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+ - ESA's long term plan to investigate the invisible universe

Submitted by xiox
xiox (66483) writes "The European Space Agency (ESA) have decided that its next two large astronomy missions (costing 2bn Euros) will be to study two aspects of the "invisible universe". The first will be a very large X-ray telescope to be launched in 2028. It will study the physics of the hottest and largest structures in the universe, investigating how they formed and evolved. It will also investigate how black holes grow and affect the universe. The second mission, launched in 2034, will be an observatory capable to measure gravitation waves, the stretches and compressions in space-time caused by massive moving systems, such as merging pairs of black holes. Although the final designs are not yet chosen, the two proposed observatories Athena and eLISA are likely choices. BBC News has more information."

Comment: Re:Windows and Mac binaries: difficult (Score 1) 176

by xiox (#44819755) Attached to: How To Turn Your Pile of Code Into an Open Source Project

It's not so difficult if it's pure Python and you're not compiling anything. The main problem was getting Qt to compile so I could compile my extensions. For your project, I'd make a virtual machine with something like WinXP (this makes it easier to make new releases if nothing changes), install Python and the associated PySide. Install any other modules you need. I used PyInstaller to make the runnable exe file. See e.g. here for my pyinstaller file. I then used NSIS to make an installer using this configuration file.

Comment: Re:Windows and Mac binaries: difficult (Score 1) 176

by xiox (#44817913) Attached to: How To Turn Your Pile of Code Into an Open Source Project

Well, there's Visual Studio Express 2005, 2008, 2010, and 2012. That's not so hard. You will want to use 2012 since that is the latest.

In theory, though Python is compiled with a particular version of Visual Studio. It's rather hard to compile for yourself, as the latest versions aren't supported. Extensions have to be compiled with the same version as Python or you get cross-compatibility C library problems. This makes it tricky if you want to link a Python extension (an old Visual Studio version) against Qt (perhaps mingw when I looked at it). I ended up having to compile everything against the version of Visual Studio that Python was built with.

Don't use the registry. DLLs = .so, installers = installers. That's about it.

I try to avoid the registry, but you have to at least register file types there and Qt uses it to store settings be default. DLLs weren't too bad until I got to the stage of manifests and conflicting crt versions.

Comment: Windows and Mac binaries: difficult (Score 4, Informative) 176

by xiox (#44817169) Attached to: How To Turn Your Pile of Code Into an Open Source Project

It can be very difficult. My scientific plotting package, veusz, was written using Python and Qt, so it should be easily portable. However setting up a sensible developer environment on Windows to compile the Python C extensions was a nightmare. Windows is pretty developer-hostile if you're used to Linux. Trying to find and install the correct version of Visual Studio Express was difficult. I had to learn far too many things about the registry, DLLs, building installers, etc. Mac OS X was rather more difficult, however. You have to download the massive Xcode and the non-standard way that Mac OS packages executables and libraries was very difficult to understand. It took a long time to get fat binaries working.

You do get a different class of user on Windows and Mac OS X, however. The Linux people are closer to being knowledgeable about development, whereas Windows and Mac OS people are primarily users, wanting more help and hand-holding.

Comment: Re:BC Breaking changes in 3 (Score 1) 242

by xiox (#44610459) Attached to: Interviews: Q&A With Guido van Rossum

You know it is entirely possible to write 2.7 code that works with nothing more than a pass through 2to3. That does mean that any libraries you depend on are available for 3.x but the problem of lacking support from 3rd party libraries is beginning to diminish as more are ported over at an increasing rate.

It's also possible to write code for 2.6/2.7 which works fine with 3.3+. With the aid of the six module or similar ideas you can work around the differences. Many people think this is the best way to have joint compatibility with python 2 and 3. It also makes it possible to do the development with python3, which running 2to3 doesn't allow. As others have mentioned, there is no good 3to2.

Comment: Re:Worked for 4 years. (Score 1) 204

by xiox (#43590253) Attached to: Helium Depleted, Herschel Space Telescope Mission Ends

The minimum design lifetime isn't the actual lifetime of the mission. I believe there is enough helium for three years, but the multistage cooler is designed to be able to run in the event of coolant loss. ASTRO-H replaces ASTRO-E2 which suffered a catastrophic coolant loss. There are more details here, but it's behind a paywall.

Comment: Re:Been saying that...Wrong, Simply Wrong. (Score 3, Insightful) 376

by xiox (#42810887) Attached to: Economists Argue Patent System Should Be Abolished

p>No CAT Scan, MRI or Cancer drugs would have been invented without patents to give the inventors time to make their years of investment back by a period of exclusivity.

Really? Most fundamental medical advances are created in academia, mostly with public money. Many companies just take the relatively small step to a commercial product. William H. Oldendorf would have done his pioneering work on the CAT scan, whether there was a patent system or not. Indeed, looking at his wikipedia biography, he worked in public institutions for most of his life.

Comment: Move to the UK? (Score 1) 421

by xiox (#40544017) Attached to: Slashdot Asks: Beating the Summer Heat?

It has been one of the wettest ever Junes here in the UK and it is still raining heavily. When it is not raining it's heavy cloud. Although that's stereotypical weather here, it's more like what you'd expect in the winter. I'm feeling like an extra in Waterworld and shall shortly be growing gills... The problems started when drought measures were brought in to combat falling water reserves.

Comment: Re:Radiation hazard? (Score 1) 684

by xiox (#40531759) Attached to: Ask Slashdot: Are Smart Meters Safe?

the effect of radio frequency exposure upon living tissue (approximatly none) is well-studied and understood.

Oh really? I trust that you will now go home and put your head in a microwave oven for a few minutes. Of course some radio waves are harmless and some are harmful, it's just a question of where the boundary lies. Given that you're unlikely to have a smart meter sitting next to you all day, it's pretty unlikely to be harmful.

Comment: Re:Swirly flat pancake thing... (Score 1) 412

by xiox (#37821834) Attached to: Ask The Bad Astronomer

The dark matter in the universe started with a random fluctuation field - see the pictures of the cosmic background radiation. The random distribution gives a tidal torque on matter, giving it angular momentum. As the dark matter collapses into smaller and smaller regions, the angular momentum is conserved. When smaller sub-units of matter collide together the momentum will also build up. See Peebles 1969 for one of the first papers.

The perversity of nature is nowhere better demonstrated by the fact that, when exposed to the same atmosphere, bread becomes hard while crackers become soft.