of our entire lives.
But, oh, how we obsess over ‘it’!!

Any Moth Experts Out There?

20 Monday Jun 2016

Posted by in nature, science

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We found these two beautiful moths that flew into the operations cabin at the Hopewell Observatory a couple of nights ago, and we have no idea what type they are. Never seen them before and can’t find any images identical to them. (One species is similar, though.)

Any suggestions will be welcome.

Ain’t they purty li’l things?

And when they opened their wings they were even more spectacular, but I didn’t get a good shot.BTW the yellow-and=red moth is sitting on the struts of a telescope made by Alan Bromborski.