In actuality, superfluids do NOT have zero viscosity at all points. They have very complex properties, depending on a combination of the container, exact conditions, etc, etc. Typically, some parts of superfluids exhibit zero viscosity (truly zero), leading to some fascinating fluid mechanics. For example, the Stokes singular problem actually has NO boundary layer, so drag goes to zero. There are plenty of other really interesting phenomenon - some that might be utilized in future technology.
Other interesting properties of superfluids include rather odd magnetic fields (Helium-3 or 4 is odd to start with, and then chilling it down and spinning it does some interesting stuff), VERY odd conduction, etc, etc. I imagine that there will be future Nobel prizes given out for research in this area (I believe one already has been, a few years back). Studying how superfluids act can give us some very interesting insights into what actually happens in various media at tiny sizes. One example would be looking at fluid/solid interfaces, and trying to determine what precisely goes on there. The possibilities are endless...
That being said, isn't the official definition of a fluid "something that deforms continuously under shear stress"? As such, does this indicate that these supersolids do NOT flow continuously?
Arthur C. Clarke was NOT the first person to propose relay satellites. He adapted the idea of a geosynchronous satellite from an older story by an obscure SF author whose name escapes me now. The author wrote a story describing a relay station put up on an asteroid to act as a bridge between Earth and Venusian colonies when the sun was in the middle. Essentially, the same concept Clarke used.
Stupid papers trying to be "Scientific"....
on
Genome Surprise
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· Score: 1
Actually, this is incredibly old. And wrong. You see, they tag new genes by searching for the locations where genes are transcribed (I won't go into the details, but there are deviations in base-pair frequency from normal "random" sequence near and inside genes due to transcriptional regulation and triggering). So once the genome is sequence, it's simple enough to search for the appropriate sequence and say, "Aha! A gene!"
The problem is, of course, is that you only see one gene for each transcriptional site. In actuality, our total number of genes may be much larger. This is primarily due to alternative splicing.
pre-mRNA directly off transcription has a number of introns, or integral non-coding sequences. These are eliminated using splicing, cutting out the introns and reconnecting the exons. However, it has been showns that a number of these genes are spliced multiple ways - in particular, it has been shown that different numbers and organizations of exons can be achieved.
Thus, a single "transcriptional location" that has been tagged as a single gene in the original search may code for a variety of mRNAs, and hence varied polypeptides. This has so far been shown (not in humans) to deal particularly for on/off traits - ie, sex determination and the like. It also seems as if alternative splicing of one gene may regulate the alternative splicing of another, producing a cascade effect in cells that can entirely change the way they express genes.
Anyways, even this is years old. Sheesh./. should be a bit more current, neh?
Slashdot Mirror
I think Gmail might be real. Because this is clearly Google's joke for today:
http://www.google.com/jobs/lunar_job.html
Heh. "Massively parallel lava lamps".
In actuality, superfluids do NOT have zero viscosity at all points. They have very complex properties, depending on a combination of the container, exact conditions, etc, etc. Typically, some parts of superfluids exhibit zero viscosity (truly zero), leading to some fascinating fluid mechanics. For example, the Stokes singular problem actually has NO boundary layer, so drag goes to zero. There are plenty of other really interesting phenomenon - some that might be utilized in future technology.
Other interesting properties of superfluids include rather odd magnetic fields (Helium-3 or 4 is odd to start with, and then chilling it down and spinning it does some interesting stuff), VERY odd conduction, etc, etc. I imagine that there will be future Nobel prizes given out for research in this area (I believe one already has been, a few years back). Studying how superfluids act can give us some very interesting insights into what actually happens in various media at tiny sizes. One example would be looking at fluid/solid interfaces, and trying to determine what precisely goes on there. The possibilities are endless...
That being said, isn't the official definition of a fluid "something that deforms continuously under shear stress"? As such, does this indicate that these supersolids do NOT flow continuously?
Arthur C. Clarke was NOT the first person to propose relay satellites. He adapted the idea of a geosynchronous satellite from an older story by an obscure SF author whose name escapes me now. The author wrote a story describing a relay station put up on an asteroid to act as a bridge between Earth and Venusian colonies when the sun was in the middle. Essentially, the same concept Clarke used.
Actually, this is incredibly old. And wrong. You see, they tag new genes by searching for the locations where genes are transcribed (I won't go into the details, but there are deviations in base-pair frequency from normal "random" sequence near and inside genes due to transcriptional regulation and triggering). So once the genome is sequence, it's simple enough to search for the appropriate sequence and say, "Aha! A gene!"
/. should be a bit more current, neh?
The problem is, of course, is that you only see one gene for each transcriptional site. In actuality, our total number of genes may be much larger. This is primarily due to alternative splicing.
pre-mRNA directly off transcription has a number of introns, or integral non-coding sequences. These are eliminated using splicing, cutting out the introns and reconnecting the exons. However, it has been showns that a number of these genes are spliced multiple ways - in particular, it has been shown that different numbers and organizations of exons can be achieved.
Thus, a single "transcriptional location" that has been tagged as a single gene in the original search may code for a variety of mRNAs, and hence varied polypeptides. This has so far been shown (not in humans) to deal particularly for on/off traits - ie, sex determination and the like. It also seems as if alternative splicing of one gene may regulate the alternative splicing of another, producing a cascade effect in cells that can entirely change the way they express genes.
Anyways, even this is years old. Sheesh.