Slashdot is powered by your submissions, so send in your scoop


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 Internet speed test! ×

Comment Re:Lauched with defects? (Score 1) 57

Yes, but H.265 is a video compression format. I dont't think they are going to take videos with the OSIRIS camera (or any of the other instruments) nor transmit video data back to earth.

Anyway, after some googling one finds that the most advanced image compression formats are based on some form of wavelet transform.
Examples would be JPEG 2000, JPEG LS and ICER. All of them predate 2004 but have seen some improvement over the last years. ICER was used on the mars exploration rovers, so it could be they use something similar on the rosetta probe.
Their compression rates are all very similar and differ only in their compational efficiency. Some comparisons can be found in this paper and here (homepage of the MRP Format (Minimum-Rate Predictors), which marginally outperforms JPEG formats but only on 8bit grayscale images).
The latter also compares against JPEG XR or HD Photo from Microsoft which was released in 2009 but seems to perform worse than JPEG-LS.

I don't see any advances in still image compression since 2004 that I would describe as huge, but that view is just based on a quick internet research. I'd be happy to change my mind on this.
Maybe NASA or ESA have been working on something much better and I just missed it (I didn't check patent databases).

Comment Lowest annual death rate since before WW2 (Score 1) 270

Meanwhile annual death rates continue to fall every year.
We still have about a month to go but it looks like 2013 will see the lowest number of air traffic casualities since
the beginning of world war 2:
Casualties since 2010

I wonder if that is because of more and more automation or despite of it?

Comment Re:A wider color spectrum... (Score 1) 456

IR vision has one caveat though: Even if you close your eyes you'd still see some glowing from the inside of your eyelids, probably making it very hard to sleep at night.

It should be tuned to only work above maybe 100C, so you won't see you're own body heat but still be able to detect dangerously hot surfaces, like hotplates you forgot to switch off.

Comment Re:better explanation (Score 1) 264

One possible intuitive explanation (at least for myself) is to imagine a system where its particles cannot exceed a maximum energy (a energy ceiling if you will). Imagine for example a one dimensional gas where its particles can reach but not exceed a certain velocity or kinetic energy (unlike the fundamental limit of light speed where the particle can approach c but not reach it while its energy goes to infinity).
If you put energy into such a system starting from a low energy state, where all particles are initially thermally distributed over many different velocities, the particles will start to reach the energy ceiling until all particles have the same maximum velocity.
Obviously as all particles now have the same maximum velocity the system is in a state with maximum order (or lowest entropy). So by putting energy E into the system we reduced the entropy S, in mathematical terms dS/dE0 or in other words the system had a negative temperature right before the highest energy was reached.

Comment Re:Aww hey.. (Score 1) 370

Same for me. I saw my first porn at the age of 5 or 6. Some friend from kindergarden brought his dads magazines to the playground. I have to admit I was kind of shocked when I saw it. My parents were totally cool with it, but for me it was odd to realize my parents were doing the same things (it didn't occure to me that what they were doing was probably very boring and awkward compared to porn).
Anyway growing up you will experience several visual shock moments:
first porn pictures, first horror movie, first porn film, first videos of real gore and violence
You see it, you're shocked, you get over it (and hopefully maintain your sanity).


Comment Re:Robots from China (Score 1, Interesting) 602

Symbotic is an U.S. based company. The robots used in the factory, are developed in the U.S. by mostly american hard- and software engineers. That's real jobs right there!
I think it's sad that here on slashdot (a site for nerds which for me means scientists and engineers) news of an automated factory is received with such negativity.
Shouldn't we be amazed about the fact that we can actually built a fully automatic factory? I mean those robots need to be programmed by someone, right?

Instead we bitch and moan about factory workers losing their jobs, I mean, what is this Slashdot bad news for blue collar workers ?

Now come on, mod me down.

Comment Re:Video of the capture (Score 1) 147

Actually to me it seemed almost too fast. Robotic arm capture in under 3 minutes (from the video) thats a short time considering all the things that could go wrong:
-crash into the berthing structure of the dragon module destryoing it->abort docking, loose all the cargo (sorry guys, no food for next month), huge loss for SpaceX
-while crashing into dragon destroy the arm itself->wait several months at least for replacement->no dragon resupply missions anymore->SapceX losses major contract->SpaceX goes out of business->1000+ people loose their jobs ...

If I were the guy controlling that arm I would have done it much slower and afterwards would have to take a long shower...

