An Ikea Bowl Has Been Setting Things on Fire
atlasobscura.com
atlasobscura.com
Every once in a while a house fire is started because the sun sat at just the right angle at a certain time of the year, placing the focal point on the curtains. But because the risk is so low (it doesn't happen that frequently) many people are completely unaware of the phenomenon.
EDIT: Found it again https://en.wikipedia.org/wiki/Campbell%E2%80%93Stokes_record...
I keep looking at it, my brain confused why I can't see through what is clearly a transparent object. It doesn't feel like I'm looking through it, though inverted; it feels like I'm seeing a weird depiction of the nature scene around me plastered on its surface.
https://www.treehugger.com/solar-technology/solar-prototype-...
https://cleantechnica.com/2013/12/23/solar-ball-lens-improve...
Not solid glass, though (I don't know what it is, but I imagine there's an upper limit on size of solid glass spheres that can be made)...
You can see the tracks of the days and the cloud cover in those photographs. Note that the multiple year ones have multiple days going over a single track.
Aside from the extreme reciprocity failure in the film, its "only" about three stops from a one day exposure to a one week exposure... and another two stops to a month, and then another three and a half stops to a year.
The correction for a 1200 second (20m) exposure on Kodak black and white film was at 12x (for 14400s, 4h). However, the extrapolation for the curve for Provia 100F put the reciprocity failure for 1200s at 2.35 for a 3000 second exposure.
Looking at the methods and results is interesting, though I've gone nearly full digital now.
Big table-top loupes for fine electronics work are similar fire hazards. Ours now all have shutters and big warnings that the shutter must be closed when not in use.
> This isn't the first time Viñoly's architecture has raised eyebrows as well as temperatures: His Vdara Hotel in Las Vegas has been criticized for directing sunbeams onto the swimming pool deck that are hot enough to melt plastic and singe people's hair. The hotspot became known as the "Vdara death ray."
Based on this I'm inclined to believe Viñoly fits the negative "rockstar architect" stereotype. I mean, making that mistake once is one thing, but then doing it again?
Actually, https://en.wikipedia.org/wiki/Solar_furnace ... The furnace in Odeillo, France can reach up to 3500 °C, and it's cross section is just about 50x50 meters. Of course, your typical skyscraper won't create those temperatures accidentially, but if you have the surface area of a skyscraper side in mirrors and can arrange them like you want... it gets pretty pretty hot.
That's the temperature, about the energy: Steel melts at 1370 °C, specific heat of carbon steel is 490 J/kg K. I can't find the actually melting energy. But this means, roughly, that you need 168.5 kWh to raise a ton of steel to melting temperature. The Wikipedia article says the Odeillo device creates 3200 kW (although that paragraph seems to be cut off)., so in principle it should be possible to melt a car. Scary thing.
Hours later as we were eating lunch the sun struck the mirror at just the right angle, and as we look over at the parking lot there's smoke billowing out of the car. Luckily there was no fire, but there was a line burned across the underside of the dashboard. It looked like someone had taken an acetylene torch to it.
Also, people can't apply what they were supposed to learn in high school physics. It's not only Brazil that has this problem:
Well, it's very rare and therefore you don't think about it.
I make telescope mirrors, so I can't be accused of being unaware of the laws of optics. Yet until now I never thought about crystal balls (heck, even acrylic balls) as a potential fire hazard inside the house.
Approximately spherical transparent objects are common. Approximately cylindrical and spherical reflective surfaces are common. Situations where you can apply high school physics are very, very common. Most of us just don't, because we're not trained to do so. We're trained to do the homework problems and answer the test questions. But don't we learn this stuff so we can use the knowledge in life?
I can't be accused of being unaware of the laws of optics. Yet until now I never thought about crystal balls (heck, even acrylic balls) as a potential fire hazard
So you're over halfway there. Now we collectively have a chance to learn the meta-lesson about applying knowledge.
Also clear water bottles (filled with water). In 1991 there was a brief period where homeowners all over Japan were putting clear PET bottles (PolyEthylene Terephthalate) at the edge of their properties because it was asserted on some talk show that the sparkles would keep animals away. This ended abruptly when a series of fires were started by the bottles.
Supposedly it confuses flies and they'll leave the area alone. I've never seen any evidence of this.
http://www.telegraph.co.uk/news/newstopics/howaboutthat/1029...
Reminds me of https://twitter.com/ThePracticalDev/status/68767208615275315...
Wikipedia: "The device, sometimes called the "Archimedes heat ray", was used to focus sunlight onto approaching ships, causing them to catch fire. "
Here's an interesting write-up about the team of MIT students that worked with them on the second try: http://web.mit.edu/2.009/www/experiments/deathray/10_Mythbus...
As near as I can tell they have put the most effort into duplicating Archimedes Heat Ray. They attempted it three times with large budgets and demonstrated why it was possible, but entirely impractical.
After they showed that just being wet was enough to save the boat (when would a boat ever be wet?!) they then offered a replacement explanation and had an example of a flaming arrow. It took one archer and required a fraction of the cost, could be reliably duplicated thousands of times (in battle) and had better range than a team of guys with mirrors.
