Sorry, I find it a difficult to believe that Apple would release a laptop that would catch on fire if you spilt a cup of coffee on it - I suspect your story has been sprinkled with a touch hyperbole. Evidence, please :)
LiPo batteries explode if you short them. Doesn't even need to be a very long short, or a very big one. They are incredibly sensitive to fast discharges. Water easily conducts well enough to cause problems, especially if it messes up another power conduit. It isn't guaranteed to catch fire, but the risk is certainly there, especially in such a thin form factor - you don't have much space in there for containment or fancy routing to reduce the chances of a short.
Again, it's not guaranteed, but Airs are rather more at risk than other laptops because of their construction.
The battery is ok for direct exposure to water as it's well sealed but as you say the power output from them in short circuit is immense which results in fires if you can't isolate the supply. Water + high current = interesting :)
use http://www.macupdate.com/app/mac/23049/smcfancontrol - when the thing gets hot, just increase the fan speed (to 5700 rpm or whatever you machine's max is) for a minute or two, and then everything gets back to normal.
One glass of water on the desk (not in the machine!). Capillary action sucked water around the seal on the base. It was turned over to remove the battery and the sucked up water rained on the logic board resulting in all sorts of crackling, smoke etc and one dead MacBook.
Being a qualified and experienced EE, I'm qualified to say that it's electronics 101 to be able to isolate power (like every other vendor allows).
Your knowledge may be obscuring the bigger picture here. I suspect the general public wouldn't behave the way you would - the only spill I've ever seen resulted in the user turning the machine over and furiously shaking it. That this is the only spill I've seen in 16 odd years of being around laptops and using laptops suggests to me that for a company like Apple optimising for spills wouldn't be a priority.
A company like apple optimises for good looks. We all knew that and we have proof since Antennagate; don't try to deny that.
After breaking my second laptop with fluids (first was ruined with coffee; second with it standing in water, which was rain accumulated in my not properly closed "watertight" bag) I started buying Thinkpads. They have specially designed "Fluid drains". Because all laptop manufacturors know that spills are one of the highest death-causes for laptops. http://youtu.be/d7cvi00OZDM
The keyboard and speaker holes are sealed with some kind of rubber plate, which is glued on the case. Therefore it takes some time for liquids to enter the casing. When turning the MB directly upside down, there should happen nothing.
But as always, you shouldn't place your drinks directly to all kind of electronic stuff. It's common sense.
However, there is no excuse not to design something with safety in mind.
If you look at the base, the edge rim of it is where it seeped in and sat in the curved section like a pool when oriented normally. There was at least 10ml of water which had been sucked off the table via that rim. The logical step is "isolate power". Any movement of the device resulted in the water spilling onto the logic board.
Macbooks catching fire is kind of what they are good at, just do a little google-fu:
The Powerbook 5300 was recalled because some batteries caught fire on the assembly line. (1995)
The batteries, manufactured by LG Chem Ltd. of South Korea, could overheat and pose a fire hazard, according to the CPSC. The recall affects laptops sold since January, which contain batteries produced last December. Approximately 28,000 batteries are affected by the recall. (2004)
Apple Computer Inc. on Thursday recalled 1.8 million Sony-built notebook batteries that could overheat and catch fire. (2006)
Great, so someone explicitly asks for evidence that Apple would release laptops that caught on fire, I provide 3 examples, Directly Answering the question; then I get downvoted.
Maybe I didn't provide references. Here's the references, most with the official statement from the U.S. Consumer Product Safety Commission.
The powerbook 5300 was explicitly recalled, by Apple, for the short-circuit problem. Reference:
This is precisely what he asked for, and now I've included references. But really, if you guys don't value facts, research, and actual answers, then to hell with it. Why do I try? Might as well hang out on Digg.
Ive spilled - in separate instances - water, coffee, and baby formula into my MBP keyboard, and had no problems, except with the formula, which made the keys sticky.
So presumably I'm so lucky I ought to be winning the lottery at least once a week.
Google for "macbook fire" and look at Google images for some other unlucky ones.
Yes you are lucky because you spilled from the top which it's obviously at least slightly better at handling. If the base gets even slightly wet, boom.
"No hyperbole, the design is simply dangerous."
"If the base gets even slightly wet, boom."
Right. No hyperbole.
But what you said before is that the notebook in your story was sitting in a puddle of water, 10ml seeped in, and then when you turned it over, you heard "crackling, smoke, etc."
An electrical short, yes. But not an explosion.
Sure, if the cathode comes into contact with water, that's a big problem. But the battery itself is well sealed. Your criticism seems to be half baked here:
When you say their design is "dangerous" that sounds like you're saying its dangerous to the user. That it will cause injury.
But your real criticism is that you can't "isolate the power." That is, the sealed case makes the battery dangerous to the machine: You turned the machine over, and logic boards, still hot with power, shorted when the water hit them.
But the implication that it's dangerous to consumers just doesn't make sense: Removable or not, if the lithium comes into contact with water, you've got a problem.
Moreover, I think it's disingenuous when you pull the "I'm an expert" card and then provide editorial analysis: Of course if you google you'll see the bad "unlucky" macbooks that got wet. The people who are "lucky" do not post pictures of a pristine, dried-out computer. There's a selection bias there.
