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


Forgot your password?

Comment: Re:The Dangers of the World (Score 1) 778

by JoeMerchant (#48833361) Attached to: Parents Investigated For Neglect For Letting Kids Walk Home Alone

At 12 years old / 1980, my school bus was dropping me off 3/4 mile from home - closest stop on the route (through a typical suburban neighborhood.)

At 10 years old, I was riding my bicycle 5+ miles from home, alone. It wasn't even imagined to be a CPS involveable issue.

Could I have been kidnapped? Sure. Just like every other unsupervised kid, everywhere in the world, 35 years ago, and today.

Rich Columbians are moving to the US so they can let their kids play on the street without fear of kidnapping, but, if you don't make yourself a target like that (1% wealthy in a poor and relatively lawless country), you shouldn't have to worry.

Here, I think the pendulum has swung to the other side, where we are now fearing the government that is "protecting us" more than the people they are protecting us from.

Comment: Re:Seems obvious but... (Score 1) 325

by JoeMerchant (#48770839) Attached to: Ask Slashdot: High-Performance Laptop That Doesn't Overheat?

If you produce value so far in excess of the cost of the equipment that it doesn't matter what the equipment costs, then, yes, that can be a very intelligent thing to do.

This isn't a common commuter vehicle, but it serves its owner's purposes very well:


Comment: Re:Old LiIon batteries, what could possibly go wro (Score 1) 143

by JoeMerchant (#48547399) Attached to: Using Discarded Laptop Batteries To Power Lights

Solar energy is actually flabby and watered down as it is typically delivered, especially on shoestring budgets.

When you have access to "mains" 110 or 220 VAC at 10+ amps, you trim it down and deliver it exactly as desired to charge your cells (within the budget constraints of how "smart" you can make the charger) in this scenario, the aged cells can probably be handled safely.

When you have 0.1sqm of budget solar cells delivering your power, and an aged LiIon cell as your storage medium, the electronics between those two are going to have to eek out every possible bit of power delivered by the solar side if you want a chance of the LED light lasting for more than a couple of hours after sunset. The saving grace here is that the solar cell _probably_ won't have enough power to make anything exciting happen in the battery, regardless of how you transform the voltage/current coming from it. The downside is that whoever is making the charger will probably scrap any cell safety considerations and just dump whatever they've got into the cell as "efficiently" as possible - and sooner or later the infinite number of users will hit on an operational scenario that makes it burn.

Comment: Old LiIon batteries, what could possibly go wrong? (Score 2) 143

by JoeMerchant (#48541097) Attached to: Using Discarded Laptop Batteries To Power Lights

So, these recycled batteries are being charged with what kind of charging controller, using what kind of input power?

If it's something creative like solar, I'd be very surprised if we don't get an impressive fire out of the first 100 unit-years of use...

Even if they have "grid power" to charge from, the charge controllers had better be good enough to sense a damaged cell, and when those sophisticated chargers refuse to charge the pack anymore, some genius level electrical engineer will hook up a "dumb" NiCad charger to the pack and get some more life out of it - the practice will spread and it won't be long before somebody sets the shanty town ablaze...

Comment: Re:Well (Score 1) 594

by JoeMerchant (#48293927) Attached to: Space Tourism Isn't Worth Dying For

No, no, NO! What the Space program really needs are a bunch of people who never actually do anything beyond their day job and some hobby reading to espouse theories about what should be done. We should give all these people a forum where they can argue about what _should_ be done and let the argument proceed until a clear and obvious answer is arrived at - then we should set about doing exactly what the masses have decided, because, obviously, that will be the right thing to do.

Until then, we should redirect the funding that would go to the Space program to subsidize the cost of Cheetos and craft beer, because that's obviously what people need today, based on their observable behavior.

Comment: Re:Jeez, just come clean (Score 4, Interesting) 146

by JoeMerchant (#48287995) Attached to: A Mysterious Piece of Russian Space Junk Does Maneuvers

Take a sailboat out in the South Pacific sea, get 500 miles from any port, and tell me how crowded the ocean surface (a 2D structure) feels.

The only thing that's crowded about space is the delta-V, there's plenty of room, but you really want that when relative velocities can be > 1 km/sec.

Comment: Re:That's a shame (Score 1) 445

by JoeMerchant (#48282795) Attached to: Virgin Galactic SpaceShipTwo Crashes

$200,000 is actually in reach of far more than 1% of the US working population... it's not an easy thing, but if it's all you ever want to do in your life, it's attainable with median income and a few decades of living frugally and wisely investing every spare penny.

This is a huge change from the late 1960s where your odds of becoming an astronaut were roughly equivalent to two lottery wins in the same year.