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Movies => Bad Movies => Topic started by: BTM on February 13, 2008, 12:43:11 AM



Title: Some random questions on stuff I've seen on tv.
Post by: BTM on February 13, 2008, 12:43:11 AM
Sometimes I watch movies and stuff, and I think, "Huh... could that REALLY happen?" or "Wait, why are they doing that?"  or even, "Does that work like that in real life?"

Sadly, most of these questions tend to revolve around weapons, weird situations, and crazy, even illegal activities.  So, where I could I ask them and not get a lot of crazy looks (or worse)? 

So, then I came up with the solution: HERE, on this board with all the other crazy people.  :)

Question 1:

Okay, ever seen those movies where you have bad guys (usually the mob) counterfeiting money?  One thing I see them do is take the newly printed bills and throw them into a clothes driver (sometimes with a bunch of poker chips.)  I believe they did that in Lethal Weapon 4, among other films. 

So, what's the deal with that?  I mean, is that to give the money a more realistic "used" look, so it isn't too brand new looking? 

Question 2:

If I were ever in a John Woo-like Mexican standoff (ie, me and bad guy standing just a few feet away, each with a gun pointed at the other person) wouldn't it all just be a matter oh who fires first?  Or could the second probably get off a shot even after the first just on pure trigger reflex?

Question 3:

Remember in the oriiginal Die Hard, there's a scene where John McClane is on a high floor and the terrorists down near the first are firing a rocket launcher at the SWAT tank?  John gets p**sed because Hans calls for another attack, so he grabs some plastic explosive (might have been C4, not sure), and starting plugging in detonators into it.  He plugs in two and says, "Ah, f**k it." and then plugs in the rest that he has on him.

Okay, I know plastique (sp?) needs an electrical charge to explode, but I'm assuming (correct me if I'm wrong) that hooking up extra detonators isn't going to add to the explosion, any more than say, lighting TWO fuses on a stick of dynamite.

Question 4:

Can water really slow down bullets enough that you wont' get killed?  You know, you see this a lot in films, guy good jumps into the water, bad guy(s) pull out guns, fire into the water, good guy isn't harmed.  I think they did a Mythbuster's ep about this, but I didn't see it.

And yes, I know the type gun of would probably make a difference in the experiment, but still.

Anyway, that's all I can think of for now. 


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Derf on February 13, 2008, 12:59:33 AM
Sometimes I watch movies and stuff, and I think, "Huh... could that REALLY happen?" or "Wait, why are they doing that?"  or even, "Does that work like that in real life?"

[....]

Question 4:

Can water really slow down bullets enough that you wont' get killed?  You know, you see this a lot in films, guy good jumps into the water, bad guy(s) pull out guns, fire into the water, good guy isn't harmed.  I think they did a Mythbuster's ep about this, but I didn't see it.

And yes, I know the type gun of would probably make a difference in the experiment, but still.

Anyway, that's all I can think of for now. 

If I recall that episode correctly, they found that weapons that fired at a high velocity (faster out of the barrel) were most affected by water (i.e., you were safer underwater as the bullets didn't penetrate very far. With slower muzzle velocity, bullets penetrated deeper. So, if someone is firing a musket at you when you are in the water, you are possibly in trouble.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: CheezeFlixz on February 13, 2008, 02:25:15 AM
Question 1 - Yes

Question 2 - Who fires first and who ducks second.

Question 3 -- C4 and the like need a concussion to detonate. If you was to roll C4 into a little ball and shot it with a sling shot it would explode upon contact. The detonators only provide the concussion blast to detonate it. The electrical is only needed for the detonators.

Question 4 - Water will also deflect bullets and alter it's trajectory in addition to slowing it down ... after all water is a tad more dense than air.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: ulthar on February 13, 2008, 07:55:47 AM

Question 1 - Yes


Isn't there a little more to it than simply trying to make the money look 'less new'?  Real money has fiber threads 'woven' into the paper.  Some counterfeiters used to (it's not really all that effective) wash the money with old rags to 'embed' the paper with lint to reproduce this.

It's better to have the threads in the paper before it's printed.

