Mass Can Be 'Created' Inside Graphene, Say Physicists

[WizWom]

http://www.technologyreview.com/blog/ar ... ?nlid=3670

Mass Can Be 'Created' Inside Graphene, Say Physicists
The amazing properties of graphene now include the ability to create mass, according to a new prediction.

The nature of mass is one of the great enduring puzzles of science. What is mass and where does it come from are questions that have puzzled scientists and philosophers for centuries.

So the suggestion that mass can be created inside carbon nanotubes will produce some significant head scratching.

The idea comes from Abdulaziz Alhaidari at the Saudi Center for Theoretical Physics in Saudi Arabia and a few pals who begin with a review of the exotic properties of graphene, a 2-dimensional sheet of carbon "chickenwire".
...
Now let's jump to the antics that theoretical physicists sometimes get up to when thinking about mass. One idea is that mass arises because the universe has extra, space-like dimensions that exist only on the tiniest scales. Physicists say these dimensions are compactified.

Compactified dimensions have an important effect in quantum mechanics, changing the equations that describe the universe so that they include a term for mass. In these theories, that's how mass arises.

Alhaidari and co's idea is that a similar effect can occur in graphene if the space-like dimensions in graphene can be compactified. In other words, if you reduce the number of space-like dimensions in graphene from two to one, the massless equations that describe the behaviour of electrons and holes will change to include a term for mass. In effect, compactifying dimensions creates mass.

So how do you compactify space-like dimensions in graphene? Simple, you roll it up. This changes the sheet into a tube that is effectively 1-dimensional, at least as far as the electrons and holes are concerned.

By the way, if this pans out, Woodward's theory of mass are dead.

[Skipjack]

Hmm, how would that not violate the conservation of energy?
Or does the mass come from somewhere else in the universe?

[WizWom]

I haven't read the paper; this blog post is the first I saw of anything like it.

[GIThruster]

By the way, if this pans out, Woodward's theory of mass are dead.

I don't think so. His theory is certainly consistent withe 5D physics. We were talking about this last week. I doubt there's anything in higher dimensional physics that he's as of yet inconsistent with.

[Betruger]

Sure would be interesting to see what he'd have to say about it on his mailing list.

[icarus]

When the M-E turns out to be a bust they can then claim to generate thrust by creating mass using graphene and throwing it aft overboard, thrust the old-fashioned way .... momentum conservation.

If you can't violate momentum conservation why not violate mass conservation instead?

[chrismb]

I guess there's no reason to doubt whatever 'theoretical physics' has conjured up this result. As already mentioned, if mass has increased then the equivalent energy must've been put in - mc^2 's worth, no less.

So what they've probably predicted is that a very large amount of energy would need to be put in to roll this material - in other words, they've predicted it is gonna be an incredibly stiff material.

Fancy that, an exotic graphene chicken-wire is gonna be a stiff material. Really! Get away!

[dnavas]

When the M-E turns out to be a bust they can then claim to generate thrust by creating mass using graphene and throwing it aft overboard...

Why throw it overboard?
Roll it up, throw it backwards, unroll it, drag it forward, repeat.

-Dave

[Aero]

Better yet, make a conveyor belt with special rollers. The front roller rolls the graphene into a tube creating mass, the rear roller unrolls the tube and the mass goes away. Or, a Deane machine, roll the graphene up at the top and unroll it at the bottom.

[GIThruster]

Chris has a valid point though, simply "rolling up" graphene poses huge difficulties. It may well be it can't be so deformed at all, but would rather break.

Just FYI, none of the papers at arxiv are peer reviewed. There's no telling at face value what they're worth.

[Enginerd]

Chris has a valid point though, simply "rolling up" graphene poses huge difficulties. It may well be it can't be so deformed at all, but would rather break.

Unless I am missing something, arn't carbon nanotubes essentially tubes of rolled up graphene?

[GIThruster]

Chris has a valid point though, simply "rolling up" graphene poses huge difficulties. It may well be it can't be so deformed at all, but would rather break.

Unless I am missing something, arn't carbon nanotubes essentially tubes of rolled up graphene?

No. Graphene is a one atom thick planar sheet. It has all sorts of odd properties because of this, one of which made it the subject of this discussion.

Nothing to do with nanotubes. Its a very different pure-carbon construction.

[Enginerd]

Chris has a valid point though, simply "rolling up" graphene poses huge difficulties. It may well be it can't be so deformed at all, but would rather break.

Unless I am missing something, arn't carbon nanotubes essentially tubes of rolled up graphene?

No. Graphene is a one atom thick planar sheet. It has all sorts of odd properties because of this, one of which made it the subject of this discussion.

Nothing to do with nanotubes. Its a very different pure-carbon construction.

Perhaps. Yet it looks an awful lot like rolled up graphene to me...

[GIThruster]

Yes, but it is graphene's peculiar property as a one-atom-thick sheet, that has made it the topic of discussion. "Rolling it up" is not necessarily a simple thing.

This needs a materials scientist with specialization in nano-tech to know the in's and out's.

Not as simple a subject as it would seem.

[GIThruster]

Mechanical properties
As of 2009, graphene appears to be one of the strongest materials ever tested. Measurements have shown that graphene has a breaking strength 200 times greater than steel.[96] However, the process of separating it from graphite, where it occurs naturally, will require some technological development before it is economical enough to be used in industrial processes,[97] though this may be changing soon.[98]
Using an atomic force microscope (AFM), the spring constant of suspended graphene sheets has been measured. Graphene sheets, held together by van der Waals forces, were suspended over silicon dioxide cavities where an AFM tip was probed to test its mechanical properties. Its spring constant was in the range 1-5 N/m and the Young's modulus was 0.5 TPa, which differs from that of the bulk graphite. These high values make graphene very strong and rigid. These intrinsic properties could lead to using graphene for NEMS applications such as pressure sensors and resonators.[99]
As is true of all materials, regions of graphene are subject to thermal and quantum fluctuations in relative displacement. Although the amplitude of these fluctuations is bounded in 3D structures (even in the limit of infinite size), the Mermin-Wagner theorem shows that the amplitude of long-wavelength fluctuations will grow logarithmically with the scale of a 2D structure, and would therefore be unbounded in structures of infinite size. Local deformation and elastic strain are negligibly affected by this long-range divergence in relative displacement. It is believed that a sufficiently large 2D structure, in the absence of applied lateral tension, will bend and crumple to form a fluctuating 3D structure. Researchers have observed ripples in suspended layers of graphene,[25] and it has been proposed that the ripples are caused by thermal fluctuations in the material. As a consequence of these dynamical deformations, it is debatable whether graphene is truly a 2D structure.[5][49][50]

http://en.wikipedia.org/wiki/Graphene#M ... properties