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In a previous post, I discussed a common misinterpretation of scientific results in which correlation and causation are confused. Another common fallacy is the misinterpretation of a lack of evidence to imply proof of a negative. In other words, there’s an important distinction between, “No evidence has been found to support this proposition,” and, “Testing has provided evidence that the proposition is false.” In one case, the proposition may turn out to be true, once further study is done. In the other case, there is less chance that the proposition is true, depending on the rigor of the testing that was performed. We could sum these up as, “no evidence found,” and, “negative evidence found.”

Here’s the actual example that got me thinking along these lines. The answer states that SIDS “has been proven” to be “in no way related” to immunizations. Whenever I hear strong negative claims, I always wonder whether the underlying science is an example of, “no evidence found,” or, “negative evidence found.” There has probably been a lot of study done on the causes of SIDS, but only if those studies specifically focused on the link between SIDS and immunizations could we say that immunizations probably do not cause SIDS. Otherwise, it would be safe to say that, “No evidence has been found linking immunization to SIDS,” but be careful, as this wording can be used to imply results that aren’t really true. For example, it would be true to say that no evidence has been found linking cancer to reading Steinbeck novels, but that’s just because no studies have bothered to examine that probably-tenuous link. In that case, the wording could be used to suggest “negative evidence found” when the truth is “no evidence found.”

Regardless, the wording of the quiz question strikes me as inappropriately strong and un-scientific. It is always better, in my opinion, to say, “Studies have found…” or, “There is strong evidence to suggest…” as opposed to, “It has been proven that…” Science, in my experience, rarely “proves” anything beyond a shadow of a doubt.

Issa recently convinced me to buy a generator. We needed one for Fucking Awesome, our theme camp at Alchemy, but last year, we relied on borrowing from others. I was reluctant to spend the money on one, but she argued that it would take one good power outage to ruin all the meat that’s in our freezer, and that was kind of hard to disagree with. Depending on the time of year, we may have the equivalent of $300-500 of meat in our freezer. The final straw was a surprise gift from a relative in response to Dylan’s birth. Well, we are all set for baby supplies, but it turns out the check would just about cover a genny! Baby needs a genny!

The most basic thing you decide on when choosing a generator is the wattage draw that it will support. The more and bigger stuff you want to run, the bigger a generator you need. For Fucking Awesome, we need somewhere around 1000-2000 watts, but if the generator is going to do double-duty as a house backup, it would be good to have a little more than that. I also wanted it to have a 240-volt output, just to cover my bases for the future. I ultimately settled on this generator from TSC.

http://www.tractorsupply.com/tools/gas-diesel-generators/champion-global-power-equipment-trade-3500-w-portable-gasoline-generator-4434023

It’s 3500 watts with one 120 and one 240 outlet, as well as an RV hookup that I won’t be using. Ah, but wait, there’s a problem. Notice the two 15-amp breakers to the left of the volt-meter. Only one of those belongs to the 120-volt outlet. That means that the maximum usable wattage on the 120-volt outlet is actually only 15 amps * 120 volts = 1800 watts. If you want to use all 3500 watts of the generator’s capacity, you have to be plugged into the 240-volt outlet! But what if your appliance is 120 volts? They make a 240-to-120 splitter cable that will do the job, but it’s $50. Why should I pay an extra $50 just to get to use the full capacity of the genny? On top of that, the genny doesn’t come with a wheel kit; that’s an additional $50.

By the time you add $100 to the price of the genny, you’re actually $50 away from the next unit up in the line, which has a 5000 watt capacity, comes with wheels, and has two separate 120-volt circuits AND a 240-volt circuit that can all be used at the same time. Not rocket science there…

The moral of the story, boys and girls, is that when you’re speccing out a genny, you need to pay attention not just to the total capacity of the unit, but also to the configuration of the outlets and breakers on the unit. It doesn’t matter how many receptacles the unit has, if it doesn’t have enough breaker capacity to run the receptacles at the same time, it’s not going to do the job. For example, this 3000 watt generator can’t run a circular saw, because the saw’s startup draw exceeds 1800 watts (15 amps at 120 volts) and will blow the breaker on the circuit. It doesn’t matter that the genny itself has ample wattage to run a saw, the configuration of the breakers precludes it. When speccing generators, they always say to buy a generator with enough capacity to run your largest appliance, but it seems like what they really should say is by a generator with enough capacity on a single circuit to run your largest appliance.

I do a lot of tinkering. Here are some useful items that I turn to again and again when building and repairing things around the homestead.

Hose Clamps

The intended use of hose clamps is to “attach and seal a hose onto a fitting, such as a barb or nib” (Wikipedia). I can honestly say I have never used one for this purpose. The way they work is that there is a captive screw and the band has slits cut into it that engage the screw threads. When you turn the screw, the band tightens and loosens. They can be tightened down very securely and apply a lot of pressure.

Although hose clamps have a lot of possible uses, I find them most useful when attaching two long, smooth objects (like a pipe, bar, or rod) to each other in parallel. If the objects are roughly the same diameter, a U-bolt might work, but when the objects are a different diameter, U-bolts don’t work so well. Also, hose clamps have a low profile that U-bolts don’t have. As an example of the use of hose clamps, I recently needed to attach a piece of rebar (1/2″ diameter) to the vertical sections on my fence gate (about 1.75″ diameter). Two hose clamps (one at the top, one at the bottom) fit the bill.

I should point out that hose clamps are not actually designed to be load-bearing, so they shouldn’t be used anywhere where safety might be a concern.

Hose clamps are sold by their minimum and maximum diameter, so before you buy, you need to know the diameter of your application. Since the application is often not circular, this can be tricky. One method is to hold the two objects to be fastened together and measure their circumference (say, with a fabric tape measure or a piece of string), then measure the hose clamps the same way at the store. Although they’re sold by diameter, what you really care about is circumference.

Pipe Strap

Pipe strap is intended for use hanging pipes from the ceiling, but my preferred use for it is mounting things to the wall—in applications where appearance doesn’t matter, of course, like the garage or the barn. It’s basically just a strap with holes in it. It comes in two varieties, galvanized steel and plastic. I use the plastic kind because it stretches a little and doesn’t damage the item I’m mounting to the wall if I cinch it a little tight. All you do is put a screw through a hole on the loose end, wrap it over the item you’re mounting, and then put another screw in another hole such that it is pulled tight over the item you’re mounting. It’s also useful for dressing loose bunches of cable or wire.

Zip Ties

You don’t need a photo of zip ties; you know what they are. Their intended use is for bundling cables, but they’ve got a zillion other uses for attaching things to other things. One thing to keep in mind is that if you’re intending to use your zip ties outdoors, you need to buy ones rated for outdoor use, or they will become brittle from UV exposure and pop after a few months.

Scotch 2229 Mastic Tape

Mastic tape is a little hard to explain. Its intended use is for waterproofing electrical connections. The tape is a stretchy, tacky, rubbery  material. When you apply it, you stretch it out and wrap it around the connection you’re waterproofing and it molds to itself, become a kind of seamless, tight seal. Since I usually have some sitting around from work, I find it’s also useful for quick patches of leaky hoses. Just wrap the mastic tape around the leaky section and voila!