Quote

Question 3 -- C4 and the like need a concussion to detonate. If you was to roll C4 into a little ball and shot it with a sling shot it would explode upon contact. The detonators only provide the concussion blast to detonate it. The electrical is only needed for the detonators.


Are you sure about that slingshot part?  There's a BIG difference between the shock generated by a cap (at least tens of kilobar moving at around 6000 meters per second) and a ball from a slingshot.

Pulling out my trusty copy of Mader's Numerical Modeling of Explosives and Propellants, in Chapter 4 we find a section titled "Projectile Initiation of Explosives."  The key parameter found in projectile initiation is V^2*d, where V is the velocity of the projectile and d is it's diameter.  If the V^2*d value for a projectile is smaller than the high explosives critial value, no detonation will occur.

I don't have numerical data for C4, but I do have for a 60-40 mix of RDX (the hi-ex component of C4) and TNT.  The critical value for this explosive is V^2*d = 5.8 mm^3/us^2.  This translates to 761 m/s for a 1 cm projectile hitting the surface of the explosive, or about 2200 fps.  For other hi-ex mixtures, such as Composition B3, the critical values are even higher.

You getting 2200 fps out of your slingshot?

Now, if you have eyeballs-on experience to the contrary, I'd love to hear about it - computational modeling of explosives, detonation initiation and the deflagration-detonation transfer is the kind of research that I do, so your observations would be relevant.

In practice, the real reason more than one detonator is used is reliability.  You also get some charge directionality from where the initiator is placed, so sometimes you can "focus" the blast a little bit with detonator placement.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: CheezeFlixz on February 13, 2008, 08:51:51 AM

Question 1 - Yes


Isn't there a little more to it than simply trying to make the money look 'less new'?  Real money has fiber threads 'woven' into the paper.  Some counterfeiters used to (it's not really all that effective) wash the money with old rags to 'embed' the paper with lint to reproduce this.

It's better to have the threads in the paper before it's printed.

There is always an easier way, but at 1:25 AM it was the best answer you could get. I think the main reason for beating up the money is to distress it and to give it that used look. Getting your hands on REAL cotton fiber paper that money is printed on is nearly impossible. Only one company makes it, and only one government buys it and it's illegal to sale to anyone else.

Question 3 -- C4 and the like need a concussion to detonate. If you was to roll C4 into a little ball and shot it with a sling shot it would explode upon contact. The detonators only provide the concussion blast to detonate it. The electrical is only needed for the detonators.


Are you sure about that slingshot part?  There's a BIG difference between the shock generated by a cap (at least tens of kilobar moving at around 6000 meters per second) and a ball from a slingshot.

Pulling out my trusty copy of Mader's Numerical Modeling of Explosives and Propellants, in Chapter 4 we find a section titled "Projectile Initiation of Explosives."  The key parameter found in projectile initiation is V^2*d, where V is the velocity of the projectile and d is it's diameter.  If the V^2*d value for a projectile is smaller than the high explosives critial value, no detonation will occur.

I don't have numerical data for C4, but I do have for a 60-40 mix of RDX (the hi-ex component of C4) and TNT.  The critical value for this explosive is V^2*d = 5.8 mm^3/us^2.  This translates to 761 m/s for a 1 cm projectile hitting the surface of the explosive, or about 2200 fps.  For other hi-ex mixtures, such as Composition B3, the critical values are even higher.

You getting 2200 fps out of your slingshot?

Now, if you have eyeballs-on experience to the contrary, I'd love to hear about it - computational modeling of explosives, detonation initiation and the deflagration-detonation transfer is the kind of research that I do, so your observations would be relevant.

In practice, the real reason more than one detonator is used is reliability.  You also get some charge directionality from where the initiator is placed, so sometimes you can "focus" the blast a little bit with detonator placement.

