Operations are complicated, messy, things, and surgeons are very interested in heads-up type displays to help answer questions like, "is my scalpel actually placed where I think it is?" Just like fighter pilots, they frequently do not want to take their eyes off of what they are doing. (I have worked in medical telepresence, and one of the things the surgeons most wanted was these kinds of headsup displays.)
"Among the possible uses for Google Glass that early adopters are dreaming up, you can now add 'surgical assistance' to the list. With approval from the institutional review board, a UCSF cardiothoracic surgeon recently utilized Glass during procedures..."
I have been involved with getting electronics into operating rooms, and it is an expensive, complicated and time consuming process. FDA requirements apply to all medical devices; with RFI being a big problem, especially in an OR environment (which is full of "mission critical" electronic gear). To be blunt, if Google glass interferes with the electronics already in the OR, patients could die, and everyone involved with getting it there would be directly responsible.
From my perspective, the note-worthy thing about this story would be getting the certification needed to take Google Glass into the OR, as that would probably be the hardest thing to do, much harder than some trivial HIPAA scrubbing, and it puzzles me that that is not mentioned in the article. So, I have to wonder, did they actually do this, or is Google and UCSF just winging it and hoping no one dies during their trials?
The linked gif seems to show the debris "tail" mostly flowing back along the comet's direction of travel, with some off-axis blow evident in the later post-encounter image. I would have expected the "tail" to always be pointing *away* from the sun as it made this fly-by. Derp?
-DC
There are generally two tails - the dust tail (which lies along the orbit path, like bread-crumbs in a fairy tale) and the (plasma) gas tail (which is blown by the solar wind, mostly directly away from the Sun). When you are just past perihelion ( as at the end of the linked-to video above) the dust tail can actually point (more or less) towards the Sun.
So, why don't you measure the position of the incoming trajectory points and the outgoingetrajectory points, and then scale according to the known incoming orbit variables, and finally determine whether the outgoing orbit trajectory is parabolic or hyperbolic?
Oh, that will be done. But not today, and probably not for a few weeks (until it gets closer to the Earth). It's more fun to predict these things before the measurements are taken.
Yes, and it spins fairly rapidly (~2.4 hours period). However, we don't know what the spin angle is. Note that the cancelation you mention only applies for the equatorial component of thrusting, so the polar component could still change the semi-major axis, unless the spin axis is exactly perpindicular to the orbit plane. Note that, I was just trying to show, in a back of the envelope fashion, that there was likely enough thrust to be significant; I think that conclusion still stands.
I've got almost no intuition at these scales, but nudging a cometary nucleus by a few m/s seems like it would take a lot of energy -- maybe more than the processes acting on this comet are likely to generate.
Now, nudging one chunk at the expense of the others is a different question. When a comet fragments, how quickly do the pieces typically separate? If the nucleus splits, forcing chunks apart at tens of m/s, the ones forced along track might get the boost they need -- but I don't know within an order of magnitude how fast the chunks are likely to be separating. Anybody?
A lot of energy was available. It was about 3 radii from the Sun. It was hot enough to boil rocks.
Suppose it lost 1/3 of its mass as water (steam) (so that the water lost had 1/2 the total mass). That steam could have left in a few jets, each with a velocity of 100 m / sec. If there were 100 jets, all distributed randomly about the surface, then the net velocity change would be ~ (1/2) * 100 m / sec / sqrt(100) or 5 m / sec, which is considerably more than 0.7 m / sec.
Did Comet ISON escape from the solar system ? Too soon to tell, but I would bet it has an even chance of being now unbound.
According to the Minor Planet Center, ISON has (had) a pre-perihelion eccentricity = 0.9999947.
At perihelion, ISON was traveling at about 370 km / sec, and (given that eccentricity) was only about 0.7 m / sec below its escape velocity. Even a small nudge (of a few m / sec) "along track" thus could have enabled it to escape from the solar system forever (or bound it even more tightly), and (given the amount of mass it probably lost) it could have been thrusted by many 100's of m / sec. It's highly unlikely the outgassing thrust was purely at right angles to the direction of motion, so I would rate the probably of escape as ~ 50%.
But this one is also relevant http://xkcd.com/1295/ given how many news sites mindlessly repeated the news "ISON disintegrated" when it was apparent in SOHO Lascar C3 imagery that that hadn't happened by 5 hours post-perihelion (see this at 2318 UTC)
eLisa (a toned-down, less costly, version of the original LISA) requires LISA Pathfinder (a technology demonstration mission). It turns out that LISA Pathfinder can be used to perform the first solar system test of MOND. This subsidiary test, largely flying under the radar, could potentially confirm (or rule out) the MOND / TeVeS hypothesis, providing an important test of fundamental physics for remarkably little expense.
