I'd be interested in a cite for systems spontaneously decreasing in entropy.
I can't find the paper at the moment but the network link from my current location is appalling bad so I've only been able to do a few simple searches. I believe the paper from from an Australian university. The claim was that, for certain, small QM systems, there could be a small decrease in entropy for a brief period of time but that, averaged over a longer time period, entropy was always increasing. I don't think this is a particularly surprising result. All it really says is that you can get spontaneous organization in a system during any given time period just so long as, over arbitrarily long periods, the entropy increases i.e. the amount of randomness is subject to random fluctuations as well.
Did you do any of that? I bet you did less to access your conclusions that Milton did!
Well, unless he copied his conclusions he probably did more since it looks as if Milton just copied the story from somewhere else. If you look at the Quote Investigator link you'll note that an incredibly similar story originated in Alberta in 1935. The Milton version is certainly far better put but it is not the original source.
If modern construction machinery is less efficient and effective than forced labour, then whoever designed such shoddy machinery should be the first in line to receive a shovel.
Never mind the construction time what I would like to know is how a 520 mph train manages to have a travel time only half that of a car which implies an average speed no more than 25% of its maximum. Either there are a ridiculous number of stops, the train's acceleration is incredibly low or someone got their numbers wrong.
Yes there is - vaccines can be weak strains of a bug which provoke an immune response without causing the disease. If the original bug diverges enough from the weak strain used in the vaccine it could, in theory, become "vaccine resistant". Of course I would imagine that it has to diverge more than it would for a simple anti-biotic because your body can adapt (an expert would have to confirm this) but I don't see why divergence away from a vaccine strain would not occur.
Bottom line, there's little hope of human civilization lasting more than 10^20th years.
Unless we find a way to escape the solar system 5*10^9 years is our rough life expectancy and if we develop a good enough understanding of science to do that then who knows? Heat death is just the result of probability and statistics and we've already seen systems which can spontaneously decrease in entropy for short periods of time.
If the article would report everything, it would be talking about momentum, and virtual particles too.
It would not report on virtual particles because the annihilation takes place in the galactic core where the densities of DM are highest and virtual particles can only exist for the tiniest fractions of an instant not the ~50k years needed to make it from the core.
The question you should be asking is where are all the anti-protons? Since DM particles generally need to have masses roughly ~100 or more times the mass of the proton their annihilations should be capable of producing all stable anti-particles below this. Hence most models predict an excess of anti-protons as well as positrons but no satellite has seen any evidence of this. So if this positron excess is due to DM (and that is a BIG if!) we may have to start looking at some of the more exotic DM models (e.g. Arkani-Hamed et al. Phys Rev D (2009) vol. 79 (1) pp. 015014) which some of us are already looking for with the LHC.
So far away that light from it has not yet had a chance to reach us, and thanks to the accelerating expansion, never will. I vaguely remember seeing some discussion of this in relation to inflation - we end up in a region which is matter dominated and another region is antimatter dominated with the two regions being causally separated by inflation.
However I believe that these theories have problems because you'd expect to be able to see gamma rays from the edges of each region...unless we happen to be strangely right in the centre of a massive matter-dominated region and cannot see the edge. Plus, since CP violation does exist it we do know that there is a matter/anti-matter asymmetry so it seems strange that, given this, there would be a completely unrelated mechanism to cause an imbalance.
CP violation in Kaon decays can be explained by the Standard Model, but if the magnitude of CP violation they have claimed exists in the D system can not.
The calculations required to predict the amount of CP violation in meson systems are extremely hard to do. When I worked on the NA48 experiment, which measured direct CPV in the kaon system, the theorists were initially adamant that there was no way the parameter we measured (espilon-prime over epsilon) could be above 0.001 in the Standard Model. Several year later after both NA48 and KTeV had published results putting the parameter at well above that I saw a theory talk saying that these results were in perfect agreement with the Standard Model!
Now the discrepancy seems a lot larger here but, nevertheless, even if the result holds I'd give the theorists time to think about this and see whether they find problems in the calculations. I have a huge amount of respect for my theory colleagues but QCD calculations like this are fantastically hard so it is not at all uncommon for the results to change.
Of cours,e the movie might stink, but there's no reason to assume so.
Yes there is. The two Cushing films were British, not Hollywood and the only time the US made a Doctor Who film we got the 8th doctor. So going on past performance there is EVERY reason to think that a Hollywood production of Dr. Who will be terrible although I really hope I'm wrong.