Yes when I was in the military we use to take small balls of C4 and other same type of explosive and blow them up in this method for craps and giggles in Lebanon ... now disclaimer did it work every time? NO, only on occasion did it work. More often than not you'd just end up with a flattened dough ball of C4. It was not a controlled environment and using the same size ball hitting the same angle each time, about the only constant in was we'd fire them at concrete/brick walls from elevation down as not to get hit with debris on the occasion it did work.
This was in early 1980's (ca 82-85) so was the manufacturing process different then, was the chemical make up different then, was it old left over Viet Nam explosives, was it near the end of it's shelf life and unstable, I don't know. I was a 20's year old kid having fun, trying to stay alive in a dangerous place.
I can say, throwing it never worked, which we heard it would this prompting this "experiment". So figuring throwing wouldn't work we'd need a something faster, and being some 20+ years down the road was the success rate 1% or 50% I don't remember, but I'd say it would be closer to 1% or less.
Sometimes we had to much time on our hands while on watch.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: ulthar on February 13, 2008, 09:03:54 AM
Okay...air bubbles or grit in the mix will drastically lower the critical value.  So I suppose especially if this was old stuff, 1% or so detonation success rate it is not undreasonable.  That it CAN work reads a little differently to me than it DOES work.

Cool.  I love experimental science.   :cheers:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Jack on February 13, 2008, 09:11:37 AM
As far as bullets travelling through water, I saw that Mythbusters episode and if memory serves, a 9 mm handgun bullet would travel about nine feet through water and still be fairly deadly.  As they increased the velocity of the firearm, the bullets became less and less effective.  The friction of the water would tear the bullet apart before it travelled very far.  At the end they fired a 50 cal rifle into a swimming pool, and despite the enormous splash, the bullet didn't even hit a target three feet under water.  I think that was actually an armor piercing round, but I can't say for sure. 


Title: Re: Some random questions on stuff I've seen on tv.
Post by: CheezeFlixz on February 13, 2008, 09:21:46 AM
Okay...air bubbles or grit in the mix will drastically lower the critical value.  So I suppose especially if this was old stuff, 1% or so detonation success rate it is not undreasonable.  That it CAN work reads a little differently to me than it DOES work.

Cool.  I love experimental science.   :cheers:

It is by luck only that I am still alive and for the more part unscarred. We'll make Napalm-like stuff from diesel and petroleum jelly. There is and I have somewhere a FMF (Fleet Marine Force) Manual that is nothing but how to make booby traps, bombs, and various other things. I do not know if it is still in government publication or not, I have boxes of old FMF and various other military manuals in storage. Maybe I'll see of I can find it one day. 


Title: Re: Some random questions on stuff I've seen on tv.
Post by: ulthar on February 13, 2008, 10:06:34 AM

There is and I have somewhere a FMF (Fleet Marine Force) Manual that is nothing but how to make booby traps, bombs, and various other things. I do not know if it is still in government publication or not, I have boxes of old FMF and various other military manuals in storage.


Dunno about the FMF manual, but the Army version of that is TM 31-210 "Improvised Munitions Handbook."  There's another one on incendiary devices, too, but I don't recall the TM number.



Title: Re: Some random questions on stuff I've seen on tv.
Post by: CheezeFlixz on February 13, 2008, 10:26:05 AM
Dunno about the FMF manual, but the Army version of that is TM 31-210 "Improvised Munitions Handbook."  There's another one on incendiary devices, too, but I don't recall the TM number.


That might be it or something like it, many Marine manuals were TM (Training Manual's) too, only branch specific manuals were tagged FMF or something like that, I haven't seen them in years. There was another called I think "Lessons Learned in Viet Nam" which also had dangerous ideas in them.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: zombie no.one on February 13, 2008, 11:43:28 AM
the ghost of WyreWizard looms over this thread...


Title: Re: Some random questions on stuff I've seen on tv.
Post by: BTM on February 13, 2008, 02:32:29 PM
I have boxes of old FMF and various other military manuals in storage. Maybe I'll see of I can find it one day. 

You could probably make a killing off some of that stuff on eBay.  (Assuming of course, they'd let you sell it, they might be iffy on "making bombs" books.)

 :smile:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: BTM on February 13, 2008, 02:34:44 PM
Yes when I was in the military we use to take small balls of C4 and other same type of explosive and blow them up in this method for craps and giggles in Lebanon

To quote the goblins from Warcraft Two, "Explosions are fun!"


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 13, 2008, 05:42:13 PM
I have boxes of old FMF and various other military manuals in storage. Maybe I'll see of I can find it one day. 