Perhaps there were a bunch of soldiers with mirrored shields, and they did shine their shields to "blind" the incoming ships. Then archers shot flaming arrows against the ships...
...and the legend of mirrored shields setting fire to a ship was born?
Getting fire with the spoon (!) in Siberia's (!!) Winter (!!!).
The sun light is not very bright at that time, just for a note. Sun is about couple tens of degrees above horizon and (infrared) light mostly caught by the atmosphere.
It's also on my list of things to bring on a desert island.
Fresnel are convenient as they're available in flexible flat rectangular plastic (e.g. credit-card sized). You lose in image quality so it's not great if you're trying to look at mosses or small critters, but to set stuff on fire it's really great as they're light, easy to pack and can be much larger than glass magnifying lenses (of equivalent or lower convenience).
I also like to scavenge the huge fresnel lens from larger (40+ inch) rear-projection TVs - these are often thrown out by people during our "bulk-trash pickup" days. It only takes a few minutes of work to remove the front screen of the TV (they are designed to be removed). A few more minutes will net you a huge silver first-surface mirror, too.
The fresnel lens from one of these TVs - mounted in a proper frame - can easily melt steel and rock. You have to be very careful when using it (wear proper clothing, plus welding goggles and gloves), and store it properly out of the sun afterward (because it can easily set things randomly on fire you don't want set on fire).
ps: a video that go well with the PrimitiveTechnology channel
http://www.instructables.com/id/Giant-Fresnel-Lens-Deathray-...
A large fresnel lens is my most wished prize right now, I consider looking into manufacturing one.
[1] to recycle glass, metals etc, maybe produce some cute things or just to ease trashing (bins won't contains large empty bottles, but nice pellets)
There's a small caveat: The bottom of the bowl is flattened (so that it doesn't roll around). That's not a big deal though if you use a dipole feed; since the dipol radiates mostly normal to its axis (look up the pattern if it's unclear what I mean) a dipole mounted at the center and perpendicular to that flatted base will actually not "see" much of that flat base and work only against the curved part.
Due to the rather small radius and being a spherical shape the directivity/gain is not that great, compared to a parabolic dish antenna. But it's cheap and works well enough if you have to cover only a couple of km.
However keep in mind that regulations likely limit maximum transmission power to something like 20dB(m) EIRP, so depending on how much directivity gain you get, you'll have to reduce the TX power by that amount to stay legal… or get a license.
So it does not set things on fire.
Maybe change the title to "An IKEA Bowl Has Been Burning Things"
https://www.rei.com/product/100561/gosun-sport-solar-camp-st...
I remember, as part of a wilderness survival challenge, being told to eat some breakfast, then they gave me one match, a juice can, a raw egg, and two uncooked pork sausage links. The "correct" solution was to build a fire, drink the juice, cut the top off the can, grease the inside of the can with cooking sausage, and then fry your egg in the greased can. Alternate solutions turned out to be a whole lot easier--left as an exercise for the reader because many of them are disgusting.
Knowing how to do this was of great comfort to me, because sausages, eggs, and juice cans actually grow on trees in the woods near me. Along with plastic tarps and alkaline batteries. It felt like the sort of thing that might give kids just enough confidence to wander off alone to die in the actual wilderness, or to miraculously return in five years speaking fluent Wolf, with plenty of helpful suggestions for the next edition of the manual--such as a primer on the intricacies of wolf pack politics.
That manual probably should have just skipped the solar oven and gone straight to starting a fire with the foil. (As though your average Boy Scout doesn't already know too many ways to set something on fire. Have you ever seen someone start a bonfire by shooting an arrow into it? That guy was probably a Boy Scout, and the secret he wouldn't tell you is that the tinder had KMnO4 in it, and the arrow popped a hidden balloon with some glycerol in it. It wasn't actually a ghost.)
I don't know if I would say most, but some may be.
From my experience, hotdogs (and other sausage products) typically contain a ton of what is known as "pink curing salt" (aka "Prague powder"):
https://en.wikipedia.org/wiki/Curing_salt
It's dyed pink to prevent confusion with common table salt (and it isn't the same as the "pink artisan table salts" you sometimes see, either); in fact, the amount used in curing sausage and other cured meats is actually very low in proportion.
Such cures are used for ham and bacon making, too. The actual meat isn't cooked in any manner, but is perfectly safe to eat - though technically raw. In the case of hame and bacon, the meat (after curing) will usually then go thru a secondary smoking process, which also tends to dry out the outer layer of meat, further protecting it from bacterial intrusion.
If it wasn't cooked or smoked, you can't call it by those names.
The most common [pathogenic] contaminant is Listeria. This would be on the surface, so if you want to be strict about food safety, you can just drop your cold hot dogs in boiling water for a few seconds before eating them. But if you're really that concerned about food, why are you eating sausages at all?
For those that don't know, KMnO4 is also known as potassium permanganate:
https://en.wikipedia.org/wiki/Potassium_permanganate
As noted in that wikipedia article, when combined with glycerol or other glycerin containing products (like automotive antifreeze) it can also be used as a fire starter. It can be easily found online or at home improvement stores, as it is sold for water softening and filtration purposes.
