I hope the rest of the advice is better than the advice for magnetizing a compass needle:
If you have a battery and some electric wire, you
can polarize the metal electrically. The wire should be
insulated. If not insulated, wrap the metal object in
a single, thin strip of paper to prevent contact. The
battery must be a minimum of 2 volts. Form a coil with
the electric wire and touch its ends to the battery's
terminals. Repeatedly insert one end of the metal
object in and out of the coil. The needle will become an
electromagnet.
No, the needle will not become an "electromagnet," once it's outside the coil. It won't even become a good permanent magnet if you follow these directions, because you'll tend to demagnetize it every time you withdraw it in the same direction you inserted it. (I actually tried it with a power supply, a spool of wire, and a couple of screws. Dropping a screw through the coil in one direction 10 times will give it the same amount of magnetism that moving it in and out about 200 times will impart.)
In any case, none of this has anything to do with the battery's voltage except to the extent that it provides more current per turn. A 1.5V 'AA' cell would work fine for creating a compass needle unless you wasted your time with those instructions.
But hey, at least now I know that polar bears are best avoided, and that drinking kerosene will get rid of intestinal parasites...
Lots of knowledge in here, but my favorite piece has always been this treatment for intestinal parasites:
"Tobacco: Eat 1 to 1.5 cigarettes. The nicotine in the cigarette will kill or stun the worms long enough for your system to pass them. If the infestation is severe, repeat the treatment in 24 to 48 hours, but no sooner."
To your actual question yes and no. In the past, yes. Currently no.
I think its more the principle. Nicotine, like caffine was evolved by planets as a pesticide. Animals (like parasites) that don't normally come in contact with it, likely don't have resitances to it.
Highly evolved Apes like us, are simply to big and evolutionarily advanced to be killed by such a small dose of poison.
A cigarette contains up to a gram of tobacco with a nicotine content of 0.5 to 2 percent. A recent estimate of nicotine's human LD50 is in the range of 0.5 to 1 grams. A four cigarette dose would seem unlikely to be lethal.
7.2.1 Human data
7.2.1.1 Adults
The mean lethal dose has been estimated to be 30 to 60 mg (0.5-1.0 mg/kg) (Gosselin, 1988).
7.2.1.2 Children
The lethal dose is considered to be about 10 mg of nicotine (Arena, 1974).
7.2.2 Relevant animal data
Dog: oral LD50: 9.2 mg/kg
mouse: oral LD50: 3.3 mg/kg (RTECS, 1985-86)
rat: oral LD50: 50 mg/kg
0.5-1.0 mg/kg, not 0.5-1.0 grams. Don't go eating cigarettes.
> Highly evolved Apes like us, are simply to big and evolutionarily advanced to be killed by such a small dose of poison.
I don't know about 'advanced'; my understanding was that our protein were simply slightly different, enough to make nicotine not a potent poison, but just another substance you don't want to take too much of.
From a document called "Combat Survival and Evasion":
> Depending upon the supplies, there is a worm remedy: swallow a couple of tablespoons of kerosene or gasoline. Kerosene is more effective but gasoline will do. Either will make you a bit sick, but will make the worms a lot sicker.
It's amazing how the wording is very similar. This document is from sometime in 50's I think, written by a Korean(?) war vet (talks about his time being a POW and "stealing" a wooden house board by board until it was slowly gone altogether. The Chinese guards were confused but weren't amused.)
Oh wow this is a great one. Can't find the link online but some of the older, Vietnam era field manuals concerning radio-wave propagation and the NVIS effect are pretty amazing. Not as usefully today in the age of SATCOM, but a great skill nonetheless.
2003 Iraq’s WMD Programs
+ Saddam failed to cooperate with UN inspectors because he was continuing to develop weapons of mass destruction.
- If Iraqi authorities had destroyed their WMD stocks and abandoned their programs, they might refuse to fully acknowledge this to the UN to maintain Iraq’s regional status, deterrence, and internal regime stability.