Worth it...just to see how wrong Q15 is
on
2011 Geek IQ Test
·
· Score: 1
It's worth slogging through to Q15 just to find this gem:
15. Related to quantum mechanics, what is the term for the observation that some physical quantities can be changed only by discrete amounts, or quanta?
The answer IS quantum mechanics (or quantum physics) and not, as they suggest, "multiples of planck's constant".
In the UK, you do more work to get your A levels than you do at college to get a degree, at least in many subjects.
Sorry but that is simply wrong. The A'levels in the UK are a shadow of what they once were thanks to the knock on effect of replacing O' levels with GCSE's. The result has been that the number of years required to get a degree has been increased in many cases so that the first year can be spent teaching students what they used to learn at A' level.
So degrees are far, far above A'levels - unless by "college degree" you mean a further education college (which never used to be able to award degrees) as opposed to a proper university degree.
Another side of this might just be that there is a difference between liking a subject academically (in high school) and deciding you want to do it for the rest of your life.
These students will usually pass the course with a reasonable grade and then transfer to a different program because they find that they are not interested. Likewise we get students who find they actually like physics at university and transfer in. So you are certainly right that this is something which happens but the result is a program transfer not dropping the course because you cannot cope with it.
The one issue I see here is that college/university is a big waste of time for many. There are basically no apprenticeship style job programs in the US as compared to Germany for example.
Yes, that's a different issue though...and it is not only a waste of time for those who would be better off in apprenticeships but it also makes it hard to offer a more challenging program at University since you have to be able to teach those who really would be better off doing an apprenticeship. The UK had it about right when I was doing my degree: about 20-25% of students went to university from school. The rest either went to vocational training polytechnics or did on the job training.
The problem is now that in the UK and Canada (and I am guessing the US too) many of the technical colleges have been allowed to convert to universities and start trying to offer academic degrees. Apart from the increased expense they, frankly, are not capable of doing this. The result is that you have students spending more money and time but ending up with a low quality degree.
Oil industry (geophysics), financial sector (data analysis on stocks+companies), industrial R&D of a very wide range of types, IT sector (programming+analysis), consultancy work, teaching, or become a physics prof like me! There is a HUGE range of things you can do with a physics degree either using your physics or using the logical analysis and problem solving skills you need to do well in physics. Just because there are not a lot of us employed as physicists does not mean that it is hard to find a job - in fact physicists have one of the highest employment rates (at least of the statistics I've seen).
Maybe if colleges understood that, going in, many students aren't really understanding what they're getting into. Maybe that would help.
You have that the wrong way around. It would help FAR more is schools understood that they are preparing students for university.
We already understand that it takes a while for a student to adjust to a university environment and that their choices may change once they take stock of the situation. This is why we start with "easy" introductory courses that let students get their bearings. The problem is that these are becoming more and more challenging due to falling academic standards at schools.
People drop out because the subjects are hard, sure. Making them fun won't make them less hard, so that won't address the problem.
No, students do not drop subject just because they are hard. They drop them because they are hard AND they have never been academically challenged ever before. I've seen this happen numerous times with smart first year students. They are completely used to coasting through school with one cylinder firing because there is no challenge at all for them. Then, when they get to university, they are suddenly faced with material that they cannot master with a quick read through and they literally do not know how to cope.
If we challenge even the brightest students at the school level then they will be used to having to think things through carefully and then, when they do finally understand it, they will get the sense of achievement which comes with that. Some of my colleagues who have a reputation for teaching very challenging, senior undergrad courses have some of the best student feedback because, by that point, the students like to be challenged and to succeed. Sadly though we lose a lot of students before we get there just because they are completely unprepared for university and don't know how to cope.
Do you get a choice of technology in your full body scanner? Do you know which is which?
Yes - you accept whichever they machine they have or chose the manual grope method. The terahertz scanners have a cubicle and a vertical sensor bar which moves across in front of you. The back-scatter X-ray are static and consist of two rectangular blocks which you stand between to get irradiated.
What surprised me, on the one occasion I saw the X-ray device, is that there was no protection for the security workers operating it. While the dosage has a low (but non-zero) risk for one passenger the cumulative dosage for someone nearby and operating the machine could be a lot larger. There is a reason the operators of X-ray machines for medical/dental use always go behind a shield before operating the machine.
Yea and flying spaghetti monster forbid you accidentally type something like chmod a+rx on your consolidated/usr/bin directory.
