* Posts by harmjschoonhoven

577 posts • joined 3 Sep 2012

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Ten 3D printers for this year's modellers

harmjschoonhoven
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Re: Cost

The problem is mass production: in 1986 the price of a Canon PJ-1080A Colour Ink-Jet printer (Made in Japan) was 2644.18 Hfl., incl. 19% VAT (equivalent to 1199.88 Euro).

The serial number of my PJ-1080A is 801057, but I doubt whether 801057 printers were made. The resolution was only 85 dpi.

May be converting it to a 3D-printer is a nice hobby project.

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Chinese boffins crack cloaking tech for camouflage

harmjschoonhoven
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FAIL

Re: Bend light here and hey presto, your aircraft becomes a bird

The research paper mentioned describes calculations for a model working at a single microwave frequency ("wavelength 30mm at the frequency of 10 GHz."). No physical experiments were involved.

Jie Sun et al., "Large-scale nanophotonic phased array" http://www.nature.com/nature/journal/v493/n7431/full shows a more interesting innovation from MIT in Cambridge Mass. working at optical wavelengths.

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Viruses infect vital control systems at TWO US power stations

harmjschoonhoven
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Megaphone

Re: @Destroy All Monsters

@ItsNotMe

One backup is no backup.

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Ten stars of CES 2013: Who made the biggest splash?

harmjschoonhoven
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Thumb Up

Re: Ultra HD ≠ "4K" (3840×2160)

On IBC 2011 NHK (Japan Broadcasting Corporation) had a demo of their Super Hi-Vision system (7680x4350 pixels, intended horizontal viewing angle 100°).

I was impressed and thought I saw the future of TV.

However when I compared the image on the 85 inch LCD with the lady in front of the camera, I noticed that the colour reproduction, especially of skincolour, was very poor.

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First rigid airship since the Hindenburg enters trials

harmjschoonhoven
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FAIL

Re: 'rare and expensive helium'

"Hydrogen has twice the lifting capability [of helium] (H2 molecules are nearly twice the volume, and only half the mass)."

1) The lifting capacity is the difference between the density of air and the density of the lifting gas.

Hydrogen: 1.293-0.0899= 1.2031 kg/m3

Helium: 1.293-0.1785= 1.1145 kg/m3

(at 1 bar, 0° C)

2) The volume of H2 molecules is irrelevant. The number of molecules present in equal volumes of gases at the same temperature and pressure are equal (Avogadro's principle).

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She's a beauty! Super WATER-RICH Mars rock FOUND

harmjschoonhoven
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Pint

Re: Planet of...

Alcohol in space!

The detection of hot ethanol in G34.3+0.15 MNRAS, Volume 273, Issue 1, pp. 25-29 (1995).

Read at http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1995MNRAS.273...25M&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES

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The amazing magical LED: Has it really been fifty years already?

harmjschoonhoven
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Boffin

Re: I'm waiting for the black LED

The black LED does not exist as it requires a radiating body at 0 K, which is impossible.

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Boffins build elastic wires with liquid metal

harmjschoonhoven
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Boffin

Re: resistance

Does anyone remember mercury?

Fill a rubber tube with mercury and stretch it. Measure the electric resistance and you know the length.

Used to have some interesting applications in medical research.

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UK cops: How we sniffed out convicted AnonOps admin 'Nerdo'

harmjschoonhoven
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Facepalm

Re: AC@13:46

You forgot the ignition coil between the car battery and the genitals.

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Three little words stall UN's 'bid for INTERNET DOMINATION'

harmjschoonhoven
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Megaphone

Re: three little words

"The traditional standard of clarity of a language is a cultural inheritance which should be carefully guarded. Language is one of the most important institutions of social life, and its clarity is a condition of its functioning as a means of rational communication." The open Society and its enemies by K.R. Popper (1945), Ch 12 note 30.

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Revealed: The Brit-built GRAVITY-powered light that costs $5

harmjschoonhoven
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FAIL

Re: Keep it going!

The nuclear energy of the sun comes from the fusion of hydrogen to helium .

The gravity of the sun with its mass of 1.989 10^33 g only provide the natural conditions for that to happen.

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harmjschoonhoven
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Re: Nice

The gears of a "knijpkat" - literal translation: "squeezecat" - make a sound not unlike the purring of a cat (Felis Catus).

On top of my "knijpkat" is imprinted: "MADE IN HOLLAND - IMPORTE DE HOLLANDE - TYPE 7424-03 - 2.5 VOLT - 0.1 A" with the Philips logo, the one with double-cross on either side of the channel, in the middle.

Modern versions with 3 LEDs, a rechargable battery and a crank are available (Made in China). Their plastic gears make a softer sound than the 1940's "knijpkat" made of steel and pertinax.

