How much math you need, and what math you need, depends on what sort of code you're doing.
I use arithmetic almost constantly (incrementing loops, avoiding redundant counters). Boolean logic (x&&b)==(!(!x||!b)) is rather common. Basic probability (p(a) > p(b)+p(c)) is required for optimization. I find myself doing proofs in my head for all the code I write to convince myself the code works. Usually really simple proofs, like TRUE works and FALSE works which implies that all cases work. One recent bug involved a count of changes that couldn't exceed 256, yet every increment had to allow a matching decrement. Tricky tricky!
On the other hand, if you ever see a calculator on my desk, you can tell I'm goofing off. (There's a calculator on my desk right now.) That usually requires combinatorics, exponentials, bell curves. Even when goofing off I've very rarely needed calculus.
I think it's a good idea to pick out the top 1% and keep them challenged. The world's engineering muscle comes disproportionately from that top 1%. Also, making the top 1% excellent costs far less than making the bottom 50% mediocre. That goes for all dimensions, not just academics.
1972-1985, I remember learning addition up to 3rd grade and multiplication and division up to grade 6. Although I was helping neighbors with multiplication in kindergarten. American History covered the revolution up to about the civil war every year, 1st through 12th grade. Never reached WW1. 8th grade introduced algebra, 9th geometry and chemistry, and gee I had to start learning things!
What would have happened if I'd been challenged all the way along, instead of coasting until 9th grade? My grade school tried, but I was just one of hundreds of students. High school had about a dozen kids at my level, and we had some special classes. College had hundreds, but they were cherrypicking from across the country. I don't see how grade school could have done much better unless they gave me my own tutor, or sent me to a different school.
These picocells sound like useful things for houses and cars and office buildings, too. Save cellphone battery and reduce the amount of radiation going through your head.
Math. When I go through the supermarket, one brand of pasta sells for $.08/ounce, and another for $0.13, but it's got a buy-two-get-one-free sale. Which do I get? No calculator, and I'm only willing to give myself fifteen seconds to decide before I go for the next item on my shopping list.
Oh, and that "organically grown evaporated cane juice" appearing on ingredient lists recently has been fun.
Here's the random shuffle I want. Have many dimensions of music, then have each song list its category in each dimension. Some example dimensions and categories in them: (slow fast) (classical pop) (loud soft) (one voice, many, instrumental) (artist). After each song, the shuffler chooses one dimension at random, then chooses a song at random that has the same category in that dimension as the current song. That way consecutive songs are related, but the relation changes from song to song. There'd also be a prohibition against playing the same song twice in a row.
Nuclear powered rockets aren't going to be it. They may be good for a few dozen heavy-lifting projects, but uranium is just too poisonous for them to become commonplace.
I'm still crossing my fingers for the space elevator.
The top might be even better than they already are if they didn't get to coast aimlessly through K-12.
One problem with coders at the top: coders in the middle can't maintain their code, they can't keep track of all the requirements. Either the top has to purposely write dumbed-down code, or whoever owns the code has to make sure that only top people get to maintain it.
The cool thing about SQL is that it's up to the compiler to figure out what the algorithm is for answering the query. If you want something more general than SQL that's still basically SQL, that means getting the compiler to be able to generate algorithms for all that too. That can be done easily if there's only one algorithm it knows to use for it, but if you want lots of options...
Whoa, what school goes up to fiftyninth grade? High school lasts long enough already !!!
Oh wait, nevermind.
Re:Alternative search engines
on
In Google We Trust
·
· Score: 2, Interesting
Teoma has occasionally found me genealogy links that I couldn't find in Google. I go straight to dictionary.com for word definitions. I haven't found any search engine at all, not even Google, that can search for expressions containing punctuation. Google [Groups] is more useful than Google [Web] about 2/3 of the time. The web is deeper than Usenet, but Usenet is more likely to be discussing the ignorant questions I want to ask than the web.
