As an engineer, I can very well understand that many of these people are living Mars Sols voluntarily; If I were one such a rover team, I would.
But exactly how voluntary is this? Or even legal? In the Netherlands,
labour law (in Dutch, I'm afraid, articles 4.7:1 and 5.8) states that one cannot be forced to perform more than 28 night-shifts in 13 consequetive weeks under normal circumstances. Under special circumstances, I which work cannot reasonably be performed during normal working hours (which would be the case for the NASA workers here), the limit is 35 nights.
(If you work for a Dutch employer who wishes to force you to do this anyway, you get support from the unions, and the employer cannot even fire you without getting a "firing permission" from a judge, and he's not likely to get it for that reason).
Do US employers have any rights whatsoever? Note, I'm not trolling here: I've heard some stories from friends, who went to work in the US, that were particularly hairraising to say the very least...
Good comment. There's one thing I'd like to correct though:
Diameter of our Galaxy = 90,000 light years or 5,865,696,000,000 (almost 6 trillion) miles across
It's a bit more than that: 90,000 light years is 5.29e+17 miles, or if you allow me to put it in a scientifically incorrect way, 529,064,983,000,000,000 miles. (Or better: 8.51e+20 m).
First off, thanks for that comment! As a engineering scientist (ok, I'll admit it, a European one;), I'm thrilled to see that we've gotten a step further in exploring Mars. The flag on the probe doesn't matter the slightest. So yes, from a common interest viewpoint, we're all in this together.
However, are we also in this together in terms of the exchange of data? That is to say: can European research institutions (and, for that matter, research institutions around the globe) get access to the data obtained by the MER? One does need data if one wishes to perform research after all... Given that that are lander->orbiter->Earth relay agreements between Europe and the US, are there also such agreements for the data that is obtained? And, the other way around, in the unlikely case that Beagle 2 starts to whine at Januari 7th, is there any agreement such that US folks can use that data?
Can anyone reassure me here?;)
On a side note: I do realize that a good deal of money has been spent on these missions, and that from an economical viewpoint, it seems only fair that the people in the country of which the tax-payers paid the mission could use the data. Personally, I strongly disagree with that, for two reasons.
First, science is a collaborative effort. IAAS (I Am A Scientist), and I know that sharing some data and ideas with other groups (even if those groups are competitors in your field), usually benifits both. In that way, I would be bad to allow only US researchers to get access to the data.
Second, exactly how much money was spent here? Let's take the two rovers together, and take a pessimistic view and assume that the total cost will be around 1 G$. Now compare this to, say, the production costs of the LOTR trilogy, which is about 400 M$. Then these missions cost only twice that, or about $4,- per citizen. (Or, since we are all in this together, about 15 cents per world citizen). Sure, the economical benefits of making a movie occur on a short timescale (a few months, or years at most), but the benefits of of Mars research will benefit us on the long run (hundreds of years)!
It is nice to see that sometimes SF authors, maybe by accident, invent some pretty accurate ideas...
Case in point here is the book
A Fire upon the Deep[1] by Vernor Vinge. The book describes our Milkyway galaxy at least 30,000 years in the future. The galaxy is divided into a number of concentric zones (the zones of thought): the Unthinking Depths, in which no intelligent life is possible, the Slow Zone, in which only moderately intelligent life such as ourselves is possible, and after that the Beyond and Transcent.
The first two zones seem to pretty accurately be fitted by the results in the article. I do not know where Vinge originally got his ideas, but it's a nice match anyway.
In Vinge's outer two zones, the Beyond and the Transcent, additional nice tricks such as faster-than-light travel are possible. Personally, I can highly recomment this book: it is well written hard technological SF.
Erm... Are you talking tons or KILOtons here? Are you sure that that explosion was 2.5 kton (about 1e13 Joules, and about 1/6th of the Little Boy bomb at Hiroshima), and not 2.5 ton (about 1e10 Joules, and about 1/6000th of the Hiroshima bomb)?
I was under the impression that the
100 ton test in 1945 (to measure spread of radioactive material in a blast) was the largest man-made explosion to that date. This was 100 ton (say, 4e11 Joules).