You could probably make a killing off some of that stuff on eBay.  (Assuming of course, they'd let you sell it, they might be iffy on "making bombs" books.)

 :smile:

Doesn't your Constitution guarantee the right to free speech?  Aren't printing materials covered by that?

I could be wrong. I'm just going by what I've seen on Law and Order.    :teddyr:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: CheezeFlixz on February 13, 2008, 06:01:32 PM
Doesn't your Constitution guarantee the right to free speech?  Aren't printing materials covered by that?

I could be wrong. I'm just going by what I've seen on Law and Order.    :teddyr:

Only the government can not restrict free speech, provided it falls within time place and manner. Meaning you yell "FIRE" in a crowded theater. BUT reseller, private companies can restrict speech and refuse to sale anything they want. Mainly if they think it will open them up to liabilities. i.e. you bought a bomb making book on ebay, you blew something up, the victim sues you and ebay. Doesn't mean they'll win, it's just the cost of the liability. 


Title: Re: Some random questions on stuff I've seen on tv.
Post by: BTM on February 14, 2008, 04:15:38 PM
Doesn't your Constitution guarantee the right to free speech?  Aren't printing materials covered by that?

I could be wrong. I'm just going by what I've seen on Law and Order.    :teddyr:

Dunno, but as a private company, I think eBay can make it's own rules about what people can and can't sell on there.  I DO know, for instance, you can not sell firearms on eBay, and I think they also banned Nazi paraphernalia.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: 316zombie on February 14, 2008, 04:27:43 PM
yup,the bomb books are off limits,due to a past experience in court from a school that was lucky not to get blown up,seems the kid who made the bomb didn't read all the ingredients and the bomb didn't blow,but ebay and the seller still got sued.they won,not sure why,though!


Title: Re: Some random questions on stuff I've seen on tv.
Post by: peter johnson on February 14, 2008, 06:48:40 PM
Once upon a time, you could buy things like "The Anarchists Cookbook" in just about any bookstore you chose -- This book contained detailed recipies for a variety of mayhem, including a wide variety of hallucinogens and explosives to be made from household chemicals.
You could also walk into any hardware store and buy enough dynamite to level a city block.
Everyone brought their guns to school (Rural Virginia, Lancaster County, circa 1969-1973), especially if you just got a new one.  Strangely, nobody was shot, nobody was killed.
I have nothing glib to say -- just that it's a sad sign of the times that all our accesses and choices get narrower and narrower based on the actions of a few --
peter johnson/denny crane


Title: Re: Some random questions on stuff I've seen on tv.
Post by: CheezeFlixz on February 14, 2008, 06:52:24 PM
Once upon a time, you could buy things like "The Anarchists Cookbook" in just about any bookstore you chose -- This book contained detailed recipies for a variety of mayhem, including a wide variety of hallucinogens and explosives to be made from household chemicals.
You could also walk into any hardware store and buy enough dynamite to level a city block.
Everyone brought their guns to school (Rural Virginia, Lancaster County, circa 1969-1973), especially if you just got a new one.  Strangely, nobody was shot, nobody was killed.
I have nothing glib to say -- just that it's a sad sign of the times that all our accesses and choices get narrower and narrower based on the actions of a few --
peter johnson/denny crane

I blame George Orwell!

You can still buy explosive here at the farm store, provided they know you and most kids still have gun racks in their truck. Sometimes being in a backwood part of the country id a good thing.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: ulthar on February 14, 2008, 07:51:59 PM

Once upon a time, you could buy things like "The Anarchists Cookbook" in just about any bookstore you chose -- This book contained detailed recipies for a variety of mayhem, including a wide variety of hallucinogens and explosives to be made from household chemicals.


The Anarchist Cookbook is pretty dangerous - but not for reasons that led to its being banned.  A number of the explosive recipes and even drug recipes are wrong enough to possibly get you killed if you follow them.  Whoever wrote those recipes know just enough to sound like they knew what they were doing when they really didn't.

So, I really don't miss that one not being "available" any more.  I'm not advocating banning books, just saying no great loss in this case.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: BTM on February 14, 2008, 08:30:06 PM
yup,the bomb books are off limits,due to a past experience in court from a school that was lucky not to get blown up,seems the kid who made the bomb didn't read all the ingredients and the bomb didn't blow,but ebay and the seller still got sued.they won,not sure why,though!

