Ed Fredkin
Apr9-04, 05:18 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Feynman Gate\n\nThe Billiard Ball Model (BBM) is a Newtonian model of computation\nwhere hypothetically perfect and identical billiard balls (diameter=1)\ninteract synchronously with each other in order to do the same kind of\nlogic as computer circuits. Collision points have integer coordinates\n(on a Cartesian Lattice) and the velocity of every ball is x dot= + or\n- 1, y dot= + or - 1. The x and y coordinates of every ball are\nintegers when time is an integer. The basic circuit is a place where\n2 billiard balls might collide. If we call the incoming paths A and\nB, then there are 4 output paths. If 2 balls collide then the 2 balls\nexiting the collision are each called "A.B" (A and B).\n\nA B\n\\ /\n\\ / The BBM Gate\n\\ /\n\\ XX / "XX" marks a possible collision point\n/ \\ / \\\n/ \\/ \\\n/ /\\ \\\n/ / \\ \\\n/ / \\ \\\nA.B ~A.B A.~B A.B\n\nIf only one Ball enters the gate, it continues in a straight line. If\nboth balls enter, both leave on different paths. The BBM gate has an\nabstract property reminiscent of QM. The only way we can "measure"\nwhether or not a ball is present on path B is to run it through a BBM\nGate along with a test ball (A) and see if the path of A is deflected\nby the potential ball B. Of course, it is obvious that you cannot\nmeasure B without deflecting it, since it must be involved in a\ncollision in order to make the measurement.\n\nIt is easy to show that any kind of digital computer can be\nconstructed within the BBM. A few days after the invention of the\nBBM, Feynman came up with a simple circuit made up out of 2 BBM gates,\nit has since been called the "Feynman Gate." This gate has an unusual\nproperty.\n\n\nA B\n\\ /\n\\ /\n\\ /\n\\ XX /\n/ \\ / \\ |\n/ \\/ \\ |Reflector\n| / /\\ / |\n| / / \\ /\n| \\ / \\\n\\ / / \\\nXX / \\\n/ \\ \\\n/ \\ \\\nB A.B A.~B\n\nIn the Feynman Gate, A detects the presence of B without affecting the\npath of B! The reason is that when A and B are both present, there\nare 2 collisions. If a ball enters at B (at the top) a ball exits at\nB (at the bottom) whether or not A is present. However when A is\npresent, a ball exits at A.B (meaning B was there) or at A.~B (meaning\nB was not there). If a ball enters at B (top) a ball always exits at\nB (bottom). Thus the signal B can be measured without being affected\nby the measurement.\n\nOne question is: "Are there analogies to this kind of phenomenon in\nQM?"\n\nEd F\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Feynman Gate
The Billiard Ball Model (BBM) is a Newtonian model of computation
where hypothetically perfect and identical billiard balls (diameter=1)
interact synchronously with each other in order to do the same kind of
logic as computer circuits. Collision points have integer coordinates
(on a Cartesian Lattice) and the velocity of every ball is x dot= + or
- 1, y dot= + or - 1. The x and y coordinates of every ball are
integers when time is an integer. The basic circuit is a place where
2 billiard balls might collide. If we call the incoming paths A and
B, then there are 4 output paths. If 2 balls collide then the 2 balls
exiting the collision are each called "A.B" (A and B).
A B
\ /
\ / The BBM Gate
\ /
\ XX / "XX" marks a possible collision point
/ \ / \
/ \/ \
/ /\ \
/ / \ \
/ / \ \
A.B ~A.B A.~B A.B
If only one Ball enters the gate, it continues in a straight line. If
both balls enter, both leave on different paths. The BBM gate has an
abstract property reminiscent of QM. The only way we can "measure"
whether or not a ball is present on path B is to run it through a BBM
Gate along with a test ball (A) and see if the path of A is deflected
by the potential ball B. Of course, it is obvious that you cannot
measure B without deflecting it, since it must be involved in a
collision in order to make the measurement.
It is easy to show that any kind of digital computer can be
constructed within the BBM. A few days after the invention of the
BBM, Feynman came up with a simple circuit made up out of 2 BBM gates,
it has since been called the "Feynman Gate." This gate has an unusual
property.
A B
\ /
\ /
\ /
\ XX /
/ \ / \ |
/ \/ \ |Reflector
| / /\ / |
| / / \ /
| \ / \
\ / / \
XX / \
/ \ \
/ \ \
B A.B A.~B
In the Feynman Gate, A detects the presence of B without affecting the
path of B! The reason is that when A and B are both present, there
are 2 collisions. If a ball enters at B (at the top) a ball exits at
B (at the bottom) whether or not A is present. However when A is
present, a ball exits at A.B (meaning B was there) or at A.~B (meaning
B was not there). If a ball enters at B (top) a ball always exits at
B (bottom). Thus the signal B can be measured without being affected
by the measurement.
One question is: "Are there analogies to this kind of phenomenon in
QM?"
Ed F
The Billiard Ball Model (BBM) is a Newtonian model of computation
where hypothetically perfect and identical billiard balls (diameter=1)
interact synchronously with each other in order to do the same kind of
logic as computer circuits. Collision points have integer coordinates
(on a Cartesian Lattice) and the velocity of every ball is x dot= + or
- 1, y dot= + or - 1. The x and y coordinates of every ball are
integers when time is an integer. The basic circuit is a place where
2 billiard balls might collide. If we call the incoming paths A and
B, then there are 4 output paths. If 2 balls collide then the 2 balls
exiting the collision are each called "A.B" (A and B).
A B
\ /
\ / The BBM Gate
\ /
\ XX / "XX" marks a possible collision point
/ \ / \
/ \/ \
/ /\ \
/ / \ \
/ / \ \
A.B ~A.B A.~B A.B
If only one Ball enters the gate, it continues in a straight line. If
both balls enter, both leave on different paths. The BBM gate has an
abstract property reminiscent of QM. The only way we can "measure"
whether or not a ball is present on path B is to run it through a BBM
Gate along with a test ball (A) and see if the path of A is deflected
by the potential ball B. Of course, it is obvious that you cannot
measure B without deflecting it, since it must be involved in a
collision in order to make the measurement.
It is easy to show that any kind of digital computer can be
constructed within the BBM. A few days after the invention of the
BBM, Feynman came up with a simple circuit made up out of 2 BBM gates,
it has since been called the "Feynman Gate." This gate has an unusual
property.
A B
\ /
\ /
\ /
\ XX /
/ \ / \ |
/ \/ \ |Reflector
| / /\ / |
| / / \ /
| \ / \
\ / / \
XX / \
/ \ \
/ \ \
B A.B A.~B
In the Feynman Gate, A detects the presence of B without affecting the
path of B! The reason is that when A and B are both present, there
are 2 collisions. If a ball enters at B (at the top) a ball exits at
B (at the bottom) whether or not A is present. However when A is
present, a ball exits at A.B (meaning B was there) or at A.~B (meaning
B was not there). If a ball enters at B (top) a ball always exits at
B (bottom). Thus the signal B can be measured without being affected
by the measurement.
One question is: "Are there analogies to this kind of phenomenon in
QM?"
Ed F