Assuming the error is normally distributed, 2.3 * sigma is p = 10. They get p=0.02.
In physics I believe the custom is to wait for 3*sigma before you get excited, and 6*sigma before you announce a discovery. In most sciences it's 1.96 (for a reasonable dof) though.
I think I have a pretty good grasp of statistics, thanks.
As I explicitly mentioned in my post, you're correct, there are different standards for "statistically significant" in different fields. Contrary to what you think, they're not particularly precise. They're basically rules of thumb and differ between fields, and even within fields, due to tradition, history, and sometimes experience. Note also that I was talking about the Slashdot headline and summary. In fact, I quoted the former. Sorry, I thought the quote made it obvious.
The headline claims "Scientists Confirm Nuclear Decay Rate Constancy." In fact, they did no such thing. They found (weak) evidence of change. In order to confirm constancy, they would have to find significant evidence of no change.
Why don't you go grab a cup of coffee, or maybe a nap? You're awfully cranky for a Saturday morning.
The process that produces fission is well understood, and the reasons why shape should play a role are well understood. If source shape affects decay rates it would be something very unexpected.
They're investigating the hypothesis that it's neutrinos that cause the variation. Did you even read the summary, or just the sensationalistic headline?
Those are some pretty big deviations to go with the headline "Scientists Confirm Nuclear Decay Rate Constancy." In any field except physics they would be considered significant evidence of a difference.
Strangely, radiation exposure isn't quite like being beaten or stroked.
Okay, let's try it another way. 12 hours of exposure to 1 mSv/hour gives you the same dose as a single cardiac CT angiogram (which takes a whole lot less than 12 hours). Happy?
Do you really think all the researchers in the Chernobyl area are putting themselves in mortal danger?
So if you hung out there for six hours you'd get about the same amount of exposure as an airline pilot who flies 1000 hours a year (20 hours in the air per week).
As I said, pretty much harmless, provided you don't stick around for too long. The scientists wearing masks and gloves to collect samples are adequately protected.
"In the dystopian novel Nineteen Eighty-Four by George Orwell, a thoughtcrime is an illegal type of thought." (http://en.wikipedia.org/wiki/Thoughtcrime).
Possession of pictures is not a thought. It's just like possession of any other proscribed item: heroin, zebra pelts, whatever. In the case of child pornography it is illegal first and foremost because it's production involves exploitation of children. You may THINK child pornography is illegal because society doesn't like pedophiles, but that's not true. The Interpol definition concentrates on products of the abuse of children, and the laws are certainly not aimed solely at suppressing people with undesirable ideas.
Other countries, including mine, also outlaw drawn or animated depictions of children in a sexual context. That is aimed at pedophiles, not child abusers. You could make a case for that being thought crime, although it still doesn't really fit with the way Orwell used the term, and I'm not sure he'd even disagree with those laws. Personally I think anyone convicted of possession of animated child pornography should be treated, not imprisoned. Of course, in civilized countries there's not always much difference between the two.
Possession of child porn isn't a thought crime. It's an anti-trafficking law. You try to catch the creators, but you also go against the consumers. Law of supply and demand and all that. Possession (which supports production), which is what you're being punished for, is not a thought.
There do seem to be a lot of people who take it too far, particularly lately, but the actual law is not a thought crime law.
If you wear a mask a gloves and don't spend an extended amount of time there, you will suffer no ill effects. That is, it is no harm has been done. It is harmless. Note my statement (read the WHOLE thing):
"Most areas around Chernobyl are pretty harmlessly radioactive unless you a) spend a long time there or b) get some of the radioactive stuff on or in you and it sticks with you for an extended period of time."
Sorry if that seems snarky, but you're not the first person who seems to have suffered from a strange inability to read the whole sentence.
You: "any exposure to radiation causes harm it is just a case of how well are bodies able to tolerate it."