That is an argument for backups NOT an argument for split bin directories. It seems to me that the original argument for split directories was, as the original poster mentioned, so that/bin could fit on the boot partition so the system would work even if no other partition can mount. Given that modern disks are easily large enough to hold/bin and/usr/bin in the same partition I really don't see a good argument for their continued separation.
The proof of the business model pudding will be when we've sold 100k and I still have a house.
Well my 6 year old son is really keen to get one. This is probably a bit younger than your target audience and I'm not sure how good he will be at programming but having a computer boot to a prompt like the old Beeb model B I learnt to program on is a really good start. All we need now are some magazines with games to type in - debugging the typos in those after entering them by hand was a great way to learn - although perhaps source code games we could download with one or two deliberate bugs in them would help cut to the educational bit!
And in any case, the "inside photos" are only being taken WITH THE EXPRESS PERMISSION AND ENCOURAGEMENT OF THE BUSINESS OWNERS
This is certainly the case at CERN where they have been photographing the LHC underground. In fact when I first heard about this several months ago I contacted the CERN press office to suggest it but they'd already invited them. In terms of repercussions my only worry is that someone will mistake a photo-stitch artifact as the initial signs of black hole formation! However I would be curious to know how they cope with the lack of GPS under-ground when stitching the photos together.
Who said anything about privatizing? Just terminate TSA and any program it currently supports.
How about just getting your government to make the TSA behave like most other western country's airport security? I've yet to see Canadian and European airport security turn up in a railway station and start frisking passengers.
they're in for the money, control is the maker and breaker in that endeavor. No control, no money.
I'm not entirely convinced that more control does mean more money today: although I'd definitely agree that the record industry believes that it does! Relaxing your control probably means a reduction in sales due to increased copying. However maintaining control costs a huge amount of money (lawyers, PIs, legal bribing of politicians etc.) and it is not clear to me that this extra expense makes more money than it costs, particularly for artists who bypass the large record companies. The problem is that you'd need to significantly change the current business model and I don't think that there are any guarantees that a new model will work so it will take a company with courage to try it.
Slashdot Mirror
I'd be interested in a cite for systems spontaneously decreasing in entropy.
I can't find the paper at the moment but the network link from my current location is appalling bad so I've only been able to do a few simple searches. I believe the paper from from an Australian university. The claim was that, for certain, small QM systems, there could be a small decrease in entropy for a brief period of time but that, averaged over a longer time period, entropy was always increasing. I don't think this is a particularly surprising result. All it really says is that you can get spontaneous organization in a system during any given time period just so long as, over arbitrarily long periods, the entropy increases i.e. the amount of randomness is subject to random fluctuations as well.
Did you do any of that? I bet you did less to access your conclusions that Milton did!
Well, unless he copied his conclusions he probably did more since it looks as if Milton just copied the story from somewhere else. If you look at the Quote Investigator link you'll note that an incredibly similar story originated in Alberta in 1935. The Milton version is certainly far better put but it is not the original source.
If modern construction machinery is less efficient and effective than forced labour, then whoever designed such shoddy machinery should be the first in line to receive a shovel.
Never mind the construction time what I would like to know is how a 520 mph train manages to have a travel time only half that of a car which implies an average speed no more than 25% of its maximum. Either there are a ridiculous number of stops, the train's acceleration is incredibly low or someone got their numbers wrong.
No such thing as vaccine resistant.
Yes there is - vaccines can be weak strains of a bug which provoke an immune response without causing the disease. If the original bug diverges enough from the weak strain used in the vaccine it could, in theory, become "vaccine resistant". Of course I would imagine that it has to diverge more than it would for a simple anti-biotic because your body can adapt (an expert would have to confirm this) but I don't see why divergence away from a vaccine strain would not occur.
Bottom line, there's little hope of human civilization lasting more than 10^20th years.
Unless we find a way to escape the solar system 5*10^9 years is our rough life expectancy and if we develop a good enough understanding of science to do that then who knows? Heat death is just the result of probability and statistics and we've already seen systems which can spontaneously decrease in entropy for short periods of time.
If the article would report everything, it would be talking about momentum, and virtual particles too.
It would not report on virtual particles because the annihilation takes place in the galactic core where the densities of DM are highest and virtual particles can only exist for the tiniest fractions of an instant not the ~50k years needed to make it from the core.
