If you are locked in a black box, there is no way to determine if you have constant linear velocity. There is also no way to distinguish between gravity and acceleration. But you can detect rotation by using a Foucault pendulum or other scientific instruments.
That's not entirely correct, I think. Acceleration is constant across the entire black box, but gravitational force depends inversely on the squared distance to the attracting mass, i.e. the force should be slightly different at the top and bottom of the box.
Both aluminum and steel are corroded by water. In fact, aluminum ions are more soluble in water than iron ions. The difference, however, is that iron oxides do not stick to the parent iron substrate and flake off, ever exposing new iron surface for corrosion. Aluminum on the other hand forms alumina (aluminum oxide, corundum), which is insoluble in water, has a very high hardness, and sticks strongly to the parent substrate, thus forming an inert layer all over the aluminum and preventing further corrosion. This is why aluminum roofs and siding works, without the aluminum dissolving in the rain water despite the very high solubility.
Perpetual motion is actually a fundamental property of the universe, though we usually call it inertia: a body will not stop moving, unless somebody moves it. Therefore, linear perpetual motion is the norm, with change of velocity depending on an outside force. To make it even more interesting: non-linear perpetual motion is actually also present in all molecules, at any given temperature, even at 0 Kelvin. Quantum chemistry shows that vibrational motion in a molecule changes by energetic quanta, where at least half a quantum is always present in a vibrational degree of motion (so-called zero-point energy). Hence, the atoms in a molecule are always in motion, even at 0 K, and the motion is non-linear. In first approximation, especially for diatomic molecules, it can be described as an oscillation with a parabolic energy profile, for multi-dimentional molecules one usually gets ergodic movement that is a bit more complex to describe, and is usually considered chaotic where only the statistical properties are relevant. But no free energy, of course.
If I read the article correctly, it takes 348 seconds to transfer 1.9GB of data. That amounts to 5.6 MB/sec copyspeed, or about 11.2 MB/s transfer speed on the disk (read + write). A simple, $50 SATA-II disk is able to sustain 50MB/s transfers, read or write, and quality hard disks even more. What is happening with the remaining bandwidth? There is some seek overhead, directory updates, etc but nothing that would slow it down. Also, 11MB/s is hardly a big strain for main memory, cache or PCI bus bandwidth, so it should not affect responsiveness at all. Somebody mentioned lack of rigorous benchmarking because no variance was measured. In this case, it seems many times too slow compared to the physical limit of the disk, so something is fundamentally wrong, irrespective of variance.
I quickly tested this on a SuSE linux machine, and found copy speeds of about 19 MB/sec including syncing to disk (so not tainted by buffering), or 38.2 MB/sec total disk transfer. Accounting for seek overhead, directory updates, etc, that feels like it is limited by the hardware (about 50MB/s for sequential access on this computer). Vista seems to lose about a factor of 4 relative to the hardware. Given the speed of the machine used (cpu, memory, videocard etc) any gui-aspects should not be the limiting factor. All other factors such as different filesystem etc should likewise have a negligable influence. I guess I'll stick to linux for the moment for my IO-intensive work...
You are assuming they are will be using a generated captcha for the "known" part that can be OCRed. They can use a word that was previously unknown (i.e. not OCRable) but has been identified by previous reCaptcha users.
they require special clusterish programming So ? On an SMP machine you need special SMP-ish programming. Great fun if your memory bandwidth runs out...
Some problems run naturally on distributed systems, some on shared-memory systems. It's a matter of choosing the right machine for the task at hand. Programming in MPI isn't that hard, and unless you are network bound (either bandwith or latency) it scales well. That is the equivalent of an SMP-machine not being memory bound (bandwidth, latency, coherency,...)
48 disks and hundreds of GB/s ? That leads to over 2 GB/s per disk. A good disk gives about 100MB/s sustained, or less. Come to think of it, memory speeds are rarely that fast, I think only the fastests graphics cards come to 100GB/s.
