The electrodes (gold) of the trap used to combine positrons and antiprotons to form antihydrogen.N. MADSEN, ALPHA/SWANSEA
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Can warp drive be far behind? A paper published in this week’s edition of Nature reports that for the first time, antimatter atoms have been captured and held long enough to be studied by scientific instruments. Not only is this a science fiction dream come true, but in a very real way this could help us figure out what happened to all the antimatter that has vanished since the Big Bang, one of the biggest mysteries of the Universe. “We’re very excited about the fact that we can actually now trap antimatter atoms long enough to study their properties and see if they’re very different from matter,” said Makoto Fujiwara, a team member from ALPHA, an international collaboration at CERN.
Antimatter is produced in equal quantities with matter when energy is converted into mass. This happens in particle colliders like CERN and is believed to have happened during the Big Bang at the beginning of the universe.
“A good way to think of antimatter is a mirror image of normal matter,” said team spokesman Jeffrey Hangst, a physicist at Aarhus University in Denmark. “For some reason the universe is made of matter, we don’t know why that is, because you could in principle make a universe of antimatter.”
In order to study antimatter, scientists have to make it in a laboratory. The ALPHA collaboration at CERN has been able to make antihydrogen – the simplest antimatter atom – since 2002, producing it by mixing anti- protons and positrons to make a neutral anti-atom. “What is new is that we have managed to hold onto those atoms,” said Hangst, by keeping atoms of antihydrogen away from the walls of their container to prevent them from getting annihilated for nearly a tenth of a second.
The antihydrogen was held in an ion trap, with electromagnetic fields to trap them in a vacuum, and cooled to 9 Kelvin (-443.47 degrees Fahrenheit, -264.15 degrees Celsius). To actually see if they made any antihydrogen, they release a small amount and see if there is any annihilation between matter and antimatter.
The next step for the ALPHA collaboration is to conduct experiments on the trapped antimatter atoms, and the team is working on a way to find out what color light the antihydrogen shines when it is hit with microwaves, and seeing how that compares to the colors of hydrogen atoms.
Images of the core of NGC 4150, taken in near-ultraviolet light with the sharp-eyed Wide Field Camera 3 (WFC3). Credit: NASA, ESA, R.M. Crockett (University of Oxford, U.K.), S. Kaviraj (Imperial College London and University of Oxford, U.K.), J. Silk (University of Oxford), M. Mutchler (Space Telescope Science Institute, Baltimore), R. O'Connell (University of Virginia, Charlottesville), and the WFC3 Scientific Oversight Committee
Like news ripped from a Hollywood tabloid, this saga includes an encounter between two individuals; one aging, and thought to be past its prime, the other youthful and vigorous. And for good measure, thrown in on this story are cannibalism and even zombies. The result of the meet-up? Babies. Baby stars, that is, and the individual galaxies in this tale ended up, seemingly, living together happily-ever-after. The Hubble Space Telescope’s Wide Field Camera 3 (WFC3) captured images of NGC 4150, an aging elliptical galaxy, and at the core of the galaxy was some vigorous star birth. The star-making days of this galaxy should have ended long ago, but here was active star birth taking place. This isn’t the first time astronomers have seen something like this, so they took a closer look. Continue reading “Hollywood-like Galactic Encounter Results in Baby Stars”
When it comes to the geological timeline, there are several periods that scientists and biologists recognize as being of extreme importance to the development of life on Earth. There’s the Hadean period, which began with the creation of the Earth and was marked by the formations of the oceans and atmosphere. Or the Cambrian period, when the massive continent of Pangaea broke up and allowed for the explosion of life which led to the development of all modern Phyla. But when it comes to us mammals, perhaps the most important period was the one known as the Tertiary Period. This period began 65 million years ago and ended roughly 1.8 million years ago and bore witness to some major geological, biological and climatological events. This included the current configuration of the continents, the cooling of global temperatures, and the rise of mammals as the planet’s dominant vertebrates. It followed the Cretaceous period and was superseded by the Quaternary.