The question you should be asking is where are all the anti-protons? Since DM particles generally need to have masses roughly ~100 or more times the mass of the proton their annihilations should be capable of producing all stable anti-particles below this. Hence most models predict an excess of anti-protons as well as positrons but no satellite has seen any evidence of this. So if this positron excess is due to DM (and that is a BIG if!) we may have to start looking at some of the more exotic DM models (e.g. Arkani-Hamed et al. Phys Rev D (2009) vol. 79 (1) pp. 015014) which some of us are already looking for with the LHC.
Hey americans, we invented fucking french fries. Don't tell us what we can put on them, yeah.
I'm not American but I'll take your word for it, I never knew they could be used in that way and I REALLY don't want to know what you put on them.
And where would the unobservable universe be?
So far away that light from it has not yet had a chance to reach us, and thanks to the accelerating expansion, never will. I vaguely remember seeing some discussion of this in relation to inflation - we end up in a region which is matter dominated and another region is antimatter dominated with the two regions being causally separated by inflation.
However I believe that these theories have problems because you'd expect to be able to see gamma rays from the edges of each region...unless we happen to be strangely right in the centre of a massive matter-dominated region and cannot see the edge. Plus, since CP violation does exist it we do know that there is a matter/anti-matter asymmetry so it seems strange that, given this, there would be a completely unrelated mechanism to cause an imbalance.
CP violation in Kaon decays can be explained by the Standard Model, but if the magnitude of CP violation they have claimed exists in the D system can not.
The calculations required to predict the amount of CP violation in meson systems are extremely hard to do. When I worked on the NA48 experiment, which measured direct CPV in the kaon system, the theorists were initially adamant that there was no way the parameter we measured (espilon-prime over epsilon) could be above 0.001 in the Standard Model. Several year later after both NA48 and KTeV had published results putting the parameter at well above that I saw a theory talk saying that these results were in perfect agreement with the Standard Model!
Now the discrepancy seems a lot larger here but, nevertheless, even if the result holds I'd give the theorists time to think about this and see whether they find problems in the calculations. I have a huge amount of respect for my theory colleagues but QCD calculations like this are fantastically hard so it is not at all uncommon for the results to change.
Of cours,e the movie might stink, but there's no reason to assume so.
Yes there is. The two Cushing films were British, not Hollywood and the only time the US made a Doctor Who film we got the 8th doctor. So going on past performance there is EVERY reason to think that a Hollywood production of Dr. Who will be terrible although I really hope I'm wrong.
15. Related to quantum mechanics, what is the term for the observation that some physical quantities can be changed only by discrete amounts, or quanta?
The answer IS quantum mechanics (or quantum physics) and not, as they suggest, "multiples of planck's constant".
In the UK, you do more work to get your A levels than you do at college to get a degree, at least in many subjects.
Sorry but that is simply wrong. The A'levels in the UK are a shadow of what they once were thanks to the knock on effect of replacing O' levels with GCSE's. The result has been that the number of years required to get a degree has been increased in many cases so that the first year can be spent teaching students what they used to learn at A' level.
So degrees are far, far above A'levels - unless by "college degree" you mean a further education college (which never used to be able to award degrees) as opposed to a proper university degree.
Another side of this might just be that there is a difference between liking a subject academically (in high school) and deciding you want to do it for the rest of your life.
These students will usually pass the course with a reasonable grade and then transfer to a different program because they find that they are not interested. Likewise we get students who find they actually like physics at university and transfer in. So you are certainly right that this is something which happens but the result is a program transfer not dropping the course because you cannot cope with it.
The one issue I see here is that college/university is a big waste of time for many. There are basically no apprenticeship style job programs in the US as compared to Germany for example.
Yes, that's a different issue though...and it is not only a waste of time for those who would be better off in apprenticeships but it also makes it hard to offer a more challenging program at University since you have to be able to teach those who really would be better off doing an apprenticeship. The UK had it about right when I was doing my degree: about 20-25% of students went to university from school. The rest either went to vocational training polytechnics or did on the job training.
The problem is now that in the UK and Canada (and I am guessing the US too) many of the technical colleges have been allowed to convert to universities and start trying to offer academic degrees. Apart from the increased expense they, frankly, are not capable of doing this. The result is that you have students spending more money and time but ending up with a low quality degree.