Because there are too many sleazy lawyers, idiot judges and moron juries that'll award bigass cash settlements to just about anyone, even dumbasses who are hurt front their own stupidity or people who just want make money off someone else who actually earned it.

Which reminds me, I'm working on my "So You Want To Be a Trial Lawyer" humor piece... if anyone's interested I'll email it to them when it's done.  ;)


Title: Re: Some random questions on stuff I've seen on tv.
Post by: BTM on February 14, 2008, 08:34:08 PM

Hey, here's another question, can you REALLY make Napalm with just orange juice concentrate and gasoline (a la Fight Club?)

No, I wouldn't actually TRY IT mind you, but I'm just curious.

Strangely enough, I DO know that, according to an interview, the writer of Fight Club Chuck "Cant spell or pronouce his last name"  actually DID make and test each recipe for all the explosive stuff mentioned in the book.  I also knows that, on publication, a few ingredients were removed to prevent impressionable morons from trying out home versions.  I don't remember the "juice and gasoline napalm" thing from the book though, think maybe that line was added for the film version.

Course, could be, been awhile since I've read the book.

So, I'm ASSUMING it's possible, but would take more than JUST OJ and gas....


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 14, 2008, 09:22:50 PM

Hey, here's another question, can you REALLY make Napalm with just orange juice concentrate and gasoline (a la Fight Club?)

No, I wouldn't actually TRY IT mind you, but I'm just curious.

Strangely enough, I DO know that, according to an interview, the writer of Fight Club Chuck "Cant spell or pronouce his last name"  actually DID make and test each recipe for all the explosive stuff mentioned in the book.  I also knows that, on publication, a few ingredients were removed to prevent impressionable morons from trying out home versions.  I don't remember the "juice and gasoline napalm" thing from the book though, think maybe that line was added for the film version.

Course, could be, been awhile since I've read the book.

So, I'm ASSUMING it's possible, but would take more than JUST OJ and gas....

Years ago I had a boyfriend in the Army.  He told me exactly how to make napalm from the stuff found under your kitchen sink.  I wish I'd paid more attention but at the time I'd only vaguely heard of napalm and certainly didn't know how destructive it could be.

There is an easier way out.  You could always make friends with a University chemistry student.  Those guys should know all the secret tips and tricks to levelling a city block.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: ulthar on February 14, 2008, 10:32:58 PM
"Napalm" in the generic sense is simply a gelled gasoline based incendiary; there are LOTS of ways to make it with readily available materials.

Orange juice?  No. 

Quote

 University chemistry student.  Those guys should know all the secret tips and tricks to levelling a city block.


 :teddyr: :teddyr:

Hey, I resemble that remark!!  (No longer student, but been a prof long enough....)   :lookingup:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: CheezeFlixz on February 14, 2008, 10:46:23 PM
"Napalm" in the generic sense is simply a gelled gasoline based incendiary; there are LOTS of ways to make it with readily available materials.

Orange juice?  No. 

But it does add Vitamin C


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 15, 2008, 12:26:49 AM
"Napalm" in the generic sense is simply a gelled gasoline based incendiary; there are LOTS of ways to make it with readily available materials.

Orange juice?  No. 

Quote

 University chemistry student.  Those guys should know all the secret tips and tricks to levelling a city block.


 :teddyr: :teddyr:

Hey, I resemble that remark!!  (No longer student, but been a prof long enough....)   :lookingup:

You must be great fun at parties!   :teddyr:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: zbranigan on February 16, 2008, 08:55:36 PM
1. used to be a printer :teddyr: its put in the dryer to set the ink, if its stacked, the face can come off onto the reverse(not a good look for money), the poker chips serve as weights in the dryer to dislodge the notes from the exterior of the drum AND give it a used look.

2. depends on how cool you are

3. more detonators = more chance of it going off..................... also in die hard he has no use for the detonators and the terrorists do, so using/destroying them is a good tactic.

