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The wonders within your head by Judith Gold.

Astronomy Picture of the Day: Through a Sun Tunnel.

Astronomy Picture of the Day: Quadrantids over Qumis

Aurora as seen in Tromsø, Norway.

Urban photography by Almiller

Corridor by Nexion

Doomsday

Kirsten Dunst

Using an adaptation of Einstein's general theory of relativity, Poplawski analysed the theoretical motion of particles entering a black hole. He concluded that it was possible for a whole new universe to exist inside every black hole, which could mean that our own universe could be inside a black hole as well. "Maybe the huge black holes at the centre of the Milky Way and other galaxies are bridges to different universes," he told New Scientist. Explaining his theory in the journal Physics Letters B, he said he used the Einstein-Cartan-Kibble-Sciama (ECKS) theory of gravity, in his analysis to account for the angular momentum of particles in a black hole. Doing this it made it possible to calculate a quality of space-time called torsion, a property believed to repel gravity. He says instead of matter reaching infinite density in a black hole called "singularities" in Einstein's theory of relativity - the behaviour of the space-time acts more like a spring being compressed with matter rebounding and expanding continuously. Dr Poplawski explains that this "bounce-back" effect is caused by the torsion of space-time having a repulsive force against the gargantuan strength of gravity in a black hole. Dr Poplawski also claims that this recoiling effect could be what has led to our expanding universe that we observe today and could explain why our universe is flat, homogeneous and isotropic without needing cosmic inflation. It is hard to see how we could test whether or not Dr Poplawski's theory is correct; the force of gravity in black holes is such that nothing can escape, so no information about what is going on inside one can ever reach us. However, according to Dr Poplawski, if we were living in a spinning black hole then the spin would transfer to the space-time inside, meaning the universe would have a preferred direction - something we would be able to measure. Such a preferred direction could be related to the observed imbalance of matter and anti-matter in the universe and could explain the oscillation of neutrinos. Poplawski says that the idea that black holes are the cosmic mothers of new universes is a natural consequence of a simple new assumption about the nature of spacetime. Poplawski points out that the standard derivation of general relativity takes no account of the intrinsic momentum of spin half particles. However there is another version of the theory, called the Einstein-Cartan-Kibble-Sciama theory of gravity, which does. This theory predicts that particles with half integer spin should interact, generating a tiny repulsive force called torsion. In ordinary circumstances, torsion is too small to have any effect. But when densities become much higher than those in nuclear matter, it becomes significant. In particular, says Poplawski, torsion prevents the formation of singularities inside a black hole. Astrophysicists have long known that our universe is so big that it could not have reached its current size given the rate of expansion we see now. Instead, they believe it grew by many orders of magnitude in a fraction of a second after the Big Bang, the period known as known as inflation. Poplawski's approach immediately solves the inflation problem, saying that torsion caused this rapid inflation, which means the universe as we see it today can be explained by a single theory of gravity without any additional assumptions about inflation. Another important corollary of Poplawski's approach is that it makes it possible for universes to be born inside the event horizons of certain kinds of black hole where torsion prevents the formation of a singularity but allows energy density to build up, which leads to the creation of particles on a massive scale via pair production followed by the expansion of the new universe. "Such an expansion is not visible for observers outside the black hole, for whom the horizon's formation and all subsequent processes occur after infinite time," says Poplawski. For this reason, he emphasizes, the new universe is a separate branch of space time and evolves accordingly. Poplawski's theory also suggests an solution lto why time seems to flow in one direction but not in the other, even though the laws of physics are time symmetric. Poplawski says the origin of the arrow of time comes from the asymmetry of the flow of matter into the black hole from the mother universe. "The arrow of cosmic time of a universe inside a black hole would then be fixed by the time-asymmetric collapse of matter through the event horizon," he says. Translated, this means that our universe inherited its arrow of time from its source. "Daughter universes," he says, "may inherit other properties from their mothers," implying that it may be possible to detect these properties, providing an experimental falsifiable proof of his idea. Casey Kazan via Ref: arxiv.org/abs/1007.0587: Cosmology With Torsion - An Alternative To Cosmic Inflation

The researchers, Lars Nyberg from Umea University in Umea, Sweden; Reza Habib from Southern Illinois University in Carbondale, Illinois; and Alice S. N. Kim, Brian Levine, and Endel Tulving from the University of Toronto in Toronto, Ontario, have published their results in a recent issue of the Proceedings of the National Academy of Sciences. "Mental time travel consists of two independent sets of processes: (1) those that determine the contents of any act of such ‘travel’: what happens, who are the 'actors,' where does the action occur; it is similar to the contents of watching a movie – everything that you see on the screen; and (2) those that determine the subjective moment of time in which the action takes place – past, present, or future," Tulving told PhysOrg.com. "In cognitive neuroscience, we know quite a bit (relatively speaking) about perceived, remembered, known, and imagined space," he said. "We know essentially nothing about perceived, remembered, known, and imagined time. When you remember something that you did last night, you are consciously aware not only that the event happened and that you were ‘there,’ as an observer or participant ('episodic memory'), but also that it happened yesterday, that is, at a time that is no more. The question we are asking is, how do you know that it happened at a time other than 'now'?" In their study, the researchers asked several well-trained subjects to repeatedly think about taking a short walk in a familiar environment in either the imagined past, the real past, the present, or the imagined future. By keeping the content the same and changing only the mental time in which it occurs, the researchers could identify which areas of the brain are correlated with thinking about the same event at different times. The results showed that certain regions in the left lateral parietal cortex, left frontal cortex, and cerebellum, as well as the thalamus, were activated differently when the subjects thought about the past and future compared with the present. Notably, brain activity was very similar for thinking about all of the non-present times (the imagined past, real past, and imagined future). Because mental time is a product of the human brain and differs from the external time that is measured by clocks and calendars, scientists also call this time “subjective time.” Chronesthesia, by definition, is a form of consciousness that allows people to think about this subjective time and to mentally travel in it. Some previous research has questioned whether the concept of subjective time is actually necessary for understanding similarities in brain activity during past and future thinking compared with thinking about the present. A few past studies have suggested that the brain’s ability for scene construction, and not subjective time, can account for the ability to think about past and future events. However, since scene construction was held constant in this study, the new results suggest that the brain’s ability to conceive of a subjective time is in fact necessary to explain how we think about the past and future. “Until now, the processes that determine contents and the processes that determine time have not been separated in functional neuroimaging studies of chronesthesia; especially, there have been no studies in which brain regions involved in time alone, rather than time together with action, have been identified,” Tulving said. “The concept of ‘chronesthesia’ is essentially brand new. (You find a few entries on it in Google, but not on Web of Science.) Therefore, I would say, the most important result of our study is the novel finding that there seem to exist brain regions that are more active in the (imagined) past and the (imagined) future than they are in the (imagined) present. That is, we found some evidence for chronesthesia. Before we undertook this study it was entirely possible to imagine that we find nothing!” He added that, at this stage of the game, it is too early to talk about potential implications or applications of understanding how the brain thinks about the past, present, and future. “Our study, we hope, is the first swallow of the spring, and others will follow,” he said. “Our findings, as I alluded to above, are promising, but they have to be replicated, checked for validity and reliability, and, above all, extended to other conditions and situations, before we can start thinking about their implications and applications (of which it is easy to think of many).”

Serious Shell Shock