Grant Thompson ("King of Random") documents how to make a survival fire starter kit using this knowledge:
https://www.youtube.com/watch?v=ja_6Yin9JuM
In short, keeping a bit of potassium permanganate in your car with you, should you get lost and don't have another source of fire making with you, might be a wise thing (then again, if you know anything about automobiles, there are tons of ways to use parts in them for starting a fire).
Got a bottle of KMnO4 next to my iron filter and at least one jug of glycol antifreeze in the garage.
Guess what I'm doing when I get home :-)
and it worked nicely (to set to fire some wood).
Admittedly the sunshine in Southern Italy where I tested that (or Andalusia, Southern Spain, as in the TV program above) is probably much different from the one in Sweden, but on a good day it is most probably strong enough even in North Europe.
http://www.motherearthnews.com/diy/how-to-build-a-solar-cook...
If you do some research, you'll find a ton more examples. When I was around 11 years old, as part of a "science project" I built a small solar cooker to cook hotdogs with. I built a linear parabolic reflector (so that the focus was a line, instead of a spot), and placed the hotdog on this line using a skewer (a straightened piece of coathanger wire). It worked rather well.
The most efficient solar cookers, though, are solar ovens. As an adult, I've built ones using cardboard and tinfoil and cooked rice, beans, and made cornbread. You usually can't get them above 100 C (because of boiling and the vapor lowering the effective temperature inside), but if you can keep them properly oriented to the sun over hours, and keep the inner temp high enough, the oven can act as a very effective slow cooker for all kinds of food.
The trick with either one (concentrator or oven) is making them portable (easier with a concentrator - but it is possible to do it with an oven, too - if you change the design a bit). Check out some of the DIY plans out there; you'll be surprised at what is possible.
The article claims that he "set a piece of newspaper on fire" using the bowl, but after watching the video I just saw some smoldering paper - no flames. I'm betting the grape stem just smoldered a bit as well.
You have to have very good airflow with dry, fine tinder in order to start a fire with a magnifying glass or parabolic mirror... unless of course you build a lens or mirror of monstrous proportions.
I'd have to agree with you. When I go hiking, I carry around 3 or 4 different kinds of "fire making" things, just in case I need them for any reason. I also practice with them on occasion to know what to do when I really need them.
It isn't easy to start a fire from scratch. It takes a bit of work, a bit of knowledge, and a ton of patience and perseverance. If you don't have any of that, you'll have a hard road ahead of you.
Even using good tinder plus magnesium bar shavings and a flint striker isn't as easy as you'd hope. In fact, it can be very frustrating. But once you get it going, it's very satisfying.
This is why I also carry a Bic lighter, strike-anywhere matches (in a waterproof container), esbit tablets, and a fresnel lens - all as backup fire sources.
For bonus geekiness use some dry-ice to better illuminate the path.
The global, quite conservative, retailer of everyday products has been disrupting the bowl industry for several decades.
For years since disrupt was far from being the buzzword de jure, and was more associated with Klingon Battlecruisers.
http://oxgvt.com/the-ox-all-terrain-vehicle/
I would so love to build and own one - sadly, I don't think I'll ever be able to, because they likely won't be sold to regular consumers here in the US. Even as a flat-pack kit, I think regulators would figure out a way to keep them out of the market due to crash-testing compliance and/or pollution control/EPA issues.
So if I ever wanted to have something like one, I would have to homebrew it myself. I know it is possible to get such a vehicle legally registered, but it probably isn't super-easy, unless I start with a donor vehicle frame.
Edit: mod just changed "this" to "an." Your a/b test is on :)
Or maybe I am just really susceptible to clickbait titles...
Compare "Florida Man Escapes Prison" to "This Florida Man Escaped Prison". You'd scroll past the first, but you might not scroll past the second, because it seems like there must be something particularly interesting about this florida man, so you might as well take a second to click and see the picture.
Or maybe not Buzzfeed, since even the summary will cause brain cancer.
So, the difference between "An IKEA bowl" and "This IKEA bowl" is that "a bowl" is a complete idea. "This bowl" stresses that it's talking about a specific bowl, but leaves out which bowl it is stressing.
Something I like to do when I'm out shopping is to look at products and figure out how to repurpose them into something else; I've often looked at this bowl and said to myself "That would be an almost perfect solar concentrator".
Usually, I'm looking to repurpose things for solar power usage or for robotics; Ikea actually has plenty of products to satisfy both.
Another one thats on the front page - "How to read and understand a scientific paper: a guide for non-scientists" is actually "A serious of unverified tips that might help you become somewhat familiar with a limited subset of scientific papers whose jargon you should already familiar with" Scientific papers are written for other scientists, no "guide" is going to allow a layperson, who is completely unfamilar with the topic, in understanding the paper. If you are not a physicist you simply can't grok the theory of the alternating-gradient synchotron. You might become kinda-sorta-familiar in a wikipedia sense by looking up each term and reading the paper but you're never going to be able to field questions on the topic (usually possible only for someone who understands a topic).