4. yes


Title: Re: Some random questions on stuff I've seen on tv.
Post by: BTM on February 17, 2008, 01:20:08 PM
1. used to be a printer :teddyr: its put in the dryer to set the ink, if its stacked, the face can come off onto the reverse(not a good look for money), the poker chips serve as weights in the dryer to dislodge the notes from the exterior of the drum AND give it a used look.

Awesome, thanks!


Title: Re: Some random questions on stuff I've seen on tv.
Post by: 316zombie on February 17, 2008, 02:57:32 PM
when i was in high school,about a thousand years ago,our chem teacher taught us how to use baking soda and a few other things to make a contact explosive paste,we blew up the doorknob and were trapped in the classroom until they removed the entire doorjamb!needless to say,he got fired...he was pretty cool! :bouncegiggle:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Ash on February 17, 2008, 03:27:11 PM
To answer your counterfeiting question, click the link below.
It's quite informative!   :thumbup:

http://money.howstuffworks.com/counterfeit.htm

One of the main reasons it's so hard to get away with counterfeiting is because of the type of paper used.
Rag paper, which is controlled by the U.S. government and not available to the public, is what gives our currency that distinctive feel.  You don't get that with other types of paper.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 17, 2008, 09:01:16 PM
To answer your counterfeiting question, click the link below.
It's quite informative!   :thumbup:

[url]http://money.howstuffworks.com/counterfeit.htm[/url]

One of the main reasons it's so hard to get away with counterfeiting is because of the type of paper used.
Rag paper, which is controlled by the U.S. government and not available to the public, is what gives our currency that distinctive feel.  You don't get that with other types of paper.



Our notes are all plastic and I understand it's pretty much impossible to counterfeit those.  It's a good idea.  Makes them last longer.  But they can tend to stick together if you get brand new ones from the ATMs.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Ash on February 17, 2008, 10:11:30 PM
I have some Aussie money I brought back from Oz.
It was weird the first time I saw it.  It's nothing like U.S. currency.
Your bills are all multi-colored and the larger the denomination, the larger the physical size of the bill.

I found that it was cheaper to convert my US dollars into Aussie dollars before I went and spent a month in Adelaide.

And Australia is a very change-heavy country.
Lots of one dollar, two dollar and 50 cent coins.  (they haven't taken off here in the US like they have there)
I managed to get my hands on almost all of those recent commemorative 50 cent pieces.
(the ones with the special designs on the back)
There was so much change in my pockets the entire time I was there, I needed a belt to keep my shorts up!     :teddyr:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 18, 2008, 12:32:30 AM
I have some Aussie money I brought back from Oz.
It was weird the first time I saw it.  It's nothing like U.S. currency.
Your bills are all multi-colored and the larger the denomination, the larger the physical size of the bill.

I found that it was cheaper to convert my US dollars into Aussie dollars before I went and spent a month in Adelaide.

And Australia is a very change-heavy country.
Lots of one dollar, two dollar and 50 cent coins.  (they haven't taken off here in the US like they have there)
I managed to get my hands on almost all of those recent commemorative 50 cent pieces.
(the ones with the special designs on the back)
There was so much change in my pockets the entire time I was there, I needed a belt to keep my shorts up!     :teddyr:

I hear that.  I love getting $1 and $2 coins.  When you put them in a jar, they look like gold dubloons and you can pretend you'e actually rich!    I love the greenish colour of the $100 notes.  Alas, I never seem to get any of them  *lol*

I had trouble with US currency when I was there.  I really had to look hard at which note I was handing over. 

I'm sorry you had to go to Adelaide.  I hope it won't stop you from visiting our country again in the future :bouncegiggle:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: zbranigan on February 18, 2008, 03:07:46 PM
I had trouble with US currency when I was there.  I really had to look hard at which note I was handing over. 

it must suck for blind people (not you :teddyr:) mistaking a $100 for a $1 because its the same size


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 18, 2008, 07:35:01 PM
I had trouble with US currency when I was there.  I really had to look hard at which note I was handing over. 

it must suck for blind people (not you :teddyr:) mistaking a $100 for a $1 because its the same size

It sure did.  Many times I thought I had more money in my purse than I actually did.  At least at home, I can just look at all the pretty colours and know exactly how much cash I have  *lol*

But I loved the US. If I could get a green card, I absolutely would move there. 


