Do throwing knives really work, and how?
mm
In the movies, and I think on the Ed Sullivan Show, people did
interesting things with "throwing knives".
They grab them by the point, I think, and throw them and they stick
into the target. It's never the case that the handle hits the target
and bounces off. Now on the Ed Sullivan Show, the thrower could stand
exactly where he wanted. Is that the trick, to be the right distance
away?
In the movies they don't seem to do that
Androcles
"mm" <NOPSAM...@bigfoot.com> wrote in message
news:gvful5lpa0qai4il5...@4ax.com...
When the girl is clamped to the wheel and starts rotating, what
you don't see is the paper covering over the holes in the wheel.
Behind the paper is a knife handle on a spring which pops
out through the paper and into view, making it appear as if the
knife has landed an inch from the girl's skin. The "thrower" never
throws a knife at all, instead he drops one the ground from his other
hand as he pretends to throw.Your eye (or the camera) isn't quick
enough to see the knife in flight and there isn't one anyway. Any
assistant can operate the fake knives behind the wheel.
ji...@specsol.spam.sux.com
Knife throwing is a learned talent like juggling.
http://www.knifethrowing.info/ has a tutorial on how to do it as well
as an explaination of the physics.
--
Jim Pennino
Remove .spam.sux to reply.
Darwin123
Professional knife throwers often use a special type of knife
that is mostly edge. They like to use knives that have very little or
no handle.
If you look through some hunter catalogues, you will find
advertisements for throwing knives and even an advertisement for a
throwing hatchet. The principle of these knives is the same. The
handle is reduced as much as possible. The hatchet is double edged and
broad. The idea is to increase the edge area as much as possible.
The throwers on Ed Sullivan probably used these special knives.
Yes, the tricks were real. However, they needed a special knife. They
didn't use a Jim Bowie knife.
I think this shows that no matter how good you are at throwing a
knife, there is always a chance that the handle will hit the target
first. If you accept that the hero is preparing for battle, then it is
reasonable that he carry a knife specially made for throwing. Your
intuition is correct. Handles can get in the way. However, there are
weapons that have been designed for throwing.
The problem is that a blade without a handle is very dangerous to
the user. The user has to be really disciplined to avoid cutting
himself while carrying it or throwing. That being said, there are
blades that have been designed for throwing.
Lets look at our most favorite heroes. I don't think a Bowie knife
is a good idea for throwing. Its good for stabbing and slashing, but
not throwing. Xena has a great knife for throwing. Perfectly circular,
with no handle! I forgot the name of her weapon, but it was actually
used by Islamic soldiers in medieval times. Maybe the name of the
blade is the chakras?
Batman has his batarang, which is sometimes used for cutting.
I suppose that it can be built with all edge, but the comic never says
so. The late Captain America, starting in the 70's, used his shield to
cut through all sorts of things. Like Zena's weapon, it was round. The
shield had a nice handle on the inside, but the handle couldn't get in
the way of the edge. Ninja death stars have a couple of points and no
handle. They were be really good throwing weapons.
The chakras and the death star were probably the best throwing
blades seen on TV or the movies.
Tom Potter
The funniest knife throwing I ever saw was
by Ed Ames on the Johnny Carson Show.
Take a look.
You'll enjoy it.
www.youtube.com/watch?v=gD0DV2vPNEQ
--
Tom Potter
--
http://tdp1001.wiki.zoho.com/
http://tdp1001.wordpress.com/
http://tdp1001.spaces.live.com
http://www.tompotter.us/misc.html
http://webspace.webring.com/people/st/tdp1001
http://notsocrazyideas.blogspot.com
-----------------------------------------------
mm
<xpriv...@mailinator.com> wrote:
>
>"mm" <NOPSAM...@bigfoot.com> wrote in message
>news:gvful5lpa0qai4il5...@4ax.com...
>> Do throwing knives really work, and how?
>>
>> In the movies, and I think on the Ed Sullivan Show, people did
>> interesting things with "throwing knives".
>>
>> They grab them by the point, I think, and throw them and they stick
>> into the target. It's never the case that the handle hits the target
>> and bounces off. Now on the Ed Sullivan Show, the thrower could stand
>> exactly where he wanted. Is that the trick, to be the right distance
>> away?
>>
>> In the movies they don't seem to do that
>
>The funniest knife throwing I ever saw was
>by Ed Ames on the Johnny Carson Show.
>
>Take a look.
>You'll enjoy it.
>
>www.youtube.com/watch?v=gD0DV2vPNEQ
I will look soon, after my back up ends.
Thank you and thanks to all of you.
It's interesting that each answer came at this from a different
direction.
>
>--
>Tom Potter
mm
This is pretty thorough.
And best of all, it turns out I'm right. The thrower has to choose
the distance to stand from the target. It says to start out with 3
meters, where one holds by the handle. If one is 4 meters away, he
should hold it by the blade. I think 5 meters would be the handle
again. All distances are subject to small adjustments as one gets to
know how it does.
Thanks a lot.
Thanks.
>
>
mm
<xpriv...@mailinator.com> wrote:
>
>"mm" <NOPSAM...@bigfoot.com> wrote in message
>news:gvful5lpa0qai4il5...@4ax.com...
>> Do throwing knives really work, and how?
>>
>> In the movies, and I think on the Ed Sullivan Show, people did
>> interesting things with "throwing knives".
>>
>> They grab them by the point, I think, and throw them and they stick
>> into the target. It's never the case that the handle hits the target
>> and bounces off. Now on the Ed Sullivan Show, the thrower could stand
>> exactly where he wanted. Is that the trick, to be the right distance
>> away?
>>
>> In the movies they don't seem to do that
>
>The funniest knife throwing I ever saw was
>by Ed Ames on the Johnny Carson Show.
>
>Take a look.
>You'll enjoy it.
>
>www.youtube.com/watch?v=gD0DV2vPNEQ
Funny.
As chance would have it, I've been watching "Daniel Boone" most
nights on RTV, DC channel 7.3, which stars Ed Ames as Mingo, the
Oxford-educated Indian friend of Daneil Boone.
>
>--
>Tom Potter
Peter Webb
thrown so its spinning very fast. As most of th mass is in the handle, the
blade mostly rotates around the handle. As long as it is spinning fast
enough, it is guaranteed to hit the target with the blade and not the handle
(as a thought experiment, imagine it spinning at 1,000 times a second - the
blade will always hit first).
So as long as you design your knife well enough and can impart enough spin
in principle its quite possible.
"mm" <NOPSAM...@bigfoot.com> wrote in message
news:gvful5lpa0qai4il5...@4ax.com...
Sam Wormley
> Imagine a knife with 90% of its mass concentrated in a small handle, and
> thrown so its spinning very fast. As most of th mass is in the handle,
> the blade mostly rotates around the handle. As long as it is spinning
> fast enough, it is guaranteed to hit the target with the blade and not
> the handle (as a thought experiment, imagine it spinning at 1,000 times
> a second - the blade will always hit first).
>
Bzzzzt - Wrong, no guarantee. Take a physics course.
mm
<webbf...@DIESPAMDIEoptusnet.com.au> wrote:
>Imagine a knife with 90% of its mass concentrated in a small handle, and
>thrown so its spinning very fast. As most of th mass is in the handle, the
>blade mostly rotates around the handle. As long as it is spinning fast
>enough, it is guaranteed to hit the target with the blade and not the handle
>(as a thought experiment, imagine it spinning at 1,000 times a second - the
>blade will always hit first).
But I don't think anyone can get it to spin at 1000 times a second.
Maybe 10 times a second would be a lot.
Anyhow http://www.knifethrowing.info/distances.html says the distance
you stand from the target makes a big difference.
I can't quite remember, but it's slowly coming to me that I tried this
when I was a little boy, with a penknife or something, and didn't get
it to stick at all. There could be a lot of reason for that of
course. For one thing, I think my target was a tree, which is a lot
harder than the targets on the Ed Sullivan show. :)
It's nice to have my questions answered after 50+ years. Thank you
all.
tadchem
>
> In the movies, and I think on the Ed Sullivan Show, people did
> interesting things with "throwing knives".
>
> They grab them by the point, I think, and throw them and they stick
> into the target.