At may 13th 2000, a fireworks storage facility (located in the middle of a residential area, of all places) in the city of Enschede in the east of the Netherlands went skyhigh. Some general info is here.
Whereas the London event would have been equivalent to 2.5 tons of TNT, the Enschede explosion was estimated as being equivalent to anywhere between 5 tons and 15 tons of TNT
(between 2e10 and 6e10 Joules, and at maximum about 1/1000th of Hiroshima in terms of energy). In the event, about 100000 kg of fireworks detonated, set off by a detonation in one of the central containers. The energy in the explosion was estimated by analyzing images of the shockfront wave set off by the explosion.
The result was similar to what has been predicted for London: in Enschede, about 1200 houses were
obliterated and 22 were killed.
Fortunately, the event led to changes in legislation and much stricter requirements for such dangerous storage facilities near residential areas.
On a personal note: I was about 6 km from Ground Zero when the event happened, and the sound from the explosion was very, very impressive even at that distance!
I could have imagined that it would have been much more than 1 atom per cubic meter, since I thought that that would be the density of interstellar "vacuum", and the dust-clouds of course are much denser than that.
Now, I'm a bit puzzled here: I always thought that there interstellar "vacuum" had about 5 atoms per cubic meter, while your figures would imply about 10e+6 per cubic meter. Where does the difference come from? It 5 atoms/m^3 the density in intergalactic space and 1e+6 atoms/m^3 that for interstellar space in a galaxy?
Then there is another thing: I've read about molecular clouds, and that they contain about 10^21 protons per square meter. I think we can definately say that the dust band in M104 is not a molecular cloud: a density of 10^21/m^3 would imply that (in order of magnitude) ~10e+80 atoms would be in the dust band, and that would be about a billionth of the total mass in the visible universe, in one dust band in a galaxy alone. So no molecular cloud there (or at least one that's much less dense than a "typical" molecular cloud.
Your rough estimate (~1e+9 atoms/m^3) comes down to a total dust-mass, in only the visible brown band that we see, of about 4e+43 kg.
This still seems high to me: the mass of the sun is
2e+31 kg, so the dust-band would weight the same as about 2e+12 suns. But there are only 8e+10 stars in that galaxy!
Indeed, it's dust. In order to get just a rough idea of how much dust that is, picture the following:
The Messier 104 (Sombrero) galaxy contains anywhere between
210,000,000,000 and 800,000,000,000 stars (although the latter figure seems more likely to me, mostly because the estimate is newer). That is a whole lot of mass!
Look at the image: given that the galaxy is about 50,000 lightyear across, the dust-band must be about 1,000 lightyears across. Just, for the sake of argument, assume that the dust is located in a ring with a diameter of 50,000 lightyears, 1,000 lightyears high and 1,000 lightyears thick. Then this ring has a volume of 1,000*pi*(51,000^2-50,000^2) is about 3e+11 cubic lightyears, which is 2.5e+59 cubic meters.
Is there any astronomer out there who can shed some light on the density of these clouds? Think about it: even if you assume only 1 (hydrogen) atom per square meter, there are 2.5e+59 hydrogen atoms there, which weight 4e+34 kg, and that's a very, very low estimate!
To put that into perspective: the earth weights about 6e+24 kg.
Using mars-orbiting spacecraft (plural) for communication with earth is not a new thing: it's very efficient since the distance to the orbiter is small and the orbiter has big solar cells and can thus send a powerful signal back to earth.
NASA has extensive plans to develop this scheme much further, the eventual goal being the Mars Network that, through a number of orbiters, will/should enable a "downlink" speed Mars->Earth of about
3 Tbit/Sol in 2015 (which is slightly less than 100 Mbps).
This network is then of course shared by all Mars surface and orbital missions.
At first, it seems that the solution portrayed in the article would make the deployment of GSM networks easier and cheaper. This would not only be a solution for developing countries, but also for rural areas in western countries. An illustration of this last point is readily made by comparing the GSM coverage of a densely populated country like
The Netherlands (former state provider KPN) to that of a much more sparsely populated country like the US (AT&T wireless).
