Scientists confirm a structural similarity found in both human cells and neutron stars

November 1, 2016 by Julie Cohen, University of California - Santa Barbara
Similar shapes — structures consisting of stacked sheets connected by helical ramps — have been found in cell cytoplasm (left) and neutron stars (right). Credit: University of California - Santa Barbara

We humans may be more aligned with the universe than we realize. According to research published in the journal Physical Review C, neutron stars and cell cytoplasm have something in common: structures that resemble multistory parking garages.

In 2014, UC Santa Barbara soft condensed-matter physicist Greg Huber and colleagues explored the biophysics of such shapes—helices that connect stacks of evenly spaced sheets—in a cellular organelle called the endoplasmic reticulum (ER). Huber and his colleagues dubbed them Terasaki ramps after their discoverer, Mark Terasaki, a cell biologist at the University of Connecticut.

Huber thought these "" were unique to soft matter (like the interior of cells) until he happened upon the work of nuclear physicist Charles Horowitz at Indiana University. Using computer simulations, Horowitz and his team had found the same shapes deep in the crust of neutron stars.

"I called Chuck and asked if he was aware that we had seen these structures in cells and had come up with a model for them," said Huber, the deputy director of UCSB's Kavli Institute for Theoretical Physics (KITP). "It was news to him, so I realized then that there could be some fruitful interaction."

The resulting collaboration, highlighted in Physical Review C, explored the relationship between two very different models of matter.

Nuclear physicists have an apt terminology for the entire class of shapes they see in their high-performance computer simulations of neutron stars: nuclear pasta. These include tubes (spaghetti) and parallel sheets (lasagna) connected by helical shapes that resemble Terasaki ramps.

"They see a variety of shapes that we see in the cell," Huber explained. "We see a tubular network; we see parallel sheets. We see sheets connected to each other through topological defects we call Terasaki ramps. So the parallels are pretty deep."

However, differences can be found in the underlying physics. Typically matter is characterized by its phase, which depends on thermodynamic variables: density (or volume), temperature and pressure—factors that differ greatly at the nuclear level and in an intracellular context.

"For , the strong nuclear force and the electromagnetic force create what is fundamentally a quantum-mechanical problem," Huber explained. "In the interior of cells, the forces that hold together membranes are fundamentally entropic and have to do with the minimization of the overall free energy of the system. At first glance, these couldn't be more different."

Another difference is scale. In the nuclear case, the structures are based on nucleons such as protons and neutrons and those building blocks are measured using femtometers (10-15). For intracellular membranes like the ER, the length scale is nanometers (10-9). The ratio between the two is a factor of a million (10-6), yet these two vastly different regimes make the same shapes.

"This means that there is some deep thing we don't understand about how to model the nuclear system," Huber said. "When you have a dense collection of protons and neutrons like you do on the surface of a neutron star, the strong nuclear force and the electromagnetic forces conspire to give you phases of matter you wouldn't be able to predict if you had just looked at those forces operating on small collections of neutrons and protons."

The similarity of the structures is riveting for theoretical and nuclear physicists alike. Nuclear physicist Martin Savage was at the KITP when he came across graphics from the new paper on arXiv, a preprint library that posts thousands of physics, mathematics and computer science articles. Immediately his interest was piqued.

"That similar phases of matter emerge in biological systems was very surprising to me," said Savage, a professor at the University of Washington. "There is clearly something interesting here."

Co-author Horowitz agreed. "Seeing very similar shapes in such strikingly different systems suggests that the energy of a system may depend on its shape in a simple and universal way," he said.

Huber noted that these similarities are still rather mysterious. "Our paper is not the end of something," he said. "It's really the beginning of looking at these two models."

Explore further: Biology meets geometry: Describing geometry of common cellular structure

More information: "Parking-garage" structures in nuclear astrophysics and cellular biophysics, Phys. Rev. C 94, 055801 – Published 1 November 2016, … 3/PhysRevC.94.055801

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3 / 5 (4) Nov 01, 2016
A nice example to demonstrate that the efffective theories of seemingly very different systems may converge or even be identitical.
Nov 01, 2016
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1.8 / 5 (5) Nov 01, 2016
Well, the internal structure of neutron stars is still deeply speculative. We are comparing apples and oranges here..

