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WMAP data

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    WMAP data

    Iedereen die een beetje de verwantte engelse fora bezoekt, en in de gaten houd weet dat er nogal veel ophef rond het WMAP (Wilkinson Microwave Anisotropy Probe) project aan het ontstaan is !..

    Nu staan er in maart na bijna 3 jaar tijd 2 persconferenties gepland. Het WMAP project was bedooeld om de door Einstein voorspelde achtergrondstraling (Lambda) te meten cq in kaart te brengen. Op dit project hebben veel wetebschappers hun zinnen gezet. in 2002 kwamen de eerste data naar buiten deze kwamen overeen met de bijbehorende theorie. Maar de laatste tijd staat het hele project onder druk er blijkt tochk iets niet te kloppen. In de afgelopen jaren zijn er veel persconferenties aangekondigd en weer afgeblazen, het lijkt er vooralsnog op dat het team het onderling niet eens kan worden.

    Er word kortom gegist en gespeculeerd in wetenschap over het WMAP project is er iets mis met de WMAP satteliet data, is de waargenomen straling alleen maar lokaal ons sterrenstelsel en directe omgeving !.. Sceptici hebben er in ieder geval wel een naam voor bedacht "The Axis of evil"...

    Ik denk dat een aantal van jullie ook al wel op de hoogte is van dit onderwerp enz. Ik denk dat veel van de wetenschappers die aan dit project deelnemen bang zijn voor hun reputaties en toch enigzins onder ogen zien dat er iets grondig mis is met die achtergrondstraling, een ding is zeker. Vabn alle kanten wordt aan de poten van stoel Lambda gezaagt, de volgende stap is wie weet ? (hoeveelheid) donkere materie, inflatie....

    Het is wachten volgens ingewijden die nauw contact hebben met de leden van het WMAP team, op de technisch geavanceerdere PLANCK sonde !!...

    Heb je misschien enkele links voor me waar ik hier mee info over kan vinden? Info waarin dit inderdaad in twijfel wordt getrokken?
    Vuja De': the strange feeling you get that nothing has happened before.


      Demelza, laatst heeft er een stuk gestaan in science gepubliceerd door Bradley Scheaffer !..

      Verder kun je kijken op http://www.universetoday.com in het forum onder de kop Space Exploration waar uitgebreid over de data weord gediscuseerd... er leuk om te volgen ...


        Thanx! Ik zal me er eens wat verder in gaan verdiepen.
        Vuja De': the strange feeling you get that nothing has happened before.


          The darkness inside of everything

          February 4, 2006
          Studies of supernovas and the developing concept of dark energy have thrown theories on the nature of the universe and its future into free-fall, writes Katherine Kizilos.

          IN 1998, AN ASTRONOMER working with Brian Schmidt from the Australian National University published a paper about supernovas that, for those who understood it, revealed the universe to be more unfathomable than had previously been imagined.

          The supernova research led to a strange conclusion: that the universe is filled with a dark energy that is causing galaxies to move away from each other at an accelerated rate. It is now believed that dark energy makes up 73 per cent of the universe; the twist is that nobody knows what dark energy is. Not so long ago, physicists speculated that an all-encompassing Theory of Everything, describing the universe and all its wonders, was within mankind's reach. That is looking less likely now.

          When Schmidt began searching the skies for supernovas he had no clue that their behaviour would lead to revelations about dark energy. Supernovas are spectacular eruptions that occur at the end of a star's life. These massive blazes, which in some cases can rival the brightness of the surrounding galaxy, are rare events, and useful to astronomers.

          They use them as signposts (standard candles is the astronomical term) which help them calculate the size and age of the universe. Schmidt and his team were searching for type Ia supernovas, which burn with an intense light for about 100 years before their final collapse.

          "We can see them three-quarters of the way across the universe," says Schmidt, "so they allow us to look back in time." The oldest supernova that has been observed is 9 billion light years from earth, which means that it exploded 9 billion years ago. (The universe is now believed to be about 13.7 billion years old, with a 5 per cent margin for error.) The team was searching for supernovas as a way of determining how the expansion of the universe has changed over time.

          The idea here is that geometry is destiny. It was believed that if the shape of the universe were known, astrophysicists would be able to predict how it would eventually end. If the shape was a plane, say, or an open curve - like a wide-mouthed letter C in which the two ends point away from each other - then the universe could, theoretically at least, expand forever. But if space was found to curve inwards, the universe could end in a final crunch; an event Schmidt calls the "gnaB giB", which is Big Bang backwards and an example of the little jokes astronomers like to tell.

          Since 1995, Schmidt and his team had been in a race with astronomers led by Saul Perlmutter at the Lawrence Berkeley National Laboratory in California, who were also studying supernovas for the same reasons. By the end of 1997, Perlmutter's team had found more supernovas than Schmidt's team, but the type Ia supernova that Schmidt's team was looking for was yielding better results.

