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LHC Discovers New Particle That Looks Like the Higgs Boson

kievit Re:Found at 125 GeV (396 comments)

Beware that there are 2 kinds of mass: (1) inertial mass and (2) gravitational mass. In principle, the Higgs particle helps explain the inertial mass, that is, the resistance of an object to a change in motion. Hence the (in my opinion somewhat poor) analogies of the Higgs field to a snow field or a bowl of syrup, where some particles are sticking into more deeply than others. It's only because of the equivalence principle that inertial and the gravitational mass are indeed "equivalent" (and quantitatively the same), which, if you think about it for long enough (or "too long" if you one of those people who think that all research should only be done for some practical purpose), is actually surprising.

more than 2 years ago

Slashdot Asks: How To Best Record Remote Video Interviews?

kievit parachuting to McMurdo (96 comments)

If you are a good linux sysadmin, you have a physics degree or related, you are in good physical health (including good teeth), you are neither claustrophobic nor agoraphobic nor nyctophobic nor frigophobic, you are a stable person with good communication skills and you are in for an adventure: apply for the position of IceCube winterover. You'll pass through McMurdo several times, possibly staying there for a few days depending on weather conditions. Parachuting is usually not part fo the deal, but who knows. They also run marathons there on the ice. Deadline for application is March 30, so if you like this idea you need to act fast.

more than 2 years ago

Ask Slashdot: How To Inform a Non-Techie About Proposed Copyright Laws

kievit Re:Good explanation of the issues with SOPA (254 comments)

Maybe parent was modded down because it was posted anonymously, but I totally agree that Sal Khan gives a very instructive explanation of SOPA/PIPA. I'm a big fan of the Khan Academy. Here is link again, this time clickable.

about 3 years ago

New Theory Challenges Need For Dark Matter

kievit Re:"Intelligent" gravity force (302 comments)

I can't wait for some religious nutbar to claim that an "intelligent" gravity theory should be joined to any other existing theory in scientific discussion.

You mean "intelligent falling"?

more than 3 years ago

LHC Research May Help Explain the Universe's Matter/Antimatter Imbalance

kievit Significance (113 comments)

Being a physicist myself I am very happy that this topic makes it into the news. But it is important to keep cool and skeptical. The statement that a statistical fluke has a probability of 0.05% implies that it is bound to happen if you let 2000 students do data analyses on independent data sets. There are indeed literally thousands of PhD students doing such analyses LHC data, trying to address hundreds of specific research questions that each require different data selections. So it is very likely that some of them will find a result several standard deviations away from the expectation. Actually 3.5 sigma deviations happen very often, because of all sorts of mistakes and inaccuracies in the analyses, but most of the time these mistakes are scrutinzed away before loud public announcements are made. After all scrutiny a few genuine statistical flukes should still remain, and recognized as such.

(For the xkcd inclined: green jellybeans linked to acne.)

More caveats:

  • On slide 14 and 15 you see a summary of the estimated systematic errors and the final result: the deviation of the observed value from the expected value is 0.82 ± 0.21(stat.) ± 0.11(sys.) %. Estimating and combining systematic errors is almost by definition dark magic. It looks like the "3.5 sigma" was obtained by adding the statistical and systematic error in quadrature, which yields a total error of 0.237, and 0.82/0.237=3.5.
  • The statement that the probability of this 3.5 sigma deviation is 0.05% is based on the assumption that if you repeat this analysis several times on more data with exactly the same experimental setup, the deviations from expectation are distributed like a Gaussian (bell curve) with a sigma equal to the total error mentioned in the previous bullet point. That is a major idealization, it could be distributed in many other ways, and then the relation between the deviation (in units of sigma, which is also defined for non-Gaussian distributions) and "the fraction of events with such a deviations or larger" can be quite different. Furthermore, when repeating the identical experiment the systematical errors do *not* fluctuate (that is one of the aspects in which they differ from statistical errors), so aforementioned idealized Gaussian would have an arbitrary offset with a magnitude of the order of the estimated systematic error (0.11), in either direction, and a width of the actual statistical error, 0.21. Depending on what this systematic error really is, the true statistical significance is much larger or much smaller than the quoted 3.5 sigma.