IIRC, a swap partition or swap file can only be about 128 MB under linux, with a maximum of 16 swap spaces, leading to a total of 2GB of swap space. Since we can now use 4GB, how are we supposed to allocate enough swap space (I prefer 2 times the physical memory). Has this annoying restriction of 128MB been removed, or can we use more swap spaces (lets see, 4 GB divided by 128 MB gives way too much swap spaces to be practical), or are we not supposed to use virtual memory any more ? If the restriction of 128 MB per swap space still exists, is there anybody working on removing this so Linux can become practical for modern computers? If the restriction is removed, is it possible to create a single 8GB swap space ?
There would be no point in connecting a SCSI card to an AGP port. The SCSI specifications only allow for data transfers speeds ( 20/40/80? MB/s ) that are but a small fraction of the PCI bus speed (135? MB/S), so it is not the PCI bus that is the bottleneck with SCSI devices. This is the reason why some disk RAID-systems work through multiple SCSI connections (on the same PCI bus) to allow for faster data transfer. There is a company that sells RAID systems that connect directly to the PCI bus, circumventing the SCSI bottleneck
The consensus is for binary notation, except for hard disk manufacturers. They insists on using decimal rather than power-2 notation because it makes the hard disk sound bigger : 4 GB (decimal) sounds better than 3.7 GB (power-2). All the confusion is just because of marketing gurus trying to make their product look good. Thank god the memory chip companies don't follow this approach to advertising.
Insane speed would by a lot here. I cannot believe that the FFTs and doppler shift we are doing now are the only useful analyses that can be run on the data. SETI should be more flexible. If they see that they have (orders of magnitude) more processing power available to them then anticipated, they could broaden the project to include those other analyses that are were considered too cpu-intensive (or too farfetched ?) to be included in the first place.
Why not release a second set of clients that go over the same data, but in different ways ?
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If you are locked in a black box, there is no way to determine if you have constant linear velocity. There is also no way to distinguish between gravity and acceleration. But you can detect rotation by using a Foucault pendulum or other scientific instruments.
That's not entirely correct, I think. Acceleration is constant across the entire black box, but gravitational force depends inversely on the squared distance to the attracting mass, i.e. the force should be slightly different at the top and bottom of the box.
Both aluminum and steel are corroded by water. In fact, aluminum ions are more soluble in water than iron ions. The difference, however, is that iron oxides do not stick to the parent iron substrate and flake off, ever exposing new iron surface for corrosion. Aluminum on the other hand forms alumina (aluminum oxide, corundum), which is insoluble in water, has a very high hardness, and sticks strongly to the parent substrate, thus forming an inert layer all over the aluminum and preventing further corrosion. This is why aluminum roofs and siding works, without the aluminum dissolving in the rain water despite the very high solubility.
Garh... I should have previewed that :-( That should read "a body will not stop moving, unless something stops it"
Perpetual motion is actually a fundamental property of the universe, though we usually call it inertia: a body will not stop moving, unless somebody moves it. Therefore, linear perpetual motion is the norm, with change of velocity depending on an outside force.
To make it even more interesting: non-linear perpetual motion is actually also present in all molecules, at any given temperature, even at 0 Kelvin. Quantum chemistry shows that vibrational motion in a molecule changes by energetic quanta, where at least half a quantum is always present in a vibrational degree of motion (so-called zero-point energy). Hence, the atoms in a molecule are always in motion, even at 0 K, and the motion is non-linear. In first approximation, especially for diatomic molecules, it can be described as an oscillation with a parabolic energy profile, for multi-dimentional molecules one usually gets ergodic movement that is a bit more complex to describe, and is usually considered chaotic where only the statistical properties are relevant.
But no free energy, of course.
