Group items tagged phys - Advanced Concepts Team

Chemical Reactions Guide Birds Home - 0 views

sciencenow.sciencemag.org/...2

phy bio magnetic_field birds

shared by pacome delva on 18 Nov 09 - Cached

Turtles, birds, and butterflies can migrate thousands of kilometers--even over vast oceans largely free of landmarks. Scientists suspect that these animals find their way by sensing Earth's magnetic field, yet the exact nature of this internal compass has remained a mystery. Now, researchers believe they have come closer to solving the puzzle: a magnetic-sensing chemical reaction within the eye.
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pacome delva on 18 Nov 09

A good occasion to get the idea out of the idea pool...?

<div class="cArrow"> </div><div class="cContentInner">A good occasion to get the idea out of the idea pool...?</div>

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Physics - Taking the wraps off cloaking - 0 views

physics.aps.org/...95

phy metamaterials cloaking

shared by pacome delva on 18 Nov 09 - Cached

pacome delva on 18 Nov 09

nice presentation...

<div class="cArrow"> </div><div class="cContentInner">nice presentation...</div>

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A Physics Paradox: Holes That Block Light -- Fox 2009 (1113): 3 -- ScienceNOW - 0 views

sciencenow.sciencemag.org/...3

phy photonics

shared by pacome delva on 18 Nov 09 - Cached

Make holes in a film of gold so thin that it's already semitransparent, and less light gets through.
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pacome delva on 18 Nov 09

A good example of "Can we use it for space.com"... For shielding of course !

<div class="cArrow"> </div><div class="cContentInner">A good example of "Can we use it for space.com"... For shielding of course !</div>

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3-D Solar Tsunami Video Shows the Extreme Waves Are Real | Wired Science | Wired.com - 1 views

www.wired.com/...solar-tsunami

phy space stars

shared by Joris _ on 26 Nov 09 - Cached

Galaxy Zoo Mergers - 0 views

news.bbc.co.uk/...8376566.stm

INF PHY crowdsourcing

shared by Kevin de Groote on 26 Nov 09 - Cached

Kevin de Groote on 26 Nov 09

Instead of classifying galaxies (image analysis), this new project asks the public to try to recreate collisions

<div class="cArrow"> </div><div class="cContentInner">Instead of classifying galaxies (image analysis), this new project asks the public to try to recreate collisions</div>

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A New Spin on Electronics - 0 views

sciencenow.sciencemag.org/...4

phy spintronics

shared by pacome delva on 26 Nov 09 - Cached

Incorporating both the magnetic leads and the underlying semiconductor, a spintronics circuit could hold its memory when turned off, as the magnetic elements remain magnetized. Manipulating spin could also require far less power than steering charges does, says Ron Jansen of the University of Twente in Enschede, Netherlands. Some physicists even aspire to create a spooky quantum connection called "entanglement" between spin-polarized currents to make a quantum computer that could crack problems that stymie an ordinary one.
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Milky Way Grew by Swallowing Other Galaxies - 0 views

sciencenow.sciencemag.org/...2

phy astrophysics globular_clusters

shared by pacome delva on 26 Nov 09 - Cached

pacome delva on 26 Nov 09

Globular clusters in our galaxy would be the remnants of dwarf galaxies eaten by our galaxy the milky way ! This assumption is quite revolutionary and would support an accretion model of the universe rather than the formation of huge galaxies. So what about the formation of giant black holes in the center of galaxies...?

<div class="cArrow"> </div><div class="cContentInner">Globular clusters in our galaxy would be the remnants of dwarf galaxies eaten by our galaxy the milky way ! This assumption is quite revolutionary and would support an accretion model of the universe rather than the formation of huge galaxies. So what about the formation of giant black holes in the center of galaxies...?</div>

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Dark Matter or Black Hole Propulsion? - 1 views

www.newscientist.com/...s-for-interstellar-travel.html

NRG propulsion star travel space PHY

shared by Ma Ru on 25 Nov 09 - Cached

Ma Ru on 25 Nov 09

Anyone out there still doing propulsion stuff? Two more papers just waiting to get busted... http://arxiv.org/abs/0908.1429v1 http://arxiv.org/abs/0908.1803

<div class="cArrow"> </div><div class="cContentInner">Anyone out there still doing propulsion stuff? Two more papers just waiting to get busted... <a href="http://arxiv.org/abs/0908.1429v1" rel="nofollow" target="_blank">http://arxiv.org/abs/0908.1429v1</a> <a href="http://arxiv.org/abs/0908.1803" rel="nofollow" target="_blank">http://arxiv.org/abs/0908.1803</a></div>

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...5 more comments...
Luzi Bergamin on 26 Nov 09

What an awful bunch of complete nonsense!!! But I don't think anybody wants to hear MY opinion on this...

