At sea level and at 15 C air has a density of approximately 1.225 kg/m3 = 0.001225 g/cm3 https://en.wikipedia.org/wiki/....00198 g/cm3 would imply a CO2 concentration of 1600% dumbass. At 400ppm a proper value is more like 0.00000049 g/cm3 so 4000 time smaller than your claim.
That does not change anything for my claims though.
Look! I am feeding the troll with ammos. Can't wait for the next shitty argument he will pull out of his ass.
I just figured out that I forgot to take into account that CO2 is heavier than O2 and N2. The molar mass of air is about 29 g/mole while that of CO2 is 44 g/mole.
In practice, that means that my hypothetical sheet of solid CO2 would be 44/29 = 1.5 times heavier than previously computed and, at 400ppm, its thickness would be 5mm instead of 3.3mm.
I assume that those 20X are referring to the sentence in the early years of this century, concentrations of methane rose by only about 0.5ppb each year, compared with 10ppb in 2014 and 2015"
There was no noticeable increases during the period 2000-2010. There was some small fluctuations and the methane concentration was even decreasing for a few yers. Computing the ratio of two values only make sense if both values are large.
Here some of the values are even negative. Can we say that between 2001 and 2015, there was an acceleration of 9.98/-0.65 = -15.3X ? If one year, the increase was exactly 0 then all other years would show an infinitely acceleration. That does not make sense
The only important value is the long term trend. Looking at the graph, the increase was approximatively 210ppb during the last 30 years so an average of 7-8ppb per year.
Increases of 12.61 ppb and 9.98 ppb measured in 2014 and 2015 are above average but not by much. The increase was even higher during the late 80th.
Also, the preindustrial CO2 concentration was 280ppm so my 'hypothetical sheet of solid CO2' was 2.3mm about 150 years ago and we added 1.0mm since then.
More generally, the argument "it is only a small percentage of the whole atmosphere" is invalid. What is important is not the percentage of the various gases but their amount and their efficiency for trapping heat.
Also, people tend to underestimate the amounts of matter involved when talking about ppm or ppb. In https://en.wikipedia.org/wiki/... we find that "A column of air one square centimeter [cm2] (0.16 sq in) in cross-section... has a mass of about 1.03 kilograms (2.3 lb)"
So the solar radiation that hits each cm2 of the earth surface has to go through about 1kg of air = 1000g.
The CO2 concentration is 400ppm so the solar radiation passes through 1000g * 400/1000000 = 0.4g of CO2 per cm2
Polycarbonate sheets used in most garden greenhouses has a density of 1.2g/cm3.
If atmospheric CO2 was compressed to that same density to form a hypothetical sheet of solid CO2 then its thickness would be 0.4/1.2 = 0.33 cm = 3.3mm
This is very comparable to the thickness of typical a polycarbonate sheet (3 to 6mm) so saying that 400ppm of CO2 cannot have any noticeable effects seems as stupid as saying that greenhouses are ineffective.
More generally, "name calling" should be the expected behavior when asking almost any complex question to any large group of persons.
However, in that specific case, Richard Dawkins has the expected default position of any atheist (including me): The existence of an invisible unproven magic being cannot be the answer to any complex phenomena observed in the real world (in that case, that would be the origin of life). That position implies that there are things that we cannot explain with our current understanding of nature (you know, that thing called science).
Improving science by looking for more clues in the real world is the right way to handle those mysteries. Claiming "Magic", "God", "Taboo" or "Holy Book" is not.
Wikipedia gives 8% more lifting power for Hydrogen vs Helium so probably not worth the risk of using an explosive gas. https://en.wikipedia.org/wiki/...
Hummm... I was under the impression that the lifting power of H2 was only marginally better than He. What matters is not the ratio of the mass of H2 with He but their difference with respect to the mass of the surrounding air.
I do not have the right numbers but let's assume that the mass of 1m3 if gas is 1000g for air, 200g for He and 100g for H2.
The lifting power of 1m3 of air is 1000-1000 = 0 (by definition) The lifting power of 1m3 of He is 1000-200 = 800g The lifting power of 1m3 of H2 is 1000-100 = 900g The lifting power of 1m3 of pure vacuum is 1000-0 = 1000g (the maximum)
So we see in that example, that the lifting power of H2 is only 12.5% more that of He even though its weight is half.