Sometimes the handle is gripped. It is often a matter of personal
preference. Depends on the knife, too.
> It's never the case that the handle hits the target
> and bounces off.
That is the value of "practice".
> Now on the Ed Sullivan Show, the thrower could stand
> exactly where he wanted. Is that the trick, to be the right distance
> away?
No. A practiced thrower can control the rate at which the knife
rotates by subtle adjustment of the grip. He can tell from the heft of
the knife and the distance to the target whether he should make the
knife rotate half a revolution, once, one-an-a-half times, or twice.
More highly skilled throwers can control a 2-1/2 and a 3 spin toss.
It all comes down to making sure the knife is going point-first when
it gets to the target. The rotation (angular momentum) is important
because it adds stability to the trajectory.
> In the movies they don't seem to do that
Knife-throwing in the movies is almost always done with a launcher
that 'shoots' the knife point-first. It is more accurate, less risky,
and probably is easier to find than a skilled human thrower.
Tom Davidson
Richmond, VA
tadchem
> "mm" <NOPSAMmm2...@bigfoot.com> wrote in message
I've seen the act up close. The thrower doesn't drop a knife - you
could hear that. He uses flat knives and fans them at the start in
his off-hand so you can see he has several. He takes one into his
throwing hand and as he goes through the throwing motion he palms it.
Meanwhile an off-stage assistant triggers the 'wooden' target where a
concealed mechanism releases a 'knife' from a spring mounting to jump
into position. When he 'reaches' for the next knife in his off-hand,
he merely readjusts the fan to show one less knife and unpalms the one
he started with.
Continue until the knife supply is depleted...
Tom Davidson
Richmodn, VA
tadchem
> mm <NOPSAMmm2...@bigfoot.com> wrote:
> > Do throwing knives really work, and how?
>
> > In the movies, and I think on the Ed Sullivan Show, people did
> > interesting things with "throwing knives".
>
> > They grab them by the point, I think, and throw them and they stick
> > into the target. It's never the case that the handle hits the target
> > and bounces off. Now on the Ed Sullivan Show, the thrower could stand
> > exactly where he wanted. Is that the trick, to be the right distance
> > away?
>
> > In the movies they don't seem to do that
>
> Knife throwing is a learned talent like juggling.
>
> as an explaination of the physics.
>
> --
> Jim Pennino
>
> Remove .spam.sux to reply.
Nice link. Thanks.
Tom Davidson
Richmond, VA
tadchem
> On Tue, 26 Jan 2010 19:43:39 -0000, j...@specsol.spam.sux.com wrote:
> >mm <NOPSAMmm2...@bigfoot.com> wrote:
> >> Do throwing knives really work, and how?
>
> >> In the movies, and I think on the Ed Sullivan Show, people did
> >> interesting things with "throwing knives".
>
> >> They grab them by the point, I think, and throw them and they stick
> >> into the target. It's never the case that the handle hits the target
> >> and bounces off. Now on the Ed Sullivan Show, the thrower could stand
> >> exactly where he wanted. Is that the trick, to be the right distance
> >> away?
>
> >> In the movies they don't seem to do that
>
> >Knife throwing is a learned talent like juggling.
>
> >as an explaination of the physics.
>
> This is pretty thorough.
>
> And best of all, it turns out I'm right. The thrower has to choose
> the distance to stand from the target. It says to start out with 3
> meters, where one holds by the handle. If one is 4 meters away, he
> should hold it by the blade. I think 5 meters would be the handle
> again. All distances are subject to small adjustments as one gets to
> know how it does.
>
> Thanks a lot.
>
> Thanks.
>
>
>
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
The distance between the target and the number of revolutions depends
also on the rotational moment of the knife.
A skilled thrower can toss anything from a a 2-penny nail to a hay
fork, controlling the rotations so that it is going point first when
it reaches the target.
Tom Davidson
Richmond, VA
tadchem
Xena's blade is called a chakram, similar to the chakkar but intended
to be thrown more than the latter, which was mainly a melee weapon.
The "death star" was the size of a small planet, far too large to be a
"throwing blade."
Read more.
Tom Davidson
Richmond, VA
tadchem
> "mm" <NOPSAMmm2...@bigfoot.com> wrote in message
That wasn't a knife, Potter. It was a small hand axe, sometimes
called a "tomahawk".
The routine also held the record for the longest sustained laugh in
television.
Tom Davidson
Richmond, VA
tadchem
<webbfam...@DIESPAMDIEoptusnet.com.au> wrote:
> Imagine a knife with 90% of its mass concentrated in a small handle, and
> thrown so its spinning very fast. As most of th mass is in the handle, the
> blade mostly rotates around the handle. As long as it is spinning fast
> enough, it is guaranteed to hit the target with the blade and not the handle
> (as a thought experiment, imagine it spinning at 1,000 times a second - the
> blade will always hit first).
>
> So as long as you design your knife well enough and can impart enough spin
> in principle its quite possible.
<snip repost>
Fascinating, but unrealistic. Also naive...
Tom Davidson
Richmond, VA
Androcles
"tadchem" <tad...@comcast.net> wrote in message
news:fde497b7-a1e6-43f8...@r19g2000yqb.googlegroups.com...
Tom Davidson
Richmodn, VA
============================================
Ok... circus rings had sawdust and grass floors when I was a kid.
I always assumed an assistant but it could as easily be Catherine
that triggered each knife in the wheel.
Nowadays kids aren't permitted knives, guns or even firecrackers
in England, only the criminals are allowed to have them, but when
I was kid I used to carry a penknife and would throw that from
the blade.
Darwin123
Ninja use a small blade in the shape of a star. The blade is too
small to ensure fatality. So in a real assassination, it is usually
poisoned.
I first learned about this in the novel, "Shogun" by Clavel.
Since then, I have seen it in many movies and TV shows. It is
sometimes called thje "death star." I don't know what the real name of
this weapon. I also scanned books on the martial arts, and have seen
it mentioned.
My literary background is slightly broader than Star Wars.
Darwin123
> On Wed, 27 Jan 2010 20:56:03 +1100, "Peter Webb"
> >> They grab them by the point, I think, and throw them and they stick
> >> into the target. It's never the case that the handle hits the target
> >> and bounces off. Now on the Ed Sullivan Show, the thrower could stand
> >> exactly where he wanted. Is that the trick, to be the right distance
> >> away?
I thought that it was for real, with the only "trick" being the
design of the knife.
>
> >> In the movies they don't seem to do that
It occurs to me that the knife doesn't have to spin. If the knife
is thrown as a spear, with linear momentum parallel to the blade, the
knife will go straight. It can then hit the target point first. If you
hold the knife by its center of gravity, you will minimize the "spin"
imparted to the knife.
Darts are thrown this way. Darts usually stick to the target
when they hit. If you throw the knife like a dart, it will probably
stick more often.
People in on TV or movies never throw it like that. Even the
professional knife throwers don't throw it like that. I think it is
because the gyroscopic effect gives the trajectory of the knife
greater stability. However, then you have the problem of the handle
hitting the target first.
A friend of mine tried to practice knife throwing for fun. He was
throwing a standard knife, with large handle. At small distances, he
could hit the target by throwing it like a spear, point forward. He
avoided spinning the knife. When he threw it by holding the point, the
handle often hit first.
It is possible that the knife throwing demonstrations that I have
seen were faked in some way. I would be disappointed if I found that
out, but it is always possible. However, I do remember that the
knives were a bit different.
I recommend repeating your childhood experiments with one slight
change. Throw the knife like a spear, point first, avoiding spin. I
bet that though you miss the target more, you will also have the knife
stick in the target more.
J. Clarke
Hence the shuriken. All blades, no handle.
Darwin123
> On Jan 26, 2:47 pm, "Androcles" <Headmas...@Hogwarts.physics_s> wrote:
>
>
>
> > "mm" <NOPSAMmm2...@bigfoot.com> wrote in message
>
> >news:gvful5lpa0qai4il5...@4ax.com...
>
> > > In the movies they don't seem to do that
>
> I've seen the act up close. The thrower doesn't drop a knife - you
> could hear that. He uses flat knives and fans them at the start in
> his off-hand so you can see he has several.
By flat knives, you mean a knife that is all edge.
The act may have been faked, as you say. However, the use of a flat
knife is consistent with the hypothesis that he was actually throwing
the knife.