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Behold ATLAS, the fastest computer of 50 years ago

harmjschoonhoven
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Happy

Re: What are the specs?

The instruction set can be found here:

http://www.cs.ucf.edu/courses/cda5106/summer03/papers/mark1.atlas.1.pdf

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harmjschoonhoven
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FAIL

Re: Compute time was billed at around £750-800 per hour

"The word you're looking for is "computer", which is a noun."

In the pre-electronic time a "computer" was a lady with a quill pen. At Harvard College Observatory they ware paid $0.25 to $0.35 per hour in the 1920s.

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Explosion of DANGEROUS IT GEAR injures and CRIPPLES MEDICS

harmjschoonhoven
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Re: I'll get downvoted, but...

The problem is, if you use Dvorak over the weekend, you 'll have to adjust to Qwerty on Monday morning.

As far as I remember the Dvorak keyboard was successfully tested on a US battleship.

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Granny upstages Microsoft, storms stage at Surface launch

harmjschoonhoven
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Mushroom

Selfdefense

The guard could be floored by the Taiwanese lady at 0:14. Every woman should be able to defend herself. My mother learned Ju-Jutsu during WW II and practised the ticks half a century later.

http://www.utrecht.nl/images/DWS/Overvecht/PDF/Dreefnieuws/Dreefnieuws_oktober_2012.pdf (pp 12,13 in Dutch).

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Big Blue bigwig: Tiny processor knobs can't shrink forever

harmjschoonhoven
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FAIL

Re: Christoph

Muons are unstable leptons. Laws of physics ....

Will computer-users be happy if their CPUs disintegrates within 2.2 µS ?

Delivering them from China at 0.999....c would help due to relativistic effects, but create I/O problems.

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'Replace crypto-couple Alice and Bob with Sita and Rama'

harmjschoonhoven
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Mushroom

Re: A lot of hostility here

@AC at 11:52 GMT

Josef Vissarionovich Djugashvili a.k.a. Stalin HAD a religion

after he lost his faith at the Tiflis seminary in 1896: Marxism.

He always has seen himself as special and deified himself

with unimaginable consequences.

Vid. "Young Stalin" by Simon S. Montefiore, page 66.

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NASA releases stunning image of our universe's distant past

harmjschoonhoven
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Meh

Re: each and every dot is an entire galaxy

The 'starry' dot near the center of the righthand lower quarter of the image is a foreground star in 'our own' galaxy.

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Swiss railways ticked off at iOS clock knock-off

harmjschoonhoven
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@frank ly

The big red blob on the end is there because swiss trains depart on time - sekundengenau.

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Gigantic Roman bathtime-fun mosaic found under Turkish field

harmjschoonhoven
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Mushroom

Re: Antiochia ad Cragnum

The Holy Hand Grenade was invented by Kallinikos in Lycia, southeastern Anatolia in the year 6163 since the creation.

Edward N. Luttwak, The Grand Strategy of the Byzantine Enpire, page 324.

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'How I CRASHED my bank, stole PINs with a touch-tone phone'

harmjschoonhoven
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Stop

Sci-Fi

As Rahul Sasi himself says in the PDF, it is Sci-Fi.

To recognize a DTMF code you use a chip like MC145436. Easy: telephone line in,

4 bits out, single 5V supply.

To use a secure or unsecure software implementation of the Goertzel algorithm you first have to digitise the telephone signal.

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Reg hack uncovers perfect antidote to internet

harmjschoonhoven
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Coat

Re: rain in the Atacama Desert

The Atacama desert may be one of the driest places on earth. But when it rains, it comes in torrents.

The ALMA observatory was also affected by a recent snowstorm.

http://www.telegraph.co.uk/news/worldnews/southamerica/chile/9083614/Worlds-driest-desert-hit-by-heavy-rains-causing-floods-and-mudslides.html

I will take my raincoat.

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Reg hack runs Windows 8 on 82-inch touchscreen

harmjschoonhoven
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FAIL

Re: Resolution

According to the info on the Perceptive Pixel website the resolution is 1920x1080.

You 'll be disappointed if you can compare it with a 4k monitor.

Oh, and if you spend 80k$ for the 82", do not forget a few decent hooks in the wall.

It weights 120 kg.

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Curiosity parks for a day, looks back in wonder

harmjschoonhoven
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Boffin

Re: Question

NSEW is derived from the spin axis, not from the magnetic North.

See: IAU Commission IV, WG IV/9, Mars geodesy/cartography working group

recommendations on mars cartographic constants and coordinate systems.

http://www.isprs.org/proceedings/XXXIV/part4/pdfpapers/521.pdf

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