What I find interesting is that the growth rate was at its maximum 2.1% in the 60's and it is now at 1.2%.
During the same time the world population went from 4 billions to 7 billions which means that the raw growth went from 4e9*0.021 = +84 millions/year to 7e9*0.012 = +84 millions/year. So the raw growth was basically constant during the last 50 years.
The current expectation is that the growth rate will continue to decrease and that the population will eventually reach a maximum around 9 billions but be aware that a decreasing growth rate is not a sufficient condition for that. For instance, 1/2+1/3+1/4+1/5+.... is well known example of an infinite sum with a decreasing growth rate. Similarly, 1/2+1/4+/1/8+1/16+... is not an infinite sum (it tends to 1) even though its growth rate remains strictly positive.
So in 1999, the terminology DRM (digital rights management) existed but was not mainstream. This is consistent with my own memory. At the time I first saw DRM (digital rights management), I already knew about the Linux DRM for a few years.
In the famous Hubble deep field image shown at https://en.wikipedia.org/wiki/... the smallest galaxies are approximatively at 10 billion = 1E10 light years. Assuming that they have a typical size of 100000=1e5 light years (as our own galaxy) that gives us the ratio 1e5/1e10 = 1e-5
The asteroid is 100m = 1e2 meters wide at a distance of 14 millions km = 14 billions meters= 14e9 meters which give a ratio of 1e2 / 14e9 = 7.14e-09
So on the Hubble deep field image, the asteroid would be about 1400 times smaller than the smallest galaxies.
The ISS is on the "low earth orbit" line in the detailed view of the Earth well (on the right).
Using the same analogy, image that you are at the bottom a 100m deep well. It is should be easy for you to walk in circles for 1000m (so horizontally). However, to exit the well you have to GO UP for 100m. That's is a lot more difficult.
So according to that definition, a specie that would reach immortality or that would find a way to prevent all mutations would not be alive anymore? I don't think so.
I won't even try to give better definition of 'alive' because I feel that this is pointless. This is a fuzzy concept so there will always be exceptions and some "things" will never be properly classified.
Also, the Red, Green and Blue components used to reproduce colors are finely tuned to match the absorption rates of the 3 types of cones found in the human eye.
Simply speaking, the colors in our movies and photographs are probably quite unrealistic for most non-human life forms.
The parent post was not about using unnecessary extensions but about having files or directories with an extension at the ROOT of the filesystem. None of/usr/etc/tmp.. match the pattern/*.* so rm -rf/*.* should be mostly harmless on most systems.
For instance, on my current box, the only thing that would be removed is the symlink/initrd.imh -> boot/initrd.img-... That would probably prevent me to boot but that is easy to repair.
Regarding the use of the.sh extension for shell script, I kind of disagree with you. Extensions are of course not strictly needed since the OS and most applications (not all) do not use them to figure out the filetype but extensions are still a convenient way to identify the nature of a file without having to open it (yeah! yeah! I know the 'file' command).
I confess! I have been using Linux/UNIX almost exclusively for the last 20 years and I still add.sh or.pl to some of my shell and perl scripts even though I know that neither the OS nor my editor will need the extension. That is not as if I had to type the extension each time I want to run the script. Completion is my friend.
I don't think so. Each pinhole can produce an image corresponding to a wide angle which only depends of the size of sensor of its distance from the pinhole. If the sensor is very close to the pinhole(s) then the image will have a wide angle (up to 180 degrees).
Slashdot Mirror
Ok! we agree that 400pp = 0.04% = 0.0004 ... and now 0.001225 * 0.04% is equal to ... I let you a few seconds to figure out .... 4.9e-07 = 0.00000049
At sea level and at 15 C air has a density of approximately 1.225 kg/m3 = 0.001225 g/cm3 .00198 g/cm3 would imply a CO2 concentration of 1600% dumbass. At 400ppm a proper value is more like 0.00000049 g/cm3 so 4000 time smaller than your claim.
https://en.wikipedia.org/wiki/...
That does not change anything for my claims though.
Look! I am feeding the troll with ammos. Can't wait for the next shitty argument he will pull out of his ass.
I just figured out that I forgot to take into account that CO2 is heavier than O2 and N2.
The molar mass of air is about 29 g/mole while that of CO2 is 44 g/mole.