Title: Re: Some random questions on stuff I've seen on tv.
Post by: BixDugan on February 18, 2008, 08:01:06 PM

Question 1 - Yes


Isn't there a little more to it than simply trying to make the money look 'less new'?  Real money has fiber threads 'woven' into the paper.  Some counterfeiters used to (it's not really all that effective) wash the money with old rags to 'embed' the paper with lint to reproduce this.

It's better to have the threads in the paper before it's printed.

Quote

Question 3 -- C4 and the like need a concussion to detonate. If you was to roll C4 into a little ball and shot it with a sling shot it would explode upon contact. The detonators only provide the concussion blast to detonate it. The electrical is only needed for the detonators.


Are you sure about that slingshot part?  There's a BIG difference between the shock generated by a cap (at least tens of kilobar moving at around 6000 meters per second) and a ball from a slingshot.

Pulling out my trusty copy of Mader's Numerical Modeling of Explosives and Propellants, in Chapter 4 we find a section titled "Projectile Initiation of Explosives."  The key parameter found in projectile initiation is V^2*d, where V is the velocity of the projectile and d is it's diameter.  If the V^2*d value for a projectile is smaller than the high explosives critial value, no detonation will occur.

I don't have numerical data for C4, but I do have for a 60-40 mix of RDX (the hi-ex component of C4) and TNT.  The critical value for this explosive is V^2*d = 5.8 mm^3/us^2.  This translates to 761 m/s for a 1 cm projectile hitting the surface of the explosive, or about 2200 fps.  For other hi-ex mixtures, such as Composition B3, the critical values are even higher.

You getting 2200 fps out of your slingshot?

Now, if you have eyeballs-on experience to the contrary, I'd love to hear about it - computational modeling of explosives, detonation initiation and the deflagration-detonation transfer is the kind of research that I do, so your observations would be relevant.

In practice, the real reason more than one detonator is used is reliability.  You also get some charge directionality from where the initiator is placed, so sometimes you can "focus" the blast a little bit with detonator placement.

Note to self:
Never mess with Ulthar.


I though you could home brew Napalm with Gasoline and styrofoam.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: ulthar on February 18, 2008, 09:51:23 PM

But I loved the US. If I could get a green card, I absolutely would move there. 


That's funny!  We are talking about moving to Australia for a year.  One of the few jobs Americans can get a temp visa for down there is teaching science, and guess what I do.   :bouncegiggle:

I'd LOVE to visit for a year....though I sometimes wonder about moving to NZ permanently.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 18, 2008, 11:28:49 PM

But I loved the US. If I could get a green card, I absolutely would move there. 


That's funny!  We are talking about moving to Australia for a year.  One of the few jobs Americans can get a temp visa for down there is teaching science, and guess what I do.   :bouncegiggle:

I'd LOVE to visit for a year....though I sometimes wonder about moving to NZ permanently.

NZ is beautiful.  It reminds me of Canada a lot and I loved it there.  Plus if you're used to snowy winters and mild summers, it's a great place.  But things are pretty expensive, that's the only drawback.  And they all have funny accents  *lol*

We'd love to have you in Aus, Ulthar, especially if your job is something interesting and worthwhile like teaching science.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Ash on February 18, 2008, 11:49:27 PM
I'm sorry you had to go to Adelaide.  I hope it won't stop you from visiting our country again in the future :bouncegiggle:

I hear that all the time when I tell people I went there!
What do people have against Adelaide?
I thought it was awesome and had a blast.
I guess it all depends on who you're there with.
Luckily, I was in good company.   :smile:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Justy on February 19, 2008, 03:33:02 PM
As far as bullets travelling through water, I saw that Mythbusters episode and if memory serves, a 9 mm handgun bullet would travel about nine feet through water and still be fairly deadly.  As they increased the velocity of the firearm, the bullets became less and less effective.  The friction of the water would tear the bullet apart before it travelled very far.  At the end they fired a 50 cal rifle into a swimming pool, and despite the enormous splash, the bullet didn't even hit a target three feet under water.  I think that was actually an armor piercing round, but I can't say for sure. 

