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Ask Slashdot: What Are the Strangest Features of Various Programming Languages?

Framboise Re:Lua[0]? (729 comments)

The discussion is not on measuring continuous quantities
  but counting discrete objects. Physicists and mathematicians have indexed, say, vectors, starting with 1 for ages, except in recent times where sometimes they use 0 for very special reason (like chapter 0 in a book).

about 3 months ago
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Ask Slashdot: What Are the Strangest Features of Various Programming Languages?

Framboise Re:Assignement in Python (729 comments)

Observe that one needs two operators, memory copy, and "point to".
What is wrong is to use only one symbol for the two, and change the meaning according to operator content.

about 3 months ago
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Ask Slashdot: What Are the Strangest Features of Various Programming Languages?

Framboise Assignement in Python (729 comments)

Assigning a number or a list in Python and many other languages (Julia) is a different operation. Such as

>>> a = 2
>>> b = a
>>> a = 1
>>> b
2

>>> a = [2]
>>> b = a
>>> a[0] = 1
>>> b
[1]

Octave (Matlab) is more consistent on this point, every assignement is a memory copy.

about 3 months ago
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Astronomers Find What May Be the Closest Exoplanet So Far

Framboise Re:Time to travel 11 light years (89 comments)

Before embarking to such a trip you had better wait the confirmation of a planet around Alpha Centauri at 4.3 ly. Even if the already announced discovery turns out to be wrong, the probability that some planets exist in the Alpha Centauri system is large.

about 2 months ago
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Researchers Find Evidence of How Higgs Particle Imparts Mass

Framboise Re:Another giant leap? (91 comments)

The Higgs is not responsible for creating mass in general, just for the mass of particles included in the Standard Model. The Standard Model is incomplete since in this model the mass of neutrinos is zero. So the Higgs doesn't explain the mass of neutrinos.

about 4 months ago
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The Big Bang's Last Great Prediction

Framboise Neutrino temperature (80 comments)

The orginal article keeps quoting the temperature of 1.96K as the neutrino background temperature, as found in most textbooks on the topic. This is a relic of the time people were assuming massless neutrinos. The confusion is maintained by people using the temperature as a synonym of energy. Actually the non-zero rest mass energy must be subtracted, providing the real kinetic energy of these particles (moving now at 100-1000 km/s) that would be exchanged with a super large thermometer (in view of the tiny interaction cross section). The effective neutrino temperature would then be measured in the milliKelvin range.

 

about 6 months ago
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Snowden Queries Putin On Live TV Regarding Russian Internet Surveillance

Framboise The art of lying (396 comments)

A good lier should not lie most of the time, otherwise one just needs to reverse the saying to know the truth with high probability.

On that account Obama is smarted than Putin IMHO. He does lie, but in a less systematic manner.

 

about 7 months ago
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Edward Snowden and Laura Poitras Win Truth-Telling Award

Framboise Re:He should get the Nobel Peace and War Prize (123 comments)

The so-called "Peace" prize is indeed badly named. Other famous war makers, H-bomb creator, mass killing authors and terrorists got it:

Yasser Arafat, Shimon Peres and Yitzhak Rabin (1994)
Mohamed Anwar al-Sadat and Menachem Begin (1978)
Andrei Dmitrievich Sakharov (1975)
Henry A. Kissinger and Le Duc Tho (1973)

So perhaps Edward Snowden and Laura Poitras have better not to be awarded
the Nobel.

about 8 months ago
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Could Earth's Infrared Emissions Be a New Renewable Energy Source?

Framboise Re:Power density? (78 comments)

The total heat produced by radioactivity in Earth is 44.2 TW (Wikipedia).
The total solar power received by Earth by the upper atmosphere is 174 PW (Wikipedia).
This means 3937 more solar energy is received by Earth than produced by radioactivity in its interior.
Furthermore geothermal energy is high entropy energy in regard of solar energy since the temperature difference between
ground (~287K) and nearby space (>10K) (DT=277K) is much less than the temperature difference between
sunlight (5778K) and ground (DT=5491K).

In short the whole idea of converting Earth heat into electricity is completely inefficient in regard of solar energy.
The only way to use efficiently geothermal energy is to find hot spots where it is concentrated by thousands with respect to average.

about 8 months ago
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How the NSA Plans To Infect 'Millions' of Computers With Malware

Framboise Cyber war preparation (234 comments)

Developing massive attack tools like that make a global cyber war more likely.
As with the initial ICBM's the first one to strike may believe to win.
Very dangerous, and foolish.

about 9 months ago
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Ask Slashdot: How Do I Change Tech Careers At 30?