Your link: "as far as anyone has been able to determine, small amounts of any kind of radiation are harmless"
If you investigate the actual scientific literature, you'll find that there is reasonable evidence that a certain level of radiation is good for organisms. The specific level where the benefits are outweighed by the negative effects differs.
Of course, you yourself are radioactive and continually emitting (and absorbing) radiation, along with absolutely everything you've ever seen, touched, smelled or tasted. And there are a lot of other things that you can't hear, smell, taste or see that can kill you, faster than all but the most extreme levels of radiation, but don't inspire comments about flesh instantly burning away.
The cities around Chernobyl have been evacuated precisely because long term exposure to the level of radioactivity in that are are likely to be harmful. Living in that area would fall under both the (a) and (b) exceptions to my statement.
In addition to what the others posted, plants tend to polyploidy. Ploidy is the number of copies of chromosomes you have. Humans are diploids, because we have two copies of all our chromosomes, (unless you're male, in which case you have a Y instead of a second X, predisposing you to all kinds of genetic diseases). A lot of plants are tetraploids - four sets. There are some ferns that are extreme cases and have hundreds of copies.
So if you're living permanently in an area with low level radiation, you're probably going to do better if you've got extra redundancy.
Note that the relationship between ploidy and radiation sensitivity seems to be more complex than I've suggested here, but most studies seem to show increased ploidy is associated with more radiation resistance.
Ah, the typical reaction to to the word "radioactivity."
Most areas around Chernobyl are pretty harmlessly radioactive unless you a) spend a long time there or b) get some of the radioactive stuff on or in you and it sticks with you for an extended period of time.
Cyanide is pretty deadly stuff too, but only if you ingest it.
As the spacecraft goes around the moon it takes pictures during the day and during the night. You take the day ones and put them in one composite, and the night ones and put them in another.
The spacecraft didn't image the whole moon (a sphere!) from 200 km up, all in one shot.
It's just like this picture, where it's night all over the planet. Or this one, where it's day everywhere and there are no clouds.
Most people who want more information beyond "almost absolute zero" probably at least remember something from high school chemistry: that absolute zero is -273 C. Most of the world also knows that water freezes at 0 C and room temperature is somewhere around 20-25 C. That gives a fair amount of information.
Most of the world has very little idea what meaningful points on the Fahrenheit scale are and I've never heard anyone refer to cryogenic temperatures in Fahrenheit before.
"Solving the input problem. Virtual keyboards are virtually awful. Maybe integrate a snap-on BT keyboard?"
The iPad will work with pretty much any bluetooth keyboard you care to use. If you buy the adapter it will also work with many USB keyboards.
"Easy to use on the couch? Have you tried it? Will someone make Chumby-style beanbag 'covers' for tablets? If only they had a cupholder, perfect!"
Yes, yes, and I'm pretty sure someone already does.
"Screen size is in opposition to portability. Show me the folding or pull-out screen, something like a windowshade. Is this technology anywhweres near production? Well, I guess I'll be waiting a while."
No. Yes, I guess you will. Meanwhile the rest of the world will be enjoying their tablets that are the oppressive surface area of a sheet of paper.
Reading (skip the e-book reader), including at home. Tablets are a more user friendly form factor (laptops are designed to be used sitting, not lounging, and are not usable at all when you're commuting by bus or subway).
Think of a tablet as a e-book reader that doesn't have an annoying flash every time you turn the page, plays games, gets your e-mail and can display decent graphics and colour diagrams. Tablets are a great device for people who want the freedom of a notebook for around the house but don't want to buy a notebook and ebook reader.
Slashdot Mirror
Assuming the error is normally distributed, 2.3 * sigma is p = 10. They get p=0.02.
In physics I believe the custom is to wait for 3*sigma before you get excited, and 6*sigma before you announce a discovery. In most sciences it's 1.96 (for a reasonable dof) though.
I think I have a pretty good grasp of statistics, thanks.
