All entries for Saturday 28 May 2005
May 28, 2005
Like before, we want to get from dot to dot.
But this time, we want to go between the dots and minimise time. We assume that we travel through the orange area with unit speed, but that we can also travel through the white area with a speed k. So, how does the optimum route change as k changes?
It seems that being environmentally friendly always has a cost. There's the fun way, the convenient way, and the environmentally friendly way. Well, not neccessarily… Here's a list of some ways you can benefit the environment, at no cost to yourself.
1. Don't use plastic/paper disposable cups. It is really kinda questionable why people would want to use them. Habit, I suppose. While it is true that most of these cups can be recycled, nowadays, recycling is still inefficient. It costs energy, and itself pollutes. While recycling is better than disposing, it is much worse that using reuseable cups, whose production costs have already been paid.
2. Reduce plastic bag usage. If you are only going a short distance, and you only have a few, large items (like a pizza, for example, or a few bottles), there is no point in getting a plastic bag. So, well, don't. If you are already carrying a bag for your books, then you can put groceries in that as well. You can also re-use plastic bags as bin bags, or for when you go shopping.
3. Store scrap paper. A piece of paper has two sides. For stuff where presentation doesn't matter – like rough, working out paper – use both sides. This will save you money, as well. If you only use one side, then keep it around for the next time you need some paper. When you are printing stuff off, take some of the discarded cover pages, for use as scrap. And when you have used both sides, then remember to recycle!
4. Turn stuff off. When you leave a room, it costs you no time to turn off the lights. When you leave a computer, turn off the monitor. (Standby mode still consumes some power, and also takes time to trigger.) Note though – this depends on whether you are going to leave for a long time or not. If you are just going to be out for a second, then don't bother. The on-off cycle itself costs energy.
5. Buy stuff on special offer. I mean, think about it? Why are they on special offer? Often, it's because the supermarket is trying to offload stuff. And if they don't offload it, it just gets wasted. Don't feel guilty about being a bargain hunter.
6. Don't switch cars. Suppose you've been convinced of the threat posed by Global Warming. Suppose you now view your dirty old vehicle with guilt… Don't just buy a new one. Remember, the construction of cars is itself hugely polluting. As is its eventual disposal. You need to balance out the incremental improvement in efficiency with the one-time cost. If you are going to buy a new car, then sell your old car second hand (if it isn't too horrible), and get a new, cleaner one.
7. Be lazy. Lazy is good. When you are asleep, you consume very little energy. So, oversleep whenever you can. This should not be difficult.
I'll add more when I can think of it.
Writing about web page http://www.shigabooks.com/shigabooks/csfolder/fleep.html
Jason Shiga majored in Maths. So, kids, you might see this as a sort of inspiration about what to do with your maths degree. I mean, how to be rich and successful and stuff.
Jason Shiga now works in a library. Ok, scratch that about inspiration…
But Shiga does make good comics. As for his maths past, it certainly shows in some of his work.
Fleep about a guy who gets trapped in a phone booth. A phone booth, that has suddenly and inexplicably become surrounded by concrete. All the words around him appear to have turned to gibberish, and all he has with him are the phone, a phonebook he can't read, a few coins, a pen, a book in Russian, and a note which he also can't read. Plus, he's running out of air.
He's also extremely smart. Can he escape? Can he figure out how he got trapped in the first place? Well, to say any more would be to spoil things.
Go. Read. Now.