In normal practice, not much. In certain circumstances (such as a Hung Parliament), the Monarch could pick a Prime Minister of her own choosing, which was last done in 1963. Also, the Queen gets to read any state paper she wants (i.e., nothing secret is supposed to be kept from her), and she has the right to meet with and advise the Prime Minister about any matter she wants to, but that's about all the actual day-to-day political power the current Queen has. (Given that she has been reigning for longer than the current PM has been alive, she probably has some insights into the working of the British government that he lacks, and my guess is that her advice is probably frequently influential, but it is just advice.)
In a crisis, potentially a lot. Although the actual power of the Queen in a crisis is (deliberately) kept vague, she presumably could temporarily take back many of her nominal powers if the crisis were dire enough. In addition, the threat to resign (abdicate) rather than approve a law or other decision could have a profound effect on wavering politicians in an emergency. The best relatively recent example is the threat of Haakon VII of Norway to abdicate rather than appoint Quisling as Prime Minister of Norway during the German invasion, which pretty much cemented the Norwegian government's opposition to Nazi rule.
I think that one of the things that people worry about with Prince Charles is that he does state opinions about a lot of things, and that, should he become King, he might start trying to turn some of his nominal powers into actual ones.
Yeah, I believed that until the Governor General went along with Harper's suspension of parliament to avoid a no-confidence vote. If that's not an un-democratic interference with the workings of democracy, I don't know what is.
the issue is pitting pro-utilities Republicans against this fledgling movement of libertarian-minded activists who see independent power generation as an individual right
If you don't think the pro-utilities crowd will win this, you don't understand the Republican party much. Of course, it will be spun as a victory for libertarianism, and of course, it might get enough Democratic votes to cover various behinds, but in the end the money will win this.
Can't we just find a way to pension people like this off, or give them jobs cleaning pay phones or something? It would be a much better use of public money.
Slashdot Mirror
I have seen demos of exactly this. Don't know if it is on the market yet.
Operations are complicated, messy, things, and surgeons are very interested in heads-up type displays to help answer questions like, "is my scalpel actually placed where I think it is?" Just like fighter pilots, they frequently do not want to take their eyes off of what they are doing. (I have worked in medical telepresence, and one of the things the surgeons most wanted was these kinds of headsup displays.)
I have been involved with getting electronics into operating rooms, and it is an expensive, complicated and time consuming process. FDA requirements apply to all medical devices; with RFI being a big problem, especially in an OR environment (which is full of "mission critical" electronic gear). To be blunt, if Google glass interferes with the electronics already in the OR, patients could die, and everyone involved with getting it there would be directly responsible.
From my perspective, the note-worthy thing about this story would be getting the certification needed to take Google Glass into the OR, as that would probably be the hardest thing to do, much harder than some trivial HIPAA scrubbing, and it puzzles me that that is not mentioned in the article. So, I have to wonder, did they actually do this, or is Google and UCSF just winging it and hoping no one dies during their trials?
The linked gif seems to show the debris "tail" mostly flowing back along the comet's direction of travel, with some off-axis blow evident in the later post-encounter image. I would have expected the "tail" to always be pointing *away* from the sun as it made this fly-by. Derp?
-DC
There are generally two tails - the dust tail (which lies along the orbit path, like bread-crumbs in a fairy tale) and the (plasma) gas tail (which is blown by the solar wind, mostly directly away from the Sun). When you are just past perihelion ( as at the end of the linked-to video above) the dust tail can actually point (more or less) towards the Sun.
So, why don't you measure the position of the incoming trajectory points and the outgoingetrajectory points, and then scale according to the known incoming orbit variables, and finally determine whether the outgoing orbit trajectory is parabolic or hyperbolic?
Oh, that will be done. But not today, and probably not for a few weeks (until it gets closer to the Earth). It's more fun to predict these things before the measurements are taken.
Yes, and it spins fairly rapidly (~2.4 hours period). However, we don't know what the spin angle is. Note that the cancelation you mention only applies for the equatorial component of thrusting, so the polar component could still change the semi-major axis, unless the spin axis is exactly perpindicular to the orbit plane. Note that, I was just trying to show, in a back of the envelope fashion, that there was likely enough thrust to be significant; I think that conclusion still stands.
I've got almost no intuition at these scales, but nudging a cometary nucleus by a few m/s seems like it would take a lot of energy -- maybe more than the processes acting on this comet are likely to generate.