In terms of major events, the Tertiary period began with the demise of the non-avian dinosaurs in the Cretaceous–Tertiary extinction event, at the start of the Cenozoic era, and lasted to the beginning of the most recent Ice Age at the end of the Pliocene epoch. In terms of geology, there was a great deal of tectonic activity that continued from the previous era, culminating in the splitting of Gondwana and the collision of the Indian landmass with the Eurasian plate. This led to the formation of the Himalayas, the gradual creation of the continent of Australia (a haven for the non-placental, marsupial mammals), the separation South America from West Africa and its connection to North America, and Antarctica taking its current position below the South Pole. In terms of climate, the period was marked by widespread cooling, beginning in the Paleocene with tropical-to-moderate worldwide temperatures and ending before the first extensive glaciation at the start of the Quaternary.
In terms of species evolution, this period was of extreme importance to modern life. By the beginning of the period, mammals replaced reptiles as the dominant vertebrates on the planet. In addition, all non-avian dinosaurs (referring to terrestrial dinosaurs and not their avian descendants) had all become extinct by the beginning of this period. Modern types of birds, reptiles, amphibians, fish, and invertebrates were already numerous at the beginning of this period but also continued to appeared early on, and many modern families of flowering plants evolved. And last, but certainly not least (at least for us human folk), the earliest recognizable hominid relatives of humans appeared. One striking example of this is the Proconsul Primate, a tree-dwelling Primate that existed from roughly 23 to 17 million years ago and who’s fossilized remains have been found today in modern Kenya, Uganda and other East African locales.
We have written many articles about Tertiary Period for Universe Today. Here’s an article about the Quaternary Period, and here’s an article about the asteroid extinction theory.
Super Magnets, the strongest type of permanent magnets
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Magnets are not only a source of endless fun – for children and children of all ages! They also happen to have endless industrial applications. But when it comes to the high-tech industry, the people who rely on magnetic materials to build appliances, electronics, or even spaceships, only one type of magnet will do. These are known as Rare Earth or Super Magnets, the kind that are used in MRI machines, computer hard drives, electric and hybrid motors, audio speakers, electric guitars, and race car engines. In spite of their name, the elements used to make super magnets are actually quite common, but were rarely found in large enough quantities to be considered economically viable. However, since the 90’s these magnets have become cheap and widely available, and are even being considered for additional processes.
The term super magnet is a broad term and encompasses several families of rare-earth magnets that include seventeen elements in the periodic table; namely scandium, yttrium, and the fifteen lanthanides. First developed in the 1970’s and 80’s, super magnets are the strongest type of permanent magnets ever made, are ferromagnetic, meaning that like iron they can be magnetized, and have Curie temperatures that are below room temperature. This means that in their pure form, their magnetism only appears at low temperatures. However, since they can form compounds with transition metals such as iron, nickel, and cobalt, metals that have Curie temperatures well above room temperature, they can be used effectively at higher temperatures as well. The main advantage they have over conventional magnets is that their greater strength allows for smaller, lighter magnets to be used, ones that can do the same job but take up less space and require less material.
Super magnets can be broken down into two categories. First, there is the neodymium magnet, which is made from an alloy of neodymium, iron, and boron to form the Nd2Fe14B tetragonal crystalline structure. This material is currently the strongest known type of permanent magnet and was developed in the 1980’s. It is typically used in the construction of head actuators in computer hard drives and has many electronic applications, such as electric motors, appliances, and magnetic resonance imaging (MRI). The second type of super magnet is the samarium-cobalt variety, an alloy of samarium and cobalt with the chemical formula of SmCo5. This second-strongest type of rare Earth magnet is also used in electronic motors, turbomachinery, and because of its high temperature range tolerance may also have many applications for space travel, such as cryogenics and heat resistant machinery.
We have written many articles about magnets for Universe Today. Here’s an article about where to buy magnets, and here’s an article about what magnets are made of.
Ready for another Where In The Universe Challenge? Here’s #125! Take a look and see if you can name where in the Universe this image is from. Give yourself extra points if you can name the spacecraft, telescope or instrument responsible for the image. We provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image and provide your answer/guess in the comment section. And Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.
UPDATE: Answer now posted below.
This is one of Saturn’s moons, Calypso, and the image was taken in February 2010.
Calypso is shaped pretty strangely for a moon, and it is one of two Trojan moons of the larger moon Tethys — the other is Telesto. Calypso trails Tethys in its orbit by 60 degrees. Like Telesto, Calypso’s smooth surface does not appear to retain the record of intense cratering that most of Saturn’s other moons have.