<div class="cArrow"> </div><div class="cContentInner">What an awful bunch of complete nonsense!!! But I don't think anybody wants to hear MY opinion on this...</div>

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pacome delva on 26 Nov 09

wow, is this serious at all...!?

<div class="cArrow"> </div><div class="cContentInner">wow, is this serious at all...!?</div>

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Luzi Bergamin on 26 Nov 09

Are you joking?? The BH drive propses a BH with a lifetime of about an year, just 10^7 tons, peanuts!! Then you have to produce it, better not on Earth, so you do this in space, with a laser that produces an equivalent of 10^9 tons highly foucussed, even more peanuts!! Reasonable losses in the production process (probably 99,999%) are not yet taken into account. Engineering problems... :-) The DM drive is even better, they want to collect DM and compress it in a propulsion chamber. Very easy to collect and compress a gas of particles that traverse the Earth without any interaction. Perhaps if the walls of the chamber are made of artificial BHs?? Who knows??

<div class="cArrow"> </div><div class="cContentInner">Are you joking?? The BH drive propses a BH with a lifetime of about an year, just 10^7 tons, peanuts!! Then you have to produce it, better not on Earth, so you do this in space, with a laser that produces an equivalent of 10^9 tons highly foucussed, even more peanuts!! Reasonable losses in the production process (probably 99,999%) are not yet taken into account. Engineering problems... :-) The DM drive is even better, they want to collect DM and compress it in a propulsion chamber. Very easy to collect and compress a gas of particles that traverse the Earth without any interaction. Perhaps if the walls of the chamber are made of artificial BHs?? Who knows??</div>

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LeopoldS on 26 Nov 09

WRONG!!! we are all just WAITING for your opinion on this ....!!!

<div class="cArrow"> </div><div class="cContentInner">WRONG!!! we are all just WAITING for your opinion on this ....!!!</div>

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pacome delva on 27 Nov 09

well, yes my remark was ironic... I'm surprised they did a magazine on these concepts...! But the press is always waiting for sensational. They do not even wait for the work to be peer-reviewed now to make an article on it ! This is one of the bad sides of arxiv in my opinion. It's like a journalist that make an article with a copy-paste in wikipedia ! Anyway, this is of course complete bullsh..., and I would have laughed if I had read this in a sci-fi book... but in a "serious" article i'm crying... For the DM i do not agree with your remark Luzi. It's not dark energy they want to use. The DM is baryonic, it's dark just because it's cold so we don't see it by usual means. If you believe the in the standard model of cosmology, then the DM should be somewhere around the galaxies. But it's of course not uniformly distributed, so a DM engine would work (if at all...) only in the periphery of galaxies. It's already impossible to get there...

<div class="cArrow"> </div><div class="cContentInner">well, yes my remark was ironic... I'm surprised they did a magazine on these concepts...! But the press is always waiting for sensational. They do not even wait for the work to be peer-reviewed now to make an article on it ! This is one of the bad sides of arxiv in my opinion. It's like a journalist that make an article with a copy-paste in wikipedia ! Anyway, this is of course complete bullsh..., and I would have laughed if I had read this in a sci-fi book... but in a "serious" article i'm crying... For the DM i do not agree with your remark Luzi. It's not dark energy they want to use. The DM is baryonic, it's dark just because it's cold so we don't see it by usual means. If you believe the in the standard model of cosmology, then the DM should be somewhere around the galaxies. But it's of course not uniformly distributed, so a DM engine would work (if at all...) only in the periphery of galaxies. It's already impossible to get there...</div>

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Luzi Bergamin on 27 Nov 09

One reply to Pacome, though the discussion exceeds by far the relevance of the topic already. Baryonic DM is strictly limited by cosomology, if one believes in these models, of course. Anyway, even though most DM is cold, we are constantly bombarded by some DM particles that come together with cosmic radiation, solar wind etc. etc. If DM easily interacted with normal matter, we would have found it long ago. In the paper they consider DM as neutralinos, which are neither baryonic nor strongly or electromagnetically interacting.