Framboise Microsoft is on decline (451 comments)

Think about the fate of dinosaurs that were replaced by smaller more agile mammals when difficult times came...

about 9 months ago
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Computing a Winner, Fusion a Loser In US Science Budget

Framboise Re:Natural gas 3.5, solar electric 35 (196 comments)

Research funding must consider mid to long term planning, so one has to project somewhat in the future, say 2020. There are many such forecasts, but perhaps this one is interesting to quote in view of the origin (US DOE) http://www.telegraph.co.uk/finance/comment/ambroseevans_pritchard/10242882/Solar-power-to-trump-shale-helped-by-US-military.html/

"The US Energy Department expects the cost of solar power to fall by 75pc between 2010 and 2020. By then average costs will have dropped to the $1 per watt for big solar farms, $1.25 for offices and $1.50 for homes, achieving the Holy Grail of grid parity with new coal and gas plants without further need for subsidies. "

about 9 months ago
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Computing a Winner, Fusion a Loser In US Science Budget

Framboise Fusion is a solved problem (196 comments)

It makes sense to cut in traditional fusion research. Indeed, by now it is clear that the best and cheapest practical fusion energy reactor for the foreseeable future has been found in the form the gravity stabilized fusion reactor called Sun. With declining costs solar panels already compete with conventional nuclear reactors. If the trend continue to ~2020 even coal and oil might be seen then as too expensive in regards of solar energy.

   

about 9 months ago
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Report: Space Elevators Are Feasible

Framboise Re:Single point of failure (374 comments)

> Sigh... your numbers are wrong, your science is wrong, and your concept is questionable.
?? You might read at least Wikipedia on the topic before looking like a pretentious person.

> Let's start with the basics: GEO is 35,768 KM from the equator. You need twice that much, at most,
No, for equal length ribbons on both sides of the GEO forces are unequal ! Gravity force decreases like 1/r^2 you know,
and centrifugal force increases like r^1.

> ribbon (not cable. Cable is dramatically less feasible and stupid besides).
In the topic people have used the words cable, ribbon and tether, this is irrelevant to the problem of fragility, so I guess you are trolling.

>No idea where you got 100,000 KM from..
Ah, you don't know the Wikipedia article, which will give you a link to a book where you will find this value.
But in more detail I did calculate the force on both sides (integrating along the radius) supposing a linear mass density decreasing
linearly with the distance to GEO, with zero endpoint values. My result for the highest point is 98178 km from Earth center.

This is probably enough food for a t... as you don't even deign to consider that a single cable/ribbon is a fragile concept.

about 9 months ago
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Report: Space Elevators Are Feasible

Framboise Single point of failure (374 comments)

A robust system should not totally break because of one point of failure. A single elevator is fragile because any natural (meteorite), man-made (space junk) or intentional (war) cause acting anywhere along the 100'000 km long cable can totally destroy it with dramatic consequences on Earth when parts of the cable impact the surface. The elevator design could be made more resistant by building a network of cables, not a single cable.

about 9 months ago
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Watch Bill Nye and Ken Ham Clash Over Creationism Live

Framboise Can a creationist explain me? (593 comments)

Why if the universe is ~6000 yr old virtually all the astronomical images returned since a century or so show objects at distances requiring more than 6000 yr for light to reach us?

Why would the Creator be so deceptive to create 6000 yr ago in the most exquisite details images of the universe looking precisely 13.8 billions yr old, and this false impression would have been reserved just for us in the recent decades?

about 10 months ago
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Where Old Hard Disks (with Digital Secrets) Go To Die

Framboise Simpler, incinerate with common trash (128 comments)

My town has a huge incinerator for common trash that will bring any computer component well over 1000C: most computer component would be finely destroyed to atomic level. As a bonus the incinerator produces electricity.
It would suffice to secure the transport to the incinerator and let heat finish the task.

about 10 months ago
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New Supernova Seen In Nearby Galaxy M82

Framboise Neutrinos? (125 comments)

THE question I am sure many will think about is how many neutrinos will be detected.
For supernova 1987a at 168'000 light years 24 neutrinos have been detected.
At 12 mega light years M82 is 71 times further, which dilutes the neutrinos by a factor ~5000.
So the answer is 0 neutrino if the detectors were the same as in 1987.
I doubt that the present detectors have improved by a factor 1000 in the meanwhile,
but I would be glad to be disproved.

about 10 months ago
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Astronomers Discover When Galaxies Got Their Spirals

Framboise Forming accretion disks (56 comments)

Retrospectively it could have been guessed long ago that disk galaxies need at least a few tens of rotation periods to look progressively like symmetric accretion disks in other astrophysical contexts (disks around black-holes, stars or planets). The difference between galaxies and smaller disks is mainly the number of rotations they could make, a few tens of rotations for spiral galaxies, millions or billions for smaller disks.

about a year ago
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Billion Star Surveyor 'Gaia' Lifts Off

Framboise Re:Total map size (77 comments)

Actually Gaia will map 1% of the stars, but a substantial (my guesstimate ~50%) volume of the region containing most of the stars, which will allow to map the principal structures of the Galaxy: its spiral arms and its stellar bar, as well as to constrain the distribution of dark matter. It is comparable to study one object, like the sun, to better understand all the stars; Gaia will map one galaxy well, ours, with the aim to better understand all spiral galaxies.

about a year ago

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