Do M or string theory imply a lower limit to size?

In summary, Smolin said that if M theory exists, it cannot describe a world in which space is continuous and one can pack an infinite amount of information into any volume, no matter how small. He believes this is a consequence of general quantum mechanics principles and is true in any theory of quantum gravity. He also believes that there is a field or subfield developing around information in physics, and that entropy is closely related to information.
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In his 2001 Three Roads to Quantum Gravity, on its p.l66, Smolin says, "M theory, if it exists, cannot describe a world in which space is continuous and one can pack an infinite amount of information into any volume, no matter how small." As a lay person, I'm hoping to get an informed opinion as to whether that is still considered to be the invariable case, either in M theory or in any other extension of string theory that may controvert it.
 
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As far as I can tell, this is more a consequence of general quantum mechanics principles and is true in any* theory of quantum gravity, rather than being specific to String Theory.

* at least in Loop Quantum Gravity, but I think also in Non-Commutative Geometry.

To clarify: I'm pretty sure what I said is true of discreteness of space, but I wouldn't know how to prove it for information content.
 
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Yeah, I had thought it was a QM thing too, and, after one or two recent disappointments about the rigor of statements by major physicists, I'm just wanting to make sure Smolin (a leader in LQG) might not have been "unintentionally trying" to expand QM's "market share" of thesis writers, etc. If he wasn't, I was thinking there might have been developments since 2001 that could have changed the view he was presenting, which seems to have been based on units called "string bits", that I'm figuring might have been a sort of workaround toward reality, just as "limits" in calculus appear (to me) to be an approach toward infinity that never quite gets there, even if they cover more of the road than any alternative. (I didn't take calculus, and I'm DEFINITELY not trying to impugn the efforts of all you millions who did; my hat's off to you!)
 
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I haven't had much of a look at it but there seems to be a whole field or at least subfield developping around information in physics - the media tag for it is "it from bit", you might want to google that. But apart from that, information is closely related to entropy and there's a lot on entropy and information in QM/QG.
 
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It appears, IMO, Smolin has moved away from that view over the past few years. Ultimately, I believe the universe will submit to an explanation consistent with information theory.
 

FAQ: Do M or string theory imply a lower limit to size?

What is the minimum size implied by M or string theory?

M and string theory do not imply a specific minimum size for particles or objects. Instead, they propose that there is a fundamental unit of length, known as the Planck length, which is the smallest measurable length in the universe. This length is incredibly tiny, approximately 1.6 x 10^-35 meters.

Does this mean that there cannot be anything smaller than the Planck length?

It is currently unknown if there are objects or particles smaller than the Planck length. Some theories, such as loop quantum gravity, suggest that there may be a minimum size for objects in the universe. However, this has not been proven and is still a topic of debate among scientists.

How does the concept of a minimum size relate to the concept of infinity?

Infinity refers to the concept of something being endless or limitless. The idea of a minimum size suggests that there is a limit to how small something can be, which may seem contradictory to the concept of infinity. However, in physics, the concept of infinity is often used to describe mathematical models and does not necessarily reflect physical reality.

Can the Planck length be measured or observed?

The Planck length is incredibly small, making it impossible to measure or observe directly using current technology. It is far beyond the capabilities of even the most advanced particle accelerators. However, scientists can use theoretical models and calculations to study and understand this fundamental unit of length.

How does the concept of a minimum size impact our understanding of the universe?

The idea of a minimum size has significant implications for our understanding of the universe and the laws of physics. It suggests that there may be limits to how small things can be, and it challenges our current understanding of space and time. Additionally, the concept of a minimum size is an important aspect of many theories, such as string theory, which attempt to unify the laws of physics and explain the fundamental workings of the universe.

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