Saturday, March 08, 2008
Friday, March 07, 2008
Suppose you have some situation where you expect (given a lot of repetitions) a result of three, on average.
For instance: Say you had 6 cells and each have a 50% chance of dying over the period of one day. Zero could die, or one etc. up to 6. The average would trend toward three if you did the experiment enough times. There is a way to calculate the probability of getting exactly zero, or one, or whatever number you are interested in.
The formula is here: If you are interested
What concerned me last night was the probability of getting exactly zero deaths and more specifically what would happen if we kept the average at 3 while increasing the sample size: For instance 6 samples with a P=0.5 should be the same as 15 samples with P=0.2 chance of death: The average would be three in either case.
What would be the probability of exactly zero deaths though? Simple. Take the probability of a cell living and raise it to the power of the sample size. This should be obvious--but just in case: Think about flipping a coin. You have p=1/2 of getting heads in one flip. p=1/4 for getting two heads in a row (1/2 x 1/2)
I put the following numbers into Excel:
Please note that I use the P for living since for there to be zero deaths, all must live. If the P for death = 0.2 the P for life = 0.8. You either live or die and the total must be 1.0 or 100%.
I am not sure why the results look like this: The probability of exactly zero deaths goes from 1.5% at the lowest end to approaching 5% at the high end, Why? (Bear in mind too, for any of these sample size probability sets, the average will always be three cell deaths). I would have thought at the low end it would be more likely to get zero since with an N of 6 there are only seven possible results: 0, 1, 2...6. At the high end there are 30 million possible results--even if some of them are pretty remote.
Thursday, March 06, 2008
I came across this movie preview based on the game.
And here is someone doing Minesweeper in 38 seconds--about 1/4 my best time...
Wednesday, March 05, 2008
So I don’t judge people who don’t want kids, but I can’t stand “breeder” and “clones” and “crotchfruit” and all the other terms of derision. It’s the worst form of misanthropy, and a curious protestation of ignorance: these people literally do not know what they’re talking about, since there’s nothing about parenthood you can observe from a distance that compares to the thing itself. Being irritated with poorly-socialized children in a restaurant does not set one up in a moral high chair. Believe me, parents are just as irritated with those people as you are.
Maybe most are as irritated, not me--at least not as much as before we had children. I make no claim here to be a better person than James (or anyone else). My reasons for not being irritated are mostly related to my own personal failings.
--It is an opportunity to feel superior: Our kids probably were just as bad, but I don't remember it that way now. Now it just seems like they were always pretty good in public.
--Remembering how embarrassing it was to have children behaving badly in public makes me feel for the parents. Mostly I feel, Wow! it is so much better to see the hate-rays aimed at someone else in the plane, restaurant etc.
--Lastly, I am just used to whining, screeching kids and it really doesn't bother like it once could. Had the disease, immune for life--or at least for a while. I have noticed that grandparents (on both sides) seem to have forgotten anything they ever knew about kids--so the immunity is long but not for life.
Tuesday, March 04, 2008
An easy mojito recipe
1.5 oz white Rum
12 fresh mint leaves
7 oz club soda
1 teaspoon granulated sugar
Muddle mint leaves with lime juice and sugar in the bottom of a glass. Toss-in a couple of ice cubes. Add rum then soda water. Garnish with a lime wedge and a few sprigs of mint.
Ever since I had one of these I haven't wanted a gin and tonic.
Note: A well done comment on a first-class blog makes a perfectly good entry on an nth string blog like this!
Monday, March 03, 2008
Sunday, March 02, 2008
Let us take a closer look...
It is sugaring season when it gets colder than freezing at night and warmer than freezing in the daytime.
We made maple syrup when we lived in Vermont. Not because we had more maple trees though. No, it was because we heated our house with a wood stove and so it was really easy to just dump the day's sap into a big stockpot on the stove.
It takes 30-40 gallons of sap to make a gallon of syrup, so collecting the sap is only half the battle. If we are not making syrup, why collect the sap? I find that it makes a very refreshing and only slightly sweet drink. I just filter the sap through a paper towel to get out any debris that might have fallen into the bucket.
In Vermont, my neighbor Joe even set-up a little wood fired sugar shack in the woods between our houses. We would share a beer or two and drag whatever wood we could find into the fire under his evaporation pan. It was great! The wood we used was too rotten to consider for use inside the house but worked fine to boil sap. An added bonus was that this work totally cleaned-up that patch of woods and made it look like a park. I think I even suggested that he put the shack in a different part of the property every year (we had about 3 acres in each of our lots). At the end of ten years, both places would have looked park-like.