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Thread: Interesting sciencey-stuff thread

  1. #3081
    αυτοκράτορας GeoModder's Avatar
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    Oh, but we can change the climate (for the better part of a century at least)! Just drop a 'roid in one of the oceans, or detonate the nuclear stockpile.

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    The total amount of solar energy absorbed by Earth is ~3,850,000 EJ per year. Note, this is absorbed energy, which is about 11% of total solar energy hitting Earth.

    As a comparison, humanity's total energy needs per year is currently around 500 EJ (electricity is around 60 EJ).

    As further comparison, TOTAL human caused climate change has contributed 5100 EJ over the last 150 years. This results in a total AGW component of 34 EJ per year (linearly to keep it simple).

    -----------------------------------------

    So yes, humans can change our climate. But when even 1% of a Sun-fart (CME) is thousands of magnitudes greater than total human climate influence, just how influential do you seriously think we are?
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  3. #3083

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    Well at the risk of sending us back in a loop, we are pumping out lots of CO2. That has raised levels beyond the natural cycle and the arguement goes that that is/will have a damaging effect on our environment (and we've covered all this ground before).

    So yeah 'global warming' and the 'green' concern is not about 1, 2 or even a few issues. It's about hundreds or thousands of different effects we are having directly on the entirity of our fragile finite environment.
    Last edited by El_Cid; 25-04-12 at 14:45.
    formerly known as child of Thor(coT) in the CTP2 section of poly.

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    See, I think the principal area of disagreement between those who believe the world is about to end and those of who accept the reality that man can produce carbon dioxide and yet approach the issue with less alarm is that we don't think the global climate is quite so fragile - at least to the severely limited capabilities of our species. Global climate has clearly changed abruptly and drastically many times over the course of Earth's history, but I'm not aware of it doing so for something as subtle and minute as the sort of impacts our still mostly insignificant species is able to produce.

    To me, one of the sources of my skepticism toward anthropogenic global warming is a manifestation, if perhaps in a more peculiar form, of the Copernican Principle. Man likes to believe he has an outsized influence on his world and an outsized place of importance in its design. Man likes to think he's at the center of everything and all important. It makes us uncomfortable to think of how utterly irrelevant we might be - whether for good or ill - and we are not the masters of our own destiny. We like to believe both that we're being looked after and important and we like to believe that we have the power to change the world for the better and save the planet we call home (which I believe is the hubris behind anthropogenic global warming). The reality that we may not be powerful enough to save our planet and there is nothing we can do, potentially irrelevant to own survival, is disquieting, yet also more likely to be true. And those who believe most fervently in the alarmist strains of anthropogenic global warming aren't accustomed to being caught on the wrong side of that divide. They're more typically in the position of scoffing at those who cling to such beliefs against evidence (such as creationists).

    And, frankly, I'd submit that anthropogenic global warming theory has a lot more in common with creationism than most of its adherents would like to admit.

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    Quote Originally Posted by El_Cid View Post
    Well at the risk of sending us back in a loop, we are pumping out lots of CO2. That has raised levels beyond the natural cycle and the arguement goes that that is/will have a damaging effect on our environment (and we've covered all this ground before).
    No it won't.

    Quote Originally Posted by Dale View Post
    The total amount of solar energy absorbed by Earth is ~3,850,000 EJ per year. The total AGW component is 34 EJ per year.
    Human influence per year is (0.88*e^-5)%. IE: basically nothing.
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    Once upon a time, some guys built a wallhttp://en.wikipedia.org/wiki/Aswan_Dam roughly 4 km long. Ever since that wall was built, a once predictable annual flood disappeared entirely, with consequences for over 1000 km of river and more than 80 million people. The builders of the wall knew there would be consequences for their actions, thinking that irrigation and electricity generation would be vastly improved, and they were largely right. What they didn't realise was that disease downstream would rise thanks to a reduction in water quality that no one predicted but became more obvious with hindsight (related diseases are now mostly gone thanks to very effective countermeasures).
    The point is, that we can impact large areas with relatively small actions, and we aren't always able to predict the results of our actions accurately.
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  7. #3087
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    Default More on Dark Matter (or the lack thereof)

    Vast Structure of Satellite Galaxies Discovered: Do the Milky Way’s Companions Spell Trouble for Dark Matter?

    ScienceDaily (Apr. 25, 2012) — Astronomers from the University of Bonn in Germany have discovered a vast structure of satellite galaxies and clusters
    of stars surrounding our Galaxy, stretching out across a million light years. The work challenges the existence of dark matter, part of the standard model
    for the evolution of the universe.