Most Interesting Part of the Article: This slight bias pales when compared with that of spinning a coin on its edge. A spinning penny will land as tails about 80 percent of the time, Diaconis says, because the extra material on the head side shifts the center of mass slightly.
I pulled out the first penny I found (a 2004 D) and spun it on a flat table 50 times. I got HTHTHTHTTHTHTTHHHTHTTTHTTHHHTHTHTTHTHTHHTTHHHHHTTT . That's 25 heads, 25 tails. 80% heads would be 40 heads, 10 tails. From my vague recollection of statistics, if you have n out of m trials go a certain way, 99.7% of the time it will be less than 3sqrt(n) from the expected mean for that way. 3*sqrt(25)=15=40-25. So I'm 99.7% sure this is wrong.
I do keep getting those dreams, though, y'know where you're back in high school because, well you're not quite sure why, and you have to take an American Literature exam in some subfield you've never heard of because you hadn't actually attended any classes for the past 20 years, and you can't remember your locker combination or even where it is because they've remodelled the building?
I had a math professor (hi Dr. Noll!) who loved to denounce phrases where an adjective-noun was not a subclass of the noun. He'd be OK with near miss, but not near hit.
Well I'll be. This might actually make sense. The way to get money into India to uplift the population is by giving money-holders outside of India something they want, in exchange for their money.
For example, big corporations outside of India want call centers and software engineers. So the government can pull money into India by making it easy for those outside corporations to hire Indians.
Wouldn't this have to make my address book public in order to work? The trend recently (among receivers of email, at least) has been to hide email addresses, not publish them and annotate them with personal information.
So if the goal of an ebook is maximum flexibility, what is the standard base format? SGML? A collection of already-processed formats, all digitally signed and timestamped? Java?
Also how do you make a profit off of providing it, once selling dead tree copies tapers off?
I would have thought the effects of gravity scale with weight. Mice are so small, they're nearly surface-oriented instead of gravity-oriented anyhow. They've got almost no gravity-induced features in the first place.
The traffic on my web site and the amount of (non-spam) email I get are less than half of what they were a year ago. The topics I'm interested in (hash functions, regression testing, voting, orbital mechanics) are mentioned on Usenet less frequently than they were a year ago.
What's up? Is there less software being developed now than a year ago? Has spam made the internet yucky? Has the internet fad passed? Or is it just me?
The article wants to use a nuclear lightbulb to heat hydrogen gas to launch a rocket. Several posters said that nuclear lightbulbs are pretty efficient, but they don't heat much gas, so they can't give you sufficient thrust to counter gravity. I googled and found a reference that said you could get.37g from a nuclear lightbulb, less than the 1+g needed to launch, but the page said that number was probably tuned for maximum efficiency. Other posters pointed out that if you put in more gas, each atom wouldn't heat up as much, but you'd get more thrust.
So my question. Does anyone know for sure if a nuclear lightbulb approach can give you enough thrust to launch a rocket?
Human eyes are pretty good at white-balancing whatever the current ambient lighting is to make sure we what we see doesn't become all red or all yellow or whatever. We can tell red from blue under sunlight, incandescent lights, and fluorescents. The only thing I've seen that totally turns off my color vision (other than darkness) is sodium streetlamps, presumably because they put out only one frequency.
Ambient lighting on Mars is probably pretty far from what is normal on Earth. To tell what Mars would actually look like to us on Mars, somebody might need to do some special testing of the responsiveness of human eyes under that ambient lighting.
I recall reading that neutron stars are largely Bose-Einstein condensates. Yes, they have ridiculously high temperatures, but relative to the amount of matter in that tiny space, it's a very low temperature compared to what it could be. I don't understand that, I'm just parroting what I remember reading.
Allowing myself to think about that, that means that making matter denser lowers the temperature at which a Bose-Einstein condensate will form. And once you start forming it at anything over 2 degrees Kelvin, all the universe is your heat sink, so it's a stable state.
I don't care how red it is, giving a color image that contains only red tones isn't useful. I could do just as well by taking the black & white and using light red instead of white. They should adjust the frequencies so that the pictures give our eyes some useful information. That is, unless there really is just one frequency of light on Mars.