This view looks toward the leading hemisphere of Calypso (21 kilometers, or 13 miles across).
A close-up view of the X-38 under the wing of NASA's B-52 mothership prior to a test launch of the vehicle. Credit: NASA
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Of all the missions and spacecraft that NASA has shelved over the years, I found the X-38 Crew Return Vehicle (CRV) to personally be one of the most disappointing. While its cancellation resulted in no loss of science and never stranded any astronauts in space, my disappointment was from strictly an aesthetic point of view: this was the cutest little spacecraft I had ever seen. The X-38 was a prototype for a wingless lifting body reentry vehicle that was to be used as a crew return and/or rescue vehicle for the International Space Station, but it was canceled in 2002 due to budget cuts. I guess cuteness doesn’t get you far in the space biz.
The image above shows a test flight in 1999 where the the X-38 research vehicle was dropped from a B-52 airplane. Three different designs of the X-38 made flight tests, and the vehicle landed by using one of the biggest aerofoil parachutes ever made. The CRV was designed to fly automatically from orbit to landing using onboard navigation and flight control systems, but backup systems also would have allowed the crew to pick a landing site and steer the parafoil to a landing, if necessary. The X-38’s landed on skids, not wheels, reminiscent of the famed X-15 lifting body research aircraft.
The X-38 was developed at NASA’s Dryden Flight Research Center at Edwards Air Force Base in California, and atmospheric test vehicles were actually built by Scaled Composites – the very same company that later built SpaceShipOne and won the X PRIZE.
The X-38 drops from a B-52 aircraft. Credit: NASA
The X-38 looks like a mini-space shuttle, and would have fit into the payload bay of the full-size space shuttles.
X-38 weighed 10,660 kg and was 9.1 meters long. The battery system, lasting nine hours, was to be used for power and life support. If the crew from the ISS had to make an emergency return to Earth, it would only take two to three hours for the CRV to reach Earth.
One of the prototypes can now be seen at the Strategic Air and Space Museum in Ashland Nebraska, located just off Interstate 80, about 20 miles southeast of Omaha.
NGC 1514, sometimes called the "Crystal Ball" nebula shows a new double ring feature in an image from WISE. Image credit: NASA/JPL-Caltech/UCLA
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It’s not like we’ve never seen the planetary nebula NGC 1514 before, but we’ve never seen it though WISE’s infrared eyes, until now. And in a stunning surprise, cylindrical rings appear to be encircling the dying star, like a neon-lit carousel, or perhaps like rolling tire surrounding a glowing blob. “I just happened to look up one of my favorite objects in our WISE catalogue and was shocked to see these odd rings,” said Michael Ressler, a member of the WISE science team at JPL. “This object has been studied for more than 200 years, but WISE shows us it still has surprises.
Space station from the movie 2001: A Space Odyssey.
At first glance the rings look like the double-ringed space station in the movie 2001: A Space Odyssey. (Too bad the Bad Astronomer beat me to that likeness. He also compared it to a tuna can.)
Other people see different things in this image.
“I am reminded of the jellyfish exhibition at the Monterey Bay Aquarium — beautiful things floating in water, except this one is in space,” said Edward (Ned) Wright, the principal investigator of the WISE mission at UCLA, and a co-author of a paper on the findings, reported in the Astronomical Journal.
WISE was able to spot the rings for the first time because their dust is being heated and glows with the infrared light that WISE can detect. In visible-light images, the rings are hidden from view, overwhelmed by the brightly fluorescing clouds of gas.
Here’s what NGC 1514 looks like in visible light from a ground observatory:
NGC1514 in visible light. Image credit: Digitized Sky Survey/STScI
The object is actually a pair of stars, seen as a single dot at the center of the blue orb. One star is a dying giant somewhat heavier and hotter than our sun, and the other was an even larger star that has now contracted into a dense body called a white dwarf. As the giant star ages, it sheds some its outer layers of material. An inner shell of ejected material is seen in bright, light blues. An outer shell can also be seen in more translucent shades of blue.
