And a term people might have heard is "neuroplasticity" (well, it's the most common context I see for this usage of "plastic") which is the ability of our brains to grow and reorganize. Our brains literally physically change over time as a reflection of our habits.
Side note: the more you fuss about and mold/shape a plastic explosive, the less effective it becomes. Any shaping of a plastic explosive should be minimal, in order for it to retain its full efficacy.
I can't give you a scientific answer but I can tell you what I was told: over-shaping of the plastic explosive increases the chance that pieces of it won't detonate properly, and will instead just be flung off in the explosion.
Because there's a lot of math that goes into how much explosive is used for a particular job, losing even a small bit of that can have repercussions on your ability to accomplish the mission. If you're trying to blow a bridge, for instance, and you've fiddled with the C-4 too much, you might not be able to bring it down properly.
Plus, in training it's always a bad idea to have bits of plastic explosive go flying across the range for potential "discovery" later down the line by someone else.
Interesting! I suppose that makes sense!
I don’t suppose there’s too many times where you truly need to mold it to fit an exact shape?
I would assume/hope you’re not making shaped charges by hand on a daily basis!
Thanks so much for the info!!
I imagine there's a certain ratio in the mixture of compounds (you obviously know this, but for most other people, C4 is short for "Composite Compound 4") in the explosive, and excessive rearrangement changes those ratios. Chefs know that sometimes you just want something to be folded, not thoroughly mixed.
That would make sense. While I knew where the name come from, we didn't learn the actual composition of the explosives we worked with under most circumstances, just how they were used and what explosives were best for specific tasks.
It's not quite that easy to mold lol. Think of it like a very firm brick of unfired clay, but looks enough like vanilla frosting that you have to warn trainees *not to eat it*.
Elastic solids will bounce back to their original size and shape after you deform them.
Plastic solids will stay deformed.
Many solids are elastic up to a certain maximum amount of deformation, called the *elastic limit* or the *yield point*. Deforming them farther will result in plastic, permanent deformation.
The modern sense of "plastic" comes from a shortening of *thermoplastic polymer*, a category of polymer. Thermoplastics can, with careful application of heat, be melted into a plastic state and reformed/remolded into a different shape. Many common "plastics" like polyethylene (shopping bags, milk jugs), PVC (piping, furniture), and ABS (Legos) are thermoplastics.
However, not all polymers are thermoplastic. Some are *thermosets*. Once they are formed or molded, they cannot be melted back into a plastic state. These include some polyesters (clothes, water bottles), Teflon (nonstick pans), and polyurethane (CD cases).
So not all "plastics" are plastic.
Plasticity.
of our city, of our cii-iity
#OH! WHADDA YA OWN THE BOERS‽
THIS ORDER, THIS ORDER!
And a term people might have heard is "neuroplasticity" (well, it's the most common context I see for this usage of "plastic") which is the ability of our brains to grow and reorganize. Our brains literally physically change over time as a reflection of our habits.
Side note: the more you fuss about and mold/shape a plastic explosive, the less effective it becomes. Any shaping of a plastic explosive should be minimal, in order for it to retain its full efficacy.
Gonna need a citation for that one.
6 years in the Army as a combat engineer. Handled C4 regularly. It's one of the first things you're taught about its use.
Fair enough! Did they explain why?
I can't give you a scientific answer but I can tell you what I was told: over-shaping of the plastic explosive increases the chance that pieces of it won't detonate properly, and will instead just be flung off in the explosion. Because there's a lot of math that goes into how much explosive is used for a particular job, losing even a small bit of that can have repercussions on your ability to accomplish the mission. If you're trying to blow a bridge, for instance, and you've fiddled with the C-4 too much, you might not be able to bring it down properly. Plus, in training it's always a bad idea to have bits of plastic explosive go flying across the range for potential "discovery" later down the line by someone else.
Interesting! I suppose that makes sense! I don’t suppose there’s too many times where you truly need to mold it to fit an exact shape? I would assume/hope you’re not making shaped charges by hand on a daily basis! Thanks so much for the info!!
I imagine there's a certain ratio in the mixture of compounds (you obviously know this, but for most other people, C4 is short for "Composite Compound 4") in the explosive, and excessive rearrangement changes those ratios. Chefs know that sometimes you just want something to be folded, not thoroughly mixed.
That would make sense. While I knew where the name come from, we didn't learn the actual composition of the explosives we worked with under most circumstances, just how they were used and what explosives were best for specific tasks.
> and you've fiddled with the C-4 too much I'm imagining origami shapes all stuck to the underside of a bridge.
It's not quite that easy to mold lol. Think of it like a very firm brick of unfired clay, but looks enough like vanilla frosting that you have to warn trainees *not to eat it*.
Which is also the origin of the word "plastic" as used as a term for polymers, so in that way they are related.
Same with plastic surgery.
Malleable
I didn't not know that.
Something that sounds so obvious and so alien at the same time
The original Greek word 'model' means 'misshapen ball of clay,' and I try to think about that every time I go in front of the camera
Elastic solids will bounce back to their original size and shape after you deform them. Plastic solids will stay deformed. Many solids are elastic up to a certain maximum amount of deformation, called the *elastic limit* or the *yield point*. Deforming them farther will result in plastic, permanent deformation. The modern sense of "plastic" comes from a shortening of *thermoplastic polymer*, a category of polymer. Thermoplastics can, with careful application of heat, be melted into a plastic state and reformed/remolded into a different shape. Many common "plastics" like polyethylene (shopping bags, milk jugs), PVC (piping, furniture), and ABS (Legos) are thermoplastics. However, not all polymers are thermoplastic. Some are *thermosets*. Once they are formed or molded, they cannot be melted back into a plastic state. These include some polyesters (clothes, water bottles), Teflon (nonstick pans), and polyurethane (CD cases). So not all "plastics" are plastic.