I wonder whether the internal decision making at the CIA before the 2003 war was really as simple as that.
I wish I could post my "Engineer Bible" but it's FOUO. It's full of all sorts of fun stuff, including improvised demolitions, various breaching charges, and weirdo WW2-era stuff like the abatis [1].
Totally impractical for anyone here but a very entertaining read. There's a lot of math that goes into explosives if you want to do it right.
PS- to above poster: saw your comments a few weeks back about leaving the Army and entering the tech workforce. I have experience with both. If you have questions or want to chat, my contact info is on chrissnell.com.
You probably can't make much out of the text, but pictures may be worth looking of, even though most of the traps demonstrated are illegal to make during peace. There's also cooking recipes in the bottom of the document, which contain oddities such as soup made from sprigs of a spruce. Though my personal favorite must be the depiction of how to kill a moose with a knife by jumping on its back.
Paddy Ashdown describes in his autobiography how one of the survival instructors on his SBS course introduced himself by place a live frog between two slices of bread and eating it and then saying "Survival is simple, if you can do that you will survive, if you can't do that you won't".
[NB For those outside of the UK or Bosnia: Paddy Ashdown is a former UK politican - now in the House of Lords who had a rather interesting career - Royal Marines, SBS, MI6 then politics becoming leaders of the LibDems, the UK's third party].
I've been told by several different people that in the Finnish service you are trained to battle against a nuke by first using your 'nuclear cloak' to wait for the fallout. After that, you are told to take a pruce branch and use it to clean others' cloaks from the fallout. Then you keep on fighting.
It's also interesting legally: most works of the federal government are born into the public domain. So how is the Army keeping copyright, or are they just mistaken?
An uncle gave me an early 90's version of this manual as a gift when I was in my teens. This manual, along with "The American Boy's Handy Book" resulted in days and days of outdoor activity and a plethora of failed boats/rafts/cabins/snares/spearfishing/etc... There are some awesome instructions in here and the print copy I have has an entire color photo plant identification guide in the back.
My only word of warning would be to make sure the kids you expose to this are responsible enough for the knowledge. There are some last resort things like "how to poison an entire stream of fish by grinding up wild plants".
> Make fish poison by immersing walnut hulls in a small area of quiet water. This poison
makes it impossible for the fish to breathe but doesn't adversely affect their edibility.
It's a way to catch a good amount of fish, quickly, without any specialized gear(nets, etc..). It also doesn't require you to sit there, in the open with a fishing pole. Drop the poison, hide. Run back and collect.
They're very edible after being poisoned. The amount of "poison" it takes to kill(really stun) a fish isn't much. No where near the amount needed to harm a human.
It is not a thing. This is crack-pottery at an insane level. From the intro: "We expect about 90 degree shift of the crust as planet-X passes earth's orbit on its way through our solar system. "
Yes, geomagnetic pole shifting is not the apocalypse, and people who think so are either stupid or crackpots (or both), on the other hand that website does indeed contain a collection of marvellous, marvellous useful documents.
To be pedantic, the survival for magnetic poles shifting is "go about life as normal". The magnetic poles are constantly shifting, just not very fast (~50km/year or so). Reversal would be a bit more dramatic, though...
Motion of the poles has sped up quite dramatically in the past century. That 50 km/year is up from almost zero in the late 1800's and 15 km/year in the early 1900's.
So it isn't entirely out there to worry a bit out reversal. Current thinking is that the Earth's magnetic field becomes multi-polar during reversals, but field strength won't dramatically diminish. So if it does happen, it'll complicate some things, and no doubt result in some economic activity, but won't be the end of the world.
The Earth's magnetic field and poles do change slightly, but it's not the end of the world as those guys would suggest. It's quite interesting really purely from a science and navigation point of view.
I think they are actually referring to geomagnetic reversal, believed by some to be a likely cataclysmic event, in which the poles could reverse entirely and it is supposed that the protective field would have a dramatic reduction in power for enough time to cause serious problems.
