 | |  |  | | | | | | | | | | | | |
 |
|
|
|
|
|
|
 |
|
 |
|
| |
| Author |
Message |
IAM1
B.V. Info-a-holic
Joined: Sep 01, 2006
Posts: 5474
|
 Posted: Sun Aug 12, 2007 8:46 am Post subject: Physicists have 'solved' mystery of levitation |
 |
|
| |
Physicists have 'solved' mystery of levitation
Photo above shows a Beijing saleswoman who demonstrates toy which levitates by magnetic force; Physicists have 'solved' mystery of levitation
08/08/2007
By Roger Highfield,
Science Editor
Levitation has been elevated from being pure science fiction to science fact, according to a study reported today by physicists.
In theory the discovery could be used to levitate a person.....
In earlier work the same team of theoretical physicists showed that invisibility cloaks are feasible.
Now, in another report that sounds like it comes out of the pages of a Harry Potter book, the University of St Andrews team has created an 'incredible levitation effects’ by engineering the force of nature which normally causes objects to stick together.
Professor Ulf Leonhardt and Dr Thomas Philbin, from the University of St Andrews in Scotland, have worked out a way of reversing this phenomenon, known as the Casimir force, so that it repels instead of attracts.
http://www.du.edu/~jcalvert/phys/casimir.htm
Casimir Force
http://physicsworld.com/cws/article/print/9747
The Casimir effect: a force from nothing - Physics World - physicsworld.com
Their discovery could ultimately lead to frictionless micro-machines with moving parts that levitate But they say that, in principle at least, the same effect could be used to levitate bigger objects too, even a person.
The Casimir force is a consequence of quantum mechanics, the theory that describes the world of atoms and subatomic particles that is not only the most successful theory of physics but also the most baffling.
The force is due to neither electrical charge or gravity, for example, but the fluctuations in all-pervasive energy fields in the intervening empty space between the objects and is one reason atoms stick together, also explaining a “dry glue” effect that enables a gecko to walk across a ceiling.
Now, using a special lens of a kind that has already been built, Prof Ulf Leonhardt and Dr Thomas Philbin report in the New Journal of Physics they can engineer the Casimir force to repel, rather than attact.
Because the Casimir force causes problems for nanotechnologists, who are trying to build electrical circuits and tiny mechanical devices on silicon chips, among other things, the team believes the feat could initially be used to stop tiny objects from sticking to each other.
Prof Leonhardt explained, “The Casimir force is the ultimate cause of friction in the nano-world, in particular in some microelectromechanical systems.
Such systems already play an important role - for example tiny mechanical devices which triggers a car airbag to inflate or those which power tiny 'lab on chip’ devices used for drugs testing or chemical analysis.
Micro or nano machines could run smoother and with less or no friction at all if one can manipulate the force.” Though it is possible to levitate objects as big as humans, scientists are a long way off developing the technology for such feats, said Dr Philbin.
The practicalities of designing the lens to do this are daunting but not impossible and levitation “could happen over quite a distance”.
Prof Leonhardt leads one of four teams - three of them in Britain - to have put forward a theory in a peer-reviewed journal to achieve invisibility by making light waves flow around an object - just as a river flows undisturbed around a smooth rock.
http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/08/06/nlevitate106.xml&CMP=ILC-mostviewedbox
Physicists have 'solved' mystery of levitation - Telegraph |
|
|
| Back to top |
|
 |
| Author |
Message |
Snyper493
B.V. Lurker
Joined: Aug 09, 2007
Posts: 32
|
| Posted: Tue Aug 14, 2007 12:14 pm Post subject: |
|
|
| |
| Its Magnetic force that keeps it up. I have seen that before, but heres the thing, you need to to spin it to get it to float or levitate. |
|
|
| Back to top |
|
|
| Author |
Message |
IAM1
B.V. Info-a-holic
Joined: Sep 01, 2006
Posts: 5474
|
| Posted: Tue Aug 14, 2007 12:40 pm Post subject: |
|
|
| |
| Snyper493 wrote: |
| Its Magnetic force that keeps it up. I have seen that before, but heres the thing, you need to to spin it to get it to float or levitate. |
Hi Snyper493!
As it states in the article, it is the magnetic force that causes the levitation, but there is no spinning here or involved in the levitation of this object seen in the photo on this post. Not sure where you got the idea the object had to spin to levitate it? Peace....IAM1 |
|
|
| Back to top |
|
|
| Author |
Message |
Rhythm
B.V. Lurker
Joined: Jul 19, 2007
Posts: 304
|
| Posted: Tue Aug 14, 2007 1:04 pm Post subject: |
|
|
| |
| the article is not talking about magnetic force. And the picture is not relevant to the article. It is a toy. |
|
|
| Back to top |
|
|
| Author |
Message |
dangermite
B.V. VIP - Contributor
Joined: Jun 25, 2006
Posts: 3586
Location: Land o´ Lincoln
|
| Posted: Wed Aug 15, 2007 12:11 am Post subject: |
|
|
| |
| Rhythm wrote: |
| the article is not talking about magnetic force. And the picture is not relevant to the article. It is a toy. |
Precisely, the Casimir effect doesn't have to do with magnetism, but with quantum mechanical vacuum fluctuations. It is a very weak force. I do not believe it is responsible for the ceiling-climbing geckos, as the article suggests, either. The force would be too weak, I believe. |
|
_________________
. . . et in Arcadia ego . . . |
|
| Back to top |
|
|
| Author |
Message |
IAM1
B.V. Info-a-holic
Joined: Sep 01, 2006
Posts: 5474
|
| Posted: Thu Aug 16, 2007 1:43 pm Post subject: |
|
|
| |
The photo and comment below the photo does go with the article. I wouldn't have posted them together unless they both came with each other. And it is a photo demonstration of the levitation written about in the article.