<div class="cArrow"> </div><div class="cContentInner">One reply to Pacome, though the discussion exceeds by far the relevance of the topic already. Baryonic DM is strictly limited by cosomology, if one believes in these models, of course. Anyway, even though most DM is cold, we are constantly bombarded by some DM particles that come together with cosmic radiation, solar wind etc. etc. If DM easily interacted with normal matter, we would have found it long ago. In the paper they consider DM as neutralinos, which are neither baryonic nor strongly or electromagnetically interacting.</div>

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pacome delva on 27 Nov 09

well then I agree, how the fu.. they want to collect them !!!

<div class="cArrow"> </div><div class="cContentInner">well then I agree, how the fu.. they want to collect them !!!</div>

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Splitting Time from Space-New Quantum Theory Topples Einstein's Spacetime - 4 views

www.scientificamerican.com/article.cfm

PHY

shared by jmlloren on 25 Nov 09 - Cached

jmlloren on 25 Nov 09

This is the guy of Luzy's joke: "Dear, this is not what it seems. I can explain EVERYTHING!"

<div class="cArrow"> </div><div class="cContentInner">This is the guy of Luzy's joke: "Dear, this is not what it seems. I can explain EVERYTHING!"</div>

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...1 more comment...
Luzi Bergamin on 25 Nov 09

Horava is a serious string theorist (if there is anything like that...) I like the last comment by Dvali: if the theory can be adjusted in such a way that it becomes indistinguishable from GR then it should be taken seriously. Gosh, am I glad to be among engineers now!!!

<div class="cArrow"> </div><div class="cContentInner">Horava is a serious string theorist (if there is anything like that...) I like the last comment by Dvali: if the theory can be adjusted in such a way that it becomes indistinguishable from GR then it should be taken seriously. Gosh, am I glad to be among engineers now!!!</div>

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pacome delva on 26 Nov 09

yeah an interesting theory, definitely worth following. But it is far from being mature, and a lot of work remains before saying that it is viable or not... I posted something on this some time ago (http://www.diigo.com/user/pacome/horava_theory) and proposed to do smthing on it in the idea storm (our new creative game...), which didn't have a lot of success... I like also the idea of matrix gravity (see Matrix general relativity: a new look at old problems, Ivan G Avramidi, CQG 21, 103)

<div class="cArrow"> </div><div class="cContentInner">yeah an interesting theory, definitely worth following. But it is far from being mature, and a lot of work remains before saying that it is viable or not... I posted something on this some time ago (<a href="http://www.diigo.com/user/pacome/horava_theory" rel="nofollow" target="_blank">http://www.diigo.com/user/pacome/horava_theory</a>) and proposed to do smthing on it in the idea storm (our new creative game...), which didn't have a lot of success... I like also the idea of matrix gravity (see Matrix general relativity: a new look at old problems, Ivan G Avramidi, CQG 21, 103)</div>

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LeopoldS on 26 Nov 09

you are among what???

<div class="cArrow"> </div><div class="cContentInner">you are among what???</div>

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Low-cost, more efficient solar cells mostly plastic - 0 views

www.eetimes.com/...ent-solar-cells-mostly-plastic

PHY NRG nan

shared by LeopoldS on 18 Apr 11 - No Cached

LeopoldS on 18 Apr 11

could not find any decent paper on this results, but they would be fantastic of course .... though am a bit sceptic

<div class="cArrow"> </div><div class="cContentInner">could not find any decent paper on this results, but they would be fantastic of course .... though am a bit sceptic</div>

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LeopoldS on 18 Apr 11

ok found one: doi:10.1038/nmat2635

<div class="cArrow"> </div><div class="cContentInner">ok found one: doi:10.1038/nmat2635</div>

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Pioneer Anomaly Solved By 1970s Computer Graphics Technique - Technology Review - 4 views

www.technologyreview.com/...26589

pioneer anomaly PHY astrophysics

shared by Luís F. Simões on 31 Mar 11 - No Cached

Nicholas Lan liked it

Now Frederico Francisco at the Instituto de Plasmas e Fusao Nuclear in Lisbon Portugal, and a few pals, say they've worked out where the thermal calculations went wrong. These guys have redone the calculations using a computer model of not only how the heat is emitted but how it is reflected off the various parts of the spacecraft too. The reflections turn out to be crucial.
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Ref: arxiv.org/abs/1103.5222: Modelling The Reﬂective Thermal Contribution To The Acceleration Of The Pioneer Spacecraft
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santecarloni on 01 Apr 11

This is really cool. I know one of the authors and he is a good guy... the only thing that leaves me unsatisfied is that if the whole issue is related to thermal effects one should have seen the Pioneer effect all the time and not only at about 10 AU... ...or is there some thermal process that kicked in only at this distance?