However, you say you saw the act up close.
Funny the camera and audience don't see the pile of knives he
leaves on the floor. Now matter how slow the eye is, it will see the
knives already dropped to the floor unless the point of view is below
the floor. Anyone whose eyes are lifted above the level of the floor
is going to see the knives he didn't throw pile up.
Are the dropped knives camouflaged against something? Is there a
slot in the floor where he slips the knives?
By any chance, did you see the knives he had dropped to the floor?
You saw it up close. You couldn't miss seeing the knives the
"thrower" dropped to the floor.
Androcles
"Darwin123" <drose...@yahoo.com> wrote in message
news:f8f8a4b4-6d16-4e75...@b2g2000yqi.googlegroups.com...
On Jan 28, 5:29 am, tadchem <tadc...@comcast.net> wrote:
> On Jan 26, 2:47 pm, "Androcles" <Headmas...@Hogwarts.physics_s> wrote:
>
>
>
> > "mm" <NOPSAMmm2...@bigfoot.com> wrote in message
>
> >news:gvful5lpa0qai4il5...@4ax.com...
>
> > > In the movies they don't seem to do that
>
> I've seen the act up close. The thrower doesn't drop a knife - you
> could hear that. He uses flat knives and fans them at the start in
> his off-hand so you can see he has several.
By flat knives, you mean a knife
==========================================
You fuckin' ignorant snipping bastard. Learn to read, shithead.
ji...@specsol.spam.sux.com
> On Jan 28, 5:29 am, tadchem <tadc...@comcast.net> wrote:
>> On Jan 26, 2:47 pm, "Androcles" <Headmas...@Hogwarts.physics_s> wrote:
>>
>>
>>
>> > "mm" <NOPSAMmm2...@bigfoot.com> wrote in message
>>
>> >news:gvful5lpa0qai4il5...@4ax.com...
>>
>
>> > > In the movies they don't seem to do that
>>
>> I've seen the act up close. The thrower doesn't drop a knife - you
>> could hear that. He uses flat knives and fans them at the start in
>> his off-hand so you can see he has several.
> By flat knives, you mean a knife that is all edge.
No, most throwing knives are flat, and flat means flat.
See http://www.knifethrowing.info/silberpfeilnieto.html#nieto
Darwin123
wrote:
> "Darwin123" <drosen0...@yahoo.com> wrote in message
>
> news:f8f8a4b4-6d16-4e75...@b2g2000yqi.googlegroups.com...
> On Jan 28, 5:29 am, tadchem <tadc...@comcast.net> wrote:
>
> > On Jan 26, 2:47 pm, "Androcles" <Headmas...@Hogwarts.physics_s> wrote:
>
> > > "mm" <NOPSAMmm2...@bigfoot.com> wrote in message
>
> > >news:gvful5lpa0qai4il5...@4ax.com...
>
> > > > In the movies they don't seem to do that
>
> > I've seen the act up close. The thrower doesn't drop a knife - you
> > could hear that. He uses flat knives and fans them at the start in
> > his off-hand so you can see he has several.
>
> By flat knives, you mean a knife
so. The handle of a knife usually isn't flat. The knife blade always
has to be flat.
He is obviously differentiating between the "flat" knives he saw
and other knives. What he saw was that the handle was either missing,
or skinnier than the handle of other knives.
What he saw was mostly blade, not handle. Otherwise, he wouldn't
have differentiated.
If I am wrong, he should be able to tell us the difference between
"flat knives" and "kitchen knives."
Darwin123
>
>
>
> > On Jan 26, 2:22 pm, mm <NOPSAMmm2...@bigfoot.com> wrote:
>
> > > Do throwing knives really work, and how?
>
> > blades seen on TV or the movies.
>
> Xena's blade is called a chakram, similar to the chakkar but intended
> to be thrown more than the latter, which was mainly a melee weapon.
>
> The "death star" was the size of a small planet, far too large to be a
> "throwing blade."
>
Androcles
On Jan 28, 12:02 pm, "Androcles" <Headmas...@Hogwarts.physics_s>
wrote:
> "Darwin123" <drosen0...@yahoo.com> wrote in message
>
> news:f8f8a4b4-6d16-4e75...@b2g2000yqi.googlegroups.com...
> On Jan 28, 5:29 am, tadchem <tadc...@comcast.net> wrote:
>
> > On Jan 26, 2:47 pm, "Androcles" <Headmas...@Hogwarts.physics_s> wrote:
>
> > > "mm" <NOPSAMmm2...@bigfoot.com> wrote in message
>
> > >news:gvful5lpa0qai4il5...@4ax.com...
>
> > > > In the movies they don't seem to do that
>
> > I've seen the act up close. The thrower doesn't drop a knife - you
> > could hear that. He uses flat knives and fans them at the start in
> > his off-hand so you can see he has several.
>
> By flat knives, you mean a knife
You are claiming that the word flat is redundant.
I'm claiming you are a worthless shithead.
mm
Who is Catherine?
>Nowadays kids aren't permitted knives, guns or even firecrackers
>in England, only the criminals are allowed to have them, but when
>I was kid I used to carry a penknife and would throw that from
>the blade.
Kids can't have knives because parents don't permit it, or the govt.
stops it?
Timo Nieminen
> Ninja use a small blade in the shape of a star. The blade is too
> small to ensure fatality. So in a real assassination, it is usually
> poisoned.
> I first learned about this in the novel, "Shogun" by Clavel.
> Since then, I have seen it in many movies and TV shows. It is
> sometimes called thje "death star." I don't know what the real name of
> this weapon. I also scanned books on the martial arts, and have seen
> it mentioned.
> My literary background is slightly broader than Star Wars.
Do keep in mind that, generally, martial arts books are not very reliable
sources, being infected with strong doses of fantasy, myth, propaganda,
and unsupported hearsay (and martial arts magazines are worse). This is
almost invariably worse when ninja are involved (just consider the hard
historical evidence for ninja, what they did, how they did it etc., and
you should be able to guess why).
Lacking any reliable sources, guess what novelists and screenplay writers
base their stuff on!
That said, the weapon is a shuriken, and the star-shaped version is often
graced with names such as "ninja star", "throwing star", "star knife" etc.
(and perhaps even "death star", but I don't recall seeing that one).
Straight spike shuriken appear to have been more common.
There are some good reliable books. The classic book is Serge Mol,
Classical weaponry of Japan. Don Cunningham, Samurai weapons, is also
good.
--
Timo
mm
<drose...@yahoo.com> wrote:
>On Jan 28, 12:55�am, mm <NOPSAMmm2...@bigfoot.com> wrote:
>> On Wed, 27 Jan 2010 20:56:03 +1100, "Peter Webb"
>
>> >> They grab them by the point, I think, and throw them and they stick
>> >> into the target. � It's never the case that the handle hits the target
>> >> and bounces off. �Now on the Ed Sullivan Show, the thrower could stand
>> >> exactly where he wanted. �Is that the trick, to be the right distance
>> >> away?
> I thought that it was for real, with the only "trick" being the
>design of the knife.
>>
>> >> In the movies they don't seem to do that
>
> It occurs to me that the knife doesn't have to spin. If the knife
>is thrown as a spear, with linear momentum parallel to the blade, the
>knife will go straight.
If you look at the webpage mentioned early on, at its "store", you'll
see one knife like that. It requires a different throwing style than
normally used. Didfferent also from what I saw on tv.
> It can then hit the target point first. If you
>hold the knife by its center of gravity, you will minimize the "spin"
>imparted to the knife.
> Darts are thrown this way. Darts usually stick to the target
>when they hit. If you throw the knife like a dart, it will probably
>stick more often.
> People in on TV or movies never throw it like that. Even the
>professional knife throwers don't throw it like that. I think it is
>because the gyroscopic effect gives the trajectory of the knife
>greater stability. However, then you have the problem of the handle
>hitting the target first.
> A friend of mine tried to practice knife throwing for fun. He was
>throwing a standard knife, with large handle. At small distances, he
>could hit the target by throwing it like a spear, point forward. He
>avoided spinning the knife. When he threw it by holding the point, the
>handle often hit first.