Now, nudging one chunk at the expense of the others is a different question. When a comet fragments, how quickly do the pieces typically separate? If the nucleus splits, forcing chunks apart at tens of m/s, the ones forced along track might get the boost they need -- but I don't know within an order of magnitude how fast the chunks are likely to be separating. Anybody?
A lot of energy was available. It was about 3 radii from the Sun. It was hot enough to boil rocks.
Suppose it lost 1/3 of its mass as water (steam) (so that the water lost had 1/2 the total mass). That steam could have left in a few jets, each with a velocity of 100 m / sec. If there were 100 jets, all distributed randomly about the surface, then the net velocity change would be ~ (1/2) * 100 m / sec / sqrt(100) or 5 m / sec, which is considerably more than 0.7 m / sec.
Did Comet ISON escape from the solar system ? Too soon to tell, but I would bet it has an even chance of being now unbound.
According to the Minor Planet Center, ISON has (had) a pre-perihelion eccentricity = 0.9999947.
At perihelion, ISON was traveling at about 370 km / sec, and (given that eccentricity) was only about 0.7 m / sec below its escape velocity. Even a small nudge (of a few m / sec) "along track" thus could have enabled it to escape from the solar system forever (or bound it even more tightly), and (given the amount of mass it probably lost) it could have been thrusted by many 100's of m / sec. It's highly unlikely the outgassing thrust was purely at right angles to the direction of motion, so I would rate the probably of escape as ~ 50%.
This one is directly relevant : http://xkcd.com/1297/
But this one is also relevant http://xkcd.com/1295/ given how many news sites mindlessly repeated the news "ISON disintegrated" when it was apparent in SOHO Lascar C3 imagery that that hadn't happened by 5 hours post-perihelion (see this at 2318 UTC)
eLisa (a toned-down, less costly, version of the original LISA) requires LISA Pathfinder (a technology demonstration mission). It turns out that LISA Pathfinder can be used to perform the first solar system test of MOND. This subsidiary test, largely flying under the radar, could potentially confirm (or rule out) the MOND / TeVeS hypothesis, providing an important test of fundamental physics for remarkably little expense.
A take from an American.
In normal practice, not much. In certain circumstances (such as a Hung Parliament), the Monarch could pick a Prime Minister of her own choosing, which was last done in 1963. Also, the Queen gets to read any state paper she wants (i.e., nothing secret is supposed to be kept from her), and she has the right to meet with and advise the Prime Minister about any matter she wants to, but that's about all the actual day-to-day political power the current Queen has. (Given that she has been reigning for longer than the current PM has been alive, she probably has some insights into the working of the British government that he lacks, and my guess is that her advice is probably frequently influential, but it is just advice.)
In a crisis, potentially a lot. Although the actual power of the Queen in a crisis is (deliberately) kept vague, she presumably could temporarily take back many of her nominal powers if the crisis were dire enough. In addition, the threat to resign (abdicate) rather than approve a law or other decision could have a profound effect on wavering politicians in an emergency. The best relatively recent example is the threat of Haakon VII of Norway to abdicate rather than appoint Quisling as Prime Minister of Norway during the German invasion, which pretty much cemented the Norwegian government's opposition to Nazi rule.
I think that one of the things that people worry about with Prince Charles is that he does state opinions about a lot of things, and that, should he become King, he might start trying to turn some of his nominal powers into actual ones.
Yeah, I believed that until the Governor General went along with Harper's suspension of parliament to avoid a no-confidence vote. If that's not an un-democratic interference with the workings of democracy, I don't know what is.
And, don't forget, he didn't know the proper way to eat at table (frequently commented on by aristocratic Prussian generals).
If you don't think the pro-utilities crowd will win this, you don't understand the Republican party much. Of course, it will be spun as a victory for libertarianism, and of course, it might get enough Democratic votes to cover various behinds, but in the end the money will win this.
You would never know, reading the original article, that neutrinos were detected from SuperNova 1987A back in, well, 1987.
Google exists to strip-mine human society. It is the essence of their business model.
The horror, the horror!
Who are these cowards ? I sure don't know any. Do they exist, or are they a convenient fiction cooked up by politicians and government contractors?
Bingo.
They won't let you take phones in there, either, for the same reason. And they haven't for decades now.
Horrors ! What's a premed to do? Surely they don't expect them to actually understand something?!?
Can't we just find a way to pension people like this off, or give them jobs cleaning pay phones or something? It would be a much better use of public money.
If you are not paying for it, you are not the customer.
Is processing for Quickoffice done off-phone? Or, to put it another way, does Quickoffice share all of your work with Google?
This will never happen if you are running your gear on the Lunar surface.
Just saying...