The 570-megapixel Dark Energy Camera in Chile captured this photo of Comet Lovejoy on Dec. 27, 2014. Credit: Fermilab’s Marty Murphy, Nikolay Kuropatkin, Huan Lin and Brian Yanny The world's most powerful digital camera caught an amazing glimpse of Comet Lovejoy when it passed in front of the sensitive field of view. The "accidental observation" of Comet Lovejoy on Dec. 27 shows the comet's nucleus and coma splayed across several frames the camera took. At the time, Lovejoy was 51 million miles (82 million kilometers) from Earth. Ordinarily, the Dark Energy Camera looks at far more distant objects; it can image things up to eight billion miles (12.8 billion kilometers) away. "Our favorite [memory] all was the accidental observation of Comet Lovejoy, " wrote the blog Dark Energy Detectives (a blog of the Dark Energy Survey) of the sighting. "It reminds us that before we can look out beyond our galaxy to the far reaches of the universe, we need to watch out for celestial objects that are much closer to home." The camera is 570 megapixels and is designed to look for lights from galaxies and stars far away from Earth. Its field of view is about 2.2 degrees, equivalent to an area of sky 20 times the size of the moon seen from Earth. Comets are debris left over after the solar system formed 4.6 billion years ago. Let's see what you know about these ancient and elusive celestial wanderers. 0 of 10 questions complete Comet Quiz: Test Your Cosmic Knowledge Comets are debris left over after the solar system formed 4.6 billion years ago. Let's see what you know about these ancient and elusive celestial wanderers. 0 of questions complete The comet, officially called Comet Lovejoy C/2014 Q2, is named after the amateur astronomer in Australia who spotted it. Terry Lovejoy has found five comets to date; all comets are automatically named after the person or entity who first discovers it. This latest one was discovered in August 2014. Lovejoy appears to glow green in telescope views of amateur astronomers, who have captured numerous images and video of the comet since its discovery. Follow Elizabeth Howell @howellspace, or Space.com @Spacedotcom. Follow us @Spacedotcom, Facebook or Google+

The Hadron Particle Collider did not destroy the world last week, and scientists at CERN outside Geneva are sipping champagne and celebrating. But if the No. 1 best-selling author of a new book is correct, they might want to re-cork the bottle. In “Temple at the Center of Time: Newton’s Bible Codex Deciphered and the Year 2012, ” by David Flynn, a book that has skyrocketed up the best-seller charts following its release this month, the author makes a correction to Isaac Newton’s research, pointing to the year 2013 as “the time of the end.” In 2003, the Daily Telegraph in London published a front-page story declaring that, according to Isaac Newton, the world would end in 2060. This was the first time that this calculation of Newton became widely known. However, various biographers and researcher of Newton’s theology had encountered it since 1991 when most of his manuscripts were released on microfilm at the Jewish National and University Library in Jerusalem. According to Flynn, in the 1660s when Newton believed that the end of days was imminent, there seemed no reason to work out the approximate year in which it would occur. With the Great Plague, the fire of London and the apocalyptic fervor of the times, it seemed obvious to Newton that the end time had already arrived. But over the ensuing decades of his life, Newton became increasingly aware that his convictions had been premature. Near the year 1705, when Newton was in his sixties, his concern for preventing the repetition of the same error compelled him to invest his considerable knowledge to setting the matter of the time of the end to rest. The paper in which Newton recorded this calculation was the subject of the article in the London Daily Telegraph in 2003. Very few readers understood Newton’s reasoning for the date, not being scholars of end time prophecy themselves. Newton wrote concerning it: This I mention not to assert when the time of the end shall be, but to put a stop to the rash conjectures of fanciful men who are frequently predicting the time of the end, & by doing so bring the sacred prophesies into discredit as often as their predictions fail. Christ comes as a thief in the night, & it is not for us to know the times & seasons which God hath put into his own breast. Newton arrived at the year 2060 in a straightforward manner. He believed that the last world empire at the coming of the Antichrist would be a revived Roman Empire, a concept wholly embraced by eschatologists in modern times as well. He also believed that this had actually occurred in A.D. 800 through the coronation of Charlemagne by Pope Leo III as ruler of the revived Roman Empire in the West. As described by the prophet Daniel, and John in Revelation, the revived Roman Empire will rule for one “week, ” a period of seven times 360 days, or 2, 520 days total. In the midst of this week, at 1, 260 days, the Antichrist will desecrate the future temple in Jerusalem. Following the day/year guideline, Newton assigned 1, 260 years of the Revived Roman empire before Antichrist’s desecration of the temple. This he did realizing that the rebuilding of the temple and the judgments of Revelation did not follow the rebirth of the Roman Empire in A.D. 800. None of the prophecies of the End of Days followed the coronation of Charlemagne as Emperor of the revived Roman Empire after 1, 260, nor for that matter, any of the years up until Newton’s day. Therefore, he established each day with a year from A.D. 800, arriving at the year A.D. 2060. In a manuscript number 7.3g, f. 13v. of the Yahuda collection, Newton was even more specific about the 2060 date. So then the time times & half a time are 42 months or 1260 days or three years & an half, reckoning twelve months to a year & 30 days to a month as was done in the Calendar of the primitive year. And the days of short lived Beasts being put for the years of lived [sic for “long lived”] kingdoms, the period of 1260 days, if dated from the complete conquest of the three kings A.C. 800, will end A.C. 2060. But Newton’s prediction of Charlemagne’s revived Roman Empire starting in A.D. 800 and existing until the return of Christ was contradicted in 1806 when Napoleon forced the Empire’s dissolution.