Slashdot Mirror
How much math you need, and what math you need, depends on what sort of code you're doing.
I use arithmetic almost constantly (incrementing loops, avoiding redundant counters). Boolean logic (x&&b)==(!(!x||!b)) is rather common. Basic probability (p(a) > p(b)+p(c)) is required for optimization. I find myself doing proofs in my head for all the code I write to convince myself the code works. Usually really simple proofs, like TRUE works and FALSE works which implies that all cases work. One recent bug involved a count of changes that couldn't exceed 256, yet every increment had to allow a matching decrement. Tricky tricky!
On the other hand, if you ever see a calculator on my desk, you can tell I'm goofing off. (There's a calculator on my desk right now.) That usually requires combinatorics, exponentials, bell curves. Even when goofing off I've very rarely needed calculus.
I think it's a good idea to pick out the top 1% and keep them challenged. The world's engineering muscle comes disproportionately from that top 1%. Also, making the top 1% excellent costs far less than making the bottom 50% mediocre. That goes for all dimensions, not just academics.
1972-1985, I remember learning addition up to 3rd grade and multiplication and division up to grade 6. Although I was helping neighbors with multiplication in kindergarten. American History covered the revolution up to about the civil war every year, 1st through 12th grade. Never reached WW1. 8th grade introduced algebra, 9th geometry and chemistry, and gee I had to start learning things!
What would have happened if I'd been challenged all the way along, instead of coasting until 9th grade? My grade school tried, but I was just one of hundreds of students. High school had about a dozen kids at my level, and we had some special classes. College had hundreds, but they were cherrypicking from across the country. I don't see how grade school could have done much better unless they gave me my own tutor, or sent me to a different school.
These picocells sound like useful things for houses and cars and office buildings, too. Save cellphone battery and reduce the amount of radiation going through your head.
Math. When I go through the supermarket, one brand of pasta sells for $.08/ounce, and another for $0.13, but it's got a buy-two-get-one-free sale. Which do I get? No calculator, and I'm only willing to give myself fifteen seconds to decide before I go for the next item on my shopping list.
Oh, and that "organically grown evaporated cane juice" appearing on ingredient lists recently has been fun.
Here's the random shuffle I want. Have many dimensions of music, then have each song list its category in each dimension. Some example dimensions and categories in them: (slow fast) (classical pop) (loud soft) (one voice, many, instrumental) (artist). After each song, the shuffler chooses one dimension at random, then chooses a song at random that has the same category in that dimension as the current song. That way consecutive songs are related, but the relation changes from song to song. There'd also be a prohibition against playing the same song twice in a row.
The thing holding back more widespread adoption of Open Source is that it doesn't ship already-installed on new computers.
Nuclear powered rockets aren't going to be it. They may be good for a few dozen heavy-lifting projects, but uranium is just too poisonous for them to become commonplace.
I'm still crossing my fingers for the space elevator.
The top might be even better than they already are if they didn't get to coast aimlessly through K-12.
One problem with coders at the top: coders in the middle can't maintain their code, they can't keep track of all the requirements. Either the top has to purposely write dumbed-down code, or whoever owns the code has to make sure that only top people get to maintain it.
The cool thing about SQL is that it's up to the compiler to figure out what the algorithm is for answering the query. If you want something more general than SQL that's still basically SQL, that means getting the compiler to be able to generate algorithms for all that too. That can be done easily if there's only one algorithm it knows to use for it, but if you want lots of options ...
Whoa, what school goes up to fiftyninth grade? High school lasts long enough already !!!
Oh wait, nevermind.
Teoma has occasionally found me genealogy links that I couldn't find in Google. I go straight to dictionary.com for word definitions. I haven't found any search engine at all, not even Google, that can search for expressions containing punctuation. Google [Groups] is more useful than Google [Web] about 2/3 of the time. The web is deeper than Usenet, but Usenet is more likely to be discussing the ignorant questions I want to ask than the web.