> It is possible that the knife throwing demonstrations that I have
>seen were faked in some way. I would be disappointed if I found that
>out, but it is always possible. However, I do remember that the
>knives were a bit different.
> I recommend repeating your childhood experiments with one slight
>change. Throw the knife like a spear, point first, avoiding spin. I
>bet that though you miss the target more, you will also have the knife
>stick in the target more.
Hmmm. That rings a bell. I might have tried this as a child too. I
may be more manually skilled by now. And when I was little, I didn't
even have a piece of scrap wood, only a tree with hard bark that
looked like a miniature Grand Canyon.
I'm sure there are fake shows where the knife pops out from the bark,
but there are also people who can throw well and hit a target.
The first knife act with a girl was probably for real, but when others
wanted to get in on something popular, but didnt' throw as well and
couldn't find a girl willing to risk her life, they devised the trick.
Especially when they changed the act to have the girl spinning. I
don't think even the best thrower could safely throw at a spinning
girl. And even if he sometimes succeeded, too many ways for it to go
wrong.
Androcles
"Timo Nieminen" <ti...@physics.uq.edu.au> wrote in message
news:Pine.LNX.4.50.1001290912430.2830-100000@localhost...
Anti-horse mines. http://en.wikipedia.org/wiki/Caltrop
sno
> Do throwing knives really work, and how?
>
> In the movies, and I think on the Ed Sullivan Show, people did
> interesting things with "throwing knives".
>
> into the target. It's never the case that the handle hits the target
> and bounces off. Now on the Ed Sullivan Show, the thrower could stand
> exactly where he wanted. Is that the trick, to be the right distance
> away?
>
I knew a kid in school, who had been practicing all his life, could
stick just about anything with a point and enough weight.....
He said the distance is the key...tried for one turn between himself and
target...estimated the twist had had to give to what he was throwing to
get one turn to accomplish a straight hit.....he was at the point where
it was instinctive to do it.....
Hope helps....have fun....sno
--
Correct Scientific Terminology:
Hypothesis - a guess as to why or how something occurs
Theory - a hypothesis that has been checked by enough experiments
to be generally assumed to be true.
Law - a hypothesis that has been checked by enough experiments
in enough different ways that it is assumed to be truer then a theory.
Note: nothing is proven in science, things are assumed to be true.
Peter Webb
"Sam Wormley" <swor...@gmail.com> wrote in message
news:0eGdna_vrdQ43f3W...@mchsi.com...
I did that already.
Why do you think what I say is wrong, exactly?
Peter Webb
On Jan 28, 12:55 am, mm <NOPSAMmm2...@bigfoot.com> wrote:
> On Wed, 27 Jan 2010 20:56:03 +1100, "Peter Webb"
> >> They grab them by the point, I think, and throw them and they stick
> >> into the target. It's never the case that the handle hits the target
> >> and bounces off. Now on the Ed Sullivan Show, the thrower could stand
> >> exactly where he wanted. Is that the trick, to be the right distance
> >> away?
I thought that it was for real, with the only "trick" being the
design of the knife.
>
> >> In the movies they don't seem to do that
It occurs to me that the knife doesn't have to spin. If the knife
is thrown as a spear, with linear momentum parallel to the blade, the
knife will go straight. It can then hit the target point first. If you
hold the knife by its center of gravity, you will minimize the "spin"
imparted to the knife.
Darts are thrown this way. Darts usually stick to the target
when they hit. If you throw the knife like a dart, it will probably
stick more often.
People in on TV or movies never throw it like that. Even the
professional knife throwers don't throw it like that. I think it is
because the gyroscopic effect gives the trajectory of the knife
greater stability. However, then you have the problem of the handle
hitting the target first.
___________________________________
No. As long as the centre of gravity of the knife is closer to the handle
end than the pointy end, and the knife is spinning fast enough, it will
always hit blade first. I think the thought experiment I provided
demonstrated that quite clearly
J. Clarke
So demonstrate this and show us your videos.
J. Clarke
While shuriken can be used as caltrops in a pinch they serve different
purposes.
Peter Webb
"J. Clarke" <jclarke...@cox.net> wrote in message
news:hjto8...@news7.newsguy.com...
I have no videos. I have a thought experiment which proves the principle
quite clearly.
Lets do it again.
I have a knife that weighs 1 kgs. It consists of a handle weighing 999 grams
and a 1 metre blade that weighs one gram. Throw it with enough spin so it
rotates end-over-end 10,000 times per second. As almost all the weight is in
the handle, its a long blade rotating around a handle at 10,000 rpm. Now
throw it at 1 metres per second. The handle could not possibly hit first, as
in the one second that it takes the handle to move the last metre to the
target the tip will have spun around the handle 10,000 times, and as it is a
metre long would have hit the target 10,000 times before the handle could
possibly hit once.
Get it?
J. Clarke
Thought experiments do not prove principles.
> Lets do it again.
>
> I have a knife that weighs 1 kgs. It consists of a handle weighing
> 999 grams and a 1 metre blade that weighs one gram. Throw it with
> enough spin so it rotates end-over-end 10,000 times per second. As
> almost all the weight is in the handle, its a long blade rotating
> around a handle at 10,000 rpm. Now throw it at 1 metres per second.
> The handle could not possibly hit first, as in the one second that it
> takes the handle to move the last metre to the target the tip will
> have spun around the handle 10,000 times, and as it is a metre long
> would have hit the target 10,000 times before the handle could
> possibly hit once.
>
> Get it?
Once again, show us your videos. One physical experiment beats a million
thought experiments.
Peter Webb
Ummm ... yes, they do.
>
>> Lets do it again.
>>
>> I have a knife that weighs 1 kgs. It consists of a handle weighing
>> 999 grams and a 1 metre blade that weighs one gram. Throw it with
>> enough spin so it rotates end-over-end 10,000 times per second. As
>> almost all the weight is in the handle, its a long blade rotating
>> around a handle at 10,000 rpm. Now throw it at 1 metres per second.
>> The handle could not possibly hit first, as in the one second that it
>> takes the handle to move the last metre to the target the tip will
>> have spun around the handle 10,000 times, and as it is a metre long
>> would have hit the target 10,000 times before the handle could
>> possibly hit once.
>>
>> Get it?
>
> Once again, show us your videos. One physical experiment beats a million
> thought experiments.
>
As I said, I haven't got any videos. And nor would a video prove what I am
saying, which is that if the knife is of the correct shape and spinning fast
enough, it will *always" hit with the blade first. A video could only show
that it *sometimes* hits blade first, which already seems agreed.
Did you understand my thought experiment? If not, what parts need
clarification?
Benj
<webbfam...@DIESPAMDIEoptusnet.com.au> wrote:
> As I said, I haven't got any videos. And nor would a video prove what I am
> saying, which is that if the knife is of the correct shape and spinning fast
> enough, it will *always" hit with the blade first. A video could only show
> that it *sometimes* hits blade first, which already seems agreed.
>
> Did you understand my thought experiment? If not, what parts need
> clarification?
I'm not sure that you are completely correct. If you look at throwing
knives it appears that the sharp end is wider than the handle end. But
that doesn't say anything about the actual balance of the knife. If
the handle end is shorter but heavier, that means that the knife when
thrown spins about it's center of gravity. Think about that. This
means that as the knife spins the tip sticks out farther than the
handle. That means if it's spinning your theory will apply. On the
other hand, I sort of remember that throwing knives are made the other
way round. The idea being that the heavy end will tend to be toward
the target when it lands. So it's an interesting theory, but I really
think the answer is simple muscular skills.
Which brings up another important point relative to sci.physics. Note
how the natural assumption here when confronted with some unusual
phenomena (throwing knives at spinning girl and having them miss) the
knee jerk reaction of all these so-called "scientists" and persons
with an interest in "science" isn't to seek data or to investigate the
phenomena in literature, nor even to view the phenomena themselves.
Nope. The first reaction is to invoke "swamp gas", "mass
hallucination" or in this case, fraud. Yes, the world is full of
fraudsters and hoaxes. But to relegate an "explanation" of the talent
of knife throwing to simple fraud simply denigrates science and
undermines the public respect for it. This is arrogance in the
extreme. It is saying "I can 'explain' everything!" "It's all fake!"
