hallettj
Programmer in NYC
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- 16 Comments
The justification for invading Iraq was a claim that they were developing nuclear weapons. It was well known at the time that the evidence was flimsy, and that even if true it was a flimsy excuse for an invasion. The main piece of evidence was an intercepted shipment of aluminum tubes that were soon shown to have nothing to do with a nuclear program. (See https://en.m.wikipedia.org/wiki/Iraqi_aluminum_tubes). That one is not a conspiracy theory.
The problem is that the way PEMDAS is usually taught multiplication and division are supposed to have equal precedence. The acronym makes it look like multiplication comes before division, but you’re supposed to read MD and as one step. (The same goes for addition and subtraction so AS is also supposed to be one step.) It this example the division is left of the multiplication so because they have equal precedence (according to PEMDAS) the division applies first.
IMO it’s bad acronym design. It would be easier if multiplication did come before division because that is how everyone intuitively reads the acronym.
Maybe it should be PE(M/D)(A/S). But that version is tricky to pronounce. Or maybe there shouldn’t be an acronym at all.
The comment from subignition explains that the phone’s answer, 16, is what you get by strictly following PEMDAS: the rule is that multiplication and division have the same precedence, and you evaluate them from left-to-right.
The calculator uses a different convention where either multiplication has higher priority than division, or where “implicit” multiplication has higher priority (where there is no multiply sign between adjacent expressions).
Wow, this is one of the most complicated Snopes analyses I’ve seen. But it seems like the statement is accurate with caveats. If the brightest component of Polaris is probably 50 million years old what was there before wasn’t really Polaris. And then it doesn’t make a difference whether sharks have been around for 450 million or 195 million years.
Thanks for looking that up! I could be wrong, but I think that boards with N-key rollover generally do use a matrix but with the addition of diodes to prevent ghosting. (Details on Deskthority.) The only designs I’ve seen that don’t use a matrix are small split boards with fewer two dozen keys per side/controller where it’s practical to get a controller with enough IO pins to use a separate pin for each key.
It’s likely fixable. It might need some switches replaced, or there might be some damaged circuit board connections or traces that could be re-soldered or bypassed. I think any fix is going to require soldering, and maybe a multimeter. Whether fixing it is cheaper than buying a new board depends on whether you can borrow tools, and the cost of replacement switches if you need those.
I know the switches are not hot-swappable, but you can de-solder switches on just about any mechanical keyboard. Add a solder sucker to your tools list if you need to do that. There are guides online for replacing keys on the specific board you have.
More details would be helpful for diagnosing the problem:
- Are there rows or columns of keys that don’t work? (This could indicate a problem with the circuit board, or maybe a diode that needs to be re-soldered or replaced. I don’t know if the Blackwidow has diodes or not. In any case it’s multimeter time.)
- Or is it a key here and there that doesn’t work? (This is more likely to be a problem with switches. The might need their solder joints touched up, or they might need to be replaced.)
If I’m doing more than one cracking two together is best. For the last one, countertop.
I get the flat, inside-the-sink idea. But I’d want to clean either way, and I clean the counters more often than I clean the sides of the sink.