    PhD student and lead author Marcel Pawlowski reports the team's findings in a paper in the journal Monthly Notices of the Royal Astronomical Society.

    The Milky Way, the galaxy we live in, consists of around three hundred thousand million stars as well as large amounts of gas and dust arranged with arms
    in a flat disk that wind out from a central bar. The diameter of the main part of the Milky Way is about 100,000 light years, meaning that a beam of light
    takes 100,000 years to travel across it. A number of smaller satellite galaxies and spherical clusters of stars (so-called globular clusters) orbit at various
    distances from the main Galaxy.

    Conventional models for the origin and evolution of the universe (cosmology) are based on the presence of 'dark matter', invisible material thought to make up
    about 23% of the content of the cosmos that has never been detected directly. In this model, the Milky Way is predicted to have far more satellite galaxies
    than are actually seen.

    In their effort to understand exactly what surrounds our Galaxy, the scientists used a range of sources from twentieth century photographic plates to images
    from the robotic telescope of the Sloan Deep Sky Survey. Using all these data they assembled a picture that includes bright 'classical' satellite galaxies, more
    recently detected fainter satellites and the younger globular clusters.

    "Once we had completed our analysis, a new picture of our cosmic neighbourhood emerged," says Pawlowski. The astronomers found that all the different objects
    are distributed in a plane at right angles to the galactic disk. The newly-discovered structure is huge, extending from as close as 33,000 light years to as far away
    as one million light years from the centre of the Galaxy.

    Team member Pavel Kroupa, professor for astronomy at the University of Bonn, adds "We were baffled by how well the distributions of the different types of
    objects agreed with each other." As the different companions move around the Milky Way, they lose material, stars and sometimes gas, which forms long streams
    along their paths. The new results show that this lost material is aligned with the plane of galaxies and clusters too. "This illustrates that the objects are not only
    situated within this plane right now, but that they move within it," says Pawlowski. "The structure is stable."

    The various dark matter models struggle to explain this arrangement. "In the standard theories, the satellite galaxies would have formed as individual objects before
    being captured by the Milky Way," explains Kroupa. "As they would have come from many directions, it is next to impossible for them to end up distributed in such a
    thin plane structure."

    Postdoctoral researcher and team member Jan Pflamm-Altenburg suggests an alternative explanation. "The satellite galaxies and clusters must have formed together
    in one major event, a collision of two galaxies." Such collisions are relatively common and lead to large chunks of galaxies being torn out due to gravitational and tidal
    forces acting on the stars, gas and dust they contain, forming tails that are the birthplaces of new objects like star clusters and dwarf galaxies.

    Pawlowski adds, "We think that the Milky Way collided with another galaxy in the distant past. The other galaxy lost part of its material, material that then formed
    our Galaxy's satellite galaxies and the younger globular clusters and the bulge at the galactic centre. The companions we see today are the debris of this 11 billion
    year old collision."

    Kroupa concludes by highlighting the wider significance of the new work. "Our model appears to rule out the presence of dark matter in the universe, threatening a
    central pillar of current cosmological theory. We see this as the beginning of a paradigm shift, one that will ultimately lead us to a new understanding of the universe
    we inhabit."

    http://www.sciencedaily.com/releases...0425094352.htm

    ----------------------------------------------------------

    Mmm, this article gives note to 23% as the amount of unaccounted mass in the cosmos as dark matter, not the 80+ % I read on in the past (for those conventional models mentioned in the 4th paragraph).

    The article boils down to the detection of even fainter globular clusters and satellite galaxies surrounding the Milky Way.

  8. #3088

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    and confusing all at the same time! It seems the more we study the universe around us, the more questions we arrive at. Which is good, but at some time it would be nice to really start to understand things!

    So yeah, i'm now more confused over the dark matter issue than before
    formerly known as child of Thor(coT) in the CTP2 section of poly.

  9. #3089

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    'Key tests for Skylon spaceplane project':

    http://www.bbc.co.uk/news/science-environment-17864782

    "UK engineers have begun critical tests on a new engine technology designed to lift a spaceplane into orbit.

    The proposed Skylon vehicle would operate like an airliner, taking off and landing at a conventional runway.

    Its major innovation is the Sabre engine, which can breathe air like a jet at lower speeds but switch to a rocket mode in the high atmosphere.

    Reaction Engines Limited (REL) believes the test campaign will prove the readiness of Sabre's key elements.

    This being so, the firm would then approach investors to raise the 250m needed to take the project into the final design phase.

