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I guess it is a symbolic way of flying the space shuttle for the last time! as JAXA does it with your name - if you want to - for all their scientific missions. Nice initiative indeed!

Perhaps some of ACTers will find this conference interesting... One of the talks: "Would Einstein be on Twitter? Exploring the potential and limits of Web 2.0 in science & science communication" [Edit] Oh, I see someone has already posted this link... a year ago. Anyway, if anyone of you plans to go, let me know - I'll be around ;-)

Just came back from ESOF 2010... I was on look for ACT agents undercover, but either they were not there or the cover was good enough... Anyway here's a few remarks from me (I could write a nice report... if you paid): 1) In general, to say that ESA was underrepresented on the conference as a whole is not enough (I guess ESA just failed to notice the event taking place). For instance, on the GMES presentation, ESA as such was not mentioned at all... at some point I started to wonder if ESA is actually involved in the project, but now I checked the website and apparently it is. On the other hand, GMES presentation was crap anyway, as after 1:15 of talking, I didn't gain any knowledge of what GMES is and what its contributions to the EU community will be. 2) There was a lot of talk about LHC and particle research (well, at least among those that I attended). Some of them were very good, some of them rather crap... 3) "Would Einstein be on Twitter? Exploring the potential and limits of Web 2.0 in science & science communication" talk - quite interesting, but focusing mainly on Science-to-Wide Public and Science-to-Journalists communication. Not really on Science-to-Science (as in Ariadnet). There was quite an extensive discussion with the public. You may be interested that Nature is trying to stimulate Web 2.0 communication, running blog service, but also I think a kind of social network - perhaps you'd like to have a look. In general the conclusion was that Web 2.0 is not so useful for scientific communication because practising it requires TIME (blogs, etc.) and often some professional skills (podcasts/videocasts, etc.), and scientists have neither of these. This can be run on corporation level (like ESA does actually), but then it looses the "intimate" character. 4) "How much can robots learn?" talk... very nicely presented: understandable by the wide public, but conveying the message... which is something like "we can already make the robots do stuff absolutely imp

Well, my comment was cut in half, and I don't feel like typing it again... the most important highlight from the rest is that the only presenter from ESA (ESTEC) did not show up on his talk because his department was undergoing some sort of audit on the same day :)

Fantastic comment - or better report!! thanks very much Marek! Who was the supposed no-show speaker from ESA?

geee... I want to see how they "exercise" it :)

The solution of thrusting in space.

Thrusting in space is solved already. Maybe you wanted to say something different?

Thrusting until your fuel runs out is solved, in this way one can produce mass from, among others, solar/star energy directly. What I like about this experiment is that we have the technology already to do it, many parts have been designed for inertial confinement fusion.

I am quite certain that it would be more efficient to use the photons directly for thrust instead of converting them into matter. Also, I am a bit puzzled at the asymmetric layout for photon creation. Typically, colliders use two beam of particle with equal but opposite momentum. Because the total momentum for two colliding particles is zero the reaction products are produced more efficiently as a minimum of collision energy is waisted on accelerating the products. I guess in this case the thermal radiation in the cavity is chosen instead of an opposing gamma ray beam to increase the photon density and increase the number of collisions (even if the efficiency decreases because of the asymmetry). However, a danger from using a high temperature cavity might be that a lot of thermionic emission creates lots of free electrons with the cavity. This could reduce the positron yield through recombination and would allow the high energetic photons to loose energy through Compton scattering instead of the Breit-Wheeler pair production.

Well, the main benefit from e-p pair creation might be that one can accelerate these subsequently to higher energies again. I think the photon-photon cross-section is extremely low, such that direct beam-beam interactions are basically not happening (below 1/20.. so basically 0 according to quantum probability :P), in this way, the central line of the hohlraum actually has a very high photon density and if timed correctly maximizes the reaction yield such that it could be measured.

I agree about the reason for the hohlraum - but I also keep my reservations about the drawbacks. About the pair production as fuel: I pretty sure that your energy would be used smarter in using photon (not necessarily high energy photons) for thrust directly instead of putting tons of energy in creating a rest-mass and then accelerating that. If you look at E² = (p c)²+(m0 c)² then putting energy into the mass term will always reduce your maximum value of p.

can we build one?

Yes, I just did :-) It is on my desk

New video here (smaller file than previous): "https://dl.dropboxusercontent.com/u/58527156/20130613_101701.mp4" Note how close to the center of the field of view the hidden objects are. I am quite surprised that such poor lenses create such a sharp focus.

Well.. I would say that it is not "fully cloaking", as the image behind is mirrored as well

That just means that you have to double the setup, i.e., put 4 glasses in a row. Of course the obvious drawback is that you can only look at this cloak from one direction.

and here is the same for bigger things http://cosmiclog.nbcnews.com/_news/2013/06/07/18831348-this-invisibility-cloak-could-conceal-satellites-or-hide-your-kids?lite

we... the article is a bit overblown in my view ... except maybe the last paragraphs: "The collision between universe's is a variation on this theme. "The "colliding universe" scenario can be realized as a simple extension of our earlier experiments simulating the spacetime geometry in the vicinity of big bang," he says. He simulates an expanding universe using concetric rings of gold separated by a dielectric. "When the two concentric ring ("universe") patterns touch each other ("collide"), a Minkowski domain wall is created, in which the metallic stripes touch each other at a small angle," he says. Being able to recreate these exotic events in the lab is certainly interesting but it is beginning to lose its novelty. The problem is that this work is not telling us anything we didn't know--the universe behaves the same way inside a metamaterial as it does outside. What Smolyaninov needs is a way of using his exotic materials to do something interesting. In other words, he needs a killer app. Any ideas? "

An interesting paper about how you should *NOT* think about free will...

I must say that the fact that the outcome of a thought process is not evident to myself in advance sounds like a more plausible explanation than 'free will' being the product of quantum mechanics. The later would not only produce unpredictable decisions but probably also irrational ones...

Even if it were the product of quantum mechanics, it's still the result of external interference and not the result of 'free' will. it doesn't matter if the external input is deterministic or random, it's still external and it's not "YOU" that decided stuff.

to begin with european industry (and probably governments) would complain that ESA was taking business away from industry? or any part that started to make money would be quickly spun-off

as a start of a peer reviewed paper this is an interesting first paragraph: "I recently saw an old friend for the first time in many years. We had been Ph.D. students at the same time, both studying science, although in different areas. She later dropped out of graduate school, went to Harvard Law School and is now a senior lawyer for a major environmental organization. At some point, the conversation turned to why she had left graduate school. To my utter astonishment, she said it was because it made her feel stupid. After a couple of years of feeling stupid every day, she was ready to do something else."

Hilarious! Mr Schwartz, who made a PhD at Stanford(!) and apparently is working as a postdoc now, has finally discovered what science is about!!! Quote: "That's when it hit me: nobody did. That's why it was a research problem." And he seems so excited about it! I think he should not only get published in 6.14 journal, but also get the Nobel Prize immediately! Seriously, after reading something like this, how one may not have superstitions about the educational system in the US?

Not sure whether the group has seen this idea before, but it seems interesting. I like it

yes, we did have a look at it, I think back in 2007 but its maybe time to re-assess it ... will put it on the miscellaneous list for Dejan, the new propulsion and plasma RF to come in January ...