Random fields. [Archive] - Physics Forums

Rozmonth@Lycos.com

Jun7-05, 10:40 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>In QFT, the fields are randomly generated in \'empty\' space so space\nisn\'t empty. In string theory, what do randomly generated gravitational\nfields look like at the scale where you would normally see them?\nConsider that in GR, the gravitational field is self interacting, and\nthat it\'s affected by the energies of the other randomly generated\nfields at a larger scale (IE lower energy scale), but at a lower scale\n(IE higher energy scale) the fields are unified.\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>In QFT, the fields are randomly generated in 'empty' space so space
isn't empty. In string theory, what do randomly generated gravitational
fields look like at the scale where you would normally see them?
Consider that in GR, the gravitational field is self interacting, and
that it's affected by the energies of the other randomly generated
fields at a larger scale (IE lower energy scale), but at a lower scale
(IE higher energy scale) the fields are unified.

Igor Khavkine

Jun8-05, 10:50 AM

<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>On 2005-06-08, Rozmonth@Lycos.com <Rozmonth@Lycos.com> wrote:\n> In QFT, the fields are randomly generated in \'empty\' space so space\n> isn\'t empty. In string theory, what do randomly generated gravitational\n> fields look like at the scale where you would normally see them?\n> Consider that in GR, the gravitational field is self interacting, and\n> that it\'s affected by the energies of the other randomly generated\n> fields at a larger scale (IE lower energy scale), but at a lower scale\n> (IE higher energy scale) the fields are unified.\n\nUnfortunately, to say that "fields are randomly generated in empty\nspace" is very ill defined. I presume you are talking about so-called\nvacuum fluctuations of quantum fields. Unfortunately, this phenomenon is\nalso ill defined without further qualification.\n\nSo the only answer I can give to your question is this: the so-called\nvacuum fluctuations are very hard to picture, so they don\'t "look" like\nanything. The only thing that comes close is spontaneous\nparticle-antiparticle pair creation. This happens in strong\nelectromagnetic (and other fields) in non-equilibrium situations.\n\nAs to gravity, not even classical gravitational waves have been observed\n(although soon, hopefully). No quantum effects specific to gravity have\nbeen observed either. Nor has gravity been succesfully quantized. So,\nno-one knows what fluctuations of the gravitational field look like, nor\ndoes anyone know whether they look like anything.\n\nIgor\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>On 2005-06-08, Rozmonth@Lycos.com <Rozmonth@Lycos.com> wrote:
> In QFT, the fields are randomly generated in 'empty' space so space
> isn't empty. In string theory, what do randomly generated gravitational
> fields look like at the scale where you would normally see them?
> Consider that in GR, the gravitational field is self interacting, and
> that it's affected by the energies of the other randomly generated
> fields at a larger scale (IE lower energy scale), but at a lower scale
> (IE higher energy scale) the fields are unified.

Unfortunately, to say that "fields are randomly generated in empty
space" is very ill defined. I presume you are talking about so-called
vacuum fluctuations of quantum fields. Unfortunately, this phenomenon is
also ill defined without further qualification.

So the only answer I can give to your question is this: the so-called
vacuum fluctuations are very hard to picture, so they don't "look" like
anything. The only thing that comes close is spontaneous
particle-antiparticle pair creation. This happens in strong
electromagnetic (and other fields) in non-equilibrium situations.

As to gravity, not even classical gravitational waves have been observed
(although soon, hopefully). No quantum effects specific to gravity have
been observed either. Nor has gravity been succesfully quantized. So,
no-one knows what fluctuations of the gravitational field look like, nor
does anyone know whether they look like anything.

Igor

Eugene Stefanovich

Jun10-05, 01:21 AM

<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>Igor Khavkine wrote:\n> On 2005-06-08, Rozmonth@Lycos.com <Rozmonth@Lycos.com> wrote:\n>\n>>In QFT, the fields are randomly generated in \'empty\' space so space\n>>isn\'t empty. In string theory, what do randomly generated gravitational\n>>fields look like at the scale where you would normally see them?\n>>Consider that in GR, the gravitational field is self interacting, and\n>>that it\'s affected by the energies of the other randomly generated\n>>fields at a larger scale (IE lower energy scale), but at a lower scale\n>>(IE higher energy scale) the fields are unified.\n>\n>\n> Unfortunately, to say that "fields are randomly generated in empty\n> space" is very ill defined. I presume you are talking about so-called\n> vacuum fluctuations of quantum fields. Unfortunately, this phenomenon is\n> also ill defined without further qualification.\n>\n> So the only answer I can give to your question is this: the so-called\n> vacuum fluctuations are very hard to picture, so they don\'t "look" like\n> anything.\n\nI would use stronger words and say that so-called vacuum fluctuations\nare completely unphysical. There is nothing to fluctuate in vacuum.\nThis should be abundantly clear in the physical particle representation\nof RQD (physics/0504062). Vacuum is just empty space with 0 particles.\n\nEugene\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>Igor Khavkine wrote:
> On 2005-06-08, Rozmonth@Lycos.com <Rozmonth@Lycos.com> wrote:
>
>>In QFT, the fields are randomly generated in 'empty' space so space
>>isn't empty. In string theory, what do randomly generated gravitational
>>fields look like at the scale where you would normally see them?
>>Consider that in GR, the gravitational field is self interacting, and
>>that it's affected by the energies of the other randomly generated
>>fields at a larger scale (IE lower energy scale), but at a lower scale
>>(IE higher energy scale) the fields are unified.
>
>
> Unfortunately, to say that "fields are randomly generated in empty
> space" is very ill defined. I presume you are talking about so-called
> vacuum fluctuations of quantum fields. Unfortunately, this phenomenon is
> also ill defined without further qualification.
>
> So the only answer I can give to your question is this: the so-called
> vacuum fluctuations are very hard to picture, so they don't "look" like
> anything.

I would use stronger words and say that so-called vacuum fluctuations
are completely unphysical. There is nothing to fluctuate in vacuum.
This should be abundantly clear in the physical particle representation
of RQD (http://www.arxiv.org/abs/physics/0504062). Vacuum is just empty space with particles.

Eugene