    "We intend to go to the Farnborough International Air Show in July with a clear message," explained REL managing director Alan Bond.

    "The message is that Britain has the next step beyond the jet engine; that we can reduce the world to four hours - the maximum time it would take to go anywhere. And that it also gives us aircraft that can go into space, replacing all the expendable rockets we use today."

    To have a chance of delivering this message, REL's engineers will need a flawless performance in the experiments now being run on a rig at their headquarters in Culham, Oxfordshire.

    The test stand will not validate the full Sabre propulsion system, but simply its enabling technology - a special type of pre-cooler heat exchanger.

    Sabre is part jet engine, part rocket engine. It burns hydrogen and oxygen to provide thrust - but in the lower atmosphere this oxygen is taken from the atmosphere.

    The approach should save weight and allow Skylon to go straight to orbit without the need for the multiple propellant stages seen in today's throw-away rockets.

    But it is a challenging prospect. At high speeds, the Sabre engines must cope with 1,000-degree gases entering their intakes. These need to be cooled prior to being compressed and burnt with the hydrogen.

    Reaction Engines' breakthrough is a module containing arrays of extremely fine piping that can extract the heat and plunge the intake gases to minus 140C in just 1/100th of a second.

    Ordinarily, the moisture in the air would be expected to freeze out rapidly, covering the pre-cooler's pipes in a blanket of frost and compromising their operation.

    But the REL team has also devised a means to stop this happening, permitting Sabre to run in jet mode for as long as is needed before making the transition to a booster rocket.

    On the test rig, a pre-cooler module of the size that would eventually go into a Sabre has been placed in front of a Viper jet engine.

    The purpose of the 1960s-vintage power unit is simply to suck air through the module and demonstrate the function of the heat exchanger and its anti-frost mechanism.

    Helium is pumped at high pressure through the module's nickel-alloy piping.

    The helium enters the system at about minus 170C. The ambient air drawn over the pipes by the action of the jet should as a consequence dip rapidly to around minus 140C.

    Sensors will determine that this is indeed the case.

    The helium, which by then will have risen to about minus 15C, is pushed through a liquid nitrogen "boiler" to bring it back down to its run temperature, before looping back into the pre-cooler.

    "It is important to state that the geometry of the pre-cooler is not a model. That is a piece of real Sabre engine," said Mr Bond.

    "We don't have to go away and develop the real thing when we've done these tests; this is the real article."

    The manufacturing process for the pre-cooler technology is already proven, but investors will be looking to see that the module has a stable operation and can meet the promised performance.

    The BBC was given exclusive access to film the rig in action.

    Because REL is working on a busy science park, it has to meet certain environmental standards.

    This means the Viper's exhaust goes into a silencer where the noise is damped by means of water spray.

    The exhaust gases are at several hundred degrees, and so the water is instantly vaporised, producing huge clouds of steam.

    Anyone standing outside during a run gets very wet because the vapour rains straight back down to the ground.

    The REL project has generated a lot of excitement. One reason for that is the independent technical audit completed last year.

    The UK Space Agency engaged propulsion experts at the European Space Agency (Esa) to run the rule over the company's engine design.

    Esa's team, which spent several months at Culham, found no obvious showstoppers.

    "Engineering is never simple. There are always things in the future that need to be resolved - problems crop up and you have to solve them," said Dr Mark Ford, Esa's head of propulsion engineering.

    "The issue is, 'do we see anything fundamental from stopping this engine from being developed?', and the answer is 'no' at this stage.

    "The main recommendation we made is that we would like next to see a sub-scale engine - so, a smaller version than the final engine - being tested.

    "So far we've looked at critical component technologies. The next step is to put those technologies together, build an engine and see it working.

    "We want a demonstration of the thermodynamic cycle. We'd also like to see the engine operating in air-breathing and rocket mode, and the transition between the two."

    This sub-scale engine is one of the activities proposed for the next phase of the project.

    Also included is a series of flight test vehicles that would demonstrate the configuration of the engine nacelles - the air intakes.

    Additionally, updated design drawings would be produced for the Sabre engine and the Skylon vehicle.

    So far, 85% of the funding for Reaction Engines' endeavours has come from private investors, but the company may need some specific government support if it is to raise all of the 250m needed to initiate every next-phase activity.

    "What we have learned is that a little bit of government money goes a long way," said Mr Bond.

    "It gives people confidence that what we're doing is meaningful and real - that it's not science fiction. So, government money is a very powerful tool to lever private investment."

