Become a fan of Slashdot on Facebook


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:Techies ARE improving the world (Score 1) 537

"We have gone 70 years without a major war."

Why did people fight in the stone age?

Over resources (mostly food).

When did they fight?

When things looked so bleak that fighting was better (on average) for their genes.

Low birth rate and any economic growth keeps the future from looking bleak and the mechanisms off that lead to wars and related social disruptions. This is the what happened in first world for most of the second half of the 20th century.

Most depressing science subject I know.

Comment No need (Score 1) 983

From the standpoint of economy, the cops did the right thing. In the end, the shooter probably would have killed himself rather than be captured. You have to be suicidal to get in a fire fight with the cops.

But they didn't have to go this direction. At some degree of risk, they could have waited till he went to sleep and captured him.

Comment Re:Shills, Shills Everywhere... (Score 1) 133

Shouldn't some blame be placed on the review sites, for not purchasing cards at retail? That's SOP for reviewing products in many industries.

High end video cards are pricy enough that reviewer are understandably not going to buy them. However, they could get same effect if they swapped the review card for an off the shelf one at retail.

Comment Something you can do. (Score 1) 281

Most of the time you can't do anything to counter such behavior in governments. But when it is companies . . . .

I had been an AT&T customer for decades, but when this happened I dropped them forever and told them why.

Looks like Citi will go into the same bin, though it's just stupid and not the kind of pain they caused Len Rose, his wife and kids.

Comment Re: If this is correct it should be easy to check (Score 1) 299

If someone can make a reactionless drive, then they have solved our energy problems as well. It's a simple thought experiment to see how a constant force can generate arbitrary amounts of power since the energy you can get out of a moving object is the product of the force and the velocity. Unless the power input goes up related to velocity, you can let it accelerate till it is going fast enough to tap for whatever amount of power you want. If the power input does depend on velocity, velocity with respect to what? And how would the device know how fast it is going?

Someone made a comment that EM drives could move power satellites to GEO. They didn't think it through. If they work, we can use them to create energy and not bother with power satellites.

Comment Simulations (Score 1) 951

The current cottage industry in philosophy departments of speculation about our living in a simulation stems from a conversation I had with Hans Moravec at the Artificial Life conference in 1987. (I was invited because I knew the organizer, when he was a volunteer at the L5 Society.) Hans was rapping about the ever falling cost of computation and waving around a two inch thick paper draft of “Mind Children.” On the spur of the moment, I stopped him and said, “Hans, do you realize how unlikely it is that this is the first time we have had this conversation?” Hans gave me this really blank look, rare on one of the brightest people I have known. I explained that, given the ever falling cost of computation, we would eventually simulate history, including this conversation. And like Civil War reenactments and SCA, we would do it many times, making the chances of this being the first time virtually zero. Hans went away sandbagged. He later wrote “Pigs in Cyberspace,” references here:

We also discussed the conversation and the topic on the Extropian mailing list in the early 1990s.

Thinking back, I must have had in the back of my mind a book, Simulacron-3, that I read many years before.

Elon Musk doesn’t take this speculation seriously because he consistently works hard to make our world a more interesting place. You can’t take a chance that this is not the base reality.

On the other hand, perhaps making the world more interesting is a way to keep the simulation sysops from turning it off. :-)

PS Speaking of making things more interesting
Shorter version that was shown at the White House recently

Comment Power satellite videoes (Score 1) 418

Rapidly ending the use of fossil fuels *without* something to replace them would result in a world wide famine. Fusion or some large number of fission plants could replace fossil fuels, or there is this

Shorter version that was shown a the White House recently

It's about power satellites as a solution for CO2


Comment Re:This is great (Score 1) 173

"Root causes" are not hard to understand given a background in evolutionary psychology.

Why do chimps and prestate people fight? It's over scares resources or a pending shortages. Humans were selected in the stone age for a behavior switch and to detect conditions where it was advantageous to their genes to switch into "war mode." For background: (Peer reviewed version behind a paywall)

How do you move the behavior switch to "peace mode" or keep it there? Steady or rising income per capita seems to do the job. Remember the IRA? The model notes that the Irish women cut the number of kids they had to about replacement. Economic growth got ahead of population growth and rising income per capital shut off the population support for the IRA. Due to their one child policy and rising standard of living, China is very unlikely to start a war. Iran has reached 2 children per woman and should become a reasonably peaceful country.

Prospects are not good for the rest of the Arab world. It's not just the high birth rates and low economic growth, it's the difficulty in changing either one either from inside Arab culture or outside it.

If you have any ideas, please email me. hkeithhenson at gmail dot com

Comment Re:Have they thought this through? (Score 1) 164

The particular problem they identify is one I was concerned with more than 40 years ago.

You can't see an open phase by voltage in a power network with electric motors on it because they will generate the missing phase voltage.

What you need to do is look at the currents flowing in the line to see an open circuit. "Single phasing" electric motors will eventually burn them out. They are usually protected from this with heaters that detect high current on two of the remaing motor connections. They don't work very well since for a lightly loaded motor the currents are not high enough to trip, but the motor, especially the rotor will get seriously hot.

Back in the days of analog controls, I used a circuit that added the currents in A+B-2C. Simple integrator circuit with different capacitors for positive and negative directions so the phase failure relay would take about the same time for any open phase to trip. As I recall (it's been a long time) the circuits took 4 opamps, 3 to do the precision rectification for the three currents and one to do the summation and integration. I can't remember exactly how we got the signal to the relay, but it used a reed relay with two 9000 turn coils on it, one closed the relay and the other coil opposed the first and opened the relay.

Comment Re:That's exactly right (Score 1) 645

There is at least one other option that could scale up to take over not only the electrical load, but the whole fossil energy use of the human race.

It's power satellites. In the last couple of years we got the cost down to where they can undercut coal. This is a little out of date

The updated version of it put the beamed power plants in space.

Comment Meta comment (sort of) (Score 1) 129

"that people wouldn't sacrifice for their strongly held beliefs?"

In an evolutionary context, why would people ever have beliefs strong enough they would die for them? Genes that contribute to such behavior should quickly vanish from the gene pool! But they clearly don't. The key to this is that the suicide bombers (or in times gone by tribal warriors) were not the only ones to carry the "die for the cause" genes. Their children did and if you work out the math, it turns out that genes for getting so wrapped up in a cause as to kill and be killed for it did better under reoccurring situations of ecological crisis than doing nothing. The main reason is that the young women who carried copies of the genes of defeated warriors were taken into the victorious tribe as wives and the warrior's genes marched on. Statistically, the effect was about 37% better survival for genes to get hyped up to kill neighbors--under some circumstances. If you work the model the other way, where circumstances did not favor this behavior, the bias was 45% against. So both the tendency to sacrifice and judging when it was effective were strongly selected over the past few million years.

It's weird, but it looks like both wars and religions (i.e., strongly held beliefs) are closely related and both stem from young women being booty in past human environment of evolutionary adaptedness.

Comment Incidental contacts (Score 1) 99

I met Theremin about a year before he died. It was at Stanford, at an electronic music celebration for him. Just about all of the big names in electronic music were there. I went because my wife is a big fan of radical music.

Many years before that, my father had Theremin's spy gadget in his office in the Pentagon when he was chief of the scientific section of G2. It was dead simple, a resonate cavity with a diaphragm to pick up sound and modulate the outgoing signal.

Slashdot Top Deals

As of next Tuesday, C will be flushed in favor of COBOL. Please update your programs.