Home Download Resources Extensions FAQ References Contact Us Models: Library Community Modeling Commons User Manuals: Web Printable Chinese Czech Japanese Note: This model is unverified. It has not yet been tested and polished as thoroughly as our other models. ## WHAT IS IT? This project displays the common natural phenomenon expressed by the inverse-square law. Essentially this displays what happens when the strength of the force between two objects varies inversely with the square of the distance between these two objects...

I’ve had a few people ask me why my blog is called Dark Matter Matters, and since I haven’t told that story in a while, I thought I’d share an excerpt from The Ad-Free Brand explaining it (and appending some more recent information). Here goes: In late 2008, I was struggling mightily with the question of how you measure and quantify the value of brand-related activities. As someone whose father is an amateur astronomer, I’d long been intrigued by the concept of dark matter in the universe. If dark matter is new to you, Wikipedia describes it as “matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy.” In other words, it is matter out there in the universe that is incredibly difficult to see, basically invisible, but that has a large gravitational effect. What’s particularly interesting about dark matter is that, apparently, there is a lot of it. Again according to Wikipedia: “Dark matter accounts for 23% of the mass-energy density of the observable universe. In comparison, ordinary matter accounts for only 4.6% of the mass-energy density of the observable universe, with the remainder being attributable to dark energy. From these figures, dark matter constitutes 83% of the matter in the universe, whereas ordinary matter makes up only 17%.” I find this fascinating. And dark matter is still a theoretical concept. Again from the Wikipedia entry: “As important as dark matter is believed to be in the cosmos, direct evidence of its existence and a concrete understanding of its nature have remained elusive.” But it was actually reading about all the problems with the Large Hadron Collider in 2008 (at the very same time I was having my own problems figuring out how to measure the value of brand-related work) that helped me make the connection between what I do for a living and this concept of dark matter. The Large Hadron Collider is the world’s largest particle accelerator. It was built on the border of France and Switzerland and is about 17 miles wide. One of the things that particle physicists hope to prove with this enormous project is the existence of dark matter. I’m no physicist, but as I understand it, the accelerator shoots protons at super-high speeds around the collider, and, if these scientists are lucky, the collisions eventually might produce a few particles that will exist for only a few milliseconds and then disappear again. And these particles might prove that dark matter isn’t just a theory. Might being the key word. In fact, noted physicist Stephen Hawking bet $100 that they won’t find anything (a bet which he may soon win). The cost of building a collider to maybe prove the existence of dark matter? About $9 billion dollars. (And as of this post, written in September 2011, three years since its was first fired up, we are still looking for evidence.) Another attempt to prove the existence of dark matter used the Hubble Space Telescope. This image below (which I also used for the header of the blog) was taken by Hubble and first shown by NASA in May, 2007. In this picture, you are looking at many galaxies a really, really long way away. But you can also see fuzzy gray areas all over that look like clouds. When the astronomers first looked at this photo, they thought the fuzzy areas were a problem with the image. But after analyzing it for over a year, they realized that the fuzziness might actually be evidence of dark matter. Their reasoning? The fuzziness is actually a gravitational distortion of the light rays from distant galaxies that are being bent by dark matter on their way to Earth. The effect you see is kind of like looking at the bottom of a pond that is being distorted by ripples on the surface.