    This public seed fund approach to space has certainly found favour recently within government.

    Ministers put more than 40m into developing the communications payload for the first satellite operated by the Avanti broadband company, and they are giving more than 20m to SSTL to make a prototype radar satellite."

    ----------------------------------------

    I'd not heard of the skylon project before, but it sounds interesting

    http://en.wikipedia.org/wiki/Skylon_%28spacecraft%29

    Although now whenever i hear of the UK doing space-stuff i always will think about the quite awesome comedy series, Hyperdrive:

    http://www.youtube.com/watch?v=Rz-1c...feature=relmfu

    That is part 1 of the series (s1e1p1/3) and the format to watch based on that is 'season 1 episode 1 part 1 of 3', well worth the chuckle of Britain in Space
    formerly known as child of Thor(coT) in the CTP2 section of poly.

  10. #3090

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    'Oetzi the Iceman's blood is world's oldest':

    http://www.bbc.co.uk/news/science-environment-17909396

    "Researchers studying Oetzi, a 5,300-year-old caveman found frozen in the Italian Alps in 1991, have found red blood cells around his wounds.

    Blood cells tend to degrade quickly, and earlier scans for blood within Oetzi's body turned up nothing.

    Now a study in the Journal of the Royal Society Interface shows that Oetzi's remarkable preservation extends even to the blood he shed shortly before dying.

    The find represents by far the oldest red blood cells ever observed.

    It is just the latest chapter in what could be described as the world's oldest murder mystery.

    Since Oetzi was first found by hikers with an arrow buried in his back, experts have determined that he died from his wounds and what his last meal was.

    There has been extensive debate as to whether he fell where he died or was buried there by others.

    In February, Albert Zink and colleagues at the Eurac Institute for Mummies and the Iceman in Bolzano, Italy published Oetzi's full genome.

    An earlier study by the group, published in the Lancet, showed that a wound on Oetzi's hand contained haemoglobin, a protein found in blood - but it had long been presumed that red blood cells' delicate nature would have precluded their preservation.

    Prof Zink and his colleagues collaborated with researchers at the Center for Smart Interfaces at the University of Darmstadt in Germany to apply what is known as atomic force microscopy to thin slices of tissue taken from an area surrounding the arrow wound.

    The technique works using a tiny metal tip with a point just a few atoms across, dragged along the surface of a sample. The tip's movement is tracked, and results in a 3-D map at extraordinary resolution.

    The team found that the sample from Oetzi contained structures with a tell-tale "doughnut" shape, just as red blood cells have.

    To ensure the structures were preserved cells and not contamination of some kind, they confirmed the find using a laser-based technique called Raman spectroscopy - those results also indicated the presence of haemoglobin and the clot-associated protein fibrin.

    But the fibrin levels were much lower than would be expected in fresh wounds.

    "Because fibrin is present in fresh wounds and then degrades, the theory that Oetzi died straight after he had been injured by the arrow, as had once been mooted, and not some days after, can no longer be upheld," Prof Zink remarked.

    The team also suggest that their methods may prove to be of use in modern-day forensics studies, in which the exact age of blood samples is difficult to determine."

    -----------------------------------

    formerly known as child of Thor(coT) in the CTP2 section of poly.

  11. #3091

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    Clone the ice man!

    Might be a relative, have roots in Switzerland.
    Certifiable expert on experts.

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  12. #3092
    Emperor PiMan's Avatar
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    Red blood cells won't do much good for that. No DNA in those.
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  13. #3093
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    Quote Originally Posted by PiMan View Post
    Red blood cells won't do much good for that. No DNA in those.
    Well, there's still the rest of the body.

  14. #3094

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    Thanks Lancer I'm now thinking of that dumb ass 'frat' type movie where a frozen caveman comes back to life as his glacier thaws out:

    http://en.wikipedia.org/wiki/Encino_Man

    The iceman was a much better take on this genre imho:

    http://en.wikipedia.org/wiki/Iceman_%28film%29



    --------------------------------------------

    Now this is not science exactly, but it is about CERN and got me thinking just how dangerous would it be to have some kind of terror attack on a large collider? They work with crazy levels of energy, but could that be sabotaged to be dangerous? I hope not!

    'France jails Cern physicist Adlene Hicheur for terror plot':

    http://www.bbc.co.uk/news/world-europe-17956202

    "A French court has sentenced a scientist at the prestigious Cern laboratory to five years in prison for plotting terrorist attacks.

    Adlene Hicheur was arrested in 2009 after police intercepted his emails to an alleged contact in al-Qaeda.