I'm sorry, my fellow morons but there are and there appear numerous
people from time to time with amazing talents. I'm sure that accurate
knife throwing is among them. It is they who are having the last
laugh and you who are the morons. If you haven't the honesty to
actually investigate any (and I said ANY) phenomena you chance to
encounter, and have to dismiss it as "hoax" then you have no place in
science and should immediately apply for a job in your local media as
propagandist (journalist).
J. Clarke
No, they don't. Proof in science comes from experiment, not theory.
>>> Lets do it again.
>>>
>>> I have a knife that weighs 1 kgs. It consists of a handle weighing
>>> 999 grams and a 1 metre blade that weighs one gram. Throw it with
>>> enough spin so it rotates end-over-end 10,000 times per second. As
>>> almost all the weight is in the handle, its a long blade rotating
>>> around a handle at 10,000 rpm. Now throw it at 1 metres per second.
>>> The handle could not possibly hit first, as in the one second that
>>> it takes the handle to move the last metre to the target the tip
>>> will have spun around the handle 10,000 times, and as it is a metre
>>> long would have hit the target 10,000 times before the handle could
>>> possibly hit once.
>>>
>>> Get it?
>>
>> Once again, show us your videos. One physical experiment beats a
>> million thought experiments.
>>
>
>
> As I said, I haven't got any videos. And nor would a video prove what
> I am saying, which is that if the knife is of the correct shape and
> spinning fast enough, it will *always" hit with the blade first. A
> video could only show that it *sometimes* hits blade first, which
> already seems agreed.
>
> Did you understand my thought experiment? If not, what parts need
> clarification?
The part where you show us that your thought experiment is confirmed by real
experiment.
tg
<webbfam...@DIESPAMDIEoptusnet.com.au> wrote:
> "J. Clarke" <jclarke.use...@cox.net> wrote in message
>
> news:hjto8...@news7.newsguy.com...
>
>
>
> > Peter Webb wrote:
I think the flaw in your reasoning is in the 'get it spinning fast
enough' part. Think about the mechanics of it in terms of forward
velocity and angular velocity. (Or momentum, if you like.) I don't
see how you get the 1 meter 1 gram blade to spin much at all.
The only way to do it would not be knife-throwing, but involve some
mechanical device that imparts spin and then 'throws' the spinning
object.
-tg
Darwin123
> "Darwin123" <drosen0...@yahoo.com> wrote in message
>
> news:8295e203-5926-4e39...@f12g2000yqn.googlegroups.com...
> On Jan 28, 12:02 pm, "Androcles" <Headmas...@Hogwarts.physics_s>
> wrote:
>
> > "Darwin123" <drosen0...@yahoo.com> wrote in message
>
> >news:f8f8a4b4-6d16-4e75...@b2g2000yqi.googlegroups.com...
> You are claiming that the word flat is redundant.
>
> I'm claiming you are a worthless shithead.
Another keen scientific insight from Androcles!
Androcles
=================================
You are learning. Watch this space.
Darwin123
> On Thu, 28 Jan 2010 06:56:35 -0800 (PST), Darwin123
>
>
>
> <drosen0...@yahoo.com> wrote:
> >On Jan 28, 12:55 am, mm <NOPSAMmm2...@bigfoot.com> wrote:
> >> On Wed, 27 Jan 2010 20:56:03 +1100, "Peter Webb"
>
> Especially when they changed the act to have the girl spinning. I
> don't think even the best thrower could safely throw at a spinning
> girl. And even if he sometimes succeeded, too many ways for it to go
> wrong.
I am not sure that spinning the girl really adds much risk. The
motion is completely predictable. Compensation for spin would only
require adjusting the release time. Compensation for spin, or uniform
motion, isn't that difficult.
I still think that the main trick is the reduction of the handle.
If the knife didn't stick to the wood, it could fall on her. This
could cause a small injury. Worse, the knife could hit her handle
first. The audience would see that the handle protects her. That would
completely ruin the appearance of the act!
What would be impressive, and I think impossible, is if the
girl were rotated in a chaotic or random way.
If the knife had no handle, and was too heavy to be affected by
air resistance, the problem becomes no more difficult than throwing a
ball. Throwing a ball precisely is difficult for most people, but it
can be done. Think of a tennis player, who hits the ball coming from
any angle. The server can't control which side of the ball is going to
face the other player, but to some extent he can control the motion of
the ball. Similarly, the one thing a knife thrower can't control is
which side of the knife hits first.
It is barely possible that some knife throwers have a precise
control of the spin, so they can figure out which side of the knife
hits the target, but I doubt it. That would be like controlling the
spin on a coin. One can throw a coin with precision, but one can't
control the spin of the coin with precision. A coin is a bit like a
handleless blade.
No handle, no problem!
Darwin123
<webbfam...@DIESPAMDIEoptusnet.com.au> wrote:
> "J. Clarke" <jclarke.use...@cox.net> wrote in message
>
> news:hjtrp...@news7.newsguy.com...
>
>
>
> > Peter Webb wrote:
> >>news:hjto8...@news7.newsguy.com...
> >>> Peter Webb wrote:
This part.
" t consists of a handle weighing 999 grams and a 1 metre blade that
weighs one gram."
I don't need the video. I need to know where one can buy a knife
like this.
If there is such a knife, I suspect it is not standard. Pocket
knives and Bowie knives are not like this.
Also implied by your illustration is a handle much smaller than
the blade. If the handle where also 1 meter long, your calculation
wouldn't work. If it were 10 cm long, the blade would hit 9 times out
of 10. However, what would a handle that is 999 g and 10 cm long look
like?
Can we all agree that movie and TV depictions of knife throwers
are nonsense?
People can not throw standard knives in the ways depicted and be
sure of hitting their targets, blade first.
The disagreement seems to be whether some knife throwing acts are
legitimate. I am sure that some are faked. However, I think most are
real. They take great skill, even if the knife is designed to help
them out.
Darwin123
> Also implied by your illustration is a handle much smaller than
> the blade. If the handle where also 1 meter long, your calculation
> of 100. However, what would a handle that is 999 g and 10 cm long look
> like?
If the handle were 100 cm long, the blade would hit 9 times out of
10. However, it would look fairly weird.
ji...@specsol.spam.sux.com
> It is barely possible that some knife throwers have a precise
> control of the spin, so they can figure out which side of the knife
> hits the target, but I doubt it.
In fact, learning how to control the spin for a given throw is how
knife throwers learn how to throw a knife.
Why don't you abandon your speculation and just READ how real people
really do it?
http://www.knifethrowing.info/
tg
They are nonsense but not for the reason you say. As someone else
pointed out, people can do all kinds of things with plenty of
practice, and there is no magic in developing the hand-eye
coordination required to stick a knife in a piece of wood from various
distances.
However, the idea that you can use this skill in personal combat is
ridiculous, and that is what we see in the movies---the knife somehow
penetrates the ribcage and kills instantly, despite the obvious
problem of clothing, rib orientation, and angular momentum.
-tg
jbriggs444
Eh? So we have a 1 meter blade and a 100 cm handle.
The handle weighs 999 g and the blade weighs 1g.
So the center of gravity of the knife is roughly at the midpoint of
the handle. The blade tip is in a 1.5 meter radius orbit about that
point. And the handle tip is in a 0.5 meter ratius around that point.
Can you justify for us your 90% calculation?
Darwin123
No. I was wrong the second time. I shouldn't rush to correct my
mistakes. Even the first time was an approximation.
jbriggs444
>
> - Show quoted text -
Sorry to jump on ya like that then.
mm
In order to be polite, I made my point weakly the last time.
No human being can make a knife turn 10,000 times a second.
Twenty times a second or less would be about right.
OTOH, a thrown knife will go a lot faster than one meter a second.
And even at 20 spins per second, the knife won't stick at every part
of its spin.
I've done a thought experiment -- I do them too -- and the knife will
only stick or penetrate if it is horizontal at the time it hits the
target, or approaching horizonatal, or a tiny bit past horizontal.
I would say at most that is -90^ to +5^ from horizontal, blade
pointing at the target. That's just over 25% of the rotation, which
means there is a 75% chance the knife won't stick or penetrate if the
distance from the target is random.
http://www.knifethrowing.info/distances.html
In his flight towards the target, the knife will turn around his
center of gravity, blade and handle will take turns pointing to the
target. The throwing knife will rotate in a way that, if thrown from
the handle, the blade will go downwards at first.