American political personality Bill O’Reilly once famously said, “Tide goes in, tide goes out—never a miscommunication. You can’t explain that.” While he probably can’t explain that, scientists can: The tides are formed by gravitational forces exerted unevenly on the Earth by the moon (video). The Earth’s gravitational pull has quite an effect on the moon as well. And since the moon doesn’t have a liquid ocean, the Earth’s tidal forces are manifested in other, strange ways. A crack in the lunar surface, called a “lobate scarp, ” formed by the shrinking of the moon...

But Tesla didn’t stop there, he was into the incredible secrets of flight and antigravity which led him to register a patent in 1928, number 1, 655, 144 for a flying machine that resembled both a helicopter and an airplane. Before his death, Tesla had developed the blueprints for the propulsion system of his aircraft. He called it “SPACE DRIVE”or the anti-electromagnetic field propulsion system. Interestingly, according to William R. Lyne in “Occult Ether Physics”, in a conference that Tesla had prepared for the Migrant Welfare Institute on May 12, 1938, he spoke about the Dynamic Theory of Gravity. Lyne inv...

Though it seems hard to believe, Earth’s gravitational pull is not the same everywhere you go. And as these gorgeously detailed maps now show, these variances are much greater than we thought. Top image: The low gravity atop Mount Everest (credit: GGMplus/Curtin University). Gravity varies on our planet owing to a number of factors. It's not perfectly spherical or uniformly dense. What’s more, gravity is weaker at the equator because of the outward centrifugal force produced by the Earth's rotation relative to the polar latitudes. And the higher you go, the further you are from the Earth’s center. Now, in an effort to visualize these discrepancies, Christian Hirt and colleagues from Curtin University in Perth, Western Australia, have devised a mapping system they call Global Gravity Model plus (GGMplus). It provides maps and data of Earth’s gravity at an astounding resolution of 200 meters for all land and near coastal areas of our planet between +-60o latitude (which covers about 80% of the Earth’s land masses). GGMplus describes Earth gravity across four domains: Gravity accelerations Gravity disturbances North-South and East-West deflections of the vertical Quasigeoid heights at 3, 062, 677, 383 points at 7.2 arc-sec spatial resolution (quasigeoid, like geoid, is a reference surface for heights) The unprecedented ultra-high resolution maps were constructed using data acquired by the GRACE and GOCE satellites. Supercomputers were used to crunch the numbers. In terms of the gravitational variations, they found that Mount Nevado Huascarán in Peru has the lowest gravitational acceleration at 9.7639 m/s2, while the surface of the Arctic Ocean has the highest gravitational acceleration at 9.8337 m/s2>. New Scientist explains what this means to you and me: These differences mean that in the unlikely event that you found yourself falling from a height of 100 metres at each point, you would hit the surface in Peru about 16 milliseconds later than in the Arctic. You would also lose 1 per cent of your body weight in moving from the Arctic to the Peruvian mountaintop, although your mass would not change. Read the entire study at Geophysical Research Letters : “New ultra-high resolution picture of Earth's gravity field.” And there’s plenty of more info — and images — at Western Australian Centre for Geodesy.

So what is dark energy? Well, the simple answer is that we don't know. It seems to contradict many of our understandings about the way the universe works. We all know that light waves, also called radiation, carry energy. You feel that energy the moment you step outside on a hot summer day. Einstein's famous equation, E = mc2, teaches us that matter and energy are interchangeable, merely different forms of the same thing. We have a giant example of that in our sky: the Sun. The Sun is powered by the conversion of mass to energy. Something from Nothing Could dark energy show a link between the physics of the very small and the physics of the large? But energy is supposed to have a source — either matter or radiation. The notion here is that space, even when devoid of all matter and radiation, has a residual energy. That "energy of space, " when considered on a cosmic scale, leads to a force that increases the expansion of the universe. Perhaps dark energy results from weird behavior on scales smaller than atoms. The physics of the very small, called quantum mechanics, allows energy and matter to appear out of nothingness, although only for the tiniest instant. The constant brief appearance and disappearance of matter could be giving energy to otherwise empty space. It could be that dark energy creates a new, fundamental force in the universe, something that only starts to show an effect when the universe reaches a certain size. Scientific theories allow for the possibility of such forces. The force might even be temporary, causing the universe to accelerate for some billions of years before it weakens and essentially disappears. Or perhaps the answer lies within another long-standing unsolved problem, how to reconcile the physics of the large with the physics of the very small. Einstein's theory of gravity, called general relativity, can explain everything from the movements of planets to the physics of black holes, but it simply doesn't seem to apply on the scale of the particles that make up atoms. To predict how particles will behave, we need the theory of quantum mechanics. Quantum mechanics explains the way particles function, but it simply doesn't apply on any scale larger than an atom. The elusive solution for combining the two theories might yield a natural explanation for dark energy. Stranger and Stranger Most of the universe seems to consist of nothing we can see. Dark energy and dark matter, detectable only because of their effect on the visible matter around them, make up most of the universe. We do know this: Since space is everywhere, this dark energy force is everywhere, and its effects increase as space expands. In contrast, gravity's force is stronger when things are close together and weaker when they are far apart. Because gravity is weakening with the expansion of space, dark energy now makes up over 2/3 of all the energy in the universe. It sounds rather strange that we have no firm idea about what makes up 74% of the universe. It's as though we had explored all the land on the planet Earth and never in all our travels encountered an ocean. But now that we've caught sight of the waves, we want to know what this huge, strange, powerful entity really is.

