it is acutely nano scale, as the components of the pictures are nanometers in length; like using a pen a few nanometers in radius to draw a picture, E-beam technique talked about in the article can remove single atoms of a structure, when my research group first got our FIB(focused ion beam) we drew a picture of Einstein a few hundred nanometers across, though it was never published.
"negative reflraction index lenses (they can be _perfect_)"
in principle they can be prefict, however you are still limited by how smooth the surface of the negative index lense. variations in the surface would casue diffraction, it would be far better than a normal lens, but still you can never be perfict.
the 2 first things you lean on any cosmology module are the postulates that space is isotropic and homogeneous, nearly all cosmology is based on this. what do you mean by red shift assumptions? i assume you are talking about large distance's (~300Mpc) everything is moving away. that is called the Hubble flow
time and distance are very difficult quantity's to define in cosmological terms. for example as the universe is expanding, distance changes with time. you measure some phenomena and work out its distance what distance are you measuring? the distance as it is now? or as it was when the phenomena occurred. Its very easy to get confused and write really long convoluted sentences about it
distance an event is does not equal the time ago it happened but is related to it, think about walking on an escalator,
how far have you traveled relative to the bottom = 10 meters
how far relative to the steps = a couple of steps.
which one is the distance you want?
it was already suspected that dark matter and dark energy were different when the universe was young, they are both linked to the hubble constant H, which is different the further back in time you go. it might be new evidence i haven't read the paper in nature yet, but its not a new idea
why didnt he publish his findings in a paper?
on
Forecasting Doomsday
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· Score: 2, Insightful
by paper i mean a scientific, rather than a news paper. one environmentalists opinion even if he is well respected does not turn his melodramatic spiel into fact. The earth may be warming, but there is still no hard evidence that human kind is the cause. and lets not forget that we are still in an ice age!
one paper was written, and it has (as far as i know) been proven to be correct. saying that dark matter has been disproved because of just one paper is foolish. scientific understanding is based on replication of results. you should wait until they are replicated. this is the problem with the media they lean on institutions to releases there informations before they are ready.
the intergalactic medium in not heavy enough to account for the effects of dark matter. the rotations curves of stars and galaxies show this.
the question over where dark matter exits is becoming more and more redundant; the evidence for dark matter is stacking up and up. but a more profound problem exits. what is this dark matter? and out of the two leading theory's MACHO's (massive compact halo objects) and WIMPS (weakly interacting massive particles) the scientific community seems to switch between them every 6 months!
a the moment people are leaning on the side of wimps, i.e super symmetric particles (very loosely back up by string theorists) and neutrinos. to me personally this sits better than lots of perfectly places macho elements ( black holes and neutron stars)
but its still really all speculation. like the article says
"In one scenario, the galaxies may have fallen towards Andromeda along an invisible filament of dark matter."
in one scenario, new scientist seems to have left out all the others?
that is just what i thought when i read the article, had a look in goggle scholar and found this abstract.
http://links.jstor.org/sici?sici=0080-4622(1984022 4)305%3A1122%3C145%3ATAOHIF%3E2.0.CO%3B2-7
it is because of vortices. the reason people did not understand how the bee's and other incests did not fly was because of there flat wings, they did not understand how lift was created with a flat structure, the theory went that the bee's were "swimming" in Air not actually flying as such, and that would not have let them be able to fly at there flap rate.
Slashdot Mirror
photonic structure in nature is not new there are many places eg http://newton.ex.ac.uk/research/emag/butterflies/downloadable_papers.html looking at structure within various insects, looking to replicate it, the beetles talked about with in the article have been studied before.
it is acutely nano scale, as the components of the pictures are nanometers in length; like using a pen a few nanometers in radius to draw a picture, E-beam technique talked about in the article can remove single atoms of a structure, when my research group first got our FIB(focused ion beam) we drew a picture of Einstein a few hundred nanometers across, though it was never published.
"negative reflraction index lenses (they can be _perfect_)"
in principle they can be prefict, however you are still limited by how smooth the surface of the negative index lense. variations in the surface would casue diffraction, it would be far better than a normal lens, but still you can never be perfict.
the 2 first things you lean on any cosmology module are the postulates that space is isotropic and homogeneous, nearly all cosmology is based on this. what do you mean by red shift assumptions? i assume you are talking about large distance's (~300Mpc) everything is moving away. that is called the Hubble flow time and distance are very difficult quantity's to define in cosmological terms. for example as the universe is expanding, distance changes with time. you measure some phenomena and work out its distance what distance are you measuring? the distance as it is now? or as it was when the phenomena occurred. Its very easy to get confused and write really long convoluted sentences about it distance an event is does not equal the time ago it happened but is related to it, think about walking on an escalator, how far have you traveled relative to the bottom = 10 meters how far relative to the steps = a couple of steps. which one is the distance you want?
it was already suspected that dark matter and dark energy were different when the universe was young, they are both linked to the hubble constant H, which is different the further back in time you go. it might be new evidence i haven't read the paper in nature yet, but its not a new idea
by paper i mean a scientific, rather than a news paper. one environmentalists opinion even if he is well respected does not turn his melodramatic spiel into fact. The earth may be warming, but there is still no hard evidence that human kind is the cause. and lets not forget that we are still in an ice age!
one paper was written, and it has (as far as i know) been proven to be correct. saying that dark matter has been disproved because of just one paper is foolish. scientific understanding is based on replication of results. you should wait until they are replicated. this is the problem with the media they lean on institutions to releases there informations before they are ready.
the intergalactic medium in not heavy enough to account for the effects of dark matter. the rotations curves of stars and galaxies show this. the question over where dark matter exits is becoming more and more redundant; the evidence for dark matter is stacking up and up. but a more profound problem exits. what is this dark matter? and out of the two leading theory's MACHO's (massive compact halo objects) and WIMPS (weakly interacting massive particles) the scientific community seems to switch between them every 6 months! a the moment people are leaning on the side of wimps, i.e super symmetric particles (very loosely back up by string theorists) and neutrinos. to me personally this sits better than lots of perfectly places macho elements ( black holes and neutron stars) but its still really all speculation. like the article says "In one scenario, the galaxies may have fallen towards Andromeda along an invisible filament of dark matter." in one scenario, new scientist seems to have left out all the others?
I am a physicist to me grammar is like the queen: i understand that she has a purpose but i don't really care about it
that is just what i thought when i read the article, had a look in goggle scholar and found this abstract. http://links.jstor.org/sici?sici=0080-4622(1984022 4)305%3A1122%3C145%3ATAOHIF%3E2.0.CO%3B2-7
it is because of vortices. the reason people did not understand how the bee's and other incests did not fly was because of there flat wings, they did not understand how lift was created with a flat structure, the theory went that the bee's were "swimming" in Air not actually flying as such, and that would not have let them be able to fly at there flap rate.