The first distance for a stick is about three meters from the target
(Always measured from the tip of your rear foot!). Grip the knife at
the handle, throw it, and after one full rotation it will stick. If it
doesn't, move back or forward a little (see chapter on training).
The second distance is about one meter behind the first. Now you grip
the knife at the blade (if possible), and after one and a half turn
the knife will stick. It is important that you do not have to do
anything to get this turns, they will just come. (In fact, later you
will be trying to get less rotations to be in better control if you
throw from further away.)
From the third distance, you once again use a handle grip, just now
you get two full rotations of the knife till it sticks. Because you
always throw with the same movements and force, the knife rotates in
the same manner, and flies with the same speed every time. Therefore
you can calculate or feel how much you have to go back so that the
knife has completed another half turn. The pros with many years of
experience can throw from distances where the knives make seven full
rotations! Once you found your distance, you should measure it off and
note it down. Note that the distance will slightly differ the next
training day.
--end quote--
mm
<drose...@yahoo.com> wrote:
>On Jan 28, 6:23�pm, mm <NOPSAMmm2...@bigfoot.com> wrote:
>> On Thu, 28 Jan 2010 06:56:35 -0800 (PST), Darwin123
>>
>>
>>
>> <drosen0...@yahoo.com> wrote:
>> >On Jan 28, 12:55�am, mm <NOPSAMmm2...@bigfoot.com> wrote:
>> >> On Wed, 27 Jan 2010 20:56:03 +1100, "Peter Webb"
>>
>
>> Especially when they changed the act to have the girl spinning. �I
>> don't think even the best thrower could safely throw at a spinning
>> girl. � And even if he sometimes succeeded, too many ways for it to go
>> wrong. �
>
> I am not sure that spinning the girl really adds much risk. The
>motion is completely predictable. Compensation for spin would only
>require adjusting the release time. Compensation for spin, or uniform
>motion, isn't that difficult.
We don't even know the wheel is spinning at a constant speed, and not
slowing down, and yet you think the motion is completely predictable.
But even if it is a motorized wheel with a constant speed, and even if
it is completely predicatable, that doesnt' mean it doesnt' make it
much harder. Mathematically, it wouldn't be hard to calulate a
formula, but in practice, sure it is. Too many things for one mind to
keep track of.
No offense meant, I woudln't let you even throw a rock at me if I were
on a spinning wheel, let alone a knife. You're too much into theory
here and ignoring the problems of reality.
Peter Webb
"Benj" <bja...@iwaynet.net> wrote in message
news:f0f8c9b5-ff5e-4377...@h2g2000yqj.googlegroups.com...
> As I said, I haven't got any videos. And nor would a video prove what I am
> saying, which is that if the knife is of the correct shape and spinning
> fast
> enough, it will *always" hit with the blade first. A video could only show
> that it *sometimes* hits blade first, which already seems agreed.
>
> Did you understand my thought experiment? If not, what parts need
> clarification?
I'm not sure that you are completely correct. If you look at throwing
knives it appears that the sharp end is wider than the handle end. But
that doesn't say anything about the actual balance of the knife. If
the handle end is shorter but heavier, that means that the knife when
thrown spins about it's center of gravity. Think about that.
___________________________________
I did think about that. The knife in my thought experiment is 1 metre long,
with 999 grams concentrated in a small handle a 1 metre blade weighing 1
gram.
This
means that as the knife spins the tip sticks out farther than the
handle. That means if it's spinning your theory will apply. On the
other hand, I sort of remember that throwing knives are made the other
way round. The idea being that the heavy end will tend to be toward
the target when it lands. So it's an interesting theory, but I really
think the answer is simple muscular skills.
_________________________________________
Perhaps you should re-read my thought experiment.
Which brings up another important point relative to sci.physics. Note
how the natural assumption here when confronted with some unusual
phenomena (throwing knives at spinning girl and having them miss) the
knee jerk reaction of all these so-called "scientists" and persons
with an interest in "science" isn't to seek data or to investigate the
phenomena in literature, nor even to view the phenomena themselves.
Nope. The first reaction is to invoke "swamp gas", "mass
hallucination" or in this case, fraud.
______________________________________
I'm not implying fraud. Knife throwers can pick whatever knives they want;
that is understood. I doubt any knife-thrower anywhere would re-do their
tricks with knives provided by an audience member.
Yes, the world is full of
fraudsters and hoaxes. But to relegate an "explanation" of the talent
of knife throwing to simple fraud simply denigrates science and
undermines the public respect for it.
____________________________________
Its not fraud.
This is arrogance in the
extreme. It is saying "I can 'explain' everything!" "It's all fake!"
I'm sorry, my fellow morons but there are and there appear numerous
people from time to time with amazing talents. I'm sure that accurate
knife throwing is among them. It is they who are having the last
laugh and you who are the morons. If you haven't the honesty to
actually investigate any (and I said ANY) phenomena you chance to
encounter, and have to dismiss it as "hoax" then you have no place in
science and should immediately apply for a job in your local media as
propagandist (journalist).
___________________________________
I didn't say its a hoax. And if you believe that selecting the knives you
use for knife-throwing, then all professional kinife throwers are frauds,
because I have never heard of one using knives selected at random.
Peter Webb
Would it be sufficient for me to post a video of somebody throwing a knife
and it sticking in blade first? Is that what you want?
And, BTW, do you learn all your science off YouTube videos? How did you
possibly learn physics if you need a video of every physics question and its
answer before you understand it?
Peter Webb
"tg" <tgde...@earthlink.net> wrote in message
news:2a3bd4ab-5b84-45f0...@o28g2000yqh.googlegroups.com...
_____________________________
Throwers impart spin.
The only way to do it would not be knife-throwing, but involve some
mechanical device that imparts spin and then 'throws' the spinning
object.
________________________________
The mechanical device they use is their right arm.
Peter Webb
________________________________
Its a thought experiment.
If there is such a knife, I suspect it is not standard. Pocket
knives and Bowie knives are not like this.
_________________________________
They don't throw standard bowie knives or pocket knives, possibly for this
exact reason.
Also implied by your illustration is a handle much smaller than
the blade. If the handle where also 1 meter long, your calculation
wouldn't work.
______________________________________
No. That is why I didn't make it 1 mtere long.
If it were 10 cm long, the blade would hit 9 times out
of 10.
________________________________
No, not if it was spinning. Imagine (as I said before) the knife was
spinning at 10,000 rpm. How could the handle get within 10 cms of the
target, when the blade is a metre long and would intersect the target almost
10,000 times before the handle could hit te target? Remember, the object is
spinning around its centre of gravity, which is effectively the handle of
the knife.
However, what would a handle that is 999 g and 10 cm long look
like?
Can we all agree that movie and TV depictions of knife throwers
are nonsense?
People can not throw standard knives in the ways depicted and be
sure of hitting their targets, blade first.
The disagreement seems to be whether some knife throwing acts are
legitimate. I am sure that some are faked. However, I think most are
real. They take great skill, even if the knife is designed to help
them out.
______________________________________
And I have just told you principles that can used in designing knives that
are easy to throw and embed in a target. Others are possible.
Peter Webb
"mm" <NOPSAM...@bigfoot.com> wrote in message
news:vuj6m59jig51jm1ls...@4ax.com...
It was a thought experiment.
>
> Twenty times a second or less would be about right.
>
> OTOH, a thrown knife will go a lot faster than one meter a second.
>
> And even at 20 spins per second, the knife won't stick at every part
> of its spin.
>
> I've done a thought experiment -- I do them too -- and the knife will
> only stick or penetrate if it is horizontal at the time it hits the
> target, or approaching horizonatal, or a tiny bit past horizontal.
>
> I would say at most that is -90^ to +5^ from horizontal, blade
> pointing at the target. That's just over 25% of the rotation, which
> means there is a 75% chance the knife won't stick or penetrate if the
> distance from the target is random.
>
No. You have ignored the fact that the knife is spinning.
Use your figures. 1 metre blade, knife thrown at 1 m/s, all mass in handle,
spinning 20 times per second.
Knife handle 1.0001 m for target, it hasn't hit the target.
