Group items tagged

The principle behind that is Nantenna.

this is fantastic!!!! waiting of somebody to make this happen since years The size of the gap is critical because it creates an ultra-fast tunnel junction between the rectenna's two electrodes, allowing a maximum transfer of electricity. The nanosized gap gives energized electrons on the rectenna just enough time to tunnel to the opposite electrode before their electrical current reverses and they try to go back. The triangular tip of the rectenna makes it hard for the electrons to reverse direction, thus capturing the energy and rectifying it to a unidirectional current. Impressively, the rectennas, because of their extremely small and fast tunnel diodes, are capable of converting solar radiation in the infrared region through the extremely fast and short wavelengths of visible light - something that has never been accomplished before. Silicon solar panels, by comparison, have a single band gap which, loosely speaking, allows the panel to convert electromagnetic radiation efficiently at only one small portion of the solar spectrum. The rectenna devices don't rely on a band gap and may be tuned to harvest light over the whole solar spectrum, creating maximum efficiency. Through atomic layer deposition, Willis has shown he is able to precisely coat the tip of the rectenna with layers of individual copper atoms until a gap of about 1.5 nanometers is achieved. The process is self-limiting and stops at 1.5 nanometer separation The size of the gap is critical because it creates an ultra-fast tunnel junction between the rectenna's two electrodes, allowing a maximum transfer of electricity. The nanosized gap gives energized electrons on the rectenna just enough time to tunnel to the opposite electrode before their electrical current reverses and they try to go back. The triangular tip of the rectenna makes it hard for the electrons to reverse direction, thus capturing the energy and rectifying it to a unidirectional current. Impressively, the rectennas, because of th

A fifth giant planet was kicked out of the early solar system, according to computer simulations by a US-based planetary scientist. The sacrifice of this gas giant paved the way for the stable configuration of planets seen today, says David Nesvorný, who believes that the expulsion prevented Jupiter from migrating inwards and scattering the Earth and its fellow inner planets.

A fifth giant planet was kicked out of the early solar system, according to computer simulations by a US-based planetary scientist. The sacrifice of this gas giant paved the way for the stable configuration of planets seen today, says David Nesvorný, who believes that the expulsion prevented Jupiter from migrating inwards and scattering the Earth and its fellow inner planets.

3-dimensional silicon solar cell produces at least 250% of the power of a basic silicon solar cell.

Any idea of the technology behind ... Sounds too much advertisement what is in the article " Now, our near term objective is to continue to improve the fabrication process and the power output, as we optimize the cost of manufacturing. We believe that the result will be a 50% reduction in the cost of solar electricity. Perhaps the installed system cost savings will be even greater"

Nonradiative resonant energy transfer in optimized QD-QW systems may provide a solar energy conversion approach with a viable tradeoff with the bottlenecks of charge carrier generation and/or transport to/in electrodes faced by excitonic solar cells.

some biomimicry used in energy systems... maybe it sparks some ideas

not much new that has not been shared here before ... BUT: we have done relativley little on any of them. for good reasons?? don't know - maybe time to look into some of these again more closely Energy Efficiency( Termite mounds inspired regulated airflow for temperature control of large structures, preventing wasteful air conditioning and saving 10% energy.[1] Whale fins shapes informed the design of new-age wind turbine blades, with bumps/tubercles reducing drag by 30% and boosting power by 20%.[2][3][4] Stingray motion has motivated studies on this type of low-effort flapping glide, which takes advantage of the leading edge vortex, for new-age underwater robots and submarines.[5][6] Studies of microstructures found on shark skin that decrease drag and prevent accumulation of algae, barnacles, and mussels attached to their body have led to "anti-biofouling" technologies meant to address the 15% of marine vessel fuel use due to drag.[7][8][9][10] Energy Generation( Passive heliotropism exhibited by sunflowers has inspired research on a liquid crystalline elastomer and carbon nanotube system that improves the efficiency of solar panels by 10%, without using GPS and active repositioning panels to track the sun.[11][12][13] Mimicking the fluid dynamics principles utilized by schools of fish could help to optimize the arrangement of individual wind turbines in wind farms.[14] The nanoscale anti-reflection structures found on certain butterfly wings has led to a model to effectively harness solar energy.[15][16][17] Energy Storage( Inspired by the sunlight-to-energy conversion in plants, researchers are utilizing a protein in spinach to create a sort of photovoltaic cell that generates hydrogen from water (i.e. hydrogen fuel cell).[18][19] Utilizing a property of genetically-engineered viruses, specifically their ability to recognize and bind to certain materials (carbon nanotubes in this case), researchers have developed virus-based "scaffolds" that

Rings of excited atoms that harness a quantum effect to absorb light at an enhanced rate could be used in future technologies such as highly sensitive cameras, solar cells and systems for optical power transmission.

An alien star passed through our Solar System just 70,000 years ago, astronomers have discovered. No other star is known to have approached this close to us. An international team of researchers says it came five times closer than our current nearest neighbour - Proxima Centauri. Passing straight through the Oort Cloud region. This must have left some sort of mark maybe? A binary system of a red and brown dwarf (8% and 6% solar masses) so maybe not a too significant impact on trajectories in the Oort cloud?

I read this earlier and thought it might be another one of those alien conspiracy stuff. Freaky stuff.

what about taking a ride on one of these? - especially if they come with some companion planets? when is the next shuttle coming?

"we conclude that HE 0437-5439 was most likely a compact binary ejected by the Milky Way's central black hole" reminds me a bit of Francesco's proposal to get rid of Mercury for the stability of our solar system ... what was the proposal: "get rid of the sucker?"