However, GSM is not the only cell-phone standard there is. Another standard which is often used in rural areas is CDMA. It seems this standard features larger cells, and fewer base stations (for, of course, a less densely populated cell). Indeed, Verizon has plans to convert parts of its network to CDMA: see here.
Does anybody have altual experience with deploying CDMA networks? (obviously, given the coverage map for GSM, I don't need that experience in Holland;)
... in which complete computer memories worked like this: those were called mercury delay line memories, in which pressure waves in mercury lines basically held information.
The UNIVAC I had such an
18-channel memory. More information can be found here, here, and here.
The idea behind rewarding a price for the commercial exploitation of space is not important, it's crucial. The purists among us might claim that space should be for all humanity, and that it should be used in an idealistic way, and that promoting commercialization of space leads to destructive capitalism out there.
However, please do wake up: as damaging as some of the forces of the free market might be, there is one thing in the free market that even governments have to a much smaller degree. That thing is money. As much as some of us (myself included) might dislike the greedy nature of mankind, fact is that if money is to be made, things will happen, and the end-result might be very good.
For example, look at the first satellites. Sure, the very first ones were launched for purely political reasons, but then the commercial communication-sats were lanched. Expericience with these kinds of satellites (launching risks, maintenance, reliability) has helped us to safely launch other kinds of satellites as well. E.g. at the moment there are a number of satellites watching over our ecosystem: the GOES, POES and others.
I firmly believe that if the exploration of space (and that's not limited to just LEO, but can also be extended to Mars or other places) must be a common venture of commercial and "idealistic" initiatives. And therefore I applaud the Heinlein Estate's prize.
However, I do have my doubt as to who might be able to win such a price: the regulations specifically exclude corporate or government-sponsored initiatives. This seems to mean that only individuals with a big bag of money can ever hope to win the prize. I've checked the main estate site, but haven't been able to find any nominations or ideas on what kind of initiatives might be nominated yet.
Allright, IAAP (I Am A Psysicist), and I think it's good two debunk a common misconception here:
Gravity waves are not the same as gravitational waves
Gravity waves are matter density waves in fluidi (fluids or gases) caused by the interaction of two forces: bouyancy and gravity. Here, bouyancy is the upward-driving force, and gravity is the downward-driving force. The essence is that these waves require a medium to propagate (e.g. air).
Gravity waves can be found in the atmosphere, e.g. clouds which form in regular bands of cloud and clear sky, where the gravity waves carry momentum and energy from the troposphere to the middle and upper atmosphere
Gravity waves can also be found on the surface of fuilds: think of the waves behind a boat. A good primer on gravity waves can be found here
Gravitational waves are a whole different ballgame! These waves have got nothing to do with matter densities as they don't require a medium to progagate: it is not matter that moves, and in that respect gravitational waves are like light (which, contrary to beliefs held at the beginnning of the century, don't require a medium such as "ether"). Gravitational waves are wacves in the spacetime-metric.
So what the hell does that mean? Well, in gravity waves, there is a wave in space (and time) in which the thing that changes over space and time is the density of matter. In gravitational waves, there also is a wave in space and time, but the thing that "wiggles" is not the density of matter (or the strength of electric and magnetic fields, like in light or EM radiation in general), but the properties of the fabric of space and time itself. You can think of it as if the coordinate system itself wiggles, so to speak. This "wiggling" results in the length of the arms of e.g. the LIGO interferometer to change ever so slightly, causing a phase shift between light beams send through both arms, which can (hopefully) be detected.
In more mathematical terms, the exact properties of space and time are called the metric. In a portion of space without any matter, the metric is flat (called the Minkovski metric), which means that the usual laws of geometry apply. In any circumstances with matter (and thus gravity) present, these laws to do hold up!