So this is a very interesting result, but more study is needed and in my experience such flukes almost always evaporate in the light of more data and scrutiny. Still, it's not completely excluded that this was indeed the first hint of a real discovery (otherwise no researcher would ever do all that work).

OK, enough for now. Sorry for misinterpretations and other errors I might have made.

more than 3 years ago

London Stock Exchange Price Errors 'Emerged At Linux Launch'

kievit Re:Effect on stockbrokers (168 comments)

Did you check your data during the 15-month testing period, and were the errors also apparent during that time? If yes, did you report the issues or take other actions to get the problems fixed during the testing period?

If you did not check your data during the testing period: why not?

more than 3 years ago

Slashdot Launches Re-Design

kievit Re:Number of replies (2254 comments)

Aha, maybe that was a bug or somesuch that was apparently fixed after I wrote my comment. Right now the number of comments is actually there, for this story it says now "Read the 2175 comments".

about 4 years ago

Slashdot Launches Re-Design

kievit Number of replies (2254 comments)

Previously, for every story on the front page the total number of replies was listed. I thought that was a nice popularity indicator and I used it when deciding if I would read a story or not. In the new design it only says "Read the comments". I did not find a setting in the "Options" that would re-enable this feature. If I overlooked it, please enlgihten me, if it's just not there then please add it...

about 4 years ago

Managing the Most Remote Data Center In the World

kievit Re:So it's possible after all... (98 comments)

Actually practically all IceCube servers at the Pole, running the data acquisistion, processing & filtering are running linux. So those penguins would not have much to do, except join the party. :-)

(And a nitpick: IceCube is actually at the geographic South Pole, too far away from the Antarctic coast for any penguin to reach it.)

more than 4 years ago

Google Considers China's "Web Mapping License"

kievit Tibet (133 comments)

All comments so far are about economic/IP aspects. What about the political/cultural aspect of mapping? China could use this policy to enforce its preferred representation of the Tibet area. Like: replace all traditional Tibet names with new Chinese ones.

more than 4 years ago

IceCube Telescope Takes Shape Below Antarctic Ice

kievit Re:Interesting... (165 comments)

I agree that the background reduction due to lack of atmosphere is very convenient, but as zero.kalvin points out, you still need a 'refracting medium', that is, a really large volume of transparent material such as water or ice (in which you can catch the Cherenkov light whenever a neutrino is kind enough to interact and produce fast charged particles). The large volume is not needed to suppress background, but to beat the very small cross section; in order to detect neutrinos you need them to interact with your detector, and the only way to achieve that is to make it as big as possible.

There is ice on the Moon, but to harvest that and turn into a detector poses some interesting challenges. To use it in frozen form is hard, because you need it with a clarity and purity similar to the exceptionally clear deep Antarctic ice that IceCube uses and which is even clearer and purer than laboratory ice. To use it in liquid form requires keeping it heated, which is probably easier (you need a solar panel farm to power the heating system, but for the ice option you would also need those panels, to power the elaborate purification system + clear ice machinery). Either way: probably science fiction.

more than 4 years ago

NASA Designs All-Electric Personal Flight Vehicle

kievit Re:Go the "Green Spin" (276 comments)

Another "green" issue is that while a puffin may consume less power than a propellor plane powered by a combustion engine, flight is still less energy-efficient than transport by wheels (train, car, bike). As far as I know currently only a tiny fraction of electric power worldwide is generated with environmentally friendly techniques. So I'd like to see the kWh scores compared between a puffin and an electric car.

about 5 years ago

Plug vs. Plug — Which Nation's Socket Is Best?

kievit 100 per cent objective (1174 comments)

I am surprised by how serious people take this light-hearted article. It clearly states:

So, let's take a 100 per cent objective* look at the plugs and plug sockets of the world,...

where the footnote clarifies: "*Objectivity in this sentence has a one-off, government-approved change in definition. Its meaning here, and only here, is the exact opposite of what it usually means." Do /. readers really recognize a tongue-in-cheek story only when the summary got the humor icon stuck on it?

more than 5 years ago

Eee Keyboard Details Released

kievit in combination with a wearable display (166 comments)

When you have toy like this or somesuch, then you do not need a regular screen. A screenless laptop plus wearable display seems to me a nice solution for mobile computing. Of course the laptop should have a battery life of 8h then. Which should actually be easy, because I would expect those display goggles to use less power than a regular screen.