This planetary nebula is also called the “Crystal Ball” nebula, and Ressler said although NGC 1514’s structure looks unique, is probably similar in overall geometry to other hour-glass nebulae, such as the Engraved Hourglass Nebula.
Planetary Nebula MyCn18: An Hourglass Pattern Around a Dying Star. Credit: Raghvendra Sahai and John Trauger (JPL), the WFPC2 science team, and NASA.
The structure looks different in WISE’s view because the rings are detectable only by their heat; they do not fluoresce at visible wavelengths, as do the rings in the other objects.
The WISE science team says that more oddballs like NGC 1514 are sure to turn up in the plethora of WISE data — the first batch of which will be released to the astronomical community in spring 2011.
The binary star system J0923+3028 consists of two white dwarfs: a visible star 23 percent as massive as our Sun and about four times the diameter of Earth, and an unseen companion 44 percent of the Sun's mass and about one Earth-diameter in size. The stars will spiral in toward each other and merge in about 100 million years. (Credit: Clayton Ellis (CfA))
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Based on results from a radial velocity survey, Warren Brown, (Smithsonian Astrophysical Observatory) and his team have placed a few more pieces into the supernova puzzle.
Supernovae come in many flavors. There are Type Ia, the “standard candles” everyone has heard of; and there are Type Ib and Ic, which also involve binary systems. We also have Type II supernovae that are believed to be the core collapse of single, super-massive stars. There are also super-luminous supernovae, which may be the explosive conversion of a neutron star into a quark star, and finally the weak-kneed cousins of the bunch, the under-performing underluminous supernovae.
Underluminous supernovae are a rare type of supernova explosion 10–100 times less luminous than a normal SN Type Ia and eject only 20% as much matter. Brown and his team have been investigating the connection between underluminous supernovae and merging pairs of white dwarfs.
In the 1980s, on the basis of our theoretical understanding of stellar and binary evolution it was predicted that many close double white dwarfs would exist. However, it was not until 1988 that the first one was actually discovered.
The way to find close double white dwarfs is to take high resolution spectra of the H-alpha absorption line of a white dwarf at several different times and look for variation that is caused by the orbital motion of the white dwarf around an unseen (dimmer) companion. The first systematic searches were not very unsuccessful. Only one system was found. Then, during the 1990s, Tom Marsh and collaborators concentrated their search on low-mass white dwarfs, which, based on current theories, could _only_ be formed in a binary system. In this way a dozen more systems were found.
Extremely low mass (ELM) white dwarfs (WDs) with less than 0.3 solar masses are the remnants of stars that never ignited helium in their cores. The Universe is not old enough to have produce ELM WDs by single star evolution. Therefore, ELM WDs must undergo significant mass loss sometime in their evolution. Producing WDs with 0.2 solar masses most likely requires compact binary systems.
“These white dwarfs have gone through a dramatic weight loss program,” said Carlos Allende Prieto, an astronomer at the Instituto de Astrofisica de Canarias in Spain and a co-author of the study. “These stars are in such close orbits that tidal forces, like those swaying the oceans on Earth, led to huge mass losses.”
Observational data for ELM WDs is pretty hard to come by because of their rarity. For example, of the 9316 WDs identified in the Sloan Digital Sky Survey, less than 0.2% have masses below 0.3 solar.
Half of the pairs discovered by Brown and collaborators are merging and might explode as supernovae in 100 million years or more.
“We have tripled the number of known, merging white-dwarf systems,” said Smithsonian astronomer and co-author Mukremin Kilic. “Now, we can begin to understand how these systems form and what they may become in the near future.” Unlike normal white dwarfs made of carbon and oxygen, these are made almost entirely of helium.
“The rate at which our white dwarfs are merging is the same as the rate of under-luminous supernovae – about one every 2,000 years,” explained Brown. “While we can’t know for sure whether our merging white dwarfs will explode as under-luminous supernovae, the fact that the rates are the same is highly suggestive.”
At least 25% of these ELM WDs belong to the old thick disk and halo components of the Milky Way. This helps astronomers know where to look for underluminous SNe and where they are unlikely to find them, if the models are correct. If merging ELM WD systems are the progenitors of underluminous SNe, the next generation of surveys such as the Palomar Transient Factory, Pan-STARRS, Skymapper, and the Large Synoptic Survey Telescope should find them amongst the older populations of stars in both elliptical and spiral galaxies.