What?!, I hear you think. Yes sir, you've been lied to in geometry class! However, you've been lied to only very, very slightly. Example: if you measure the radius of a sphere (say: R), you expect to find a surface area of exactly 4/3 * pi * R^3. If the earth would be a perfect sphere (which it isn't), and you would be able to measure its radius and surface very accurately, you would find that the surface area is ever so slightly smaller than expected. Or, in other words, the radius seems to be a bit too large (in the order of 3 cm or 30 cm IIRC). Read more about space time curvature here/
A primer on gravitational waves can be found here. A more detailed description here.
It's not just illegal in Italy, it's illegal in the European Union as a whole: on May 20, 2002, the European parliament voted for a common
point-of-view on spam and other forms of electronic privacy intrusion.
Then, on August 1 2003, the EU Directive 2002/58/EC came into effect, effectively granting member states until October 1 2003 to adjust their national laws to fit the EU directive.
The Dutch "Wet Bescherming Persoonsgegevens" (law for the protection of person-related data) now has an article 13 that reads:
Artikel 13
Ongewenste communicatie
1. Het gebruik van automatische oproepsystemen zonder menselijke tussenkomst (automatische oproepapparaten), fax of e-mail met het oog op direct marketing kan alleen worden toegestaan met betrekking tot abonnees die daarin vooraf hebben toegestemd.
Roughly translated:
Article 13
Unwanted communication
The use of automatic paging devices without human intervention (automatic paging devices), fax or e-mail, aimed at direct marketing, can only be allowed with respect to subscribers that have given prior permission.
There you go: opt-in. A "do-not-call" list, that recently raised questions in the US, has been in effect for years now in the Netherlands. As far as e-mail is concerned, Dutch internet providers actually defend their customers and sue Dutch spam-perpetrators. If anybody has related stories from other EU member states, please do list them here.
Now, to put my previous remarks in perspective, it might seem that I'm being overly EU-zealous here. However, it is by no means my intention to adopt an attitude like that.
But think about it: this legislation works: the only Dutch bulk email that I recieve comes from a site at which I have a free e-mail account; when obtaining that account, I actually did opt-in. And it's only about one message per week. So, without the intention of adopting an EU-superiority attitude, I'm just asking a plain and sincere question:
What, if any, is the big problem with disallowing companies in the US to send unsollicited bulk e-mail to customers?
Can anyone give a decent overview of interests at stake here, and (if any) US regulations on the subject?
First off, this election will generate a"vote-databases" larger than about any other election on this planet. Given that about a billion people live in India, there will be hundreds of millions of votes. Although electronic voting is nothing new (in the Netherlands the elections are almost 100% electronic for years now), the sheer scale of this electronic election makes it interesting.
But exactly how many people eligible for voting are there? Obviously, a significant number of the about 1 billion inhabitants will be under the legal voting age.
And then, how about the caste system? Please note that I'm not trying to be a troll here: I know the caste system doesn't officially exist anymore, but I've been in India for work for a month, and I found it pretty clear that people from different castes are treated differently. Are people from the lowests castes (or the caste-less) discouraged from voting in any way? And does the mandatory presentation of an ID-card prevent many of these people from voting?
Is there anyone who can provide a decent, and honest, background on this? It is an interesting sociological issue.
Although the solution proposed in the article would increase storage capacity by, say, a factor 2 or 4, it still is a temporary solution that does not solve the fundamental problem at hand.
The fundamental problem is the superparamagnetic limit: if you make a magnetic domain (a bit) smaller than a certain size, it becomes thermodynamically unstable. In English, this means that very small bits loose their value after a while. It also means that for the time being, we'll have to use tricks to pack the bits closer together while keeping them large enough to be stable.
It should be noted that perpendicular recording is not the only effort to achieve higher recording densities in the looming shadow of the superparamagnetic limit. Indeed, harddrive manufacturers have seen this problem coming for a number of years now, and have had meeting to discuss possible solutions.
On a brighter note, there seems to be progress in circumventing the superparamagnetic limit: very recent research show promising results for the future.
Slashdot Mirror
As an engineer, I can very well understand that many of these people are living Mars Sols voluntarily; If I were one such a rover team, I would.