As I explicitly mentioned in my post, you're correct, there are different standards for "statistically significant" in different fields. Contrary to what you think, they're not particularly precise. They're basically rules of thumb and differ between fields, and even within fields, due to tradition, history, and sometimes experience. Note also that I was talking about the Slashdot headline and summary. In fact, I quoted the former. Sorry, I thought the quote made it obvious.
The headline claims "Scientists Confirm Nuclear Decay Rate Constancy." In fact, they did no such thing. They found (weak) evidence of change. In order to confirm constancy, they would have to find significant evidence of no change.
Why don't you go grab a cup of coffee, or maybe a nap? You're awfully cranky for a Saturday morning.
Good. Maybe this will be a lesson to the town about the importance of voting in elections. Maybe turnout will be better at the next election.
The process that produces fission is well understood, and the reasons why shape should play a role are well understood. If source shape affects decay rates it would be something very unexpected.
They're investigating the hypothesis that it's neutrinos that cause the variation. Did you even read the summary, or just the sensationalistic headline?
Those are some pretty big deviations to go with the headline "Scientists Confirm Nuclear Decay Rate Constancy." In any field except physics they would be considered significant evidence of a difference.
Strangely, radiation exposure isn't quite like being beaten or stroked.
Okay, let's try it another way. 12 hours of exposure to 1 mSv/hour gives you the same dose as a single cardiac CT angiogram (which takes a whole lot less than 12 hours). Happy?
Do you really think all the researchers in the Chernobyl area are putting themselves in mortal danger?
So if you hung out there for six hours you'd get about the same amount of exposure as an airline pilot who flies 1000 hours a year (20 hours in the air per week).
As I said, pretty much harmless, provided you don't stick around for too long. The scientists wearing masks and gloves to collect samples are adequately protected.
No it isn't.
"In the dystopian novel Nineteen Eighty-Four by George Orwell, a thoughtcrime is an illegal type of thought." (http://en.wikipedia.org/wiki/Thoughtcrime).
Possession of pictures is not a thought. It's just like possession of any other proscribed item: heroin, zebra pelts, whatever. In the case of child pornography it is illegal first and foremost because it's production involves exploitation of children. You may THINK child pornography is illegal because society doesn't like pedophiles, but that's not true. The Interpol definition concentrates on products of the abuse of children, and the laws are certainly not aimed solely at suppressing people with undesirable ideas.
Other countries, including mine, also outlaw drawn or animated depictions of children in a sexual context. That is aimed at pedophiles, not child abusers. You could make a case for that being thought crime, although it still doesn't really fit with the way Orwell used the term, and I'm not sure he'd even disagree with those laws. Personally I think anyone convicted of possession of animated child pornography should be treated, not imprisoned. Of course, in civilized countries there's not always much difference between the two.
Possession of child porn isn't a thought crime. It's an anti-trafficking law. You try to catch the creators, but you also go against the consumers. Law of supply and demand and all that. Possession (which supports production), which is what you're being punished for, is not a thought.
There do seem to be a lot of people who take it too far, particularly lately, but the actual law is not a thought crime law.
The GP doesn't say shot. He could rob the caretaker at gunpoint, put not shoot him.
I'm sure if you took a shot at a kid they'd give you at least 12 years.
I'm not sure if there are any units on that (I don't read Russian), so it's pretty meaningless.
But I see somebody's hand. Did that person suffer harm? If not, the situation (him being there) was pretty harmless hey?
Harmless: without the power or desire to do harm
If you wear a mask a gloves and don't spend an extended amount of time there, you will suffer no ill effects. That is, it is no harm has been done. It is harmless. Note my statement (read the WHOLE thing):
"Most areas around Chernobyl are pretty harmlessly radioactive unless you a) spend a long time there or b) get some of the radioactive stuff on or in you and it sticks with you for an extended period of time."
Sorry if that seems snarky, but you're not the first person who seems to have suffered from a strange inability to read the whole sentence.
