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Linking Drought and Climate Change: Difficult To Do

Framboise Mean and fluctuations (185 comments)

The climate has always been a highly fluctuating system where extreme temperatures oscillate over seasons and location by, say typically +/-20K (Kelvin), around a mean value around 287K, slowly growing. In some countries the fluctuations are larger, in some others smaller. All the discussion about the human-induced warming is about the effect of changing this mean value by a couple of K (now +0.5K, in the next century by +2-4K). So even in the most pessimistic scenarios the warming remains in amplitude a small fraction of the typical annual fluctuations. No wonder that it will be difficult to prove that any extreme fluctuations will result from the warming.

2 days ago

Eric Schmidt: To Avoid NSA Spying, Keep Your Data In Google's Services

Framboise Re:Under US Jurisdiction? (274 comments)

Google is investing massively abroad, such as in Zurich, Switzerland, where privacy laws are especially strong. Expect that if US laws continue to have negative effects on Google income, the company is going to be more and more international.

3 days ago

Berkeley Lab Builds World Record Tabletop-Size Particle Accelerator

Framboise Re:Only good news for science. (90 comments)

Indeed low cost means more affordable devices for more labs, and new technology means possible expansion to bigger (then more exensive) such devices, allowing to explore new frontiers in physics.

about a week ago

Who Needs NASA? Exoplanet Detected Using a DSLR

Framboise Real advantage (108 comments)

One cannot escape the fact that bigger apperture telescopes can record fainter
stars, and/or perfom the photometry of bright stars with more precision than a simple camera.

To detect exoplanets one needs both large samples of stars recorded as continuously as
possible over several years and high precision photometry. Besides being cheap, the advantage
of a small camera is than the field is larger. But with a larger telescope in space like Kepler one
can target regions of the sky with density of stars optimal for the CCD/camera combination, and
observe continuously for months with the same instruments, which is crucial for differential
photometry. Thousands of amateurs worldwide detecting as many new exoplantes as Kepler
would face the problem of coordinating the analysis of huge amounts of heterogeneous and
incomplete data (due to day/night and weather interruptions in differently dark and transparent skies).

The real question is wether crowdsourcing planet detection is cheaper for global economy at equal scientific return than with state sponsored research. Perhaps the most important benefit of such an
activity is educational and promotional for research in general.


about two weeks ago

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

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

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

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

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

about 3 months ago

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 4 months ago

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 5 months ago

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 7 months ago

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 8 months ago

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

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 9 months ago

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

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

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

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

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 10 months ago

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 10 months ago


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