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His Snarky Porcupine
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His Snarky Porcupine
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His Snarky Porcupine
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His Snarky Porcupine
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His Snarky Porcupine
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Can't wait for my new shirt to get here:
luvthedesserts
luvherdesserts
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luvthedesserts
luvherdesserts
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Not everyone is as fortunate as you, sweetie.
Understatement of the millennium. They're totally freaking AWESOME!!!!!!
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luvthedesserts
luvherdesserts
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I wouldn't say awesome, but you're more than welcome to describe them as such.
No need to describe them, I have a bronzed bust of them on my desk. Get it? Bust.
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No need to describe them, I have a bronzed bust of them on my desk. Get it? Bust.
*snort* Hilarious.
Yeah, I have a few more comments on that one, but they'll just have to wait.
luvthedesserts
luvherdesserts
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*snort* Hilarious.
Yeah, I have a few more comments on that one, but they'll just have to wait.
Who's the winner? That's right, me is the winner. Go ahead, give me the silent treatment. I'll pretend it bothers me.
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luvthedesserts
luvherdesserts
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You don't like silence. At least not in certain situations.
Is this THAT situation? Really? Just can't help but have the last word, huh?
EDIT See that post down there? Yep, last word. Nailed it.
Last edited:
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No, and it wasn't that situation last night either. Nor will it be tonight.
*sigh*
Porkwarrior
Midlife Man Whore
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Given up on your chatroom or just no time latelyÉ (damn French keyboard...can`t find the question mark!)
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Just super busy!
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Cosmologist claims Universe may not be expanding
Particles' changing masses could explain why distant galaxies appear to be rushing away.
It started with a bang, and has been expanding ever since. For nearly a century, this has been the standard view of the Universe. Now one cosmologist is proposing a radically different interpretation of events — in which the Universe is not expanding at all.
In a paper posted on the arXiv preprint server1, Christof Wetterich, a theoretical physicist at the University of Heidelberg in Germany, has devised a different cosmology in which the universe is not expanding but the mass of everything has been increasing. Such an interpretation could help physicists to understand problematic issues such as the so-called singularity present at the Big Bang, he says.
Although the paper has yet to be peer-reviewed, none of the experts contacted by Nature dismissed it as obviously wrong, and some of them found the idea worth pursuing. “I think it’s fascinating to explore this alternative representation,” says Hongsheng Zhao, a cosmologist at the University of St Andrews, UK. “His treatment seems rigorous enough to be entertained.”
Astronomers measure whether objects are moving away from or towards Earth by analysing the light that their atoms emit or absorb, which comes in characteristic colours, or frequencies. When matter is moving away from us, these frequencies appear shifted towards the red, or lower-frequency, part of the spectrum, in the same way that we hear the pitch of an ambulance siren drop as it speeds past.
In the 1920s, astronomers including Georges Lemaître and Edwin Hubble found that most galaxies exhibit such a redshift — and that the redshift was greater for more distant galaxies. From these observations, they deduced that the Universe must be expanding.
Red herring
But, as Wetterich points out, the characteristic light emitted by atoms is also governed by the masses of the atoms' elementary particles, and in particular of their electrons. If an atom were to grow in mass, the photons it emits would become more energetic. Because higher energies correspond to higher frequencies, the emission and absorption frequencies would move towards the blue part of the spectrum. Conversely, if the particles were to become lighter, the frequencies would become redshifted.
Because the speed of light is finite, when we look at distant galaxies we are looking backwards in time — seeing them as they would have been when they emitted the light that we observe. If all masses were once lower, and had been constantly increasing, the colours of old galaxies would look redshifted in comparison to current frequencies, and the amount of redshift would be proportionate to their distances from Earth. Thus, the redshift would make galaxies seem to be receding even if they were not.
Work through the maths in this alternative interpretation of redshift, and all of cosmology looks very different. The Universe still expands rapidly during a short-lived period known as inflation. But prior to inflation, according to Wetterich, the Big Bang no longer contains a 'singularity' where the density of the Universe would be infinite. Instead, the Big Bang stretches out in the past over an essentially infinite period of time. And the current cosmos could be static, or even beginning to contract.
Purely theory
The idea may be plausible, but it comes with a big problem: it can't be tested. Mass is what’s known as a dimensional quantity, and can be measured only relative to something else. For instance, every mass on Earth is ultimately determined relative to a kilogram standard that sits in a vault on the outskirts of Paris, at the International Bureau of Weights and Measures. If the mass of everything — including the official kilogramme — has been growing proportionally over time, there could be no way to find out.
