# bots: tiny machinery, nanobots (molecule-sized bots) from 1k to millions swarming together to perform tasks

<< Multi-disciplinary research has led to the innovative fabrication of molecule-sized robots. Scientists are now advancing their efforts to make these robots interact and work together in the millions. >>

AA << have made molecular robots with three key components: microtubules, single-stranded DNA, and a light-sensing chemical compound. The microtubules act as the molecular robot's motor, converting chemical energy into mechanical work. The DNA strands act as the information processor due to its incredible ability to store data and perform multiple functions simultaneously. The chemical compound, azobenzene derivative, is able to sense light, acting as the molecular robot's on/off switch. (..) (They) have successfully controlled the shape of those swarms by tuning the length and rigidity of the microtubules. Relatively stiff robots swarm in uni-directional, linear bundles, while more flexible ones form rotating, ring-shaped swarms.>>

<< A continuing challenge, though, is making separate groups of robots swarm at the same time, but in different patterns. This is needed to perform multiple tasks simultaneously. >>

Scientists working to make molecule-sized robots swarm together to perform tasks. National Institute for Materials Science. Jun 18, 2020.

https://phys.org/news/2020-06-scientists-molecule-sized-robots-swarm-tasks.html   

Arif Md. Rashedul Kabir, Daisuke Inoue,  Akira Kakugo. Molecular swarm robots: recent progress and future challenges.  Science and Technology of Advanced Materials. 21:1, 323-332. doi: 10.1080/ 14686996.2020.1761761. Jun 16, 2020. 

https://www.tandfonline.com/doi/full/10.1080/14686996.2020.1761761 

Also

keyword 'bot' in FonT

https://flashontrack.blogspot.com/search?q=bot

keyword 'self-assembly' in FonT

https://flashontrack.blogspot.com/search?q=self-assembly

# life: unaware racisms

<< racism is about action in everyday life, not just words or hashtags at a time of uprising. We can be careful about what we say – language is conscious and controllable. But it is perfectly possible to hold deep-seated racist views, sometimes subconsciously, and simultaneously announce you are definitely not racist. >>

Geoff Beattie. Black Lives Matter: you may be a vocal supporter and still hold racist views. Jun 17, 2020

https://theconversation.com/black-lives-matter-you-may-be-a-vocal-supporter-and-still-hold-racist-views-140816    

Also

keyword "CTZ" in FonT

https://flashontrack.blogspot.com/search?q=ctz

# gst: critical points seem to act behind the complex behavior of collectives.

<< Current experiments support the controversial hypothesis that a well-known concept in physics—a critical point—is behind the striking behavior of collective animal systems. >>

AA << showed that light-controlled microswimming particles can be made to organize into collective states such as swarms and swirls. By studying the particles fluctuating between these states, they provide evidence for critical behavior—and support for a physical principle underlying the complex behavior of collectives.>>

<< What we observed is that the system can make sudden transitions from one state to the other, which demonstrates the flexibility needed to react to an external perturbation like a predator, (..) and provides clear evidence for a critical behavior. >> Clemens Bechinger

<< Through very simple interactions, they have shown that you can tune a physical system to a collective state - criticality - of balance between order and disorder. >> Iain Couzin

Physics principle explains order and disorder of swarms. University of Konstanz. Jun 11, 2020.

https://phys.org/news/2020-06-physics-principle-disorder-swarms.html

Bauerle T., Loffler R.C., Bechinger C. Formation of stable and responsive collective states in suspensions of active colloids. Nat Commun 11, 2547. doi: 10.1038/ s41467-020-16161-4. May 21, 2020.

https://www.nature.com/articles/s41467-020-16161-4

Also 

keyword 'self-assembly' in FonT

https://flashontrack.blogspot.com/search?q=self-assembly

# life: apropos of extreme swing (5); POTUSrace, he will accept a hypothetical defeat or, conversely, he will not

<< Joe Biden said Wednesday night that he believes if President Donald Trump loses the election and refuses to leave the White House, many of the former generals who used to work for him "will escort him from the White House with great dispatch." >>

<< "Mark my words I think he is gonna try to kick back the election somehow, come up with some rationale why it can't be held," Biden said in April. But the real danger here is not that Trump changes the date of the general election, which is virtually impossible, or that he seeks to claims squatter's rights in the White House. The thing that could threaten Biden's potential presidency -- and the ability of the country to move on from what will be one of the nastiest elections in modern history -- is if Trump simply refuses to admit he lost, never conceding that Biden is the fair-and-square president.>>

<< And it's very easy to imagine Trump -- with his 80-plus million Twitter followers and the potential that he would be the head of a TV network post-presidency -- beating the drum of illegitimacy day in and day out. Because, well, it is in his interest to do so and, as he has shown repeatedly during his presidency, he has very little regard for either the office or its status as a moral beacon within the country and the world. The result isn't hard to imagine: An even deeper divide within the country between the Trumpists and everyone else. >>

Chris Cillizza. Here's the real danger if Donald Trump loses the 2020 election. Updated 1513 GMT (2313 HKT) June 11, 2020.

