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Bacteria found at 8-15 km altitude could play a much bigger role in cloud formation and precipitation than previously thought... According to this study bacteria represent around 20 % of the total atmospheric aerosols in their size range! They say it could also have implications for the spread of diseases...

20% ????

electric bus driving at 250 km/h (and braking within 200m!) project related to former astronaut Wubbo ...

They were able to compare the ticking rates of two optical clocks separated by 2000 km, with the objective of computing sea level based on the effect gravity has on the clock ticking rate. They did the experiment using glass optical fibers, but I wonder if we could one day do the same from orbit, to measure the gravitational field around Earth.

isn't this is effectively what pacome has been doing with his time for the last few years? e.g. http://arxiv.org/pdf/1308.6766v1.pdf also mentioning the ACES experiment

To follow up our discussio at breakfast

For all your statistics needs. The "Plastic Debris in the World's Oceans Report - UNEP" www.unep.org/regionalseas/marinelitter/.../docs/plastic_ocean_report.pdf‎ "Densities of plastic debris (Moore et al. 2001). Using nets to collect debris, the abundance of floating plastic averaged 334,271 pieces/km2" More worrying maybe is (http://www.ncbi.nlm.nih.gov/pubmed/22610295) "Our oceans eventually serve as a sink for these small plastic particles ("UV degraded surface plastic") and in one estimate, it is thought that 200,000 microplastics per km(2) of the ocean's surface commonly exist."

the Alaskan bar-tailed godwit (Limosa lapponica baueri) (Figure 1), makes its eight-day, 11,000-km autumn migration from Alaska to New Zealand in one step, with no stopovers to rest or refuel. This roughly doubles the previous maximum direct flight distance in birds, challenging experts to square this remarkable marathon migration with our understanding of aerodynamic theory and endurance physiology.

Extending quantum communication to space environments would enable us to perform fundamental experiments on quantum physics as well as applications of quantum information at planetary and interplanetary scales. Here, we report on the first experimental study of the conditions for the implementation of the single-photon exchange between a satellite and an Earth-based station. We built an experiment that mimics a single photon source on a satellite, exploiting the telescope at the Matera Laser Ranging Observatory of the Italian Space Agency to detect the transmitted photons. Weak laser pulses, emitted by the ground-based station, are directed toward a satellite equipped with cube-corner retroreflectors. These reflect a small portion of the pulse, with an average of less-than-one photon per pulse directed to our receiver, as required for faint-pulse quantum communication. We were able to detect returns from satellite Ajisai, a low-Earth orbit geodetic satellite, whose orbit has a perigee height of 1485 km.

hello Jose! Interesting it was proposed to do the same with the ISS as part of the ACES experiment. I don't remember the paper but i can look if you're interested

July 14, 2009 NASA Dryden Flight Research Center, Edwards Air Force Base, Mojave, CA 6 Teams [KCSP, LM, USST, NSS, McGill, U MICH] 1 km vertical raceway, laser-powered vehicles $2,000,000 Total prize purse (two levels)

nice development! - not sure if it survives a crash test in this form at 70 or 110 km/h

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.

TU/e is participating in the new Cruiser class of the World Solar Challenge. This competition entails building an eco friendly family car (instead of a racer) to prove that solar powered transportation is possible. Actually this car produces more solar power than it needs and has a range of 300+ km.

A wide scale 8 year experiment in China on combating desertification seems to have been successful. Instead of using cyanobacteria blooms in the sea, the tested method proposes to spray them on the boundaries of desert/farmland every few days, so that the carbon they capture stays on the ground. It is useful in fixing the organic material against wind erosion only complementary to planting hardy grasses. Very fast result, nevertheless. Could be classified as a geoengineering activity.

130 km2 as next step will be quite an area

The WorldView2 satellite has a maximum 50 cm resolution and a water penetrating coastal band in the far-blue part of the spectrum that allows it to see deeper into the water column. Using an image covering 113 km2, we identified 55 probable whales and 23 other features that are possibly whales, with a further 13 objects that are only detected by the coastal band.

Problem solved.

Those would also work very well to keep the Kaiju's out..

Good point!

Elon Musk is moving forward with space based internet service...

Facebook announced they are ready to test of of their High Altitude Platform element, a drone of the size of a Boeing 737. See the new here http://phys.org/news/2015-07-facebook-ready-giant-drone-internet.html?utm_source=nwletter&utm_medium=email&utm_content=ctgr-item&utm_campaign=daily-nwletter. It seemed interesting for me that they are developing also a reliable optical communication between this element and scattered ground stations.

Nice link, that thing is huge and I would love to see a drone that size fly. Also, Facebook's Aerospace Team? :)

Francesco pointed out this research one year ago, we dropped it as noone was really considering it ... but in space a low CPU power consumption is crucial!! Maybe we should look back into this?

I don't remember what is the speed factor, but I guess this might do it! Although, I remember when using an IMU that you cannot have the data above a given rate (e.g. 20Hz even though the ADC samples the sensor at a little faster rate), so somehow it is not just the CPU that must be re-thought. When I say qualification I also imply the "hardened" phase.

I don't know if the (promised) one-order-of-magnitude improvements in power efficiency and performance are enough to justify looking into this. For once, it is not clear to me what embracing this technology would mean from an engineering point of view: does this technology need an entirely new software/hardware stack? If that were the case, in my opinion any potential benefit would be nullified. Also, is it realistic to build an entire self-sufficient chip on this technology? While the precision of floating point computations may be degraded and still be useful, how does all this play with integer arithmetic? Keep in mind that, e.g., in the Linux kernel code floating-point calculations are not even allowed/available... It is probably possible to integrate an "accelerated" low-accuracy floating-point unit together with a traditional CPU, but then again you have more implementation overhead creeping in. Finally, recent processors by Intel (e.g., the Atom) and especially ARM boast really low power-consumption levels, at the same time offering performance-boosting features such as multi-core and vectorization capabilities. Don't such efforts have more potential, if anything because of economical/industrial inertia?

At a meeting of the American Geophysical Union in San Francisco in December, he reported an average figure that was between 0.005 and 0.008 per cent greater than the value for Earth's mass established by the International Astronomical Union. A disc of dark matter around the equator 191 kilometres thick and 70,000 km across can explain this, he says. Harris has yet to account for perturbations to the satellites' orbits due to relativity, and the gravitational pull of the sun and moon. Maybe relativistic GPS could improve this even further? As a side note however, the Juno spacecraft flyby showed an gravity acceleration which matched the calculations, casting doubts on the earlier calculations.

The scientific rationale behind it is that at km-depth there could be a) water resources (which could support a biosphere) and b) understand the formation of Mars. I would argue that an efficient drilling (robot) is also valuable for possible developing underground habitation (caves) at some point. This paper mentions two drilling concepts, but we could come up with many more (bio-inspired) probably. Daniel already came up with a nice one.. microwave drilling Also, the NASA InSight probe to Mars in 2016 is using a DLR-designed 'Mole' drill that is designed to reach a depth of... 5 meters

In this case I was thinking more about a smaller and controlled digging effort.. not ablating a football field sized hole

Nice one! plenty of examples in nature for this

Of interest Ana ?