For Wetterich, the lack of an experimental test misses the point. He says that his interpretation could be useful for thinking about different cosmological models, in the same way that physicists use different interpretations of quantum mechanics that are all mathematically consistent. In particular, Wetterich says, the lack of a Big Bang singularity is a major advantage.
He will have a hard time winning everyone over to his interpretation. “I remain to be convinced about the advantage, or novelty, of this picture,” says Niayesh Afshordi, an astrophysicist at the Perimeter Institute in Waterloo, Canada. According to Afshordi, cosmologists envisage the Universe as expanding only because it is the most convenient interpretation of galaxies' redshift.
Others say that Wetterich’s interpretation could help to keep cosmologists from becoming entrenched in one way of thinking. “The field of cosmology these days is converging on a standard model, centred around inflation and the Big Bang,” says physicist Arjun Berera at the University of Edinburgh, UK. “This is why it’s as important as ever, before we get too comfortable, to see if there are alternative explanations consistent with all known observation.”
http://www.nature.com/news/cosmologist-claims-universe-may-not-be-expanding-1.13379
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There has been some remarkable weather over the United States for the last week, relating to the formation and migration of the low pressure center highlighted in this image from the GOES-13 weather satellite.
Late last week, a low pressure system set up over the U.S. Midwest and the Ohio valley. As the low began to move towards the Atlantic Coast, it drew moisture in, dropping >10 inches of rain along portions of the coast.
This low pressure system became separated from the normal circulation patterns, forming what is called a “cutoff low”. The low pressure center became isolated and spun on its own, moving slowly wherever the surrounding systems pushed it.
Starting over the weekend, a hot, high-pressure system set in over the U.S. Northeast, bringing high summer temperatures throughout the U.S. Northeast. The formation of this high-pressure system began pushing the cutoff low out of the way, and it started migrating…from East to West.
Over the weekend, the cutoff low passed along the Ohio valley, moving all the way to the Great Plains over Texas and New Mexico. This spinning low pulled up moisture from the Gulf of Mexico into those regions, producing rains and the lowest July temperatures recorded in those areas since the 1940’s. Meanwhile, the high pressure system over the northeast has brought near record temperatures to that region.
This weather has literally been backwards. This system has migrated across more than half the continent…in the wrong direction!
Late last week, a low pressure system set up over the U.S. Midwest and the Ohio valley. As the low began to move towards the Atlantic Coast, it drew moisture in, dropping >10 inches of rain along portions of the coast.
This low pressure system became separated from the normal circulation patterns, forming what is called a “cutoff low”. The low pressure center became isolated and spun on its own, moving slowly wherever the surrounding systems pushed it.
Starting over the weekend, a hot, high-pressure system set in over the U.S. Northeast, bringing high summer temperatures throughout the U.S. Northeast. The formation of this high-pressure system began pushing the cutoff low out of the way, and it started migrating…from East to West.
Over the weekend, the cutoff low passed along the Ohio valley, moving all the way to the Great Plains over Texas and New Mexico. This spinning low pulled up moisture from the Gulf of Mexico into those regions, producing rains and the lowest July temperatures recorded in those areas since the 1940’s. Meanwhile, the high pressure system over the northeast has brought near record temperatures to that region.
This weather has literally been backwards. This system has migrated across more than half the continent…in the wrong direction!
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His Snarky Porcupine
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How the dinosaurs did it:
This model of dinosaur copulation is on display at the Jurassic Museum of Asturias in Spain. It’s impossible to know how exactly dinosaurs would have mated, but we can look at modern crocodiles and birds and try to get a realistic idea of what might have been.
http://www.australiangeographic.com.au/journal/how-did-dinosaurs-have-sex.htm
This model of dinosaur copulation is on display at the Jurassic Museum of Asturias in Spain. It’s impossible to know how exactly dinosaurs would have mated, but we can look at modern crocodiles and birds and try to get a realistic idea of what might have been.
http://www.australiangeographic.com.au/journal/how-did-dinosaurs-have-sex.htm
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Question: Could a propulsion system be designed that propels a craft through space by using the EMR from the distant stars and even background radiation? Perhaps by converting it to electricity, but more interestingly, by using precisely placed reflective and absorbent surfaces to push it? For example a perfectly reflective parabola if front that directs all EMR to a surface that absorbs it.