https://edition.cnn.com/2020/06/11/politics/donald-trump-joe-biden-2020-election/index.html

Also (quasi-stochastic poetry)

2151 - a voting machine (to explain precisely). Notes. Jan 15, 2008.

https://inkpi.blogspot.com/2008/01/2151-voting-machine-to-explain.html

# evol: traces of weird evolution, ancient crocodiles walked on two legs, like dinosaurs

<< some species of ancient crocodiles walked on their two hind legs like dinosaurs and measured over three meters in length. >>

<< At one site, the footprints were initially thought to be made by a giant bipedal pterosaur walking on the mudflat, we now understand that these were bipedal crocodile prints, (..) "And while footprints were everywhere on the site, there were no handprints. (..) Dinosaurs and their bird descendants walk on their toes. Crocodiles walk on the flat of their feet leaving clear heel impressions, like humans do. >> Anthony Romilio.

Ancient crocodiles walked on two legs like dinosaurs. University of Queensland. Jun 11, 2020.

https://phys.org/news/2020-06-ancient-crocodiles-legs-dinosaurs.html 

Kim, K.S., Lockley, M.G., et al. Trackway evidence for large bipedal crocodylomorphs from the Cretaceous of Korea. Sci Rep 10, 8680. doi: 10.1038/ s41598-020-66008-7. 

https://www.nature.com/articles/s41598-020-66008-7

# chem: bizarre phase transitions in tantalum disulfide, it should be a conducting metal, but in the real world, it acts like an insulator

<< It has long been known that  crystalline materials should be good conductors when they have an odd number of electrons in each repeating cell of the structure, but may be poor conductors when the number is even. However, sometimes this formula does not work, with one case being "Mottness," a property based on the work of Sir Nevill Mott. According to that theory, when there is strong repulsion between electrons in the structure, it leads the electrons to become "localized"-paralyzed, in other words-and unable to move around freely to create an electric current. >>

<< For the current study, (..) the research group decided to look at tantalum disulfide, a material with 13 electrons in each repeating structure, which should therefore make it a conductor. However, it is not, and there has been controversy over whether this property is caused by its "Mottness" or by a pairing structure. >>

<< The exact nature of the insulating state and of the phase transitions in tantalum disulfide have been long-standing mysteries, and it was very exciting to find that Mottness is a key player, aside from the pairing of the layers. This is because theorists suspect that a Mott state could set the stage for an interesting phase of matter known as a quantum spin liquid. >> Christopher Butler. 

Jens Wilkinson. 'Tantalizing' clues about why a mysterious material switches from conductor to insulator. 

 RIKEN. May 18, 2020.

https://phys.org/news/2020-05-tantalizing-clues-mysterious-material-conductor.html   

AA << also observe the collapse of Mottness at an extrinsically re-stacked termination, demonstrating that the microscopic mechanism of insulator-metal transitions lies in degrees of freedom of inter-layer stacking. >>

C. J. Butler, M. Yoshida, et al. Mottness versus unit-cell doubling as the driver of the insulating state in 1T-TaS2. Nat Commun 11, 2477. doi: 10.1038/ s41467-020-16132-9. May 18, 2020

https://www.nature.com/articles/s41467-020-16132-9   

Also

Quantum spin liquid. 

https://en.m.wikipedia.org/wiki/Quantum_spin_liquid

# astro: oops? apropos of rapid expansion of trajectories, the nomadic escape propensity of Titan.

As a vision of a fuzzy snooker, << decades of measurements and calculations have revealed that Titan's orbit around Saturn is expanding- meaning, the moon is getting farther and farther away from the planet- at a rate about 100 times faster than expected. The research suggests that Titan was born much closer to Saturn and migrated out to its current distance of 1.2 million kilometers (about 746,000 miles) over 4.5 billion years. >>

<< Titan is expected to gravitationally squeeze Saturn with a particular frequency that makes the planet oscillate strongly, similarly to how swinging your legs on a swing with the right timing can drive you higher and higher. This process of tidal forcing is called resonance locking. Fuller (Jim Fuller) proposed that the high amplitude of Saturn's oscillation would dissipate a lot of energy, which in turn would cause Titan to migrate outward away from the planet at a faster rate than previously thought. >>

<< The resonance locking theory can apply to many astrophysical systems. I'm now doing some theoretical work to see if the same physics can happen in binary star systems, or exoplanet systems, >> Jim Fuller.

Lori Dajose. Titan is migrating away from Saturn 100 times faster than previously predicted. Jun 8, 2020.

https://phys.org/news/2020-06-titan-migrating-saturn-faster-previously.html

Valery Lainey, Luis Gomez Casajus, et al. Resonance locking in giant planets indicated by the rapid orbital expansion of Titan. Nat Astron. doi: 10.1038/ s41550-020-1120-5. Jun 8, 2020.

https://www.nature.com/articles/s41550-020-1120-5   

Also (quasi-stochastic poetry)

1648b - tenuta di rigo della sonda. Notes. Jan 15, 2005.

https://inkpi.blogspot.com/2005/01/1648b-tenuta-di-rigo-della-sonda.html