But exactly how voluntary is this? Or even legal? In the Netherlands, labour law (in Dutch, I'm afraid, articles 4.7:1 and 5.8) states that one cannot be forced to perform more than 28 night-shifts in 13 consequetive weeks under normal circumstances. Under special circumstances, I which work cannot reasonably be performed during normal working hours (which would be the case for the NASA workers here), the limit is 35 nights.
(If you work for a Dutch employer who wishes to force you to do this anyway, you get support from the unions, and the employer cannot even fire you without getting a "firing permission" from a judge, and he's not likely to get it for that reason).
Do US employers have any rights whatsoever? Note, I'm not trolling here: I've heard some stories from friends, who went to work in the US, that were particularly hairraising to say the very least...
Good comment. There's one thing I'd like to correct though:
Diameter of our Galaxy = 90,000 light years or 5,865,696,000,000 (almost 6 trillion) miles across
It's a bit more than that: 90,000 light years is 5.29e+17 miles, or if you allow me to put it in a scientifically incorrect way, 529,064,983,000,000,000 miles. (Or better: 8.51e+20 m).
See here
First off, thanks for that comment! As a engineering scientist (ok, I'll admit it, a European one ;), I'm thrilled to see that we've gotten a step further in exploring Mars. The flag on the probe doesn't matter the slightest. So yes, from a common interest viewpoint, we're all in this together.
However, are we also in this together in terms of the exchange of data? That is to say: can European research institutions (and, for that matter, research institutions around the globe) get access to the data obtained by the MER? One does need data if one wishes to perform research after all... Given that that are lander->orbiter->Earth relay agreements between Europe and the US, are there also such agreements for the data that is obtained? And, the other way around, in the unlikely case that Beagle 2 starts to whine at Januari 7th, is there any agreement such that US folks can use that data?
Can anyone reassure me here? ;)
On a side note: I do realize that a good deal of money has been spent on these missions, and that from an economical viewpoint, it seems only fair that the people in the country of which the tax-payers paid the mission could use the data. Personally, I strongly disagree with that, for two reasons.
First, science is a collaborative effort. IAAS (I Am A Scientist), and I know that sharing some data and ideas with other groups (even if those groups are competitors in your field), usually benifits both. In that way, I would be bad to allow only US researchers to get access to the data.
Second, exactly how much money was spent here? Let's take the two rovers together, and take a pessimistic view and assume that the total cost will be around 1 G$. Now compare this to, say, the production costs of the LOTR trilogy, which is about 400 M$. Then these missions cost only twice that, or about $4,- per citizen. (Or, since we are all in this together, about 15 cents per world citizen). Sure, the economical benefits of making a movie occur on a short timescale (a few months, or years at most), but the benefits of of Mars research will benefit us on the long run (hundreds of years)!
It is nice to see that sometimes SF authors, maybe by accident, invent some pretty accurate ideas...
Case in point here is the book A Fire upon the Deep[1] by Vernor Vinge. The book describes our Milkyway galaxy at least 30,000 years in the future. The galaxy is divided into a number of concentric zones (the zones of thought): the Unthinking Depths, in which no intelligent life is possible, the Slow Zone, in which only moderately intelligent life such as ourselves is possible, and after that the Beyond and Transcent.
The first two zones seem to pretty accurately be fitted by the results in the article. I do not know where Vinge originally got his ideas, but it's a nice match anyway.
In Vinge's outer two zones, the Beyond and the Transcent, additional nice tricks such as faster-than-light travel are possible. Personally, I can highly recomment this book: it is well written hard technological SF.
[1] A Fire upon the Deep.
Erm... Are you talking tons or KILOtons here? Are you sure that that explosion was 2.5 kton (about 1e13 Joules, and about 1/6th of the Little Boy bomb at Hiroshima), and not 2.5 ton (about 1e10 Joules, and about 1/6000th of the Hiroshima bomb)?
I was under the impression that the 100 ton test in 1945 (to measure spread of radioactive material in a blast) was the largest man-made explosion to that date. This was 100 ton (say, 4e11 Joules).
2.5 kton in Halifax seems an awful lot to me!