    The emails suggested Algerian-born Hicheur was willing to be part of an "active terrorist unit", attacking targets in France.

    Defence lawyers argued that their client had never been part of a plot.

    Hicheur, who is a particle physicist, worked as a researcher studying the origins of the universe at Cern.

    His father embraced him in the Paris courtroom before he was taken away to prison.

    Hicheur has already spent two and a half years in jail while awaiting trial.

    He came under suspicion when threatening messages were sent to President Sarkozy in early 2008.

    The security services uncovered a series of email exchanges between Hicheur and an alleged al-Qaeda member called Mustapha Debchi.

    After his arrest in 2009 police found a large quantity of Islamist literature at his parents' home.

    At the start of his trial the 35-year-old scientist admitted that he had been going through a psychologically "turbulent" time in his life when he wrote the emails.

    He had suffered a serious back injury, for which he had been taking morphine.

    But he always denied he intended to carry out any attacks.

    His lawyer, Patrick Baudouin, described the verdict as "scandalous".

    "Everything has been done to demonise him," he said.

    Hicheur has not yet decided whether or not to appeal.

    If he decides not to, with time off for good behaviour, he should be released soon, Mr Baudouin said."

    -----------------------

    I wasn't aware of this case, but i wonder if this kind of high level science plot stuff is on the rise maybe? I'd be gutted if a stupid terror strike was to damage useful science for the world
    formerly known as child of Thor(coT) in the CTP2 section of poly.

  15. #3095

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    In the U.S., a conspiracy charge must be supported by at least one substantive act towards the carrying out of the crime. I don't see that here. But France could well have differing laws.
    "I never learned from a man who agreed with me." ... Robert A Heinlein

  16. #3096

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    France has been swinging towards the right over recent years (Marine Le Pen nearly got into presidential consideration recently!), and there has been changes to laws etc so in certain circumstances around the 'war on terror' i suspect their laws are more like the usa's in this particular area. They don't have a gitmo though, so the rule of law (both international and national) probably applies more in just about every other country bar the usa. Gitmo and what it represents will be remembered as a black day in the history of law and democracy (and american ideals), and it will be used by less democratic countries for their own ends. Sad but true.

    In this case it seems like the guy being held was a danger to the wider public, just because he hadn't carried out any acts yet probably doesn't out wiegh that he was in contact with known terrorist groups. I mean you don't contact people like that unless you really really want to. So there may be enough just behind that action of his? But yeah i don't like the idea of 'terrorists' getting control over the power to create black-holes etc
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  17. #3097

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    Anyone seen it?

    'Bigger and brighter 'supermoon' graces the night sky'

    http://www.bbc.co.uk/news/science-environment-17972782

    A "supermoon" has graced the skies, appearing bigger and brighter than usual, as it comes closer to the Earth - and is likely to bring higher tides.

    The phenomenon, known as a perigee full moon, means the Moon appears up to 14% bigger and 30% brighter than when it is furthest from the planet.

    The optimum effect was seen - cloud permitting - at 04:30 BST (03:30 GMT).

    The Royal Astronomical Society's Dr Robert Massey said the Moon's size may be more obvious than its brightness.

    "The eye is so good at compensating for changes in brightness that you simply don't notice (that element) so much," he said.

    When the Moon appears at its biggest it will be just 356,400km (221,457 miles) away, compared to its usual distance from Earth of 384,000km (238,606 miles).

    Dr Massey said: "When the Moon is closest to the Earth and full or new, you get an increase in the tidal pull in the ocean because the gravity of the moon and the sun line up."

    He added: "The Moon is always beautiful and a full moon is always dramatic."

    Scientists have dismissed the idea the perigee could cause strange behaviour - like lycanthropy - or natural disasters.

    The Moon's distance from Earth varies because it follows an elliptical orbit instead of a circular one."

    ----------------------

    The pictures in the article look amazing. I hope to see the moon later this evening (cloud cover permitting).
    formerly known as child of Thor(coT) in the CTP2 section of poly.

  18. #3098
    αυτοκράτορας GeoModder's Avatar
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    Well, in reality it won't be all that different from April's full moon, and June's full moon next month.
    You might notice the difference if you could see full moon on perigee and apihee after one another.

  19. #3099
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    I got a crap phone and we got some thin high level cloud, but this is what I see tonight.

    No zoom.


    Zoomed in.
    Attached Images Attached Images
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    Yeah, you definitely had the cam handheld (not supported).
    The sky is completely clouded here. No chance to see the moon.

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