As a side note: for tall people like me this would be kind of ideal for computing in an airplane. Unless I'm in an exit row or bulk head seat there is no way I can see my regular laptop screen. With display goggles that problem is completely solved.

more than 5 years ago

Encryption? What Encryption?

kievit Re:How about a password to kill the machine (500 comments)

Different ending:

You: The full decrypt was "1337Crypt" but if it is corrupt were both screwed

(An assistant, who is listening in from the other room, has a few bitwise clones of your harddrive, and tries the "1337Crypt" password on a clone.)

Officer: Yep still says corrupt. Cannot decrypt information. Well were both screwed I guess.

(The assistant successfully decrypts the cloned partition with the "1337Crypt" and switches on the airco of the interrogation room, as a covert signal to the officer inside that the decryption of the clone was successful. The officer continues the interrogation while pretending to believe that the harddrive is lost. In your triumphant mood you make some remarks which by themselves would not mean much but combined with the data from the decrypted drive they are sufficient to prove whatever the officer wants to prove.)

more than 5 years ago

Staying In Shape vs. a Busy IT Job Schedule?

kievit Re:Madness (865 comments)

I agree with that, but I also wonder if the work times that he quotes are really the ones specified in his contract. 60 hours per week, really, for a support job? Could it be that he is just adding some extra hours before and/or after, every day, out of some social habit, to make a good impression maybe? If that is the case then he should break that habit. Having physical exercise during those salvaged hours will make his regular working hours also way more productive and effective, so his employer and colleagues should be happy with this more health behavior as well.

Plus: would it be negotiable to telecommute one of the working days? That saves travel time, which can be spent on exercise.

more than 5 years ago

Do We Need Running Shoes To Run?

kievit Re:The Daily Mail (776 comments)

So what if the article is published in a magazine with a bad reputation, I find the resulting discussion quite informative and entertaining. And thinking about this topic might inspire some immobile nerds to get a workout, with or without shoes.

Besides, as a previous poster already pointed out, the text is actually not written by a DM journalist; about halfway the page you can find the confession that the whole story is extracted from a book that will go on sale soon.

more than 5 years ago

PG&E Makes Deal For Solar Power From Space

kievit Solar sail (392 comments)

Instead of reflecting light it is absorbing light, so as a sail this is about half as efficient as a fully reflective solar sail, but nonetheless I was wondering whether this contraption would not be "blown" out of orbit by all that light it is capturing? I have no time to read the full wikipedia article about solar sails but some sections mention that a solar sail can even travel towards the Sun by aiming its "thrust" against its orbital direction. This trick and similar tricks make the sail capable of manoeuving. I wonder if this capability remains if the surface is 99% absorbing instead of 99% reflective.

more than 5 years ago

Sharing Lives As Stories On the Web

kievit Major disconnect (30 comments)

I was very confused when I read the summary. The first half and second half seem to deal with totally different topics.

Life, stories and stories of lives are only interesting if they have good content. Content, content, content. Meet interesting people, visit interesting places, do interesting things.

If technology helps you improving your life/story content: nice. We could have an interesting discussion about how that could come about.

The second half of the story is about this dude's work at Amazon and boring technical details. When I glanced through TFA I saw that it is mostly about that, and the dude doing his best to distinguish his product from all those other web 2.0 products. This has nada nothing zero to do with an interesting life story.

Of course the blame is on the story submitter. The title fitting TFA should be something onionesque like 'area man stares at navel and creates his own special unique superior web2.0 niche'.

(And bad summaries are getting sort of the standard here on /., I should know better not be fooled by them anymore, maybe I am getting too old for this place.)

more than 5 years ago


kievit hasn't submitted any stories.


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