At may 13th 2000, a fireworks storage facility (located in the middle of a residential area, of all places) in the city of Enschede in the east of the Netherlands went skyhigh. Some general info is here.
Whereas the London event would have been equivalent to 2.5 tons of TNT, the Enschede explosion was estimated as being equivalent to anywhere between 5 tons and 15 tons of TNT (between 2e10 and 6e10 Joules, and at maximum about 1/1000th of Hiroshima in terms of energy). In the event, about 100000 kg of fireworks detonated, set off by a detonation in one of the central containers. The energy in the explosion was estimated by analyzing images of the shockfront wave set off by the explosion.
The result was similar to what has been predicted for London: in Enschede, about 1200 houses were obliterated and 22 were killed.
Fortunately, the event led to changes in legislation and much stricter requirements for such dangerous storage facilities near residential areas.
On a personal note: I was about 6 km from Ground Zero when the event happened, and the sound from the explosion was very, very impressive even at that distance!
I could have imagined that it would have been much more than 1 atom per cubic meter, since I thought that that would be the density of interstellar "vacuum", and the dust-clouds of course are much denser than that.
Now, I'm a bit puzzled here: I always thought that there interstellar "vacuum" had about 5 atoms per cubic meter, while your figures would imply about 10e+6 per cubic meter. Where does the difference come from? It 5 atoms/m^3 the density in intergalactic space and 1e+6 atoms/m^3 that for interstellar space in a galaxy?
Then there is another thing: I've read about molecular clouds, and that they contain about 10^21 protons per square meter. I think we can definately say that the dust band in M104 is not a molecular cloud: a density of 10^21/m^3 would imply that (in order of magnitude) ~10e+80 atoms would be in the dust band, and that would be about a billionth of the total mass in the visible universe, in one dust band in a galaxy alone. So no molecular cloud there (or at least one that's much less dense than a "typical" molecular cloud.
Your rough estimate (~1e+9 atoms/m^3) comes down to a total dust-mass, in only the visible brown band that we see, of about 4e+43 kg. This still seems high to me: the mass of the sun is 2e+31 kg, so the dust-band would weight the same as about 2e+12 suns. But there are only 8e+10 stars in that galaxy!
Shouldn't that density be much less then?
Indeed, it's dust. In order to get just a rough idea of how much dust that is, picture the following:
The Messier 104 (Sombrero) galaxy contains anywhere between 210,000,000,000 and 800,000,000,000 stars (although the latter figure seems more likely to me, mostly because the estimate is newer). That is a whole lot of mass!
Look at the image: given that the galaxy is about 50,000 lightyear across, the dust-band must be about 1,000 lightyears across. Just, for the sake of argument, assume that the dust is located in a ring with a diameter of 50,000 lightyears, 1,000 lightyears high and 1,000 lightyears thick. Then this ring has a volume of 1,000*pi*(51,000^2-50,000^2) is about 3e+11 cubic lightyears, which is 2.5e+59 cubic meters.
Is there any astronomer out there who can shed some light on the density of these clouds? Think about it: even if you assume only 1 (hydrogen) atom per square meter, there are 2.5e+59 hydrogen atoms there, which weight 4e+34 kg, and that's a very, very low estimate!
To put that into perspective: the earth weights about 6e+24 kg.
Using mars-orbiting spacecraft (plural) for communication with earth is not a new thing: it's very efficient since the distance to the orbiter is small and the orbiter has big solar cells and can thus send a powerful signal back to earth.
NASA has extensive plans to develop this scheme much further, the eventual goal being the Mars Network that, through a number of orbiters, will/should enable a "downlink" speed Mars->Earth of about 3 Tbit/Sol in 2015 (which is slightly less than 100 Mbps).
This network is then of course shared by all Mars surface and orbital missions.
(And yes, I've commented on this before)
At first, it seems that the solution portrayed in the article would make the deployment of GSM networks easier and cheaper. This would not only be a solution for developing countries, but also for rural areas in western countries. An illustration of this last point is readily made by comparing the GSM coverage of a densely populated country like The Netherlands (former state provider KPN) to that of a much more sparsely populated country like the US (AT&T wireless).