          What both teams discovered, independently of each other, was surprising and bizarre. (For the record, the Perlmutter team made the announcement first, but Schmidt's team was the first to publish a paper.) Each observed that the rate of the universe's expansion was not slowing, as expected, but speeding up. In Schmidt's words "the universe was behaving in a way that could not be explained".

          The expanding universe is sometimes compared to a currant cake rising in the oven, with the currants representing galaxies and the dough of the cake representing expanding space.

          The teams led by Schmidt and Perlmutter found that the galaxies were moving apart at a much faster rate than the laws of physics, as they are presently understood, are able to explain. Speculation about the momentum generated by the big bang, and the laws of gravity and motion, cannot account for the phenomenon. Scientists call the force that is responsible for this expansion dark energy - dark because it fills the blackness of space but also dark as in obscure, unknown, mysterious.

          Physicists now believe that only 4 per cent of the universe is made up of matter that can be measured by instruments now at mankind's disposal, which they call baryonic matter. Baryonic matter includes stars, galaxies, planets - and also ourselves, our shoelaces and the Earth as we know it. This means that 96 per cent of what makes up the universe is in a form that has never been detected directly in a laboratory: 73 per cent is believed to be dark energy and 23 per cent an enigmatic substance known as dark matter.

          Einstein taught us that energy and matter are essentially interchangeable. Dark energy and dark matter may be related, although most astronomers don't think they are; at this stage not enough is known about them to say for certain.

          Since the supernova data was gathered, two other observations have independently confirmed that the universe is expanding at an accelerated rate. One of these observations was made by a team of astronomers working with the telescope at the Anglo-Australian Observatory near Coonabarabran in NSW.

          Matthew Colless and his team of astronomers set about measuring the total density of the universe by making a map of 1/20th of the sky, an area encompassing 250,000 galaxies.

          Colless said the survey, which was the largest ever undertaken, allowed them to determine how much matter existed in the universe with better than 10 per cent accuracy. (The other observation was made by NASA's Wilkinson Microwave Anisotropy Probe - WMAP - a space instrument that measures the cosmic microwave background of the universe. WMAP was able to measure the ratio of baryonic to non-baryonic matter in the universe and has also determined that the universe is flat.) Colless' work, and the WMAP data, each corroborated the supernova findings and their implications.

          In 1998, Schmidt and his colleagues understood that if their observations were correct, our understanding of how the universe operated would have to change. And so they checked and rechecked the data, fearing the derision of their peers.

          "I was still shaking my head," said Schmidt after he was named Australian Scientist of the Year in 2004 for his work in the field, "but we had checked everything. I was very reluctant to tell people because I truly thought that we were going to get massacred."

          Seven years later, the observations made by Schmidt's team have been vindicated, but the mystery remains. For Schmidt, his findings suggest a future in which the galaxies become even more isolated as they move further apart in the vastness of space.

          "If I really start thinking about it - and I try to avoid doing that - it's really very bleak," he says. "I like the idea of a finite universe that has a life cycle that begins with the Big Bang and ends with the gnaB giB, but this doesn't seem to be the way of the universe."

          Schmidt's team was not derided by their peers as he had feared, although some remained sceptical. Schmidt didn't blame the sceptics - who have now been all but silenced - and even goes so far as to say that they were the rational ones. It will take more than a generation for the nature of dark energy to be understood by scientists, he says, maybe it will take 50 years.

          After all, it took about 30 years before scientists grasped the counter-intuitive world of quantum physics in which the observer influences the behaviour of sub-atomic particles, which are inherently unpredictable. (Quantum physics also allows for the theoretical possibility of parallel worlds, an idea physicists still playfully toss about.) Physicists agree that another revolutionary leap is what is required now. A hundred years after Einstein wrote E = MC2, another Einstein is needed to explain the universe anew.

          Interestingly, however, the findings have revived a concept that Einstein first proposed in 1917 when he published his general theory of relativity. At the time of writing he believed the universe consisted of the Milky Way and that it was eternal and unchanging.

          As part of his theory of relativity, Einstein posited the existence of a cosmological constant that he called lambda - the 11th letter in the Greek alphabet - to explain the force that kept the universe in a steady state. By 1930, Edwin Hubble's observations that galaxies were moving away from each other put paid to Einstein's assumption that the universe was static. Einstein, in turn, duly ditched the cosmological constant, calling it, apocryphally perhaps, his "greatest blunder".

          Seventy years later, lambda is being revisited because, in Schmidt's words, "it tells us what the energy of nothing is". Einstein theorised that the cosmological constant was a force that exerted negative pressure.

          Positive pressure is what you experience when you touch the surface of an inflated balloon. Negative pressure would cause the balloon to collapse at your touch.

          "It is not like anything you can imagine here on earth," says Schmidt. For years physicists considered the cosmological constant to be a joke - Einstein's mathematical fudge - but since the supernova data has been accepted it has gained new respectability as a way of solving the problem and of describing dark energy.