I pulled out the first penny I found (a 2004 D) and spun it on a flat table 50 times. I got HTHTHTHTTHTHTTHHHTHTTTHTTHHHTHTHTTHTHTHHTTHHHHHTT
Nice try! I graduated 15 years ago.
I do keep getting those dreams, though, y'know where you're back in high school because, well you're not quite sure why, and you have to take an American Literature exam in some subfield you've never heard of because you hadn't actually attended any classes for the past 20 years, and you can't remember your locker combination or even where it is because they've remodelled the building?
I had a math professor (hi Dr. Noll!) who loved to denounce phrases where an adjective-noun was not a subclass of the noun. He'd be OK with near miss, but not near hit.
Well I'll be. This might actually make sense. The way to get money into India to uplift the population is by giving money-holders outside of India something they want, in exchange for their money.
For example, big corporations outside of India want call centers and software engineers. So the government can pull money into India by making it easy for those outside corporations to hire Indians.
No no no -- it's the companies whose names look like ***tronics that are sure bets. Look at revenue growth, too, just to be safe.
If that doesn't work, invest in gold.
(I think that was the 1963 mantra. Did I get it? Did I miss something?)
Wouldn't this have to make my address book public in order to work? The trend recently (among receivers of email, at least) has been to hide email addresses, not publish them and annotate them with personal information.
So if the goal of an ebook is maximum flexibility, what is the standard base format? SGML? A collection of already-processed formats, all digitally signed and timestamped? Java?
Also how do you make a profit off of providing it, once selling dead tree copies tapers off?
I had a dumb terminal once. That's how I first browsed Usenet.
I would have thought the effects of gravity scale with weight. Mice are so small, they're nearly surface-oriented instead of gravity-oriented anyhow. They've got almost no gravity-induced features in the first place.
The traffic on my web site and the amount of (non-spam) email I get are less than half of what they were a year ago. The topics I'm interested in (hash functions, regression testing, voting, orbital mechanics) are mentioned on Usenet less frequently than they were a year ago.
What's up? Is there less software being developed now than a year ago? Has spam made the internet yucky? Has the internet fad passed? Or is it just me?
The article wants to use a nuclear lightbulb to heat hydrogen gas to launch a rocket. Several posters said that nuclear lightbulbs are pretty efficient, but they don't heat much gas, so they can't give you sufficient thrust to counter gravity. I googled and found a reference that said you could get .37g from a nuclear lightbulb, less than the 1+g needed to launch, but the page said that number was probably tuned for maximum efficiency. Other posters pointed out that if you put in more gas, each atom wouldn't heat up as much, but you'd get more thrust.
So my question. Does anyone know for sure if a nuclear lightbulb approach can give you enough thrust to launch a rocket?
Human eyes are pretty good at white-balancing whatever the current ambient lighting is to make sure we what we see doesn't become all red or all yellow or whatever. We can tell red from blue under sunlight, incandescent lights, and fluorescents. The only thing I've seen that totally turns off my color vision (other than darkness) is sodium streetlamps, presumably because they put out only one frequency.
Ambient lighting on Mars is probably pretty far from what is normal on Earth. To tell what Mars would actually look like to us on Mars, somebody might need to do some special testing of the responsiveness of human eyes under that ambient lighting.
I recall reading that neutron stars are largely Bose-Einstein condensates. Yes, they have ridiculously high temperatures, but relative to the amount of matter in that tiny space, it's a very low temperature compared to what it could be. I don't understand that, I'm just parroting what I remember reading.
Allowing myself to think about that, that means that making matter denser lowers the temperature at which a Bose-Einstein condensate will form. And once you start forming it at anything over 2 degrees Kelvin, all the universe is your heat sink, so it's a stable state.
I don't care how red it is, giving a color image that contains only red tones isn't useful. I could do just as well by taking the black & white and using light red instead of white. They should adjust the frequencies so that the pictures give our eyes some useful information. That is, unless there really is just one frequency of light on Mars.