[math-fun] Has someone repealed the laws of physics?
Science News reports in "Out of Sight" [15 July 2006, vol 170 no 3 p 42]: "Electromagnetic radiation typically exerts a repulsive pressure on objects, so it should, in theory, attract metamaterials. Also, the well-known Doppler shift, in which the frequency of electromagnetic radiation from an object increases as the object approaches, is expected to reverse for metamaterials. Experiments have yet to confirm those two predictions." IMHO, attractive pressure from EM radiation would violate conservation of energy and momentum, while reverse Doppler shift would violate relativity. Am I confused, or should Science News be embarassed? --ms
On 7/29/06, Mike Speciner <ms@alum.mit.edu> wrote:
IMHO, attractive pressure from EM radiation would violate conservation of energy and momentum
I haven't read it, but this happens with the Casimir effect (OK, so it's not attraction, but rather, less repulsion from one side.) -- Mike Stay metaweta@gmail.com http://math.ucr.edu/~mike
Mike's original suspicion is entirely correct. If someone would post a URL to the Science News article, we could try to figure out what they're talking about. Gene --- "Cordwell, William R" <wrcordw@sandia.gov> wrote:
IMHO, attractive pressure from EM radiation would violate conservation of energy and momentum, while reverse Doppler shift would violate relativity. Am I confused, or should Science News be embarassed?
Casimir Effect?
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
http://www.sciencenews.org/articles/20060715/bob9.asp Eugene Salamin wrote:
Mike's original suspicion is entirely correct. If someone would post a URL to the Science News article, we could try to figure out what they're talking about.
Gene
--- "Cordwell, William R" <wrcordw@sandia.gov> wrote:
IMHO, attractive pressure from EM radiation would violate
conservation of energy and momentum, while reverse Doppler
shift would violate relativity. Am I confused, or should Science News be embarassed?
Casimir Effect?
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
After reading the article, I agree with Bill. Such materials would still be repelled by EM radiation. Less, perhaps, than some other materials, at least in some cases. But the basic range for this repulsion is from a maximum for a perfect mirror, to zero for a perfectly transparent object. These materials would fall into that range. The reverse Doppler shift doesn't make any sense to me at all. Franklin T. Adams-Watters --- "Cordwell, William R" <wrcordw@sandia.gov> wrote:
IMHO, attractive pressure from EM radiation would violate conservation of energy and momentum, while reverse Doppler shift would violate relativity. Am I confused, or should Science News be embarassed?
On 7/31/06, franktaw@netscape.net <franktaw@netscape.net> wrote:
After reading the article, I agree with Bill.
Such materials would still be repelled by EM radiation. Less, perhaps, than some other materials, at least in some cases. But the basic range for this repulsion is from a maximum for a perfect mirror, to zero for a perfectly transparent object. These materials would fall into that range.
The reverse Doppler shift doesn't make any sense to me at all.
Franklin T. Adams-Watters
I found a better explanation; it's only *within* the medium that you'd see a reverse doppler effect. http://www.aip.org/pnu/2000/split/pnu476-1.htm -- Mike Stay metaweta@gmail.com http://math.ucr.edu/~mike
Here's a paper on the subject. http://www.mit.edu/~soljacic/rev_dopp_PRL.pdf -- Mike Stay metaweta@gmail.com http://math.ucr.edu/~mike
Actually, that would be Mike Speciner <ms@alum.mit.edu> wrote: "IMHO, attractive pressure from EM radiation would violate conservation of energy and momentum, while reverse Doppler shift would violate relativity. Am I confused, or should Science News be embarassed?" (My apologies for not including enough attribution) Bill C. -----Original Message----- From: math-fun-bounces+cordwell=sandia.gov@mailman.xmission.com [mailto:math-fun-bounces+cordwell=sandia.gov@mailman.xmission.com] On Behalf Of franktaw@netscape.net Sent: Monday, July 31, 2006 2:13 PM To: math-fun@mailman.xmission.com Subject: Re: [math-fun] Has someone repealed the laws of physics? After reading the article, I agree with Bill. Such materials would still be repelled by EM radiation. Less, perhaps, than some other materials, at least in some cases. But the basic range for this repulsion is from a maximum for a perfect mirror, to zero for a perfectly transparent object. These materials would fall into that range. The reverse Doppler shift doesn't make any sense to me at all. Franklin T. Adams-Watters --- "Cordwell, William R" <wrcordw@sandia.gov> wrote:
IMHO, attractive pressure from EM radiation would violate conservation of energy and momentum, while reverse Doppler shift would violate relativity. Am I confused, or should Science News be embarassed?
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
--- franktaw@netscape.net wrote:
After reading the article, I agree with Bill.
Such materials would still be repelled by EM radiation. Less, perhaps, than some other materials, at least in some cases. But the basic range for this repulsion is from a maximum for a perfect mirror, to zero for a perfectly transparent object. These materials would fall into that
range.
The reverse Doppler shift doesn't make any sense to me at all.
Franklin T. Adams-Watters
--- "Cordwell, William R" <wrcordw@sandia.gov> wrote:
IMHO, attractive pressure from EM radiation would violate conservation of energy and momentum, while reverse Doppler shift would violate relativity. Am I confused, or should Science News be embarassed?
There is zero net force only in the case of a perfectly transparent body that does not change the direction of propagation of the transmitted light. If the direction changes, e.g. if the object is a prism, then there is a recoil. Gene __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
participants (6)
-
Cordwell, William R -
Eugene Salamin -
franktaw＠netscape.net -
Mike Speciner -
Mike Speciner -
Mike Stay