Regarding the statement below about the Casimir force, the article, I feel, is trying to explain how this force works, which seems to be like a suction or dry glue type effect. I think it's important to remember that this Casimir force is still just a theory of physics:
'The force is due to neither electrical charge or gravity, for example, but the fluctuations in all-pervasive energy fields in the intervening empty space between the objects and is one reason atoms stick together, also explaining a “dry glue” effect that enables a gecko to walk across a ceiling.'
The scientist's engineered the Casimir force to repel rather than attract and that is how they achieved this levitation. Peace....IAM1 |
|
|
| Back to top |
|
|
| Author |
Message |
dangermite
B.V. VIP - Contributor
Joined: Jun 25, 2006
Posts: 3586
Location: Land o´ Lincoln
|
| Posted: Thu Aug 16, 2007 1:53 pm Post subject: |
|
|
| |
| IAM1 wrote: |
'The force is due to neither electrical charge or gravity, for example, but the fluctuations in all-pervasive energy fields in the intervening empty space between the objects and is one reason atoms stick together, also explaining a “dry glue” effect that enables a gecko to walk across a ceiling.'
|
I have never before heard of the Casimir force being responsible for the gecko's ceiling climbing abilities. A back of the envelope calculation of the magnitudes of the forces needed pretty much rules it out. Also, it is more than jsut a theory, it has been measured experimentally.
http://www.du.edu/~jcalvert/phys/casimir.htm
The picture linked to the article does not represent the Casimir effect. I am sure it is through no fault of your's, IAM1. The authors of the article are mistaken, or misrepresenting their case. |
|
_________________
. . . et in Arcadia ego . . . |
|
| Back to top |
|
|
| Author |
Message |
IAM1
B.V. Info-a-holic
Joined: Sep 01, 2006
Posts: 5474
|
| Posted: Thu Aug 16, 2007 2:34 pm Post subject: |
|
|
| |
| dangermite wrote: |
| IAM1 wrote: |
'The force is due to neither electrical charge or gravity, for example, but the fluctuations in all-pervasive energy fields in the intervening empty space between the objects and is one reason atoms stick together, also explaining a “dry glue” effect that enables a gecko to walk across a ceiling.'
|
I have never before heard of the Casimir force being responsible for the gecko's ceiling climbing abilities. A back of the envelope calculation of the magnitudes of the forces needed pretty much rules it out. Also, it is more than jsut a theory, it has been measured experimentally.
http://www.du.edu/~jcalvert/phys/casimir.htm
The picture linked to the article does not represent the Casimir effect. I am sure it is through no fault of your's, IAM1. The authors of the article are mistaken, or misrepresenting their case. |
Hi dangermite!
I agree with you in that I don't think the article was put together well, I apologize for that one, but I wasn't able to find any other article's written about this (and there were a few of them) levitation discovery that explained it clearly.
In regards to the gecko on the ceiling, it was my understanding that the person who wrote that was using it as an example and not a literal explanation of a force in physics which caused the gecko to adhere and/or walk along the ceiling.
Thanks for the link and your understanding  , because when it comes to physics.... things can get quite complicated. Peace....IAM1 |
|
|
| Back to top |
|
|
| Author |
Message |
dangermite
B.V. VIP - Contributor
Joined: Jun 25, 2006
Posts: 3586
Location: Land o´ Lincoln
|
| Posted: Fri Aug 17, 2007 4:40 am Post subject: |
|
|
| |
I think when I first came across the Casimir effect, there was some talk of possibly using it to generate useful work (turn a turbine to generate electricity, etc.). For instance, if you brought two plates close together, the Casimir effect would push them together and that force could be coupled to drive some mechanism and the work could be extracted. The problem was that once the plates were together, you would have to do some work to gt them separated again, and that amount of work would pretty much equal the work extracted from when they came together.
This finding might change things a little bit in that regard. I wasn't able to find their paper, yet, but will have to give it a look once I track it down.
EDIT:
Found it
link |
|
_________________
. . . et in Arcadia ego . . . |
|
| Back to top |
|
|
|
|
|
 |
|
 |
|
| | | | | | | |
| |
blocks-left.jpg
blocks-left.jpg
blocks-left.jpg
|  |
Online Stats: 