          But there are difficulties with the cosmological constant too. One is that the rate of the universe's expansion has not been constant but has changed over time. It is theorised that micro-seconds after the Big Bang the universe experienced a moment of hyper-expansion, when space and matter increased at an extraordinary rate.

          Then the rate of expansion speeded up again about 5 billion years ago, which also happens to be the time our own sun came into existence. It is a coincidence that makes astronomers and physicists uncomfortable. Creationism may be popular among religious conservatives, but astronomers are philosophically wary of a science that suggests an anthropocentric universe.

          "Why did it happen, just when we happen to be around?" asks Schmidt. "It begs the question that maybe we are missing something."

          For Colless, one possible solution is that this universe - the one that allows us to exist and to speculate about its meaning and origins - is simply one of many and may not be typical.

          An alternative theory calls the unknown force that is causing the universe's expansion quintessence. (In ancient Greece it was believed that the world was made up of earth, water, air, fire and quintessence - a sublime fifth element that stopped the sky from falling in.)

          According to the theorists, quintessence also exerts negative pressure, but it has the capacity to change over time, depending on conditions. Theoretically at least, this means the nature of quintessence could also change in order to bring about the renewal of the universe at some distant future date.

          Colless says he is personally delighted by the riddle posed by dark energy. He explains that because he is not a genius he never expected the task of understanding the workings of the cosmos to be straightforward.

          Pragmatically, the latest discoveries also mean that there is a great deal left for a working astronomer like him to do.

          For the rest of us, the advent of dark energy marks the official return of mystery to its traditional place at the centre of the universe. And you do not have to be a physicist to appreciate that where mystery lurks, awe and wonder are not far behind.

          Galaxies' heart of darkness

          DARK MATTER HAS NEVER been seen because it emits no light. Its existence is inferred by the gravitational pull it exerts. This exotic form of matter was first speculated about 50 years ago as a means of explaining why the outer arms of a galaxy travel at roughly the same speed as the dense centre.

          Astronomer Fritz Zwicky proposed that galaxies were engulfed in a ball of invisible dark matter that accounted for the uniform density suggested by their travelling speed.

          Astronomers have since unsuccessfully attempted to account for dark matter by estimating the mass of hard-to-find astronomical phenomena such as black holes and brown dwarfs (stars that do not shine brightly enough to be detected by telescopes).

          But all observations made to date suggest these objects do not occur often enough to account for the missing matter. The question of what dark matter is remains unanswered.

          A dark galaxy, which emits no starlight and is composed predominantly of dark matter, is believed to exist in the Virgo Cluster, 50 million light years from Earth.

          The discovery of VIRGOH21 may also explain why another nearby galaxy, NGC 4254, is lopsided, with one spiral arm much larger than the rest.

          This is usually caused by the influence of a companion galaxy, but none could be found until now; astronomers believe VIRGOH21 is responsible.

          http://www.theage.com.au/news/in-depth/ ... =fullpage#


            Interessant stuk, alles wat we weten over donkere materie en donkere energie kort samengevat. Maar weinig info over de WMAP gegevens.
            This person attempts not to panic, with the aid of several towels.


              Gisteren vond ik dit artikel ove Donkere energie. Het is een goed teken dat er aan verschillende kanten getrokken word Donkere energie, Donkere materie achtergrongstraling er is van alles gaande nou nog de juiste richting vinden !.....



                zeker een samenvatting van wat al langer bekend is, maar niettemin weer genoeg stof voor een nieuwe discussie :lol:
                er is ook al eens gezegd dat de versnelling word veroorzakt door de zwaartekracht die op afstand juist een afstotend effect zou hebben.
                en nog iets: zou "dark energy" echt 75 % van alle energie uitmaken?
                Geniet meer van de kleine dingen in het leven,
                Word macro-fotograaf! Canon 350d +180mm macro/sigma + 90 mm macro/tamron :D


                  Ligt eraan of dark energy echt een op zichzelf staande energievorm is, oftewel de energie van het vacuum. Er zijn zat theoriŽn die daar helemaal niet vanuit gaan, al zijn ze niet mainstream.

                  Zoals bijvoorbeeld het feit dat gravitonen weglekken van onze 'braan' (heelalvlak), waardoor de zwaartekracht relatief zwak is, en invloed kunnen uitoefenen op andere branen (heelallen). Afhankelijk van de ruimtelijke orientatie van die andere heelallen t.o.v. het onze 'voelen' we die 'exo-gravitonen' soms als donkere materie en soms als donkere energie.

                  Maar ja, is allemaal niet verifieerbaar.
                  This person attempts not to panic, with the aid of several towels.


                    gaan ze daar niet mee experimenteren met de nieuwste deeltjes-versneller?
                    Geniet meer van de kleine dingen in het leven,
                    Word macro-fotograaf! Canon 350d +180mm macro/sigma + 90 mm macro/tamron :D