12 new NIAC 1 studies - many topics familiar to us ... please have a look at those closest to your expertise to see if there is anything new/worth investigating (and in general to be knowledgeable on them since we will get questions sooner or later on them)
Principal Investigator Proposal Title Organization City, State, Zip Code
Atchison, Justin Swarm Flyby Gravimetry Johns Hopkins University Baltimore, MD 21218-2680
Boland, Eugene Mars Ecopoiesis Test Bed Techshot, Inc. Greenville, IN 47124-9515
Cash, Webster The Aragoscope: Ultra-High Resolution Optics at Low Cost University of Colorado Boulder, CO 80309-0389
Chen, Bin 3D Photocatalytic Air Processor for Dramatic Reduction of Life Support Mass & Complexity NASA ARC Moffett Field, CA 94035-0000
Hoyt, Robert WRANGLER: Capture and De-Spin of Asteroids and Space Debris Tethers Unlimited Bothel, WA 98011-8808
Matthies, Larry Titan Aerial Daughtercraft NASA JPL Pasadena, CA 91109-8001
Miller, Timothy Using the Hottest Particles in the Universe to Probe Icy Solar System Worlds John Hopkins University Laurel, MD 20723-6005
Nosanov, Jeffrey PERISCOPE: PERIapsis Subsurface Cave OPtical Explorer NASA JPL Pasadena, CA 91109-8001
Oleson, Steven Titan Submarine: Exploring the Depths of Kraken NASA GRC Cleveland, OH 44135-3127
Ono, Masahiro Comet Hitchhiker: Harvesting Kinetic Energy from Small Bodies to Enable Fast and Low-Cost Deep Space Exploration NASA JPL Pasadena, CA 91109-8001
Streetman, Brett Exploration Architecture with Quantum Inertial Gravimetry and In Situ ChipSat Sensors Draper Laboratory Cambridge, MA 02139-3539
Wiegmann, Bruce Heliopause Electrostatic Rapid Transit System (HERTS) NASA MSFC Huntsville, AL 35812-0000

Eh, the swarm flyby gravimetry is very similar to the "measuring gravitational fields" project I proposed in the brewery

An exhaustive overview of all possible advanced rocket concepts, eg.. "As an example, consider a photon rocket with its launching mass, say, 1000 ton moving with a constant acceleration a =0.1 g=0.98 m/s2. The flux of photons with E γ=0.5 MeV needed to produce this acceleration is ~1027/s, which corresponds to the efflux power of 1014 W and the rate of annihilation events N'a~5×1026 s−1 [47]. This annihilation rate in ambiplasma l -l ann corresponds to the value of current ~108 A and linear density N ~2×1018 m−1 thus any hope for non-relativistic relative velocity of electrons and positrons in ambiplasma is groundless." And also, even if it would work, then one of the major issues is going to be heat dispersal: "For example, if the temperature of radiator is chosen T=1500 K, the emitting area should be not less than 1000 m2 for Pb=1 GW, not less than 1 km2 for Pb=1 TW, and ~100 km2 for Pb=100 TW, assuming ε=0.5 and δ=0.2. Lower temperature would require even larger radiator area to maintain the outer temperature of the engine section stable for a given thermal power of the reactor."

The problem is not achieving a high energy density, that we can already do with nuclear fission, the question however is how to confine or harness this power with relatively high efficiency, low waste heat and at not too crazy specific mass. I see magnetic confinement as a possibility, yet still decades away and also an all-or-nothing method as we cannot easily scale this up from a test experiment to a full-scale system. It might be possible to extract power from such a plasma, but definitely well below breakeven so an additional power supply is needed. The fission fragments circumvent these issues by a more brute force approach, thereby wasting a lot of energy for sure but at the end probably providing more ISP and thrust.

Sure. However, the annihilation based photon rocket concept unifies almost all relevant drawbacks if we speak about solar system scales, making itself obsolete...it is just an academic testcase.

NASA announced it was seeking proposals for mission concept studies of a high-power solar electric propulsion (SEP) system that could be used in a "space tugboat." Such a ship would be used ferry payloads in low Earth orbit (LEO) into higher energy orbits,

here's something we didn't consider yesterday in the meeting on extra-solar planets!

this is because you did not read the nature paper I have posted (see post a few lines below ...)

still only a few percent of conversion efficiency but very promising since working at reasonably focussing and unpolarised light; they announce the publication of a first design of such a system .... to be followed!! Duncan: you wanna have a closer look at it?

99% house advertising, 1% scientific results. I think this is still a conservative guess... And I'm sure this "completely new" effect that you don't see when "staring at the equations of motion" (doggone, how I love this USish "I-am-better-than-the-rest-of-the-world" jargon) certainly has been predicted at least 50 years ago by some smart USSR researcher!!

We finally have an understanding of how Mars transformed from a once habitable, Earth-like planet, into the dry world we see today. NASA researchers have just announced that Mars' once rich atmosphere was stripped away by solar winds in the early days of the Solar System, causing the planet to dry out.

NASA's oldest interstellar spacecraft is suddenly measuring changes more dramatic than any it has seen during its 35 year journey

this is very nice! in either of the explanations Voyager will likely be in good enough shape to send data when outside of the boundary layer ...

Nice overview about past missions to other bodies of our solar system.

Nice... Now I have a lame question: after you have discovered ~500k asteroids, all moving (I assume more or less) chaotically in that asteroid belt, how do you tell one from another?

That's what I thought but when presented as a green "goo" in the video, it appears rather unordered... so I guess this is just an impression evoked by a not-to-scale presentation?

It depends... orbits can be chaotic if the orbital period is in a resonance with Jupiter, although such orbits are not stable. Such configurations tend to get disrupted pretty quickly (in cosmic terms :P) http://en.wikipedia.org/wiki/Kirkwood_gap

We had some discussion about the Lotus-effect roughly two years ago. Zoe said that NASA surely worked on it. Well, she was right.