When the knife hande is 0.8 m from target, its 0.2 seconds later, the blade
has rotated around the handle 4 times why the handle has moved 0.2 metres
closer (0.2 seconds * 20 rotations/sec = 4 rotations). As the blade is 1
metre long, it must have hit the target at least 3 times before the handle
even gets within 0.8 metres of the target. By the time the handle is 10 cms
from the target - and hence could hit it - the knife would have spun 0.9
seconds * 20 rotations/second = 18 times. As the blade is 1 metre long, it
*must* hit the target at least 17 times before the handle possibly comes
close enough.
Do you get it now?
J. Clarke
One designed and thrown according to your precepts sticking 100 times out of
100 throws would do.
> And, BTW, do you learn all your science off YouTube videos? How did
> you possibly learn physics if you need a video of every physics
> question and its answer before you understand it?
<plonk>
Benj
<webbfam...@DIESPAMDIEoptusnet.com.au> wrote:
___________________________________
> I didn't say its a hoax. And if you believe that selecting the knives you
> use for knife-throwing, then all professional kinife throwers are frauds,
> because I have never heard of one using knives selected at random.
Not you, but some of the initial posters talking about knives punched
through paper from the rear.
Peter Webb
As I said, I have no such video. And as you don't understand the theory,
perhaps you should just take my word for it. Or even better, try and
understand the theory, and ask questions about parts you don't understand.
sno
I believe you do not have a theory you have a hypothesis (see my sig)....
Two things you need to remember....when dealing with science....
The easiest person to fool is yourself...
and
Just because something makes sense logically/mathematically
Does not necessarily make it reality
thank you for listening to my thoughts....have fun.....sno
--
Correct Scientific Terminology:
Hypothesis - a guess as to why or how something occurs
Theory - a hypothesis that has been checked by enough experiments
to be generally assumed to be true.
Law - a hypothesis that has been checked by enough experiments
in enough different ways that it is assumed to be truer then a theory.
Note: nothing is proven in science, things are assumed to be true.
Peter Webb
"sno" <s...@opelc.com> wrote in message
news:4b63d5ef$0$77542$892e...@auth.newsreader.octanews.com...
No.
I simply used elementary dynamics to show what would happen. I did not
hypothesis anything at all, I just stated the boundary conditions and
provided an elementary proof that the blade will always hit first.
> Two things you need to remember....when dealing with science....
>
> The easiest person to fool is yourself...
>
> and
>
> Just because something makes sense logically/mathematically
> Does not necessarily make it reality
>
> thank you for listening to my thoughts....have fun.....sno
>
Did you understand my thought experiment? If not, which parts?
sno
I understood your experiment....however just because it makes logical
sense does not mean it will work if you perform the experiment....
So called "thought experiments" are not experiments...
Until a thought experiment is actually tested it is not an experiment....
An example of this is einsteins hypothesis which were developed from
"thought experiments".....it took years of actual experiments until they
were assumed to be correct....and became theories....
thank you for listening to my thoughts....sno
Androcles
============================================
The reality:
http://www.youtube.com/watch?v=Xbgop7DWUZ8
tg
<webbfam...@DIESPAMDIEoptusnet.com.au> wrote:
> "tg" <tgdenn...@earthlink.net> wrote in message
I suspect you have never tried it yourself. To impart spin in the act
of throwing requires the center of gravity to be located some distance
from your hand. What you are suggesting is like throwing an axe by
gripping the head, and there is insufficient distance between the
wrist joint and the COG to impart spin.
You need to redesign your projectile so that it has 2 'blades'. Think
about it and get back to me. (It usually helps to make a sketch.)
-tg
tadchem
> On Thu, 28 Jan 2010 13:34:55 -0000, "Androcles"
>
>
>
>
>
> <Headmas...@Hogwarts.physics_s> wrote:
>
> >"tadchem" <tadc...@comcast.net> wrote in message
> >news:fde497b7-a1e6-43f8...@r19g2000yqb.googlegroups.com...
> >On Jan 26, 2:47 pm, "Androcles" <Headmas...@Hogwarts.physics_s> wrote:
> >> "mm" <NOPSAMmm2...@bigfoot.com> wrote in message
>
> >>news:gvful5lpa0qai4il5...@4ax.com...
>
> >> > Do throwing knives really work, and how?
>
> >> > In the movies, and I think on the Ed Sullivan Show, people did
> >> > interesting things with "throwing knives".
>
> >> > They grab them by the point, I think, and throw them and they stick
> >> > into the target. It's never the case that the handle hits the target
> >> > and bounces off. Now on the Ed Sullivan Show, the thrower could stand
> >> > exactly where he wanted. Is that the trick, to be the right distance
> >> > away?
>
>
> >> you don't see is the paper covering over the holes in the wheel.
> >> Behind the paper is a knife handle on a spring which pops
> >> out through the paper and into view, making it appear as if the
> >> knife has landed an inch from the girl's skin. The "thrower" never
> >> throws a knife at all, instead he drops one the ground from his other
> >> hand as he pretends to throw.Your eye (or the camera) isn't quick
> >> enough to see the knife in flight and there isn't one anyway. Any
> >> assistant can operate the fake knives behind the wheel.
>
> >I've seen the act up close. The thrower doesn't drop a knife - you
> >could hear that. He uses flat knives and fans them at the start in
> >his off-hand so you can see he has several. He takes one into his
> >throwing hand and as he goes through the throwing motion he palms it.
> >Meanwhile an off-stage assistant triggers the 'wooden' target where a
> >concealed mechanism releases a 'knife' from a spring mounting to jump
> >into position. When he 'reaches' for the next knife in his off-hand,
> >he merely readjusts the fan to show one less knife and unpalms the one
> >he started with.
>
> >Continue until the knife supply is depleted...
>
> >Tom Davidson
> >Richmodn, VA
> >============================================
> >Ok... circus rings had sawdust and grass floors when I was a kid.
> >I always assumed an assistant but it could as easily be Catherine
> >that triggered each knife in the wheel.
>
> Who is Catherine?
Androcles reveals his education with this one. "Catherine" is a
reference to St. Catherine of Alexandria, who was martyred on a
'breaking wheel"
http://en.wikipedia.org/wiki/Breaking_wheel
around 305 CE. Since then the breaking wheel has also been called the
"Catherine wheel".The name has since been inherited by a type of
firework and (perhaps more appropriately) by a rotating target used by
knife-throwers:
http://www.knifethrower.com/images/msc/DSC00682.JPG
AKA "the Wheel of Death"/
"Catherine" has become the generic nickname for the knife-throwers'
assistant.
Another interesting page on the topic:
http://tvtropes.org/pmwiki/pmwiki.php/Main/KnifeThrowingAct
> >Nowadays kids aren't permitted knives, guns or even firecrackers
> >in England, only the criminals are allowed to have them, but when
> >I was kid I used to carry a penknife and would throw that from
> >the blade.
>
> Kids can't have knives because parents don't permit it, or the govt.
> stops it?
I can't speak for the UK, but here in the US kids get suspended from
school for possession of anything that scares the teachers - knives,
*pictures* of guns, opinionated T-shirts, etc.
"Political correctness" is tyranny.
Tom Davidson
Richmond, VA
tadchem
> On Jan 28, 5:43 am, tadchem <tadc...@comcast.net> wrote:
>
>
>
>
>
> > On Jan 26, 6:16 pm, Darwin123 <drosen0...@yahoo.com> wrote:
>
> > > On Jan 26, 2:22 pm, mm <NOPSAMmm2...@bigfoot.com> wrote:
>
> > > > Do throwing knives really work, and how?
>
> > > that is mostly edge. They like to use knives that have very little or
> > > no handle.
> > > If you look through some hunter catalogues, you will find
> > > advertisements for throwing knives and even an advertisement for a
> > > throwing hatchet. The principle of these knives is the same. The
> > > handle is reduced as much as possible. The hatchet is double edged and
> > > broad. The idea is to increase the edge area as much as possible.
> > > The throwers on Ed Sullivan probably used these special knives.
> > > Yes, the tricks were real. However, they needed a special knife. They
> > > didn't use a Jim Bowie knife.