Comment Re:Time dilation (Score 1) 658

On a side note I always find it fascinating that the time traveling part actually does not happen during constant travel near c as both the earth and the traveller are more or less inertial systems so each observer will see the same time dilation in relation to the other observer.
The important part is how you reconnect those two systems, i.e. the acceleration and deceleration part at the turning point. They can be interpreted as gravity-like fields placing the traveller in a deep potential well (in relation to earth) so that time is running much slower than on earth (similar to how gps satellites see a time dilation effect relative to the earth surface).
So the time traveling happens due to the inertial system change at a large distance from earth. Of course this interpretation is academic since when travelling at near light speed for sufficiently long time it will automatically put you at great distance to earth. The more costly alternative is to stay close in an "orbit" near light speed which places the traveller in an extreme acceleration field (due to centrifugal forces in the rotating system) which again is equivalent to a very high gravity potential difference between earth and traveller and therefore there will be time dilation. The acceleration is directed away from earth therefor the traveller sits deeper in the "gravity" well and he ages slower than someone on earth.

Comment Link to Paper (Score 1) 333

Here is the link to the paper on arxiv without paywall:
Quantum teleportation using active feed-forward between two Canary Islands

By the way nowadays almost all physics papers can be found as a preprint on arxiv, the difference to the puplished version is usually not significant for the layman.

Anyway, the main application of this is that you can use it to prepare entangled pairs of qubits to be used in various quantum secure communication schemes.

Comment Since 1968 (Score 1) 71

Her website shows a list of papers on this subject:

First one is from 1968. I know it is a bit pessimistic but this seems like the skin tight space suit is one of those perpetual tech dreams (alongside flying cars, fusion power plants, space elevators, hypersonic aircraft etc.) where once in a while someone comes up and says that we have the technology now or is just around the corner (only wait for 5 more years...).
From looking at the history of technological innovation one realizes that if some new technology takes longer than at most 5 years to be turned into a promising(!) prototype chances are it will never ever really work (but will still be funded because the potential benefits are so huge).

Ah you know what I just looked up the history of the jet engine (Timeline of jet power) and realized it took almost 40 years from the first prototype to the first jet powered aircraft, so scratch the above comment.


Comment Re:Air conditioning? Open a window. (Score 1) 813

Well as I said you must be the weird guy. First of all I never mentioned that smelling bad is the problem and I'd like you to point me to scientific evidence that shows that there is a relation between the odor of sweat and lifestyle and eating habits (and I'd happily change my mind about that).
And second of all I find your advice of dressing accordingly rather funny. Would you like me to go to the office in my underwear or what?
I have no problem doing that at home, but when there are 20 people in a room they on average release 20*40W=800W of heat energy that you need to get rid of.
Healthy lifestyle or not that's just not comfortable after a while.

And by the way thank you for implying I smell bad, I mean that was some brilliant deduction from my answer (wtf?) and suggests that you seem to have had problems with that in the past (maybe a girlfriend or two pointed that out) and that made you change your lifestyle so that you are not so socially isolated.
You probably are also one of those people who jog through the city for the sole purpose of loosing weight so that the women folk will like you more.
Your just pathetic!

Comment Re:Air conditioning? Open a window. (Score 1) 813

Man, you must be the weird unpopular guy at your office and I'm sure your coworkers all agree with you that it is absolutely brilliant having to sit 8 hours a day in a nice cozy 30C office especially in a meeting with 20 other people in the room all sweating their asses off. I live in the south part of germany and every summer I am asking myself why we don't have air conditioned houses here like they have in the US. I quite envy the US in this respect. I once stayed in Florida for 3 weeks and every hotel room and house had full air conditioning and I thought to myself this is paradise!
The company I work for (in Munich) has an air conditioning system where cold groundwater is pumped through the building to cool it down. I don't think I could be very productive at 35C inside, also a lot of Computers would get problems with their thermal management. Apart from that we build sensitive electronics, so we actually need stable temperatures.

Anyway I'd gladly trade some of our supposedly superior infrastructure for a little bit of US air conditioning. Travelled with german trains lately? Maybe IC or ICE? They have those brilliant AC systems designed for max. 30C outside which means they regularly fail during hot summer days exactly when you'd need them.
It is totally brilliant to sit uncomfortably in a train fully packed with hundreds of people for 3 hours with 33C outside and the AC is not working. You'd think that the third most powerful economy in the world could build trains with some decent AC, but no. I guess that is because of people like you who think that it costs to much power what with our nuclear power plants switched off and all. But that is a whole different chapter in the book of recent german/european sociopolitical decisions of utter brilliance (dumping hundreds of billions of euros in essentially fucked up southern european economies would be another great one).
But I better stop now before I wander of into pointless political rant and use the word 'brilliant' too often.

Slashdot Top Deals

Money cannot buy love, nor even friendship.