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Melroy
Apr21-04, 10:44 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>Hi\n\nYesterday Gravity Probe B experiment (http://einstein.stanford.edu/)\nwas launched. My naive questions to people working on Brane Worlds and\nstring theory is that do any of the brane world/extra dimensions models\nmake any predictions about geodetic and Lense Thirring precession which is\ndifferent from GR and which could be tested by Gravity Probe B?\n\nThanks\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>Hi

Yesterday Gravity Probe B experiment (http://einstein.stanford.edu/)
was launched. My naive questions to people working on Brane Worlds and
string theory is that do any of the brane world/extra dimensions models
make any predictions about geodetic and Lense Thirring precession which is
different from GR and which could be tested by Gravity Probe B?

Thanks
Lubos Motl
Apr22-04, 08:47 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 Wed, 21 Apr 2004, Melroy wrote:\n\n&gt; Yesterday Gravity Probe B experiment (http://einstein.stanford.edu/)\n&gt; was launched. My naive questions to people working on Brane Worlds and\n&gt; string theory is that do any of the brane world/extra dimensions models\n&gt; make any predictions about geodetic and Lense Thirring precession which is\n&gt; different from GR and which could be tested by Gravity Probe B?\n\nDear Melroy,\n\nsomeone else may correct me if my answer is incomplete or wrong, but my\nanswer will probably be disappointing for you. Gravity Probe B is meant to\ntest *classical* general relativity, as constructed in 1915 (for example\nframe dragging, which can be called a "Machian" effect that survived in\ngeneral relativity), and the effects of the extra dimensions and quantum\ngravity are negligible at such long distances and therefore this\nexperiment won\'t be able to say anything about these matters. Well, there\nare some other provocative "particle physics" theories around, such as\nghost condensation, that could in principle be supported by Gravity Probe\nB, but it is also unlikely.\n\nAll the best\nLubos\n_____________________________________ _________________________________________\nE-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/\neFax: +1-801/454-1858 work: +1-617/496-8199 home: +1-617/868-4487 (call)\n^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\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>On Wed, 21 Apr 2004, Melroy wrote:

> Yesterday Gravity Probe B experiment (http://einstein.stanford.edu/)
> was launched. My naive questions to people working on Brane Worlds and
> string theory is that do any of the brane world/extra dimensions models
> make any predictions about geodetic and Lense Thirring precession which is
> different from GR and which could be tested by Gravity Probe B?

Dear Melroy,

someone else may correct me if my answer is incomplete or wrong, but my
answer will probably be disappointing for you. Gravity Probe B is meant to
test *classical* general relativity, as constructed in 1915 (for example
frame dragging, which can be called a "Machian" effect that survived in
general relativity), and the effects of the extra dimensions and quantum
gravity are negligible at such long distances and therefore this
experiment won't be able to say anything about these matters. Well, there
are some other provocative "particle physics" theories around, such as
ghost condensation, that could in principle be supported by Gravity Probe
B, but it is also unlikely.

All the best
Lubos
__{_______________________________________________ _____________________________}
E-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/
eFax: +1-801/454-1858 work: +1-617/496-8199 home: +1-617/868-4487 (call)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sol2
Apr23-04, 10:46 PM
Hi

Yesterday Gravity Probe B experiment (http://einstein.stanford.edu/)
was launched. My naive questions to people working on Brane Worlds and
string theory is that do any of the brane world/extra dimensions models
make any predictions about geodetic and Lense Thirring precession which is
different from GR and which could be tested by Gravity Probe B?

Thanks

From a novice perspective, the Vasant corporation ideas here in terms of spin,
would be revealing to me on how the dynamics of how this gyroscope might work?

http://www.newscientist.com/data/images/ns/9999/99994875F1.JPG

"The balls inside the encased gyroscope....."

This is a question about what might be revealling from dynamics on the brane?


"Once we can measure the effect in the Solar System, says Kip Thorne, a gravitational physicist at the California Institute of Technology, "we can definitely understand how the same phenomena are working in the distant Universe and around black holes," which cause much stronger warping."

http://www.newscientist.com/news/news.jsp?id=ns99994875

We needed a way in which to bring Penroses issue of "Quanglement" to the forefront for consideration? A call for a new language.

I would see this as a necessary feature of what might be revealing of the instantaneous understanding of the spacetime fabric.

I would need correction here from those of better minds to speak this.

Regards