Sat Jun 8, 2013, 04:51 PM
n2doc (47,953 posts)
A Universe Made of Tiny, Random Chunks
Physics: A new idea holds that the spacetime that makes up our universe is inherently uncertain.
BY CARL FREDERICK ne of science’s most crucial yet underappreciated achievements is the description of the physical universe using mathematics—in particular, using continuous, smooth mathematical functions, like how a sine wave describes both light and sound. This is sometimes known as Newton’s zeroth law of motion in recognition of the fact that his famed three laws embody such functions. In the early 20th century, Albert Einstein gave a profound jolt to the Newtonian universe, showing that space was both curved by mass and inherently linked to time. He called the new concept spacetime. While this idea was shocking, its equations were smooth and continuous, like Newton’s. But some recent findings from a small number of researchers suggest that randomness is actually inherent in spacetime itself, and that Newton’s zeroth law also breaks down, on small scales. Let’s explore what this means. more http://nautil.us/issue/2/uncertainty/auniversemadeoftinyrandomchunks

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5 replies  Author  Time  Post 
A Universe Made of Tiny, Random Chunks (Original post) 
n2doc  Jun 2013  OP 
longship  Jun 2013  #1  
Jim__  Jun 2013  #2  
Faygo Kid  Jun 2013  #3  
heaven05  Jun 2013  #4  
postulater  Jun 2013  #5 
Response to n2doc (Original post)
Sat Jun 8, 2013, 05:19 PM
longship (40,416 posts)
1. Well, this has been basic physics since I studied it in the 70's.
We live in a quantum universe. That's a core finding in physics. Due to inherent problems of scale, we have not yet resolved gravity at the quantum scale. Nevertheless, there is little doubt that there lies something new there.
This article is nothing new but it is a clear exposition of the issues. Happy to R&K. 
Response to n2doc (Original post)
Sat Jun 8, 2013, 05:34 PM
Jim__ (13,765 posts)
2. A paper from 2011 disagrees that the size of quantum graininess can be the Planck length.
The article referenced in the OP says:
The Planck length turns out to be a very short distance: about 10[sup]35[/sup] meters. It is a hundred million trillion times smaller than the diameter of a proton—too small to measure and, arguably, too small to ever be measured.
... There is another important aspect of the Planck length. Relativity predicts that distances as measured by an observer in a fastmoving reference frame shrink—the socalled Lorentz contraction. But the Planck length is special—it’s the only length that can be derived from the constants c, G, and h without adding some arbitrary constant—so it may retain the same value in all reference frames, not subject to any Lorentz contraction. But the Planck length is derived from universal constants, so it must have the same value in all reference frames; it can’t change according to a Lorentz contraction. This implies that relativity theory does not apply at this size scale. We need some new scientific explanation for this phenomenon, and stochastic spacetime might provide it. The idea that the Planck length cannot be shortened by the Lorentz contraction suggests that it is a fundamental quantum, or unit, of length. As a result, volumes with dimensions smaller than the Planck length arguably don’t exist. The Planck length then, is a highly likely candidate for the size of a spacetime “grain,” the smallest possible piece of spacetime. A description of the 2011 paper says: Einstein’s General Theory of Relativity describes the properties of gravity and assumes that space is a smooth, continuous fabric. Yet quantum theory suggests that space should be grainy at the smallest scales, like sand on a beach.
... Some theories suggest that the quantum nature of space should manifest itself at the ‘Planck scale’: the minuscule 10[sup]35[/sup] of a metre, where a millimetre is 10[sup]3[/sup] m. However, Integral’s observations are about 10 000 times more accurate than any previous and show that any quantum graininess must be at a level of 10[sup]48[/sup] m or smaller. “This is a very important result in fundamental physics and will rule out some string theories and quantum loop gravity theories,” says Dr Laurent. more ... 
Response to n2doc (Original post)
Sat Jun 8, 2013, 06:53 PM
Faygo Kid (21,473 posts)
3. This Universe, and all the others
Bubbles. Everywhere.

Response to n2doc (Original post)
Sat Jun 8, 2013, 07:36 PM
heaven05 (18,124 posts)
4. I
feel like a tiny random chunk of the universe living on a very messy planet.

Response to n2doc (Original post)
Sun Jun 9, 2013, 04:00 PM
postulater (5,075 posts)
5. I know for sure that MY universe is inherently uncertain.