Your link explicitly contradicts your statement:
You: "any exposure to radiation causes harm it is just a case of how well are bodies able to tolerate it."
Your link: "as far as anyone has been able to determine, small amounts of any kind of radiation are harmless"
If you investigate the actual scientific literature, you'll find that there is reasonable evidence that a certain level of radiation is good for organisms. The specific level where the benefits are outweighed by the negative effects differs.
Of course, you yourself are radioactive and continually emitting (and absorbing) radiation, along with absolutely everything you've ever seen, touched, smelled or tasted. And there are a lot of other things that you can't hear, smell, taste or see that can kill you, faster than all but the most extreme levels of radiation, but don't inspire comments about flesh instantly burning away.
The cities around Chernobyl have been evacuated precisely because long term exposure to the level of radioactivity in that are are likely to be harmful. Living in that area would fall under both the (a) and (b) exceptions to my statement.
In addition to what the others posted, plants tend to polyploidy. Ploidy is the number of copies of chromosomes you have. Humans are diploids, because we have two copies of all our chromosomes, (unless you're male, in which case you have a Y instead of a second X, predisposing you to all kinds of genetic diseases). A lot of plants are tetraploids - four sets. There are some ferns that are extreme cases and have hundreds of copies.
So if you're living permanently in an area with low level radiation, you're probably going to do better if you've got extra redundancy.
Note that the relationship between ploidy and radiation sensitivity seems to be more complex than I've suggested here, but most studies seem to show increased ploidy is associated with more radiation resistance.
Yes. Although plants have quite a few advantages over us where it comes to tolerating radiation.
Ah, the typical reaction to to the word "radioactivity."
Most areas around Chernobyl are pretty harmlessly radioactive unless you a) spend a long time there or b) get some of the radioactive stuff on or in you and it sticks with you for an extended period of time.
Cyanide is pretty deadly stuff too, but only if you ingest it.
http://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/apollosites.html
As the spacecraft goes around the moon it takes pictures during the day and during the night. You take the day ones and put them in one composite, and the night ones and put them in another.
The spacecraft didn't image the whole moon (a sphere!) from 200 km up, all in one shot.
It's just like this picture, where it's night all over the planet. Or this one, where it's day everywhere and there are no clouds.
Even better. The average person doesn't do much typing most of the time, and probably should do even less.
Most people who want more information beyond "almost absolute zero" probably at least remember something from high school chemistry: that absolute zero is -273 C. Most of the world also knows that water freezes at 0 C and room temperature is somewhere around 20-25 C. That gives a fair amount of information.
Most of the world has very little idea what meaningful points on the Fahrenheit scale are and I've never heard anyone refer to cryogenic temperatures in Fahrenheit before.
You have no idea what a laser actually is, do you?
"Solving the input problem. Virtual keyboards are virtually awful. Maybe integrate a snap-on BT keyboard?"
The iPad will work with pretty much any bluetooth keyboard you care to use. If you buy the adapter it will also work with many USB keyboards.
"Easy to use on the couch? Have you tried it? Will someone make Chumby-style beanbag 'covers' for tablets? If only they had a cupholder, perfect!"
Yes, yes, and I'm pretty sure someone already does.
"Screen size is in opposition to portability. Show me the folding or pull-out screen, something like a windowshade. Is this technology anywhweres near production? Well, I guess I'll be waiting a while."
No. Yes, I guess you will. Meanwhile the rest of the world will be enjoying their tablets that are the oppressive surface area of a sheet of paper.
So 100% of what the average person would use a notebook for.
Reading (skip the e-book reader), including at home. Tablets are a more user friendly form factor (laptops are designed to be used sitting, not lounging, and are not usable at all when you're commuting by bus or subway).
Think of a tablet as a e-book reader that doesn't have an annoying flash every time you turn the page, plays games, gets your e-mail and can display decent graphics and colour diagrams. Tablets are a great device for people who want the freedom of a notebook for around the house but don't want to buy a notebook and ebook reader.