<div class="cArrow"> </div><div class="cContentInner">This is really cool. I know one of the authors and he is a good guy... the only thing that leaves me unsatisfied is that if the whole issue is related to thermal effects one should have seen the Pioneer effect all the time and not only at about 10 AU... ...or is there some thermal process that kicked in only at this distance?</div>

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Luís F. Simões on 26 Jul 11

Here's an update on this theory: NASA Releases New Pioneer Anomaly Analysis "The mysterious force acting on the Pioneer spacecraft seems to be falling exponentially. That's a strong clue that on-board heat is to blame, says NASA." Heat emission 'most likely cause' of pioneer anomaly "What's more interesting is that, contrary to the original analysis conducted all those years ago, the deceleration does seem to be decelerating at an exponential rate -- just as one might expect from the radioactive decay of plutonium-238, which powers the two spacecraft. Turyshev concludes, "The most likely cause of the Pioneer anomaly is the anisotropic emission of on-board heat.""

<div class="cArrow"> </div><div class="cContentInner">Here's an update on this theory: NASA Releases New Pioneer Anomaly Analysis "The mysterious force acting on the Pioneer spacecraft seems to be falling exponentially. That's a strong clue that on-board heat is to blame, says NASA." Heat emission 'most likely cause' of pioneer anomaly "What's more interesting is that, contrary to the original analysis conducted all those years ago, the deceleration does seem to be decelerating at an exponential rate -- just as one might expect from the radioactive decay of plutonium-238, which powers the two spacecraft. Turyshev concludes, "The most likely cause of the Pioneer anomaly is the anisotropic emission of on-board heat.""</div>

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Heaviest ever antimatter discovered - physicsworld.com - 1 views

physicsworld.com/...45544

phy antimatter

shared by pacome delva on 29 Mar 11 - No Cached

LeopoldS liked it

Physicists at the Relativistic Heavy Ion Collider (RHIC) in New York say they have created nuclei of antihelium-4 for the first time – the heaviest antimatter particles ever seen on Earth.
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Physics - Free falling - 2 views

physics.aps.org/...PhysRevA.83.031804

phy atoms

shared by pacome delva on 29 Mar 11 - No Cached

In a Rapid Communication appearing in Physical Review A, Pengfei Zhang and colleagues at Shanxi University, China, describe experiments where they tracked an atom’s path with a spatial resolution of 100 nanometers and in a measurement time of 10 microseconds.
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Damping in quantum love affairs - 1 views

arxiv.org/1103.5907

phy love_affairs

shared by pacome delva on 31 Mar 11 - No Cached

Luzi Bergamin on 31 Mar 11

I stop complaining about "useless" research such as infeasible invisibility devices... At least I start to understand why Italy is a country with one of the highest publication rates per researcher.

<div class="cArrow"> </div><div class="cContentInner">I stop complaining about "useless" research such as infeasible invisibility devices... At least I start to understand why Italy is a country with one of the highest publication rates per researcher.</div>

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Observation of the antimatter helium-4 nucleus : Nature : Nature Publishing Group - 1 views

www.nature.com/...nature10079.html

NRG PHY

shared by LeopoldS on 27 Apr 11 - No Cached

LeopoldS on 27 Apr 11

more antimatter ...

<div class="cArrow"> </div><div class="cContentInner">more antimatter ...</div>

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Realization of a gravity-resonance-spectroscopy technique : Nature Physics : Nature Pub... - 1 views

www.nature.com/...nphys1970.html

PHY science NRG

shared by LeopoldS on 18 Apr 11 - No Cached

LeopoldS on 18 Apr 11

Sante have a look at this ... sounds fascinating ...

<div class="cArrow"> </div><div class="cContentInner">Sante have a look at this ... sounds fascinating ... </div>

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Solar power without solar cells - 2 views

physicsworld.com/...45787

phy solar_radiation insulator

shared by pacome delva on 27 Apr 11 - No Cached

pacome delva on 27 Apr 11

not very advanced and maybe non practical but...

<div class="cArrow"> </div><div class="cContentInner">not very advanced and maybe non practical but...</div>

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