In practice, that means that my hypothetical sheet of solid CO2 would be 44/29 = 1.5 times heavier than previously computed and, at 400ppm, its thickness would be 5mm instead of 3.3mm.
I assume that those 20X are referring to the sentence in the early years of this century, concentrations of methane rose by only about 0.5ppb each year, compared with 10ppb in 2014 and 2015"
As usual the article is misleading.
Look at the data in https://www.esrl.noaa.gov/gmd/....
There was no noticeable increases during the period 2000-2010. There was some small fluctuations and the methane concentration was even decreasing for a few yers. Computing the ratio of two values only make sense if both values are large.
Here some of the values are even negative. Can we say that between 2001 and 2015, there was an acceleration of 9.98/-0.65 = -15.3X ?
If one year, the increase was exactly 0 then all other years would show an infinitely acceleration.
That does not make sense
The only important value is the long term trend. Looking at the graph, the increase was approximatively 210ppb during the last 30 years so an average of 7-8ppb per year.
Increases of 12.61 ppb and 9.98 ppb measured in 2014 and 2015 are above average but not by much. The increase was even higher during the late 80th.
Also, the preindustrial CO2 concentration was 280ppm so my 'hypothetical sheet of solid CO2' was 2.3mm about 150 years ago and we added 1.0mm since then.
No. Neither Nitrogen (N2) nor Oxygen (O2) are greenhouse gases and they compose most of the atmosphere.
Ozone (O3) is a form of oxygen that is considered a greenhouse gas but its concentration is small.
The following pages summarize quite well the situation: http://cdiac.ornl.gov/pns/curr...
More generally, the argument "it is only a small percentage of the whole atmosphere" is invalid. What is important is not the percentage of the various gases but their amount and their efficiency for trapping heat.
Also, people tend to underestimate the amounts of matter involved when talking about ppm or ppb. In https://en.wikipedia.org/wiki/... we find that "A column of air one square centimeter [cm2] (0.16 sq in) in cross-section ... has a mass of about 1.03 kilograms (2.3 lb)"
So the solar radiation that hits each cm2 of the earth surface has to go through about 1kg of air = 1000g.
The CO2 concentration is 400ppm so the solar radiation passes through 1000g * 400/1000000 = 0.4g of CO2 per cm2
Polycarbonate sheets used in most garden greenhouses has a density of 1.2g/cm3.
If atmospheric CO2 was compressed to that same density to form a hypothetical sheet of solid CO2 then its thickness would be 0.4/1.2 = 0.33 cm = 3.3mm
This is very comparable to the thickness of typical a polycarbonate sheet (3 to 6mm) so saying that 400ppm of CO2 cannot have any noticeable effects seems as stupid as saying that greenhouses are ineffective.
More generally, "name calling" should be the expected behavior when asking almost any complex question to any large group of persons.
However, in that specific case, Richard Dawkins has the expected default position of any atheist (including me): The existence of an invisible unproven magic being cannot be the answer to any complex phenomena observed in the real world (in that case, that would be the origin of life). That position implies that there are things that we cannot explain with our current understanding of nature (you know, that thing called science).
Improving science by looking for more clues in the real world is the right way to handle those mysteries. Claiming "Magic", "God", "Taboo" or "Holy Book" is not.
Wikipedia gives 8% more lifting power for Hydrogen vs Helium so probably not worth the risk of using an explosive gas.
https://en.wikipedia.org/wiki/...
Hummm... I was under the impression that the lifting power of H2 was only marginally better than He.
What matters is not the ratio of the mass of H2 with He but their difference with respect to the mass of the surrounding air.
I do not have the right numbers but let's assume that the mass of 1m3 if gas is 1000g for air, 200g for He and 100g for H2.
The lifting power of 1m3 of air is 1000-1000 = 0 (by definition)
The lifting power of 1m3 of He is 1000-200 = 800g
The lifting power of 1m3 of H2 is 1000-100 = 900g
The lifting power of 1m3 of pure vacuum is 1000-0 = 1000g (the maximum)
So we see in that example, that the lifting power of H2 is only 12.5% more that of He even though its weight is half.
I hate that when someone tries to obfuscate the debate with facts.
The first chart on https://ourworldindata.org/wor... shows both the growth rate and the population.
What I find interesting is that the growth rate was at its maximum 2.1% in the 60's and it is now at 1.2%.