No, there is nothing in the article about apples & oranges. Did you actually read the article or is it something you're smoking?
Nov 01, 2016
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5 / 5 (5) Nov 01, 2016
Also parking garages...
not rated yet Nov 01, 2016
Nov 01, 2016
This comment has been removed by a moderator.
not rated yet Nov 01, 2016
How about the similarity in the structure of neurons and the cosmic web?
not rated yet Nov 01, 2016
1 / 5 (6) Nov 02, 2016
There goes another group of physicists running around naked yelling Eureka whenever they see some apparent pattern in living things. No scientists from other fields make such a huge fuss about every trivial observation they make. Common virtues such as rigor, substantiation, sincerity etc. seems to simply disappear from their mind when they treat problems in biological or social sciences. Such pathological mentality, which probably comes out of an odd mixture of simultaneous feelings of contempt and inferiority toward those other fields, is a hallmark of physicists' mind.
4.2 / 5 (5) Nov 02, 2016
Well, if you don't like it then stop reading science news.

@218astatine: Research findings are usually meant to be published, not kept under the rug. If they are not dangerous, then there is no reason to hide them out of modesty.
1 / 5 (1) Nov 02, 2016
Könnte es sein, dass ein Sonnensystem das Gleiche ist wie ein Atom - z. B. einer Kaffeetasse? Das Atom betrachten wir mit einem Microskop, das Sonnensystem mit einem Teleskop. Sehen wir mit beiden Messgeräten womöglich exakt das Gleiche?

Die Stringtheorie postuliert mehrere Dimensionen. Könnte eine dieser Dimensionen der Makrokosmos und eine andere Dimension der Mikrokosmos sein?

Ist das alles nur eine Frage des Messgeräts, welche Dimension wir von irgendetwas Bestimmten sehen?

Falls alles zusammenhängt und der Makrokosmos nur eine vergrößerte Darstellung des Mikrokosmos ist, was passiert dann mit Sternen oder Sonnensystemen, wenn wir in Atomkraftwerken Kerne spalten?
5 / 5 (4) Nov 02, 2016
I'll hazard a hypothesis of when similar structures appear in different contexts:

It may be when two (or more forces/states) of different dimensionality act at similar strength in a particular region (e.g. 3D vs. 2D forces or quantized vs. non-quantized states )
In the case of the 'parking garage' structures) it looks like a surface energy force is vying with a quantized state.

In case of the membrane structures the polar nature of lipids in membranes make for a natural quantization into layers, while the surface energy constraint makes for localization of the connections.

Oh...and if your local restaurant offers nuclear pasta: don't order it. It'll pass right through you.
1 / 5 (3) Nov 02, 2016
Well, the internal structure of neutron stars is still deeply speculative. We are comparing apples and oranges here..

Hehe...more like apples and theoretical apples. Very interesting if this prediction turns out to be accurate'll likely be a few hundred years (if not a few thousand) before humanity is capable of making a direct observation of neutron star material so we may all be long-dead by then assuming that we don't wipe ourselves out through sheer stupidity or run afoul of random space rocks. Here's to hoping that Kurzweil's on the right track.

Oh...and if your local restaurant offers nuclear pasta: don't order it. It'll pass right through you.

Highest-brow diarrhea joke ever. 1k points!!

not rated yet Nov 04, 2016
I'm ok with being despised and rejected, but meanwhile..I would appreciate any tips on best ways to spot pseudo science... Clearly, it would be half witted to accept sci information as truth..without reasonable ..already established as trustworthy...backing... from recognised authorities.? But they cannot ...I trusted in the same way that humans, without question...accept the "word of god" or god substitutes..My own GUESS (as a sci illiterate) is that language used in reports CAN indicate phoney bases... for instance..this statement jars in my head at once.. "This means that there is some deep thing we don't understand about how to model the nuclear system," Huber said. The use of the idea of an obscure "deep thing".....just sounds crummy, uninformed?...badly put....?...Please advise...what is it..if there is anything...that makes serious scientists...groan and recognise tripe? I don't want to waste hours of my life reading..OR...sharing...untrue, unreliable,information.
5 / 5 (3) Nov 04, 2016
.I would appreciate any tips on best ways to spot pseudo science

Look for outrageous claims.
Look for missing references or references to non-peer reviewed journals
Look for scientese goobledygook or redefinition of technical terms
Look for qualitative instead of quantitative statements (i.e. lots of soft adjectives like "very", "most", "largely", "highly", etc. instead of hard numbers)
Look to an active avoidance of putting theories into hard math
Look to anything that avoids testability by making only very vague predictions (or none at all...e.g. people always saying "this article is in line with my theory" but never positing a novel prediction based on their theory)
Look for someone not following the scientific method
(especially the "gather data and test predictions" part)
Look for someone saying "it's like this: prove me wrong"

If that doen't help. Read this:
Nov 04, 2016
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5 / 5 (2) Nov 04, 2016
According to the claims of these "eyewitnesses", and these stars are some living beings, about: no? No one has made this claim. Where do you get this crazy idea?

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