## Two Source Interference

<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>Hello,\n\nThis must be an elementary question, so I apologize in advance. I\'m having\ndifficulty grasping what happens when we have two laser beams, identical and\ncollinear, but perfectly out of phase, impingent on a screen. I understand\nthis is impossible in practice.\n\nI\'ve tried approaching this problem in particular from the transactional QM\nmodel, but end up with violations of causality. I would much appreciate an\nexplanation from any QM perspective.\n\nThank you,\nMuslaf\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">&nbsp;&nbsp;View this Usenet post in original ASCII form </a></div><P></jabberwocky>Hello,

This must be an elementary question, so I apologize in advance. I'm having
difficulty grasping what happens when we have two laser beams, identical and
collinear, but perfectly out of phase, impingent on a screen. I understand
this is impossible in practice.

I've tried approaching this problem in particular from the transactional QM
model, but end up with violations of causality. I would much appreciate an
explanation from any QM perspective.

Thank you,
Muslaf

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Muslaf Nemon wrote: > > Hello, > > This must be an elementary question, so I apologize in advance. I'm having > difficulty grasping what happens when we have two laser beams, identical and > collinear, but perfectly out of phase, impingent on a screen. I understand > this is impossible in practice. > > I've tried approaching this problem in particular from the transactional QM > model, but end up with violations of causality. I would much appreciate an > explanation from any QM perspective. Where does the input energy go when an optical interferometer is perfectly nulled? This is not merely an academic question. There are two purely huge high energy optical interferometers run at null for days and weeks at a crack, one in Washington state, one in Louisiana. Ask yourself, "where do all the LIGO kilowatts go?" -- Uncle Al http://www.mazepath.com/uncleal/ (Toxic URL! Unsafe for children and most mammals) http://www.mazepath.com/uncleal/qz.pdf



Uncle Al writes >Where does the input energy go when an optical interferometer is >perfectly nulled? This is not merely an academic question. >There are two purely huge high energy optical interferometers run >at null for days and weeks at a crack, one in Washington state, >one in Louisiana. Ask yourself, "where do all the LIGO kilowatts >go?" One would imagine that the power in the beam is mostly just reflected back and forth. The input photon energy must thus be dumped in the mirrors, beamsplitters and the lasers themselves. Hmmm. I imagine even small amounts of inputted thermal energy to beamsplitters and mirrors wouldn't help the accuracy one little bit. -- Oz This post is worth absolutely nothing and is probably fallacious. BTOPENWORLD address about to cease. DEMON address no longer in use. >>Use oz@farmeroz.port995.com (whitelist check on first posting)<< ozacoohdb@despammed.com still functions.

## Two Source Interference

<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>\n* Uncle Al writes:\n\n&gt; Muslaf Nemon wrote:\n&gt;&gt;\n&gt;&gt; Hello,\n&gt;&gt;\n&gt;&gt; This must be an elementary question, so I apologize in advance. I\'m having\n&gt;&gt; difficulty grasping what happens when we have two laser beams, identical and\n&gt;&gt; collinear, but perfectly out of phase, impingent on a screen. I understand\n&gt;&gt; this is impossible in practice.\n&gt;&gt;\n&gt;&gt; I\'ve tried approaching this problem in particular from the transactional QM\n&gt;&gt; model, but end up with violations of causality. I would much appreciate an\n&gt;&gt; explanation from any QM perspective.\n\n&gt; Where does the input energy go when an optical interferometer is\n&gt; perfectly nulled? This is not merely an academic question.\n&gt; There are two purely huge high energy optical interferometers run\n&gt; at null for days and weeks at a crack, one in Washington state,\n&gt; one in Louisiana. Ask yourself, "where do all the LIGO kilowatts\n&gt; go?"\n\nBack to the laser, of course (Watts, BTW, not kilowatts). And to\nprevent this appalling waste of light, the people at LIGO are\neco-friendly enough to recycle the light - a mirror in the *input*\nreflects the light back to the interferometer, thus forming a cavity\nwith the interferometer.\n\nAs usual in steady-state cavity, the power coupled to the cavity is\nequal to the power dissipated by the cavity - if no light is allowed\nto get out, all of it will be converted to heat in the optical\nelements.\n\n\n--\nSpace - the final frontier\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">&nbsp;&nbsp;View this Usenet post in original ASCII form </a></div><P></jabberwocky>* Uncle Al writes:

> Muslaf Nemon wrote:
>>
>> Hello,
>>
>> This must be an elementary question, so I apologize in advance. I'm having
>> difficulty grasping what happens when we have two laser beams, identical and
>> collinear, but perfectly out of phase, impingent on a screen. I understand
>> this is impossible in practice.
>>
>> I've tried approaching this problem in particular from the transactional QM
>> model, but end up with violations of causality. I would much appreciate an
>> explanation from any QM perspective.

> Where does the input energy go when an optical interferometer is
> perfectly nulled? This is not merely an academic question.
> There are two purely huge high energy optical interferometers run
> at null for days and weeks at a crack, one in Washington state,
> one in Louisiana. Ask yourself, "where do all the LIGO kilowatts
> go?"

Back to the laser, of course (Watts, BTW, not kilowatts). And to
prevent this appalling waste of light, the people at LIGO are
eco-friendly enough to recycle the light - a mirror in the *input*
reflects the light back to the interferometer, thus forming a cavity
with the interferometer.

As usual in steady-state cavity, the power coupled to the cavity is
equal to the power dissipated by the cavity - if no light is allowed
to get out, all of it will be converted to heat in the optical
elements.

--
Space - the final frontier



"Muslaf Nemon" wrote in message news:VT2Hc.45249\$P7.19176@pd7tw3no... > Hello, > > This must be an elementary question, so I apologize in advance. I'm having > difficulty grasping what happens when we have two laser beams, identical and > collinear, but perfectly out of phase, impingent on a screen. I understand > this is impossible in practice. > > I've tried approaching this problem in particular from the transactional QM > model, but end up with violations of causality. I would much appreciate an > explanation from any QM perspective. > > Thank you, > Muslaf > Am I right in thinking that this might involve suppressed emission? If so, does that give rise to issues of causality? Thank you, Muslaf

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