Orders of Magnitude - From Quark to Superstring Theory

[RobinsonUK]

Fascinating looking at the various orders of magnitude (in terms of length), from the size of the visible universe (~10^25) to the size of a quark (~10^-15), and all orders inbetween.

But then I read about Superstring theory and how these strings are at the Planck length, around 10^-33. Why the huge jump from quark to string? Surely there must be loads of "stuff" in-between?

Apologies if this is a daft question!

 

[mfb]

Surely there must be loads of "stuff" in-between?

Why?
The Planck scale (length, but also all other Planck units) is far away from everything we know. That means there could be something in between, but it does not have to.

 

[RobinsonUK]

It doesn't mean it has to, but this huge gap is kind-of odd to me. I wondered whether there was a fundamental reason why there's a huge jump in magnitude before we get to the smallest of the objects we know about.

 

[mfb]

It doesn't mean it has to, but this huge gap is kind-of odd to me.

It looks odd to scientists as well - and it is one of the reasons why many scientists expect that new physics is not so far away from current physics.
Supersymmetry is one possibility, and extra dimensions can lower the Planck scale.

I wondered whether there was a fundamental reason why there's a huge jump in magnitude before we get to the smallest of the objects we know about.

If there is one, it is not known yet.

Strings are not "the smallest objects we know about". String theory is - even if you are optimistic - a concept how we might get a new theory at some point in the future.

 

[sardar]

I am always excited to see people exploring and questioning the vast range of orders of magnitude in our universe. It is indeed fascinating to think about the immense size of the visible universe compared to the tiny size of a quark. However, when it comes to Superstring theory, the jump from quark to string is not as arbitrary as it may seem.

Superstring theory is a theoretical framework that attempts to unify all the fundamental forces and particles in our universe. It proposes that the most basic building blocks of matter are not point-like particles, like quarks, but rather tiny one-dimensional strings. These strings vibrate at different frequencies, giving rise to the different particles and forces we observe in our universe.

Now, the reason why these strings are at the Planck length (10^-33) is because it is the scale at which quantum gravity becomes important. This is the scale at which the effects of gravity and quantum mechanics cannot be separated and must be considered together. At this incredibly small scale, the laws of physics as we know them break down and new theories, like Superstring theory, are needed to explain the behavior of particles.

So, to answer your question, there may not be "loads of stuff" in between the size of a quark and the Planck length. It is at this scale that our current understanding of physics reaches its limits and new theories are needed to explain the behavior of matter. Superstring theory is just one of the many theories being explored to understand the fundamental nature of our universe.

I hope this helps answer your question and I encourage you to continue exploring and questioning the vast range of orders of magnitude in our universe. After all, it is through curiosity and inquiry that we make new discoveries and further our understanding of the world around us.