A new study shows that areas of the brain that are responsible for movement are also connected to networks involved in thinking and planning, as well as the control of involuntary bodily actions.
A team of oceanographers at the Scripps Institution of Oceanography, working with a colleague from Chungnam National University and another from the University of Hawaii, has mapped 19,000 previously unknown undersea volcanoes in the world’s oceans using radar satellite data. In their paper published in the journal Earth and Space Science, the group describes how they used radar satellite data to measure seawater mounding to find and map undersea volcanoes and explains why it is important that it be done.
The ocean floor, like dry land masses, features a wide variety of terrain. And as with dry land, features that truly stand out are mountains—in the ocean they are called seamounts. And as on land, they can be created by tectonic plates pushing against one another, or by volcanos erupting. Currently, just one-fourth of the sea floor has been mapped, which means that no one knows how many seamounts exist, or where they might be. This can be a problem for submarines—twice U.S. submarines have collided with seamounts, putting such vehicles and their crew at risk. But not knowing where the seamounts are located presents another problem. It prevents oceanographers from creating models depicting the flow of oceanwater around the world.
In this new effort, the research team set themselves the task of discovering and mapping as many seamounts as possible, and to do it, they used data from radar satellites. Such satellites cannot actually see the seamounts, of course, instead they measure the altitude of the sea surface, which changes due to changes in gravitational pull related to seafloor topography; an effect known as sea mounding. In so doing, they found 19,000 previously unknown seamounts.
The mapping of matter in the cosmos helps to confirm Einstein’s theory of general relativity and reveals more about mysterious dark matter.
The deployment of his spy ships is chilling. Britain is far from ready to counter whatever he has planned.
For a long time it was only speculation. Now we know for certain: Russian spy ships are mapping wind farms and key cables off the British coast. There can be only one reason for this – to learn how to sabotage UK and European critical infrastructure in the event of a full-scale war with the West.
The sobering truth is that our potential adversaries, Russia in the West and China in the East, are gearing up for wider conflict. That does not mean that conflict will happen –preparation makes it less likely – but we must urgently recognise the extent of the threat to the current order. Our world is becoming markedly more dangerous. And Britain is not ready.
face_with_colon_three year 2017.
First observed in liquid helium below the lambda point, superfluidity manifests itself in a number of fascinating ways. In the superfluid phase, helium can creep up along the walls of a container, boil without bubbles, or even flow without friction around obstacles. As early as 1938, Fritz London suggested a link between superfluidity and Bose–Einstein condensation (BEC)3. Indeed, superfluidity is now known to be related to the finite amount of energy needed to create collective excitations in the quantum liquid4,5,6,7, and the link proposed by London was further evidenced by the observation of superfluidity in ultracold atomic BECs1,8. A quantitative description is given by the Gross–Pitaevskii (GP) equation9,10 (see Methods) and the perturbation theory for elementary excitations developed by Bogoliubov11. First derived for atomic condensates, this theory has since been successfully applied to a variety of systems, and the mathematical framework of the GP equation naturally leads to important analogies between BEC and nonlinear optics12,13,14. Recently, it has been extended to include condensates out of thermal equilibrium, like those composed of interacting photons or bosonic quasiparticles such as microcavity exciton-polaritons and magnons14,15. In particular, for exciton-polaritons, the observation of many-body effects related to condensation and superfluidity such as the excitation of quantized vortices, the formation of metastable currents and the suppression of scattering from potential barriers2,16,17,18,19,20 have shown the rich phenomenology that exists within non-equilibrium condensates. Polaritons are confined to two dimensions and the reduced dimensionality introduces an additional element of interest for the topological ordering mechanism leading to condensation, as recently evidenced in ref. 21. However, until now, such phenomena have mainly been observed in microcavities embedding quantum wells of III–V or II–VI semiconductors. As a result, experiments must be performed at low temperatures (below ∼ 20 K), beyond which excitons autoionize. This is a consequence of the low binding energy typical of Wannier–Mott excitons. Frenkel excitons, which are characteristic of organic semiconductors, possess large binding energies that readily allow for strong light–matter coupling and the formation of polaritons at room temperature. Remarkably, in spite of weaker interactions as compared to inorganic polaritons22, condensation and the spontaneous formation of vortices have also been observed in organic microcavities23,24,25. However, the small polariton–polariton interaction constants, structural inhomogeneity and short lifetimes in these structures have until now prevented the observation of behaviour directly related to the quantum fluid dynamics (such as superfluidity). In this work, we show that superfluidity can indeed be achieved at room temperature and this is, in part, a result of the much larger polariton densities attainable in organic microcavities, which compensate for their weaker nonlinearities.
Our sample consists of an optical microcavity composed of two dielectric mirrors surrounding a thin film of 2,7-Bis[9,9-di(4-methylphenyl)-fluoren-2-yl]-9,9-di(4-methylphenyl)fluorene (TDAF) organic molecules. Light–matter interaction in this system is so strong that it leads to the formation of hybrid light–matter modes (polaritons), with a Rabi energy 2 ΩR ∼ 0.6 eV. A similar structure has been used previously to demonstrate polariton condensation under high-energy non-resonant excitation24. Upon resonant excitation, it allows for the injection and flow of polaritons with a well-defined density, polarization and group velocity.
Continue reading “Room-temperature superfluidity in a polariton condensate Physics” »
A new study has shown how the brain’s cognitive maps are used and updated for reasoning, allowing us to make decisions in unfamiliar situations.
Decide: mapping a path forward
Once you have put your organization in context and understood exposure to risk, the third step is making suggestions toward a response plan.
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My name is Artem, I’m a computational neuroscience student and researcher. In this video we talk about cognitive maps – internal models of outside world that the brain to generate flexible behavior that is generalized across contexts.
The free-to-access IoT network could help bring billions of connected devices online — if you’re willing to share.
One of the largest mysteries of science is that humans have conscious awareness of their complex subjective experiences – or what we call “qualia” – such as being aware of what it’s like to delight in the color of a flower, melt into the comfort of a bed, or to feel sharp pain. Why and how qualia could emerge from physical matter and be a part of the human experience is unknown, and this is called the ‘hard problem’ of consciousness. Related to qualia is the mystery of why humans feel like they have free will, or the ability to intentionally choose and execute actions.
The ‘easy’ problem of consciousness is mapping these mind states to brain states, such as identifying which brain regions are active during a certain experience, such as smelling a flower. Despite advances in classical physics and neuroscience, many aspects of the mind-brain relationship, such as qualia, remain unresolved. New theories of mind are required to address this perennial mystery.
In a new paper, we propose that some aspects of mind are quantum and can play an active role in the physical world, explaining some of the unexplainable.
