Become a fan of Slashdot on Facebook


Forgot your password?

Comment Re: So which sensors? (Score 1) 153

Just some clarification from an amateur ECU hacker, with extensive experience in direct OBD2/CAN comms with various controllers in cars (including VWs):

The various vehicle speed sensors (individual wheel speed/ABS, differential/transmission speed/speedometer, accelerometer/gyro for ESC) are not CAN-connected.
They connect into the various controllers directly (ABS/accel -> ABS/TC/ESC computer, speedo -> ECU)
The controllers themselves communicate over CAN.

Specifically here, the TC/ESC logic absolutely has its hands in engine performance. That's the principle method of traction control- limit engine output when traction is lost. Secondary remedial measures are automatic brake application.

Author is still an idiot.

Comment Re:So which sensors? (Score 1) 153

Any ABS equipped car needs those for at least 3, and usually 4 wheels so that ABS works properly.

Any car built past ~1985 with electronic transmission speed sensors for the speedometer will do the job for you without ABS wheel speed sensors, even.
The author is entirely ignorant, and speaking from a position of feigned authority and research. He should be drowned in his own bullshit.

Comment Re:ummmm (Score 1) 389

Many abolitionists were racist. Slavery was considered evil by most of the western world at that time period, but racism was more or less expected due to beliefs of white supremacy.

That's not to say that you aren't at least in part correct. I'm confident the majority of Union combatants weren't really fighting to end slavery. Most likely they were simply marching to their nation's drum, which was currently fighting to preserve the Union after the South opened fire on a Federal fort, but there was a very solid belief that slavery was in fact an intolerable evil in the north.

Comment Re:Why can only humans read and write? (Score 1) 172

We have brain circuitry that facilitates that ability. They do not.
Broca's area, when damaged, makes one talk very similar to how an Ape who has been taught sign language does.
Wernicke's area, when damaged, while Broca's area is not, renders someone who can speak fluently and without labor... but makes no sense in the words they are using.

The apes seem to have at least a somewhat evolved Wenicke's area, but absolutely no Broca's area.

The important factor here- is even a person, with both of those areas damaged, is likely just as intelligent and emotional as they were before- but you would never know, by anything but their facial expressions.

Our ability to process language and speak in complex syntactic structures isn't a product of our intelligence, it's some very specific brain circuitry that evolved out of our existence as a social species that wasn't very high on the food chain.

Comment Re:11 rear enders (Score 1) 549

I was driving in some suddenly icy conditions once, and had just crested a large hill that went steeply downward after the crest. ABS, by some miracle of technology brought my car to a stop before the bottom, saving me from sliding right into a busy de-iced street with 45mph traffic flowing.
It pains me every time I hear uber-drivers talking about how they hate ABS.

Comment Re: Webassembly means... (Score 1) 175

I concur emphatically.
My first forays into machine code (manually constructed with a book and poked) was on a Z80... And it really was an amazingly fun experience.
These days, dealing with assembly in modern ARM and MIPS processors, while so much more capable, and having features that make writing assembly ridiculously powerful, I do miss the utter simplicity of that Z80- so simple a kid was able to pick it up.
It really was great fun.

Comment Re:Effect of nukes on NEOs (Score 1) 272

No, because those millions of small pieces release the same amount of energy into the Earth system, just now into the atmosphere now rather than the planet surface

You start with an incontrovertible claim,

Rather than ejecting material, earthquakes, tsunamis, you flash fry the hemisphere

And you use it to justify pure poppycock?
The atmosphere is big. The earth- it's also really goddamn big. The energy required to raise a hemisphere's atmospheric temperature enough to "fry" us is so goddamn big that there's no point in worrying about it. If something the size of Texas is about to hit us, we're just fucked.

The beast that (I guess contentiously, now?) knocked out the dinosaurs, spread across an entire hemisphere would yield about 193MW/m^2, to dissipate through a 100km column, giving us... 1.9kW/m^3 of dissipation, assuming impossibly worst case scenario (instantaneous thermal conversion across entire air volume)... which is quite survivable.

Realistically, the dissipation will be far better distributed over time and area (a lot of impactors will take long paths through the atmosphere, being not direct hits, better improving their dissipation at high altitudes)

It's not a... "good" thing, for sure... But it's not the total annihilation of a hemisphere.

Comment Re:Effect of nukes on NEOs (Score 1) 272

What sort of nuclear engine are you envisioning that would match the thrust of bombs boiling off the asteroid's surface in a big plasma wave?

I'm pretty confident that absorbing half of the energy output of a significantly sized fusion explosive (say, dozens of megatons) is going to do a lot more for you than just the ablative propulsion effects of the vaporized surface.

You're still going to send a pressure wave through that rock that is going to be a very formidable force in comparison to the very weak gravity holding it together.
This obviously isn't too helpful for a world-ending impactor (hundreds of miles+), but I'm guessing highly dangerous ones of that size and smaller could be reduced to buck shot.

One NASA-funded plan involved hitting it with an impactor first and then having the nuclear explosive follow it in. Even more energy absorption, and even more fertile ground for a very serious pressure wave.

The 5MT device detonated 1.8km deep on Amchitka lifted the ground at the surface by 20 feet. Imagine what that'd be like without 9.8m/s^2 of force pulling it back together, and without the weight of nearly 2km of rock to fight the expansion.

Comment Re: Effect of nukes on NEOs (Score 1) 272

Some of them will go in the opposite direction

Unlikely. This isn't a stationary object, and the velocity of it is almost stupid. Sure you'll slow a lot of pieces down a lot, but I sincerely doubt you'll reverse their trajectory.

That's assuming that the nuke actually blows it up. Nukes are FAR less effective in space because there's no atmosphere for the thermal energy to create a big shockwave, and there's no solid ground beneath it to amplify the intended direction of said shockwave.

That's ok, rock absorbs high energy photons and neutrons even better than air. The shockwave of a nuke causes the serious damage away from the fireball, but I assure you the people within the area of atmospheric ignition due to high-energy radiation couldn't give two squirts of piss about the pressure of the atmosphere there. Definitely detonate close to the bolide.

IMO if you want to blow up an NEO, you'll probably want some kind of kinetic weapon akin to a giant bullet, maybe a space born railgun or something.

You could be right... But I doubt it. Someone would have to do the math to see what portion of the energy output of a large hydrogen bomb would hit the object, how much the object would absorb, and how it would react to the incidental heating. (my guess is very traumatic explosion of the object itself)

Still though, nudging is probably a better approach.

I think we all agree here

Slashdot Top Deals

Egotist: A person of low taste, more interested in himself than in me. -- Ambrose Bierce