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https://phys.org/news/2018-04-astronomers-witness-galaxy-megamerger.html Peering deep into space—an astounding 90 percent of the way across the observable universe—astronomers have witnessed the beginnings of a gargantuan cosmic pileup, the impending collision of 14 young, starbursting galaxies. This ancient megamerger is destined to evolve into one of the most massive structures in the known universe: a cluster of galaxies, gravitationally bound by dark matter and swimming in a sea of hot, ionized gas. Read more at: https://phys.org/news/2018-04-astronomers-witness-galaxy-megamerger.html#jCp The results are published in the journal Nature. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> the paper: https://www.nature.com/articles/s41586-018-0025-2 A massive core for a cluster of galaxies at a redshift of 4.3: Abstract Massive galaxy clusters have been found that date to times as early as three billion years after the Big Bang, containing stars that formed at even earlier epochs1,2,3. The high-redshift progenitors of these galaxy clusters—termed ‘protoclusters’—can be identified in cosmological simulations that have the highest overdensities (greater-than-average densities) of dark matter4,5,6. Protoclusters are expected to contain extremely massive galaxies that can be observed as luminous starbursts7. However, recent detections of possible protoclusters hosting such starbursts8,9,10,11 do not support the kind of rapid cluster-core formation expected from simulations12: the structures observed contain only a handful of starbursting galaxies spread throughout a broad region, with poor evidence for eventual collapse into a protocluster. Here we report observations of carbon monoxide and ionized carbon emission from the source SPT2349-56. We find that this source consists of at least 14 gas-rich galaxies, all lying at redshifts of 4.31. We demonstrate that each of these galaxies is forming stars between 50 and 1,000 times more quickly than our own Milky Way, and that all are located within a projected region that is only around 130 kiloparsecs in diameter. This galaxy surface density is more than ten times the average blank-field value (integrated over all redshifts), and more than 1,000 times the average field volume density. The velocity dispersion (approximately 410 kilometres per second) of these galaxies and the enormous gas and star-formation densities suggest that this system represents the core of a cluster of galaxies that was already at an advanced stage of formation when the Universe was only 1.4 billion years old. A comparison with other known protoclusters at high redshifts shows that SPT2349-56 could be building one of the most massive structures in the Universe today. ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Three questions arising from this article and paper. I have highlighted the relevant sentences. [1] Is this further evidence for DM? [2]Forming stars up to a 1000 times faster than our own galaxy....because of the abundance of accreting hydrogen [and helium] gas I presume? [3] Re all these starburst galaxies lying at 4.31 redshift....I'm pretty sure we have observed galaxies at far greater redshifts...up to 7, 8 and 9 in fact. Awesome cosmological science sure, but other then the observation of a galactic pileup, what is the real significance of this? [I'm probably missing something]

The kids who don't grow out of asking "yes, but why?" become scientists.

Coriolis only affects horizontal motion, it does not affect vertical motion. Tides are a vertical movement of water so are unaffected directly. However in order for the water surface to rise and fall, water must advect in and out horizontally. These tidals streams are affected by Coriolis, though to a lesser amount than ocean currents. This is because the biggest effects are close-to-shore effects. In the open ocean the tidal rise and fall is small as are the oceanic tidals streams. Here the local flow is small but spread over such a vast area that the volume is substantial. Close-to shore effect demonstate resonance and/or forced oscillation effects such as the amphidromic points in the North Sea. The size and timing of the vertical water movements and the direction of the horizontal ones are strongly influenced by the topography.

Is that the net acceleration, or is that gravity? Is this not accounted for by the earth's rotation?

Earth travellers would certainly have a far more involved and difficult task in slowing down for a Martian landing [as various probes have shown] then taking off again.

There's also a possibility of the flip side of this; aliens who can get into space relatively easily. They would have a problem retaining light gases in their atmos[here.

Thank you very much for your reply! I will take it all into consideration and reform my ideas. When I remember, Light was defined as the union of a particle and a wave moving at a constant speed... is this still accurate? Seems the definition has changed.

Not sure you need all that. The effect can be repeated in other ways. I've set my phone down on my knee while playing a game with screens that shift to the side, and my mind is so convinced the phone is falling off my knee that I'll move to compensate. Another variation is sitting in the grocery parking lot when the car in the space next to you backs out, and you jab the brakes because you think you're the one moving. They mention the vestibular sense, but I think the key ingredient here is the interaction with your peripheral vision. The scope out at the edges of your vision isn't particularly well focused, and color sense is poor, but it's designed to pick up movement, and it seems to translate instantly into a reaction from us; we duck, we step back, we turn our heads to look, we grab things that might fall or shift.

But just to ram home the point, "this is not a question for science" or do I have to shout it?

This is an ethics question... get the hint?

The last stages of life contain a lot of medically relevant information about the progress of an illnesses or a medical condition. You should look this question from point of science, i.e. you should help the individual and research the medical conditions till One can bare. I would say that if one can not bare, the support for peaceful death (euthanasia) should be provided. It should be a personally asked, state permitted, medically supported process...