Young stars have a disk of gas and dust around them called a protoplanetary disk. Credit: NASA/JPL-Caltech
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Awhile ago I wrote on the difficulty of finding young planets. There, I mentioned one team announcing the potential discovery of a planet a mere 1-5 million years old. But what are astronomers to do if they want to find even younger planets?
The chief difficulty in this instance is that such planets would still be hidden in the circumstellar disks from which they formed, hiding them from direct observation. Additionally, depending on how far along the process had advanced, they may not yet have accreted sufficient mass to show up in radial velocity surveys, if such surveys could even been conducted with interference from the disc.
One way astronomers have proposed to detect forming planets is to observe their effects on the disc itself. This could come in a number of ways. One would be for the planet to carve out grooves in the disc, clearing its orbit as it sweeps up matter. Another possibility is to look for the “shadows” caused by the local overdensity an accreting planet would cause.
But recently, another new method caught my eye. In this one, proposed by astronomers at the Crimean National Observatory in the Ukraine, astronomers could potentially look for again turns to the characteristics of the parent star. Earlier, astronomers had made a link between the properties of the disc around classes of protostars (such as T Tauri and Herbig Ae stars) and the variable luminosity of the star itself.
The authors suggest that, “[t]wo different mechanisms can be involved in interpretation of these results: 1) circumstellar extinction and 2) accretion.” In either scenario, a body present in the disc itself concentrating the material would be necessary to explain these results. In the first case, a protoplanet would draw a swarm of material around it again creating a local overdensity in the disc which would be dragged around with the planet, creating a dimming of the star as it passed near the line of sight. In the second, the planet would draw out tidal structures in the disc in much the same way tidal interactions can draw out spiral structure in galaxies. As these veins of matter fall onto the star, it feeds the star, temporarily causing an outburst and increasing the brightness.
The team conducted an analysis of periodicity in several protostellar systems and found several instances in which the periods were similar to those of planetary systems discovered around mature stars. Around one star, V866 Sco, they discovered, “two distinct periods in light variations, 6.78 and 24.78 days, that persist over several years.” They note that the shorter period is likely “due to axial rotation of the star” but could not offer an explanation for the longer period which leaves it open to the possibility of being a forming planet and they suggest that spectral observations may be possible. Other systems the team analyzed had periods ranging from 25 – 120 days also hinting at the possibility for young planetary systems.
The advantage to this method is that finding candidate systems can be done relatively easily using photometric systems which can survey great numbers of stars at once whereas radial velocity measurements generally require dedicated observations on a single object. This would allow astronomers to discriminate against candidates unlikely to harbor forming planets. Ultimately, finding young systems with forming planets will help astronomers understand how these systems form and evolve and why our own system is so different than many others found thus far.
Ancient woodcarving of where heaven and earth meet. Credit: Heikenwaelder Hugo at Wikimedia Commons.
Cosmology is a fairly young science, one which attempts to reconstruct the history of our Universe from billions of years ago. Looking back so far in time is extremely difficult, and adding to the complexity is that many of the pillars upon which the theories of cosmology rest have only been conceived within the last 20 years or so. That hasn’t given scientists and theorists much time to fully flesh out and comprehend the situation, and cosmologist Michael Turner says either some important new physics will have to be discovered or we’re going to find a fatal flaw in our prevailing view of the Universe.
So, what will it take to push cosmology over the edge, where it goes fully from theory to science, and we have at least a grasp of cosmological understanding? I had the chance to ask that question to Turner at last week’s National Association of Science Writers conference. Turner, who coined the term “dark energy,” is the Director of the Kavli Institute for Cosmological Physics at the University of Chicago. Here are his top four wishes for discoveries in cosmology:
Wish # 1: Figure out the nature of dark matter.
“I think we’re very close to solving this dark matter problem and I think its going to be stunning when it sinks in to everyone that most of the stuff in the Universe is made of something other than what we are,” Turner said.
Dark matter holds universe together, according to cosmologists. But since it does not emit electromagnetic radiation and we can’t see it, how do we know it is there? “It is needed to hold galaxies together, it is needed to hold clusters together, it is that simple,” Turner said. “There is not enough gravity in all the stars put together to hold clusters together.”