LoL... This discussion is running parallell to the current book I'm reading The Butlerian Jihad its one of the Dune prequels. In it the scientist Tio Holtzman just created the personal body shields. If you've read the later Dune novels or saw the movies you know the shields that I am talking about. They may not be exactly the same but the first models were just created. Anyways, one of the flaws of the shields is that they are great for stopping high velocity attacks, projectiles, concussion, explosions, etc. The higher the velocity the better they work. However, they are ineffective against slow moving objects. The principle must be the same. I guess as the velocity of the object increases the greater the resistance of the water because the molecules are not being pushed away fast enough. A slow moving object just lazily makes it way through the liquid pushing the molecules away as it encounters them.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: AndyC on February 19, 2008, 07:01:21 PM
I hear that.  I love getting $1 and $2 coins.  When you put them in a jar, they look like gold dubloons and you can pretend you'e actually rich!    I love the greenish colour of the $100 notes.  Alas, I never seem to get any of them  *lol*

I wasn't too sure about $1 and $2 coins when they introduced them in Canada. More bulky change in your pocket.

But I quickly came to love the "Loonie" and "Tooney" because I could have an empty wallet, feel broke, then reach into my pocket full of change and find a few dollars without even having to do much counting. It's nice when you feel like buying a coffee to find more cash than you thought you had on you.

American money - definitely confusing when you're used to differentiating bills by colour.


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 19, 2008, 08:30:02 PM
I'm sorry you had to go to Adelaide.  I hope it won't stop you from visiting our country again in the future :bouncegiggle:

I hear that all the time when I tell people I went there!
What do people have against Adelaide?
I thought it was awesome and had a blast.
I guess it all depends on who you're there with.
Luckily, I was in good company.   :smile:

It's just a joke here.  We always need someone to pick on!  Basically Adelaide is perceived as boring.  We call it the city of churches for obvious reasons.  But anyone who voluntarily lives in Adelaide is seen as slow and dim witted  *lol*

Like people who live in Tasmania are perceived as being inbred because it's mainly forests and mountains and uninhabited places and you can easily get lost.  So there's a lot of "your parents must have been brother and sister" type humour.  It's our version of having rednecks.

It's all just good fun.  I've never been to Tassie or Adelaide, but I'd really like to visit.  I'm sure I'd love it there as well.  Word of advice though, don't visit Adelaide in our summer (Dec - Feb).  You'll be regularly hit with scorching temps.  It's not unheard of for Adelaide to have constant temps in summer between 95F and 113F (35C - 45C).  Even here in Brisbane where it's sub tropical and the summers are hot and humid we say, "wow, that's hot weather!"


Title: Re: Some random questions on stuff I've seen on tv.
Post by: Killer Bees on February 19, 2008, 08:34:35 PM
I hear that.  I love getting $1 and $2 coins.  When you put them in a jar, they look like gold dubloons and you can pretend you'e actually rich!    I love the greenish colour of the $100 notes.  Alas, I never seem to get any of them  *lol*

I wasn't too sure about $1 and $2 coins when they introduced them in Canada. More bulky change in your pocket.

But I quickly came to love the "Loonie" and "Tooney" because I could have an empty wallet, feel broke, then reach into my pocket full of change and find a few dollars without even having to do much counting. It's nice when you feel like buying a coffee to find more cash than you thought you had on you.

American money - definitely confusing when you're used to differentiating bills by colour.

I loved the loonie and the toonie when I was in Canada.  Just the name cracked me up!  And the fact that one of them had a hole in it and was dual coloured.  You gotta love multi coloured holey coins as currency.   :smile:


Title: Re: Some random questions on stuff I've seen on tv.
Post by: AndyC on February 20, 2008, 05:37:33 PM
Two metals in one coin is pretty cool. When they came out, I remember a few people were trying to break the centre loose by alternating heat and cold. That didn't last long. They are quite durable.

The biggest complaint I heard about the toonie was from friends who used to frequent strip bars. Suddenly, the smallest bill you could stuff between a stripper's boobs was a five. That was back when most of my friends got married, and these guys would hoard every $2 bill they got their hands on for bachelor parties.