During the same time the world population went from 4 billions to 7 billions which means that the raw growth went from 4e9*0.021 = +84 millions/year to 7e9*0.012 = +84 millions/year. So the raw growth was basically constant during the last 50 years.
The current expectation is that the growth rate will continue to decrease and that the population will eventually reach a maximum around 9 billions but be aware that a decreasing growth rate is not a sufficient condition for that. For instance, 1/2+1/3+1/4+1/5+.... is well known example of an infinite sum with a decreasing growth rate. Similarly, 1/2+1/4+/1/8+1/16+... is not an infinite sum (it tends to 1) even though its growth rate remains strictly positive.
The acronym DRM (direct rendering management) first appeared in the Linux Kernel in 1999.
https://en.wikipedia.org/wiki/...
DRM (digital rights management) is more difficult to trace back because it is a generic term and not a specific technology.
Here are the number of references by Google Scholar for "Digital Rights Management" DRM
https://scholar.google.fr/scho...
1999 = 17 ...
2000 = 43
2001 = 205
2002 = 378
2003 = 740
2010 = 1610
So in 1999, the terminology DRM (digital rights management) existed but was not mainstream. This is consistent with my own memory. At the time I first saw DRM (digital rights management), I already knew about the Linux DRM for a few years.
In the famous Hubble deep field image shown at https://en.wikipedia.org/wiki/... the smallest galaxies are approximatively at 10 billion = 1E10 light years. Assuming that they have a typical size of 100000=1e5 light years (as our own galaxy) that gives us the ratio 1e5/1e10 = 1e-5
The asteroid is 100m = 1e2 meters wide at a distance of 14 millions km = 14 billions meters= 14e9 meters which give a ratio of 1e2 / 14e9 = 7.14e-09
So on the Hubble deep field image, the asteroid would be about 1400 times smaller than the smallest galaxies.
This XKCD picture explains it all in a very intuitive way: https://xkcd.com/681/
The ISS is on the "low earth orbit" line in the detailed view of the Earth well (on the right).
Using the same analogy, image that you are at the bottom a 100m deep well. It is should be easy for you to walk in circles for 1000m (so horizontally). However, to exit the well you have to GO UP for 100m. That's is a lot more difficult.
or more likely, the other half don't know what Addicted means.
So according to that definition, a specie that would reach immortality or that would find a way to prevent all mutations would not be alive anymore? I don't think so.
I won't even try to give better definition of 'alive' because I feel that this is pointless. This is a fuzzy concept so there will always be exceptions and some "things" will never be properly classified.
I hate how the article talks about how he has access to an xbox or whatever
A xbox? That is not a humane treatment! He was right to sue!
Not all patents are available.
https://en.wikipedia.org/wiki/...
Also, the Red, Green and Blue components used to reproduce colors are finely tuned to match the absorption rates of the 3 types of cones found in the human eye.
Simply speaking, the colors in our movies and photographs are probably quite unrealistic for most non-human life forms.
If you are not sure then remove it :-)
The parent post was not about using unnecessary extensions but about having files or directories with an extension at the ROOT of the filesystem. /usr /etc /tmp .. match the pattern /*.* so rm -rf /*.* should be mostly harmless on most systems.
None of
For instance, on my current box, the only thing that would be removed is the symlink /initrd.imh -> boot/initrd.img-...
That would probably prevent me to boot but that is easy to repair.
Regarding the use of the .sh extension for shell script, I kind of disagree with you.
Extensions are of course not strictly needed since the OS and most applications (not all) do not use them to figure out the filetype but extensions are still a convenient way to identify the nature of a file without having to open it (yeah! yeah! I know the 'file' command).
I confess! I have been using Linux/UNIX almost exclusively for the last 20 years and I still add .sh or .pl to some of my shell and perl scripts even though I know that neither the OS nor my editor will need the extension. That is not as if I had to type the extension each time I want to run the script. Completion is my friend.
I am pleased to see that there are indeed 10 kinds of people :-)
Really? I still see them in base 10
Does that mean that if we kill all mouses then we will have a better memory?
I don't think so. Each pinhole can produce an image corresponding to a wide angle which only depends of the size of sensor of its distance from the pinhole. If the sensor is very close to the pinhole(s) then the image will have a wide angle (up to 180 degrees).