However, GSM is not the only cell-phone standard there is. Another standard which is often used in rural areas is CDMA. It seems this standard features larger cells, and fewer base stations (for, of course, a less densely populated cell). Indeed, Verizon has plans to convert parts of its network to CDMA: see here.
Does anybody have altual experience with deploying CDMA networks? (obviously, given the coverage map for GSM, I don't need that experience in Holland ;)
... in which complete computer memories worked like this: those were called mercury delay line memories, in which pressure waves in mercury lines basically held information.
The UNIVAC I had such an 18-channel memory. More information can be found here, here, and here.
These channels could hold a whopping kilobit!
The idea behind rewarding a price for the commercial exploitation of space is not important, it's crucial. The purists among us might claim that space should be for all humanity, and that it should be used in an idealistic way, and that promoting commercialization of space leads to destructive capitalism out there.
However, please do wake up: as damaging as some of the forces of the free market might be, there is one thing in the free market that even governments have to a much smaller degree. That thing is money. As much as some of us (myself included) might dislike the greedy nature of mankind, fact is that if money is to be made, things will happen, and the end-result might be very good.
For example, look at the first satellites. Sure, the very first ones were launched for purely political reasons, but then the commercial communication-sats were lanched. Expericience with these kinds of satellites (launching risks, maintenance, reliability) has helped us to safely launch other kinds of satellites as well. E.g. at the moment there are a number of satellites watching over our ecosystem: the GOES, POES and others.
I firmly believe that if the exploration of space (and that's not limited to just LEO, but can also be extended to Mars or other places) must be a common venture of commercial and "idealistic" initiatives. And therefore I applaud the Heinlein Estate's prize.
However, I do have my doubt as to who might be able to win such a price: the regulations specifically exclude corporate or government-sponsored initiatives. This seems to mean that only individuals with a big bag of money can ever hope to win the prize. I've checked the main estate site, but haven't been able to find any nominations or ideas on what kind of initiatives might be nominated yet.
Any ideas?
Ah crap, you're right of course... ;)
Allright, IAAP (I Am A Psysicist), and I think it's good two debunk a common misconception here:
Gravity waves are not the same as gravitational waves
Gravity waves are matter density waves in fluidi (fluids or gases) caused by the interaction of two forces: bouyancy and gravity. Here, bouyancy is the upward-driving force, and gravity is the downward-driving force. The essence is that these waves require a medium to propagate (e.g. air).
Gravity waves can be found in the atmosphere, e.g. clouds which form in regular bands of cloud and clear sky, where the gravity waves carry momentum and energy from the troposphere to the middle and upper atmosphere Gravity waves can also be found on the surface of fuilds: think of the waves behind a boat. A good primer on gravity waves can be found here
Gravitational waves are a whole different ballgame! These waves have got nothing to do with matter densities as they don't require a medium to progagate: it is not matter that moves, and in that respect gravitational waves are like light (which, contrary to beliefs held at the beginnning of the century, don't require a medium such as "ether"). Gravitational waves are wacves in the spacetime-metric.
So what the hell does that mean? Well, in gravity waves, there is a wave in space (and time) in which the thing that changes over space and time is the density of matter. In gravitational waves, there also is a wave in space and time, but the thing that "wiggles" is not the density of matter (or the strength of electric and magnetic fields, like in light or EM radiation in general), but the properties of the fabric of space and time itself. You can think of it as if the coordinate system itself wiggles, so to speak. This "wiggling" results in the length of the arms of e.g. the LIGO interferometer to change ever so slightly, causing a phase shift between light beams send through both arms, which can (hopefully) be detected.
In more mathematical terms, the exact properties of space and time are called the metric. In a portion of space without any matter, the metric is flat (called the Minkovski metric), which means that the usual laws of geometry apply. In any circumstances with matter (and thus gravity) present, these laws to do hold up!
