Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror

Comment Re:DC power? (Score 1) 231 231

Modern power control electronics can produce a smooth sign wave, at a pretty good efficiency. The first harmonic as at like the 8th overtone, which is easily filtered. However, there are motor controllers that don't use sign waves, but form the current to match the motor characteristics. Even better.

Comment Re:DC power? (Score 2) 231 231

Here are two reasons why AC is generally better than DC at consumer level:

1: AC arcs are self-extinguishing every half cycle. ...

2: Human safety: ...

The first is true, but the second is not so much. 60Hz current can scramble the coded signals used by your nervous system, in effect "crashing your network". And 60Hz can cause muscle contraction, it just shakes a bit. I think it is harder to let go when hit by 60Hz. It does depend on frequency, though, higher frequencies do not cause this. I think 400Hz was considered less dangerous, in that way.

It's beside the point,though. The application in question does not require long distance or high voltage. For one house, 24 volts might be fine.

I think the real news is, that they are using the newer high efficiency DC motor technology allowed by electronic motor controls.
Brushes and mechanical commutators were why this was not done long ago.

Comment Re:"...the same as trespassing." (Score 1) 1165 1165

... But deadly force should only be used to defend people, not stuff.

That is a common philosophy, but it is philosophy not law or even morality.
Many people believe that deadly force is justified, morally at least, to protect property.
The alternative is to allow criminals to steal anything that they can escape quickly with, and there is no way to stop them.
That may not be practical.

Besides, I put part of my soul into much of what I have. The one who steals it steals part of me.

Comment Re:Right to Privacy in One's Backyard? (Score 1) 1165 1165

Firing a weapon in a populated area except in defense of life and limb is a colossally stupid idea and patently against the law, just because your privacy is being violated is no excuse.

A city person, no doubt...

We go target shooting in the back yard, here.

If a prowler was sneaking around people's property, looking over people's daughters. he would get shot with something a lot heavier than a bird-shot. They should expect no less for a drone...

Comment Needed (Score 1) 679 679

Many people, who type professionally, find it less tiring to hit the capslock key and then type a letter, rather than having to hold down the shift key while typing a letter at the same time. Of course, it might depend on keyboard layout.

However, it is very bad to assume a small statistical usage means something is not needed. Like a seat belt, it might not be used very often, but if you need it and don't have it you could be in big trouble.

It is likely that no one, with any brains, would buy a keyboard with no capslock! 8-)

Comment Re: Looking more and more likely all the time... (Score 1) 502 502

Yes, but it's distinguished from the steam engine, from what I understand, in that the power output is comparable enough to the margin of error that they're still in the process of verifying that it's actually doing something.

They seem to think it is doing "something". Exactly what, may be in question. 8-)

They are being cautious with the power levels. Microwave energy at high levels can be very dangerous, as shown by the injuries when Radar was being developed. I don't blame them for using the minimum drive levels, to get a reading.

Comment Re:Blimey (Score 1) 502 502

It's one thing to question the very preliminary theory of operation for the thing, it's quite another to demand that it is doing nothing just because it would be inconvenient. ...

True.

If you have something that works, no theory is required to build one. People built things long before they invented the scientific method.

A good theory is -very- useful for improving things and making them more reliable. But it is not -required-.

Comment Re: Looking more and more likely all the time... (Score 1) 502 502

It's worth noting that there's a big difference between those theories and this engine. With this engine, they're putting forward a piece of technology and saying, "We don't know how this works, but we're claiming it does." In the case of Newton and Einstein, they put forward a mathematical model that was internally consistent, and the question was whether it applied to reality. ...

This is much more like the invention of the steam engine. Look it up, they had steam engines working for many years with no valid theory at all. The designs changed radically, when they began to develop some parts of the theory. It was decades before they had it working right, but they got good use out of them, anyway.

Just because you don't have a theory (that works), doesn't mean the tech can't work.
Theory is very helpful to technology, but technology does not -require- theory.

Comment Re: Looking more and more likely all the time... (Score 1) 502 502

Except, claiming that you know it is a scam is just as "shaky" as claiming it is definitely a true thing.

Of course, we get trashed for having the courage to say "I don't know". So I understand some of the statements. Just be aware, when you have to lie to the public, and don't go believing your own "spin".

Most of the time, the real truth is that we -don't- know. We just suspect a lot... 8-)

Comment Re:Effective cataract eye drops are already availa (Score 1) 70 70

Um ... the phama companies can't make money on it?

There are a lot of traditional remedies, that actually work, that are not "pushed" because there is no way to make money on them. And no way to cover the cost of medical testing required, before you can say they work.

So those that know, use them. And those that don't, loose out.

Of course, there are many traditional remedies that don't work, or not enough to be better than new stuff. But not as many as the "establishment" claims.

"What I've done, of course, is total garbage." -- R. Willard, Pure Math 430a

Working...