> > > I think this shows that no matter how good you are at throwing a
> > > knife, there is always a chance that the handle will hit the target
> > > first. If you accept that the hero is preparing for battle, then it is
> > > reasonable that he carry a knife specially made for throwing. Your
> > > intuition is correct. Handles can get in the way. However, there are
> > > weapons that have been designed for throwing.
> > > The problem is that a blade without a handle is very dangerous to
> > > the user. The user has to be really disciplined to avoid cutting
> > > himself while carrying it or throwing. That being said, there are
> > > blades that have been designed for throwing.
> > > Lets look at our most favorite heroes. I don't think a Bowie knife
> > > is a good idea for throwing. Its good for stabbing and slashing, but
> > > not throwing. Xena has a great knife for throwing. Perfectly circular,
> > > with no handle! I forgot the name of her weapon, but it was actually
> > > used by Islamic soldiers in medieval times. Maybe the name of the
> > > blade is the chakras?
> > > Batman has his batarang, which is sometimes used for cutting.
> > > I suppose that it can be built with all edge, but the comic never says
> > > so. The late Captain America, starting in the 70's, used his shield to
> > > cut through all sorts of things. Like Zena's weapon, it was round. The
> > > shield had a nice handle on the inside, but the handle couldn't get in
> > > the way of the edge. Ninja death stars have a couple of points and no
> > > handle. They were be really good throwing weapons.
> > > The chakras and the death star were probably the best throwing
> > > blades seen on TV or the movies.
>
> > Xena's blade is called a chakram, similar to the chakkar but intended
> > to be thrown more than the latter, which was mainly a melee weapon.
>
> > The "death star" was the size of a small planet, far too large to be a
> > "throwing blade."
>
> > Read more.
>
> > Tom Davidson
> > Richmond, VA
>
> Ninja use a small blade in the shape of a star. The blade is too
> small to ensure fatality. So in a real assassination, it is usually
> poisoned.
From http://www.secrets-of-shuriken.com.au/techniques2.htm
"Tipping the shuriken with poison
"Mention has been made of the use of poison being applied to the tips
of shuriken, thus giving them lethal capability. There are two
traditional poisons I know of used for this purpose, one is the
extract of Wolfsbane, or Aconite (Aconitum japonicum), which contains
highly toxic and extremely fast acting alkaloids, for which there is
no specific antidote. Substantial doses of Aconite cause almost
instantaneous death (2, 3). The active constituent Aconitine causes
neuro-muscular paralysis and contractions, affecting the heart and
respiration. As a side note, there is a variety of Aconite in Japan
called Aconitum Aizuense, an interesting connection to either the Aizu
area, or the Aizu clan...
"The second poison is not so fast acting, but nevertheless lethal.
Death is caused by severe and fast acting infection from a mixture of
horse manure, chicken's blood and oysters, which together contain the
broadest spectrum possible of infectious bacteria, making it almost
impossible to treat. This poison was not strictly limited to shuriken,
but also used on many types of edged weapons, particularly among
Ninjutsu schools.
"Mention has been made by some that the poison from the fugu, or
Japanese Puffer fish may have been used for tipping blades. I am not
sure this is correct, as fugu poison is neutralised by oxygen after 24
hours. There has been extensive research into fugu poisoning, and it
has been found that one can survive its paralysing and fatal effects
if one submits to an artificial respiration machine for a period of 24
hours. That is, the effect of the poison wears off after 24 hours."
> I first learned about this in the novel, "Shogun" by Clavel.
> Since then, I have seen it in many movies and TV shows. It is
> sometimes called thje "death star."
A Google of "death star"-"star wars" indicates that the phrase may
indicate a supernova or a source of a gamma ray burst, or perhaps a
Swedish metal band.
> I don't know what the real name of
> this weapon. I also scanned books on the martial arts, and have seen
> it mentioned.
> My literary background is slightly broader than Star Wars.
Reading is good.
- Hide quoted text -
>
> - Show quoted text -
Shuriken (alternate spelling "shurken") are also called "throwing
stars" or "ninja stars"
http://en.wikipedia.org/wiki/Shuriken
http://www.gungfu.com/cart-htm/htm-resources/articles-how-to-throw-a-ninja-star-shuriken.htm
Tom Davidson
Richmond, VA
tg
Being sued by parents whose kids get hurt is not politically anything,
but it happens. When someone can wear a T-shirt that says "Jesus Was A
Fag" without incident, then you can invoke talk-radio tropes like
'political correctness' for what the schools do.
-tg
Peter Webb
I suspect you have never tried it yourself. To impart spin in the act
of throwing requires the center of gravity to be located some distance
from your hand. What you are suggesting is like throwing an axe by
gripping the head, and there is insufficient distance between the
wrist joint and the COG to impart spin.
______________________________
I didn't say anything about launching it from the handle. For exactly the
reasons you have given, you would throw it from the tip end. So I googled
"how to throw a knife" and this is exactly shown on the first hit
http://www.knifethrowing.info/grips.html#pinchgrip , and they are in fact
holding the knife at the tip end.
Androcles
"tadchem" <tad...@comcast.net> wrote in message
news:0611a1f2-27d6-4521...@r24g2000yqd.googlegroups.com...
"Political correctness" is tyranny.
Tom Davidson
Richmond, VA
=======================================
My grandfather gave me the penknife and showed me how to
sharpen a pencil with it, finely paring the graphite to a needle.
But who needs a pencil to take an eye out when you can take
a $500 i-Pad to school and beat the teacher over the head
with it? Whatever happened to soggy blotting paper catapulted
from a latex band, I wonder?
As to tyranny, nowadays you have to have a hard hat to lay
bricks, a hi-vis vest to drive a bus, wear a seat belt in a car
and a helmet to ride a bike, all at the insistence of Nanny State,
both here and in the US.
During the recent snow those schools that were actually open
for business as usual did not permit the kids outside during
recess following a pandemic of snowballphobia. That is very
different to the highly polished slide I remember, when my
classmates formed an orderly queue to take their turn at
attempting to break a leg.
http://www.guy-sports.com/fun_pictures/polar_bear_ice.jpg
No legs were broken while sliding and instinctively remaining
upright on slippery banana skins was greatly improved later in
life, having learned the skill in childhood.
-- Androcles
tg
> holding the knife at the tip end.
You are confused---perhaps because you didn't make a sketch, and also
because you have no experience with either knives or axes.
I am saying that it is like throwing an axe, but in your scenario,
the handle of the axe is the 'blade', and the head of the axe is what
you are using as your 'handle'. Now, I have way too much experience
with an 8-pound maul, which I am currently using to catch up on my
(inadequate) firewood supply. And it is quite obvious that I cannot
impart very much spin using the 'knife-throwing' motion, because of
the location of the center of gravity.
What would work for you is a two-bladed knife, as I suggested.
-tg
Peter Webb
On Jan 30, 8:16 am, "Peter Webb"
<webbfam...@DIESPAMDIEoptusnet.com.au> wrote:
> I suspect you have never tried it yourself. To impart spin in the act
> of throwing requires the center of gravity to be located some distance
> from your hand. What you are suggesting is like throwing an axe by
> gripping the head, and there is insufficient distance between the
> wrist joint and the COG to impart spin.
>
> ______________________________
> I didn't say anything about launching it from the handle. For exactly the
> reasons you have given, you would throw it from the tip end. So I googled
> "how to throw a knife" and this is exactly shown on the first
> hithttp://www.knifethrowing.info/grips.html#pinchgrip, and they are in
> fact
> holding the knife at the tip end.
You are confused---perhaps because you didn't make a sketch, and also
because you have no experience with either knives or axes.
I am saying that it is like throwing an axe, but in your scenario,
the handle of the axe is the 'blade', and the head of the axe is what
you are using as your 'handle'.
_________________________
No. I would throw it from the blade end, for exactly the reason you gave.
Now, I have way too much experience
with an 8-pound maul, which I am currently using to catch up on my
(inadequate) firewood supply. And it is quite obvious that I cannot
impart very much spin using the 'knife-throwing' motion, because of
the location of the center of gravity.
________________________
Yeah. hold it at the end furthest from the c-o-g. For an exe, its the
handle; for a knife constructed as I have recommended, the end of the blade.
What would work for you is a two-bladed knife, as I suggested.
___________________________
Even easier with a two bladed knife.
-tg