Group items tagged

We had a short discussion yesterday about using nuclear isomers as batteries for spacecraft. The principle is that energy is stored as an excitation of the nucleus which can then release the energy as a gamma-photon. However angular momentum has to be conserved an this suppresses the decay strongly - making these states stable up to 10^35 longer than a typical decay.

The key is the triggering of the dacay wheras the triggering comsumes less energy than the decay provides. The x-ray based triggering of the gamma photon decay turned out to be quite controversial and needs significantly more scientific attention.

I think that there should be some references and traces of the discussions we had on this on the shared drive or wiki ... One other aspect: converting the omnidirectional gamma bursts into useful energy ....

Less impressive than the headline, since they actually just tested their conversion system at suboptimal conditions on an existing reactor setup, but still since done within six month and with less than 1M€ ...

An acoustic analogue of the dynamical Casimir effect (DCE) has been demonstrated for the first time.

The Florida team generated a specially shaped laser beam that could self-accelerate, or bend, sideways.

very nice!!! read this e.g. "In addition to this self-bending, the beam's intensity pattern also has a couple of other intriguing characteristics. One is that it is non-diffracting, which means that the width of each intensity region does not appreciably increase as the beam travels forwards. This is unlike a normal beam - even a tightly collimated laser beam - which spreads as it propagates. The other unusual property is that of self-healing. This means that if part of the beam is blocked by opaque objects, then any disruptions to the beam's intensity pattern could gradually recover as the beam travels forward."

Its a big one!

"The metamaterial aperature is only 40 centimeters long and it doesn't move. It's a circuit-board-like structure consisting of two copper plates separated by a piece of plastic. One of the plates is etched with repeating boxy structures, units about 2 millimeters long that permit different lengths of microwaves to pass through. Scanning the scene at various microwave frequencies allows the computer to capture all the information necessary to reproduce a scene."

where is Luzi's comment when one needs it ???

title is misleading, but the paper is interesting (and as obvious as ignored)

sure was a fun assignment ...

apart from the doppler shift the perspective also changes when you look at objects while traveling close to the speed of light: http://www.spacetimetravel.org/tompkins/node1.html

Bartolomé call's workshop paper ... with some nice words also for the ACT "I want to congratulate the Advanced Concepts Team of the ESA and the Faculty of Mathematics and Physics of Ljubljana for this initiative." congrats Sante and Pacome again!

loads of new solution classes to the three body problem found by Bulgarians ... Francesco and Sante, you will love these

ups, should have looked at diigo before ... Luis was faster again

The type is much weaker than normal supernovas and seems to have a new mechanism underlying it.

MOND again .... you might also have a look at this study: http://www.esa.int/gsp/ACT/doc/ARI/ARI%20Study%20Report/ACT-RPT-PHY-ARI-07-1301-Non-perturbative-effects-Vienna.pdf

for Sante to review - or believe in dark matter :-)

ESA Science & Technology: A leap forward in probing magnetic reconnection in space: Magnetic reconnection is a fundamental physical process in the Universe, playing a major role in various phenomena such as star formation or solar explosions, but also preventing plasma confinement in fusion reactors on Earth. However, a lack of precise measurements at the heart of this physical process prevents a full understanding of this phenomenon.

I did not even know about the existance of the station ... fantastic results it seems ...

any idea if what the canadians claim to sell is closer to a quantum computer than what they did 2011? (I remember Luzi's comment back then that this had nothing to do with a quantum computer) Canada being member state of ESA ... should we start getting interested?

Nice visualization of the structure of the accretion disk surrounding a black hole