Turner has likened dark matter to an outdoor tree decorated with Christmas lights. From far away, all that can be seen are the lights, but it is the unseen tree that holds the lights where they are and gives them their shape. More poetically Turner said, “The universe is a web of dark matter that is decorated by stars.”
Turner made a bold prediction: “The 2010 is the decade of dark matter – we are going to finish this thing off.”
Dark matter in the Bullet Cluster. Otherwise invisible to telescopic views, the dark matter was mapped by observations of gravitational lensing of background galaxies. Credit: X-ray: NASA/CXC/CfA/ M.Markevitch et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/ D.Clowe et al. Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.;
Wish # 2. Figure out the nature of dark energy.
“Dark energy may be most profound problem in cosmology today, and I’ve been wandering around for 10 years saying this,” Turner said. “If dark matter holds the Universe together, dark energy controls its destiny.”
Dark energy likely makes up 66% of the cosmos, and it’s existence has only been theorized since 1998 when astronomers realized that contrary to the prevailing notion that the expansion of the universe should be slowing down, it is actually moving faster as time goes on.
What is the current theoretical understanding of dark energy? “We don’t have a clue,” said Turner. “But let me go out here on a limb with dark energy, and say we may find it is not vacuum energy. Vacuum energy is mathematical equivalent to Einstein’s cosmological constant, and I hope we’ll figure out it is something weirder than the energy of nothing. That doesn’t solve the problem, but it would be a gift to my younger colleagues, because science is all about big questions and they need clues and something big they can sink their teeth into.”
Yes, dark energy is a big problem, but for theorists it’s a big opportunity. However, Turner has some doubts. “Dark energy is one of the big questions that will occupy the next decade, and I don’t know if we’ll be able to solve it,” he said.
Michael Turner at the 2010 National Association of Science Writers conference at Yale University. Image: Nancy Atkinson
Wish # 3: Confirming inflation with the discovery of B-Mode polarization.
Our current best theory about the earliest moments of the universe is called inflation, where during a tiny fraction of a second after the Big Bang, the Universe appears to have expanded exponentially. In particular, high precision measurements of the so-called B-modes (evidence of gravity waves) of the polarization of the cosmic microwave background radiation would be evidence of the gravitational radiation produced by inflation, and they will also show whether the energy scale of inflation predicted by the simplest models is correct.
“That is the smoking gun for inflation.” said Turner. “It explains where all the structure came from – that quantum mechanical fluctuations at the subatomic scale were blown up by this enormous expansion. That is an amazing idea, and in one equation we could figure out exactly when inflation took place. You’ll notice in all our talk of inflation no one ever tells you when it took place, because we don’t know. But those B-modes would tell us.”
Wish #4. Make the mulitiverse go away.
If there was inflation, that means there is also very likely a multitude of Universes out there.
Turner called the concept of the multiverse the 800 lb gorilla in the room.
“The dilemma is, we have evidence that inflation took place and the equations of inflation say that if it took place once, it took place twice and it’s sort of like the mouse and the cookie – if it took place twice it could have taken place an infinite number of times,” he said.
The multiverse hypothesizes multiple universes or parallel universes comprise everthing that is, not just our one “local” universe. “If there is a mulitverse structure, and if you marry this with string theory you end up with a picture of a Universe where there might be different local laws of physics and the different sub-universes might be incredibly different from each other – differences in space and time, some don’t have stable particles, many don’t have life, and so on. This is an incredibly bold idea and may even be the most important idea since Copernicus.”
But, Turner asked, how do you test it? “And if you can’t test it, therefore you can’t call it science,” he said. “So I call it the mulitiverse headache – you have this incredibly important idea, but is it science?”
“That’s where we are in cosmology,” he said. “We are the blind cosmologists feeling the Universe and each piece of data describes something. There are still big questions to be answered, and what we’re doing in cosmology is trying to put it all together, and we might actually, in the next 10-15 years put it all together. That is absolutely amazing; the universe is very big and our abilities are very primitive. But look what we’ve done so far.”
Slide from Turner's presentation showing the Universe as an elephant. Image: Nancy Atkinson