Oil industry (geophysics), financial sector (data analysis on stocks+companies), industrial R&D of a very wide range of types, IT sector (programming+analysis), consultancy work, teaching, or become a physics prof like me! There is a HUGE range of things you can do with a physics degree either using your physics or using the logical analysis and problem solving skills you need to do well in physics. Just because there are not a lot of us employed as physicists does not mean that it is hard to find a job - in fact physicists have one of the highest employment rates (at least of the statistics I've seen).
Maybe if colleges understood that, going in, many students aren't really understanding what they're getting into. Maybe that would help.
You have that the wrong way around. It would help FAR more is schools understood that they are preparing students for university. We already understand that it takes a while for a student to adjust to a university environment and that their choices may change once they take stock of the situation. This is why we start with "easy" introductory courses that let students get their bearings. The problem is that these are becoming more and more challenging due to falling academic standards at schools.
People drop out because the subjects are hard, sure. Making them fun won't make them less hard, so that won't address the problem.
No, students do not drop subject just because they are hard. They drop them because they are hard AND they have never been academically challenged ever before. I've seen this happen numerous times with smart first year students. They are completely used to coasting through school with one cylinder firing because there is no challenge at all for them. Then, when they get to university, they are suddenly faced with material that they cannot master with a quick read through and they literally do not know how to cope.
If we challenge even the brightest students at the school level then they will be used to having to think things through carefully and then, when they do finally understand it, they will get the sense of achievement which comes with that. Some of my colleagues who have a reputation for teaching very challenging, senior undergrad courses have some of the best student feedback because, by that point, the students like to be challenged and to succeed. Sadly though we lose a lot of students before we get there just because they are completely unprepared for university and don't know how to cope.
Depends which airports you go through, I guess.
I think it also depends on the country. As far as I know Canada only has the safe, terahertz scanners.
Do you get a choice of technology in your full body scanner? Do you know which is which?
Yes - you accept whichever they machine they have or chose the manual grope method. The terahertz scanners have a cubicle and a vertical sensor bar which moves across in front of you. The back-scatter X-ray are static and consist of two rectangular blocks which you stand between to get irradiated.
What surprised me, on the one occasion I saw the X-ray device, is that there was no protection for the security workers operating it. While the dosage has a low (but non-zero) risk for one passenger the cumulative dosage for someone nearby and operating the machine could be a lot larger. There is a reason the operators of X-ray machines for medical/dental use always go behind a shield before operating the machine.
Yea and flying spaghetti monster forbid you accidentally type something like chmod a+rx on your consolidated /usr/bin directory.
That is an argument for backups NOT an argument for split bin directories. It seems to me that the original argument for split directories was, as the original poster mentioned, so that /bin could fit on the boot partition so the system would work even if no other partition can mount. Given that modern disks are easily large enough to hold /bin and /usr/bin in the same partition I really don't see a good argument for their continued separation.
via the USB port.
The proof of the business model pudding will be when we've sold 100k and I still have a house.
Well my 6 year old son is really keen to get one. This is probably a bit younger than your target audience and I'm not sure how good he will be at programming but having a computer boot to a prompt like the old Beeb model B I learnt to program on is a really good start. All we need now are some magazines with games to type in - debugging the typos in those after entering them by hand was a great way to learn - although perhaps source code games we could download with one or two deliberate bugs in them would help cut to the educational bit!
And in any case, the "inside photos" are only being taken WITH THE EXPRESS PERMISSION AND ENCOURAGEMENT OF THE BUSINESS OWNERS
This is certainly the case at CERN where they have been photographing the LHC underground. In fact when I first heard about this several months ago I contacted the CERN press office to suggest it but they'd already invited them. In terms of repercussions my only worry is that someone will mistake a photo-stitch artifact as the initial signs of black hole formation! However I would be curious to know how they cope with the lack of GPS under-ground when stitching the photos together.
Who said anything about privatizing? Just terminate TSA and any program it currently supports.
How about just getting your government to make the TSA behave like most other western country's airport security? I've yet to see Canadian and European airport security turn up in a railway station and start frisking passengers.
they're in for the money, control is the maker and breaker in that endeavor. No control, no money.
I'm not entirely convinced that more control does mean more money today: although I'd definitely agree that the record industry believes that it does! Relaxing your control probably means a reduction in sales due to increased copying. However maintaining control costs a huge amount of money (lawyers, PIs, legal bribing of politicians etc.) and it is not clear to me that this extra expense makes more money than it costs, particularly for artists who bypass the large record companies. The problem is that you'd need to significantly change the current business model and I don't think that there are any guarantees that a new model will work so it will take a company with courage to try it.