Gravity or gravitational forces are forces of attraction. We're not talking about finding someone really cute and adorable. It's like the Earth pulling on you and keeping you on the ground. That pull is gravity at work. Every object in the universe that has mass exerts a gravitational pull, or force, on every other mass. The size of the pull depends on the masses of the objects. You exert a gravitational force on the people around you, but that force isn't very strong, since people aren't very massive. When you look at really large masses, like the Earth and Moon, the gravitational pull becomes very impressive. The gravitational force between the Earth and the molecules of gas in the atmosphere is strong enough to hold the atmosphere close to our surface. Smaller planets, that have less mass, may not be able to hold an atmosphere. Obviously, gravity is very important on Earth. The Sun's gravitational pull keeps our planet orbiting the Sun. The motion of the Moon is affected by the gravity of the Sun AND the Earth. The Moon's gravity pulls on the Earth and makes the tides rise and fall every day. As the Moon passes over the ocean, there is a swell in the sea level. As the Earth rotates, the Moon passes over new parts of the Earth, causing the swell to move also. The tides are independent of the phase of the moon. The moon has the same amount of pull whether there is a full or new moon. It would still be in the same basic place. We have to bring up an important idea now. The Earth always produces the same acceleration on every object. If you drop an acorn or a piano, they will gain velocity at the same rate. Although the gravitational force the Earth exerts on the objects is different, their masses are just as different, so the effect we observe (acceleration) is the same for each. The Earth's gravitational force accelerates objects when they fall. It constantly pulls, and the objects constantly speed up. People always say, "What about feathers? They fall so slowly." Obviously, there is air all around us. When a feather falls, it falls slowly because the air is in its way. There is a lot of air resistance and that resistance makes the feather move slower. The forces at work are the same. If you dropped a feather in a container with no air (a vacuum), it would drop as fast as a baseball. But what keeps the Moon from falling down, if all of this gravity is so strong? Well, the answer is that the moon IS falling; all the time, but doesn't get any closer to us! Remember that if there wasn't a force acting, the Moon would be traveling in a straight line. Because there IS a force of attraction toward the Earth, the moon "falls" from a straight line into a curve (orbit) around the Earth and ends up revolving around us. The Earth's gravity holds it in orbit, so it can't just go off in a straight line. Think about holding a ball on a string and spinning it in a circle. If you were to cut that string (no more gravity), the ball would fly off in a straight line in the direction it was going when you cut the string. That direction, by the way, is not directly away from your hand, but tangent to the circle. Tangent is a geometry term used to describe a direction that are related to the slope of a curve. Math stuff. The pull of the string inward (toward your hand) is like the Earth's gravitational pull (inward toward the center of the Earth). Or search the sites for a specific topic. How Gravity Affects Molecules (NASA-eClips Video) Encyclopedia.com (Specific Gravity):

Definitions of Fact, Theory, and Law in Scientific Work Science uses specialized terms that have different meanings than everyday usage. These definitions correspond to the way scientists typically use these terms in the context of their work. Note, especially, that the meaning of “theory” in science is different than the meaning of “theory” in everyday conversation. Fact: In science, an observation that has been repeatedly confirmed and for all practical purposes is accepted as “true.” Truth in science, however, is never final and what is accepted as a fact today may be modified or even discarded tomorrow. Hypothesis: A tentative statement about the natural world leading to deductions that can be tested. If the deductions are verified, the hypothesis is provisionally corroborated. If the deductions are incorrect, the original hypothesis is proved false and must be abandoned or modified. Hypotheses can be used to build more complex inferences and explanations. Law: A descriptive generalization about how some aspect of the natural world behaves under stated circumstances. Theory: In science, a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.