Asked By: Curtis Kayfish:
Yes. In fact such a craft has already been built. The Ikaros craft was launched by the Japan Aerospace exploration agency in 2010. Its destination was Venus, and it passed within 80,000 km of the planet. It deployed a solar sail that used solar power to generate electricity, and took advantage of a phenomenon known as radiation pressure, which actually used the momentum of photons to propel the craft.
Radiation pressure was theorized by James Clerk Maxwell in 1873. Its effects were first observed by Peter Lebedew around 1900. Although radiation pressure is fairly feeble under most conditions, it can have a very noticeable effect on spacecraft travelling long distances over long periods of time. The Viking spacecraft would have missed Mars by about 15,000 km had scientists not taken the pressure of the Sun’s radiation on the spacecraft into account.
The Parabolic mirror you’ve described, however, wouldn’t be the best way to go about it. The equation for determining the radiation pressure from a reflected surface is P=2I/c, where P is the pressure, I is the intensity of the radiation, and c is the speed of light. The equation for determining the pressure from radiation absorbed by a surface is P=I/c. This means that you get twice as much “push” from reflecting a photon as you do from absorbing one. So, assuming that you were using a source of radiation that was uniform (emanating from all points in space with equal intensity from all directions) you would be better off using a convex mirror on the rear of the ship, perhaps one with a surface that could be modified to either absorb or reflect light depending on the desired trajectory. In order to be effective in providing propulsion for a ship of any appreciable size using something as faint as the cosmic background radiation though, the reflective surface would have to be really, really, really big, and really, really, really light.
~Kenneth
Sources and Further research:
Ikaros:
http://www.jspec.jaxa.jp/e/activity/ikaros.html
J.C. Maxwell, A treatise on Electricity and Magnetism (1st edition), 2, 391. Oxford, 1873.
P. Lebedew, Rapports presents a Congres international de Physique (2) p. 133. Paris, 1900
Eugene Hecht, “Optics”, 4th edition
Image Source:
http://www.jaxa.jp/press/2010/06/20100611_ikaros_e.html
Asked By: Curtis Kayfish:
Yes. In fact such a craft has already been built. The Ikaros craft was launched by the Japan Aerospace exploration agency in 2010. Its destination was Venus, and it passed within 80,000 km of the planet. It deployed a solar sail that used solar power to generate electricity, and took advantage of a phenomenon known as radiation pressure, which actually used the momentum of photons to propel the craft.
Radiation pressure was theorized by James Clerk Maxwell in 1873. Its effects were first observed by Peter Lebedew around 1900. Although radiation pressure is fairly feeble under most conditions, it can have a very noticeable effect on spacecraft travelling long distances over long periods of time. The Viking spacecraft would have missed Mars by about 15,000 km had scientists not taken the pressure of the Sun’s radiation on the spacecraft into account.
The Parabolic mirror you’ve described, however, wouldn’t be the best way to go about it. The equation for determining the radiation pressure from a reflected surface is P=2I/c, where P is the pressure, I is the intensity of the radiation, and c is the speed of light. The equation for determining the pressure from radiation absorbed by a surface is P=I/c. This means that you get twice as much “push” from reflecting a photon as you do from absorbing one. So, assuming that you were using a source of radiation that was uniform (emanating from all points in space with equal intensity from all directions) you would be better off using a convex mirror on the rear of the ship, perhaps one with a surface that could be modified to either absorb or reflect light depending on the desired trajectory. In order to be effective in providing propulsion for a ship of any appreciable size using something as faint as the cosmic background radiation though, the reflective surface would have to be really, really, really big, and really, really, really light.
~Kenneth
Sources and Further research:
Ikaros:
http://www.jspec.jaxa.jp/e/activity/ikaros.html
J.C. Maxwell, A treatise on Electricity and Magnetism (1st edition), 2, 391. Oxford, 1873.
P. Lebedew, Rapports presents a Congres international de Physique (2) p. 133. Paris, 1900
Eugene Hecht, “Optics”, 4th edition
Image Source:
http://www.jaxa.jp/press/2010/06/20100611_ikaros_e.html
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His Snarky Porcupine
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Astronomers have spied a huge gas cloud being pulled like taffy around the supermassive black hole at the heart of the Milky Way. http://www******.com/21994-giant-black-hole-devours-space-cloud.html?cmpid=514630
These observations from ESO's Very Large Telescope show how a gas cloud is being stretched and ripped apart as it passes close to the supermassive black hole at the center of the galaxy.
These observations from ESO's Very Large Telescope show how a gas cloud is being stretched and ripped apart as it passes close to the supermassive black hole at the center of the galaxy.
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