If I read the article correctly, it takes 348 seconds to transfer 1.9GB of data. That amounts to 5.6 MB/sec copyspeed, or about 11.2 MB/s transfer speed on the disk (read + write). A simple, $50 SATA-II disk is able to sustain 50MB/s transfers, read or write, and quality hard disks even more. What is happening with the remaining bandwidth? There is some seek overhead, directory updates, etc but nothing that would slow it down. Also, 11MB/s is hardly a big strain for main memory, cache or PCI bus bandwidth, so it should not affect responsiveness at all. Somebody mentioned lack of rigorous benchmarking because no variance was measured. In this case, it seems many times too slow compared to the physical limit of the disk, so something is fundamentally wrong, irrespective of variance.
I quickly tested this on a SuSE linux machine, and found copy speeds of about 19 MB/sec including syncing to disk (so not tainted by buffering), or 38.2 MB/sec total disk transfer. Accounting for seek overhead, directory updates, etc, that feels like it is limited by the hardware (about 50MB/s for sequential access on this computer). Vista seems to lose about a factor of 4 relative to the hardware. Given the speed of the machine used (cpu, memory, videocard etc) any gui-aspects should not be the limiting factor. All other factors such as different filesystem etc should likewise have a negligable influence. I guess I'll stick to linux for the moment for my IO-intensive work...
You are assuming they are will be using a generated captcha for the "known" part that can be OCRed. They can use a word that was previously unknown (i.e. not OCRable) but has been identified by previous reCaptcha users.
Some problems run naturally on distributed systems, some on shared-memory systems. It's a matter of choosing the right machine for the task at hand. Programming in MPI isn't that hard, and unless you are network bound (either bandwith or latency) it scales well. That is the equivalent of an SMP-machine not being memory bound (bandwidth, latency, coherency,...)
48 disks and hundreds of GB/s ? That leads to over 2 GB/s per disk. A good disk gives about 100MB/s sustained, or less. Come to think of it, memory speeds are rarely that fast, I think only the fastests graphics cards come to 100GB/s.
IIRC, a swap partition or swap file can only be about 128 MB under linux, with a maximum of 16 swap spaces, leading to a total of 2GB of swap space. Since we can now use 4GB, how are we supposed to allocate enough swap space (I prefer 2 times the physical memory).
Has this annoying restriction of 128MB been removed, or can we use more swap spaces (lets see, 4 GB divided by 128 MB gives way too much swap spaces to be practical), or are we not supposed to use virtual memory any more ?
If the restriction of 128 MB per swap space still exists, is there anybody working on removing this so Linux can become practical for modern computers? If the restriction is removed, is it possible to create a single 8GB swap space ?
There would be no point in connecting a SCSI card to an AGP port. The SCSI specifications only allow for data transfers speeds ( 20/40/80? MB/s ) that are but a small fraction of the PCI bus speed (135? MB/S), so it is not the PCI bus that is the bottleneck with SCSI devices. This is the reason why some disk RAID-systems work through multiple SCSI connections (on the same PCI bus) to allow for faster data transfer. There is a company that sells RAID systems that connect directly to the PCI bus, circumventing the SCSI bottleneck
The consensus is for binary notation, except for hard disk manufacturers. They insists on using decimal rather than power-2 notation because it makes the hard disk sound bigger : 4 GB (decimal) sounds better than 3.7 GB (power-2). All the confusion is just because of marketing gurus trying to make their product look good. Thank god the memory chip companies don't follow this approach to advertising.
Insane speed would by a lot here. I cannot believe that the FFTs and doppler shift we are doing now are the only useful analyses that can be run on the data. SETI should be more flexible. If they see that they have (orders of magnitude) more processing power available to them then anticipated, they could broaden the project to include those other analyses that are were considered too cpu-intensive (or too farfetched ?) to be included in the first place.
Why not release a second set of clients that go over the same data, but in different ways ?
FWIW : The Belgian national soccer team is called the "Red Devils". Too bad they play soccer like Wet Drivels when they get on the field :-)
M$ also has a W95 patch for this. I installed on our Winboxes just in case...