This site is literally talking about the entire planet being forced to rotate 90 degrees due to a rogue planet passing nearby. This sudden rotation would supposedly cause the crust of the planet itself to slip and rotate due to inertia.
Well, we see evidence for magnetic reversal in the geological record. It happened before, and a lot. Also, the strength has gone down to about 5% before. This much I'd take as fact.
What is not clear is the effect this has on the biosphere. Calculations have been made for different magnetic field strenghts during the reversal and it seems that radiation can go up. By how much and how much of a problem that would be.. well. Speculations plus calculations.
The effect on the biosphere likely isn't vast. We can't see much effect in the fossil record and reversals have happened a lot.
Far more interesting--as in the case of climate change--is the effect on the economy, which is much more finely tuned and sensitive to change than the biosphere.
The hypothetical timescale of 1000-10000 years is based mostly on the low resolution of the data and the seeming implausibility of much more rapid mechanisms, but as the Wikipedia article suggests there are data that point to much higher rates.
Furthermore, the current theory is most consistent with a multi-polar field during the reversal, which would make magnetic compasses awkward, although probably not unusable. I used to sail in an area that had a large local magnetic anomaly (22 degrees over the course of a few nautical miles) and compasses weren't completely useless, just a tag tedious to use.
So if a magnetic reversal is about to occur there is likely to be a market for a "smart compass" or "compass as a service" that updates daily to your local conditions. Never a wind so ill it doesn't blow somebody good.
Just for clarity, they know the poles change slightly, the "end-of-the-world" view is based on the theory that once they shift a certain distance, there is a pole swap... not a shift, that causes all kinds of havoc on the ecosystem. I have never seen any good papers on the subject though, so am inclined to agree with your skepticism.
i think bears have got nothing on people surviving through lean agile scrum process innovatively implemented at a BigCo in a communication and collaboration fostering open floor office.
I think the following two paragraphs are very applicable to founders:
It takes much more than the knowledge and skills to build shelters, get food, make fires,
and travel without the aid of standard navigational devices to live successfully through a
survival situation. Some people with little or no survival training have managed to survive
life-threatening circumstances. Some people with survival training have not used their
skills and died. A key ingredient in any survival situation is the mental attitude of the
individual(s) involved. Having survival skills is important; having the will to survive is
essential. Without a desk to survive, acquired skills serve little purpose and invaluable
knowledge goes to waste.
There is a psychology to survival. The soldier in a survival environment faces many
stresses that ultimately impact on his mind. These stresses can produce thoughts and
emotions that, if poorly understood, can transform a confident, well-trained soldier into an
indecisive, ineffective individual with questionable ability to survive. Thus, every soldier
must be aware of and be able to recognize those stresses commonly associated with
survival. Additionally, it is imperative that soldiers be aware of their reactions to the wide
variety of stresses associated with survival.
If anyone here is interested in the topic I can really recommend the survival courses run by Ray Mears company called Woodlore. They are brilliant. The guys there are so good it becomes less about survival and more about living!
This used to be published as "Survival, Evasion, and Escape" with the same field manual number. I have an old printed copy dated 1969 which includes the missing Evasion and Escape sections.
That sounds suspiciously similar to the SERE course the military does: "Survival, Evasion, Resistance, and Escape". "Resistance" entails resisting torture without divulging secrets to the enemy; in SERE training they will actually put you into stress positions and waterboard you, which is where they got the idea to do that kind of thing to prisoners.
Oh, I know much of it like the back of my hand, and have spent plenty of time doing outdoorsy stuff, and have found myself in a few genuine survival situations, and I'm here to spout crap opinions on the web still, so...!
It's mostly handy for "was it the one with the serrated leaves, or the one with the smooth leaves which is toxic?".
In any case, none of this has anything to do with the battery's voltage except to the extent that it provides more current per turn. A 1.5V 'AA' cell would work fine for creating a compass needle unless you wasted your time with those instructions.
But hey, at least now I know that polar bears are best avoided, and that drinking kerosene will get rid of intestinal parasites...