Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


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 World domination has a cost (Score 0) 404

The USA spend about as much for "defense" than the rest of the world. This is a huge cost (of order 1T$/yr) that the main superpower is unable to let other countries cover in a way or another (say by buying USD for free). In the end being US citizen has a cost that translates in more work time, lower life quality than a couple of other countries.

Comment Disinformation, no thanks (Score 1) 297

Anyone knowing how autopilot works should find the report sounding fishy. One doesn't "activate the car's Autopilot driver assist system at the beginning of the trip", so at zero speed, but when the road is appropriate, like being on a highway, at positive speed. Activating autopilot at zero speed doesn't work.
Further this incident, which remains to be confirmed on several points, didn't caused any fatality. Slashdot doen't improve its declining aura in participating to what looks like a disinformation campaign about Tesla.

Comment Average W/person (Score 0) 149

I think your are off by a big factor. A usual home (4 persons) needs an average electrical power of 400W (Europe) to 1000W (US). Add full electrical AC/heating by heat pumps, the power may double or triple. So even assuming for each person average total power 1000W = 1kW yields at most a daily storage capacity of maximum

24kWh = 0.024MWh.

If one includes for each person the industry, transport and government energy expenses, 4 times the previous value is still below your lower value. Obviously not all renewable energies needs to be stored at day for night use. Wind power is intermittent but works day and night, with tendency to average out over continental networks, while hydro power is very good for being used day and night, but also as energy buffer and storage with short and long cycles.

Comment Geothermal vs Solar (Score 1) 53

The global power produced by Earth in the form of heat (high entropy energy) amounts to less than 50TW. The average global power received by Earth from the Sun in the form of light (low entropy energy) amounts to 174,000 TW. (wikipedia).

So you are comparing a minuscule heat flow percolating upwards compared to a large photon flow raining downwards. By the way plants show in which direction to look to collect low entropy energy.

Needless to say that you need exceptional spots, like Iceland, concentrating locally geothermal power to be more effective than solar.


Comment Tobacco and sugar (Score 1) 314

The tobacco industry deliberately plotted to kill Amecicans in way larger proportion that the 9/11 Saudis. The food industry via sugar over intake also kills much more people than terrorists. The government kills much more Americans with unjustified wars.

Actually anything threatening the top wealthy 1% is considered as much more dangerous than when threatening the 99% rest.

Comment Ignorance is not a solution (Score 1) 908

In the past most people ignored how to read and write. Scribes were upper class people able to help them handling documents and letters, for money of course.
Fortunately the obligatory school system has elevated the skills of most people regarding reading and writing so that scribes are no longer necessary. This represents a huge empowering of people, and actually has allowed the emergence of democratic societies. People can read by themselves and *think*: societies then count millions of thinkers instead of a few hundreds, that's a huge progress. In modern societies people lacking such an education are called illiterate, and are considered as handicapped.

A similar concept applies when dealing with quantities and numbers. Nowadays even well educated scholars may struggle with numbers, innumeracy is actually widespread. For many journalists millions and billions seem synonyms. The innumeracy neologism was invented by John Allen Paulos, who in 1988 wrote the book "Innumeracy: Mathematical Illiteracy and its Consequences", a recommended reading. Innumeracy is endemic and actually handicaps many aspects of common life, starting with mastering the house budget. The insufficient proficiency regarding quantities and numbers then leads to more difficulties when dealing with higher math, like algebra and calculus.

In my opinion, the problem with math education is not algebra or calculus, but the insufficient mastering of the elementary math levels, starting with arithmetic. Statistics and probability are in no way simpler conceptually than algebra and calculus. Lowering the general math level has for effect of preventing people to be empowered by math. Since US students already under-perform at the international level, I would say the proposition to reduce math education is a sure recipe to weaken the country on the long term.

Comment Lack of imagination (Score 1) 720

The authors estimate the probability that terrestrial planets emerge and find a small number. Fine. The more we understand Earth history, the more we see that there were many singular events leading to an Earth as we have. So it is hardly surprising. It is a bit like asking the a priori probability for humanity to produce Wolfgang Amadeus Mozart. Of course it is tiny.

My guess is that the universe produces many more kinds of planets than the already diverse sample seen in the solar and exoplanet systems, with a huge variety of physical conditions and chemical composition, each allowing nature to explore new phenomena we have not even a starting clue. Some of them may develop phenomena as complex and interesting as life, but too different for our poor imagination to predict them.

Slashdot Top Deals

"You need tender loving care once a week - so that I can slap you into shape." - Ellyn Mustard