What?!, I hear you think. Yes sir, you've been lied to in geometry class! However, you've been lied to only very, very slightly. Example: if you measure the radius of a sphere (say: R), you expect to find a surface area of exactly 4/3 * pi * R^3. If the earth would be a perfect sphere (which it isn't), and you would be able to measure its radius and surface very accurately, you would find that the surface area is ever so slightly smaller than expected. Or, in other words, the radius seems to be a bit too large (in the order of 3 cm or 30 cm IIRC). Read more about space time curvature here/
A primer on gravitational waves can be found here. A more detailed description here.
Or, for that matter:
http://slashdor.org.
It's not just illegal in Italy, it's illegal in the European Union as a whole: on May 20, 2002, the European parliament voted for a common point-of-view on spam and other forms of electronic privacy intrusion.
Then, on August 1 2003, the EU Directive 2002/58/EC came into effect, effectively granting member states until October 1 2003 to adjust their national laws to fit the EU directive.
The Dutch "Wet Bescherming Persoonsgegevens" (law for the protection of person-related data) now has an article 13 that reads:
Artikel 13
Ongewenste communicatie
1. Het gebruik van automatische oproepsystemen zonder menselijke tussenkomst (automatische oproepapparaten), fax of e-mail met het oog op direct marketing kan alleen worden toegestaan met betrekking tot abonnees die daarin vooraf hebben toegestemd.
Roughly translated:
Article 13
Unwanted communication
The use of automatic paging devices without human intervention (automatic paging devices), fax or e-mail, aimed at direct marketing, can only be allowed with respect to subscribers that have given prior permission.
There you go: opt-in. A "do-not-call" list, that recently raised questions in the US, has been in effect for years now in the Netherlands. As far as e-mail is concerned, Dutch internet providers actually defend their customers and sue Dutch spam-perpetrators. If anybody has related stories from other EU member states, please do list them here.
Now, to put my previous remarks in perspective, it might seem that I'm being overly EU-zealous here. However, it is by no means my intention to adopt an attitude like that. But think about it: this legislation works: the only Dutch bulk email that I recieve comes from a site at which I have a free e-mail account; when obtaining that account, I actually did opt-in. And it's only about one message per week. So, without the intention of adopting an EU-superiority attitude, I'm just asking a plain and sincere question:
What, if any, is the big problem with disallowing companies in the US to send unsollicited bulk e-mail to customers?
Can anyone give a decent overview of interests at stake here, and (if any) US regulations on the subject?
First off, this election will generate a"vote-databases" larger than about any other election on this planet. Given that about a billion people live in India, there will be hundreds of millions of votes. Although electronic voting is nothing new (in the Netherlands the elections are almost 100% electronic for years now), the sheer scale of this electronic election makes it interesting.
But exactly how many people eligible for voting are there? Obviously, a significant number of the about 1 billion inhabitants will be under the legal voting age.
And then, how about the caste system? Please note that I'm not trying to be a troll here: I know the caste system doesn't officially exist anymore, but I've been in India for work for a month, and I found it pretty clear that people from different castes are treated differently. Are people from the lowests castes (or the caste-less) discouraged from voting in any way? And does the mandatory presentation of an ID-card prevent many of these people from voting?
Is there anyone who can provide a decent, and honest, background on this? It is an interesting sociological issue.
Although the solution proposed in the article would increase storage capacity by, say, a factor 2 or 4, it still is a temporary solution that does not solve the fundamental problem at hand.
The fundamental problem is the superparamagnetic limit: if you make a magnetic domain (a bit) smaller than a certain size, it becomes thermodynamically unstable. In English, this means that very small bits loose their value after a while. It also means that for the time being, we'll have to use tricks to pack the bits closer together while keeping them large enough to be stable.
It should be noted that perpendicular recording is not the only effort to achieve higher recording densities in the looming shadow of the superparamagnetic limit. Indeed, harddrive manufacturers have seen this problem coming for a number of years now, and have had meeting to discuss possible solutions.
On a brighter note, there seems to be progress in circumventing the superparamagnetic limit: very recent research show promising results for the future.
This is actually a long-term project which, in 2015 (probably 2030 in reality ;) boasts a downlink of several Tbits per day to earth.
Check out the info here.