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Post by ironhold on Jan 17, 2019 4:47:38 GMT
Battery Fire - once again, I register how uneasy I am with minors being brought in to do experiments that involve fire and explosions. That being said, I'm not entirely satisfied with the full-scale experiment and Adam simply lobbing batteries into the bin like that.
Arrow Through Axes - this myth reminded me of a particular movie-related company known as, IIRC, The Shield Group or something to that effect. The logo animation that plays at the start of movies they were involved in has an arrow going through the axes themselves. That is, there's a hollow area in the ax heads themselves through which the arrow is shot. Perhaps a revisit?
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Post by mrfatso on Jan 17, 2019 5:07:59 GMT
I know the movie production company you mean, but I have not seen any Mythbusters Jr.
I think there is a certain axe design from Greek antiquity that had a blade with holes in it, either to save weight or reduce the amount of metal which was quite precious in the Bronze Age used to make it.
As the original myth is from the Odyessy theta might be relavent.
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Post by ironhold on Jan 17, 2019 5:35:01 GMT
Yeah; the holes would be bigger, but they'd be an irregular shape.
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Post by GTCGreg on Jan 18, 2019 4:42:47 GMT
The high speed videos showed that all arrows oscillated along the flight axis of the arrow. Some arrow/bow combinations produced less and some more, but they all oscillated. The trick is that if the amplitude of that oscillatory deflection is greater than the diameter of the rings, the arrow will eventually hit one of the rings and be deflected. The cross bow had the lowest oscillation but they decided to go with the compound bow because they could get better repeatability at lining it up. If properly aligned with the target, the cross bow could have passed through smaller diameter rings.
I found the segment on the arrows more interesting and educational than the battery segment. Everyone, well just about everyone, already knows that Li-Ion batteries will catch fire if smashed or exposed to excess heat (just ask Tesla.) So they went through a whole lot of trouble to demonstrate a known fact.
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Post by the light works on Jan 19, 2019 23:22:27 GMT
"straight as an arrow" not necessarily. it is commonly believes that it is a malapropism from "straight and narrow." it is also quite possible it refers to the fact that in order to fly straight, an arrow has to BE straight.
battery crushing - first, I was distracted, did they mention a short can cause a catastrophic overheat?
anecdotally, I was talking to another construction worker who said he once accidentally caught a toolbag full of screws on fire with a Makita "stick" battery. for a worst case short, I would have siggested doing a "redneck handwarmer" I.E. "plug" two 9V batteries together.
also, a third interpretation of the hole in the axe heads - the one the handle fits through.
as for the actual feat - I think the fact they were firing from so close actually handicapped them. in theory, the longer the arrow flies, the less flex it will have.
a sidenote - if I had been the FD invited, I would have had at least a telesquirt, just in case.
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Post by GTCGreg on Jan 20, 2019 0:29:51 GMT
a sidenote - if I had been the FD invited, I would have had at least a telesquirt, just in case. I think the FD was there just for show. You could have peed on that fire and put it out. |
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Post by ironhold on Jan 20, 2019 0:48:23 GMT
a sidenote - if I had been the FD invited, I would have had at least a telesquirt, just in case. I think the FD was there just for show. You could have peed on that fire and put it out. Probably a mix of insurance requirements and local ordinances. |
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Post by GTCGreg on Jan 20, 2019 1:56:55 GMT
I think the FD was there just for show. You could have peed on that fire and put it out. Probably a mix of insurance requirements and local ordinances. And showmanship. What would you rather look at. A garbage truck half full of used baby diapers and rotting food, or a fire truck? I'd opt for the fire truck. In fact, I rather like fire trucks. Always have. And lucky TLW gets to play on them all the time. In fact, they actually pay him to play on them. How good is that? |
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Post by the light works on Jan 20, 2019 12:27:57 GMT
Probably a mix of insurance requirements and local ordinances. And showmanship. What would you rather look at. A garbage truck half full of used baby diapers and rotting food, or a fire truck? I'd opt for the fire truck. In fact, I rather like fire trucks. Always have. And lucky TLW gets to play on them all the time. In fact, they actually pay him to play on them. How good is that? "pay" is a relative term. but they do pay FOR my toys. but yes, their garbage sample did help control the fire, and the design of the truck and the test made it easy to eject the burning trash if things threatened to get out of control. I still would have wanted to have a telesquirt there with the boom deployed, just in case I needed to squirt water into the top of the truck. |
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Post by GTCGreg on Jan 20, 2019 13:52:43 GMT
And showmanship. What would you rather look at. A garbage truck half full of used baby diapers and rotting food, or a fire truck? I'd opt for the fire truck. In fact, I rather like fire trucks. Always have. And lucky TLW gets to play on them all the time. In fact, they actually pay him to play on them. How good is that? "pay" is a relative term. but they do pay FOR my toys. but yes, their garbage sample did help control the fire, and the design of the truck and the test made it easy to eject the burning trash if things threatened to get out of control. I still would have wanted to have a telesquirt there with the boom deployed, just in case I needed to squirt water into the top of the truck. Still, overall I would give the arrow myth a B+ and the battery myth a C-. |
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Post by the light works on Jan 20, 2019 15:35:35 GMT
"pay" is a relative term. but they do pay FOR my toys. but yes, their garbage sample did help control the fire, and the design of the truck and the test made it easy to eject the burning trash if things threatened to get out of control. I still would have wanted to have a telesquirt there with the boom deployed, just in case I needed to squirt water into the top of the truck. Still, overall I would give the arrow myth a B+ and the battery myth a C-. both tests made assumptions. |
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Post by GTCGreg on Jan 20, 2019 15:54:12 GMT
Still, overall I would give the arrow myth a B+ and the battery myth a C-. both tests made assumptions. I wonder just how common trash truck fires are (you may know that). How often do you have to respond to one on fire? One would think that with picking up all kinds of hazardous trash such as batteries and propane lighters and flammable paint and such, and then compacting it with other flammable materials, fires would be fairly common. What's SOP if they do get a fire? Do the trucks have some sort of fire suppression system built in? Do they just dump the load in the middle of the street? I've never seen a flaming pile of trash in the middle of the street so I guess it's not all that common. Of course, I've never seen a trash truck on fire either. |
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Post by the light works on Jan 20, 2019 16:08:33 GMT
both tests made assumptions. I wonder just how common trash truck fires are (you may know that). How often do you have to respond to one on fire? One would think that with picking up all kinds of hazardous trash such as batteries and propane lighters and flammable paint and such, and then compacting it with other flammable materials, fires would be fairly common. What's SOP if they do get a fire? Do the trucks have some sort of fire suppression system built in? Do they just dump the load in the middle of the street? I've never seen a flaming pile of trash in the middle of the street so I guess it's not all that common. Of course, I've never seen a trash truck on fire either. one call that I remember in my area. trash cans/dumpster fires are more common, and the most common cause is smoldering ashtrays or fireplace/barbecue ashes. |
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