The Euro/Aus scanners don't show the direct image. It is processed to separate the "normal" (clothes and body) from "abnormal" (weapons), and then displays the "abnormal" against a generic silhouette. The idea is that the scanners will be easier to introduce into countries with stronger privacy laws/culture than the US. However, it seems to be fooled by variations in bodies and clothing.
TSA systems have human operators interpret the images directly. They quickly get used to ghosting and artifacts and stop issuing false positives. However, tests (official and otherwise) show that they also fail to detect actual weapons.
It's a quick and dirty way to test whether the inserted gene is being expressed in all tissues.
Step two is to attach your desired test gene to the bioluminescent gene. Now you can see where the test gene is being expressed. That removes the doubt from a failure to get the expected result; is it because the experimental treatment doesn't work properly, or because the gene isn't active in the desired tissue? Failure+glow means the treatment failed. Failure+no-glow means a problem with the insertion.
Don't be so quick to give up. The chimney effect works just as well in reverse. If you cool the air at the top of a tall chimney, say by misting a small amount of water, it will become denser than the air beneath and "fall" down the chimney (become more dense as it does so, displacing the air at the bottom.) Apparently the amount of water needed is quite small compared to the volume of cool air displaced. And like the solar tower, the taller the chimney, the stronger the effect.
(I'm not saying it is worth either the water or the cost of a double-tower, I'm just saying it's a genuine effect.)
Under rational decision making, money already spent should not have any influence over forward looking financial decisions. The argument that "we've spend $X billions already which will go to waste" is fallacious logic.
While I agree with your description of the sunk-cost fallacy, I disagree that "money already should not have any influence" on funding decisions. Past performance is a predictor of future performance. SpaceX reportedly spent about $600m on two rockets and a capsule. I'm not just playing fanboi, it just sets the current known limits of what is physically possible. NASA spent $9b (according to the congressman) on a program that failed to deliver a single launcher, in spite of taking the supposed "cheaper" path of reusing existing shuttle technology. That suggests, in the future, that any argument about "Proven Technology" is bullshit. Similarly, any program that using the same system of contracting and NASA design, will probably also fail. OTOH, even if we double SpaceX development budget to $1.2b, then for the $9b spent on Constellation, NASA could have issued seven $1.2b contracts for seven alternative launchers/capsules, payable on first launch. Pick the best three launchers for the next round of funding.
FTFA: "Instead, NASA was directed to pursue a riskier course, diverting billions of dollars to a group of companies– most devoid of experience in manned space vehicles"
Ah, Republicans, all for market solutions, as long as the money goes to the your preferred part of the market.
(Even better, they're blaming Obama for wasting $9b on the ridiculous Constellation.)
the two full-rotation sets already scheduled (and I presume completed) during approach, [...] The main issue is that they're not releasing the pictures they have -- particularly the full-rotation sets mentioned above,
Thanks for the details. I didn't realise they had the images I wanted, and just weren't releasing them. At least if the probe dies, or the camera fails, or some other disaster, there will be some data available. What's left is just my nerd-rage-impatience.
When the ion drive isn't running, there is plenty of power. There's no reason to not gather as much data as possible. After all, if something went bung during insertion (when the probe was out of comms with Earth) it would be the only data they have. Given the detail in the last image (from ten days ago), what prevented them from at least getting a full surface sequence?
Other NASA probes take images from distant approach, trying to milk as much data as they can before the arrive, as well as PR for the mission. I can't find an explanation of why the Dawn team have been so reticent to image their target. It doesn't bode well for the rest of the mission.
I'm annoyed by the lack of images from the Dawn team. Compared to other NASA probes, they've really skimped on the public images. (Every week or so they've posted a single image from the low-res navigation imager. Not even a complete sequence of Vesta's surface (it rotates every 5 hours, so not exactly difficult.)) I hope that isn't going to set the standard for the entire mission.
(They have an excuse for the insertion burn, but not during coasting.)
It's true, I think I read somewhere that for every penny that is invested in NASA, there's a full dollar that is returned
Decades ago, some organisation worked out that every dollar spent by the government produced $7 in GDP. This somehow got picked up by NASA promoting science-writers as "Every dollar invested in NASA has returned $7 to the country!" (And now, apparently, that has been exaggerated further, into pennies for dollars.) It's crap though.
Also crap is...
I don't know what Obama was thinking...
Obama requested an increase in NASA's budget. Republican dominated congress cut it. You seem to be blaming the wrong side.
Bit late, but hopefully you have notification turned on...
I've actually thought about having them go through the early arithmetic videos a bit this summer as review, rather than just doing the occasional practice problems
Don't do that. Even the practice problems. If your kids really are brighter than average, then do not pre-study material they'll be covering in normal classes, or else when they encounter it in normal classes they'll be bored out of their minds. If they are smart, they specifically don't need to study the same material twice.
If you want to push them further than the school is, go wider, not deeper. Ie, instead of pre-studying what the school is going to cover, teach them things the school won't cover. (Especially if they've shown an interest in something obscure.)
And it is 20+ year old technology. Things have advanced significantly since Hubble was designed.
Rubbish. Tube with mirrors. Everything out of date is electronic, much of which they had already updated to upgrade Hubble itself. Had they been able to try riskier upgrades on proven Hubble-clones over the last 20 years, Webb wouldn't be such a gamble. (The folding mirror gimmick was first proposed ten or fifteen years ago as a Hubble upgrade.)
I know common sense says that building just one complex system is much quicker and cheaper than doing several partial systems and the full design. One is cheaper than five, right? But history has shown us otherwise. Your first one is always the worst, so keep it simple. Learning your craft, a bit at a time, ends up saving you time and money. What I don't understand is why NASA keeps forgetting the lesson, it used to be their primary operating principle, one mission, one problem.
You are aware of course that Hubble shoehorned a bunch of new technology in and came in about 2-3X over budget. You did know that right?
[Sigh] You think that somehow argues against my point? The lesson isn't "well, shucks, that's just how things work", the lesson is "don't do that again". How many times do you need to burn your hand on the pot before you figure out you're holding it wrong?
Webb, like Hubble before it, pushes the boundaries of science and engineering.
Webb may never fly. Hell of a design flaw.
For twenty years, we could have been testing the specific technologies, the multi-segmented mirror, the heat-shield, the cryo-cameras, the robo-spectrometer, etc, on working 'scopes. Webb would just be the "next generation"; that would be it's novel problem, integration of the proven technologies in a new chassis. If it works, it then becomes the proven base model for the next series of incremental developments which seed the next generation.
[SpaceX vs Constellation] You are presuming they are pursuing the same goal.
I think it is a real bad design error to use an e-mail address as a login. What happens if you change your provider? Do you log in with your new (thus unknown) e-mail address? Or do you want to send the lost password to the no longer existing one?
It's not using an e-mail address as a login. It's using a private-key signed challenge packet as a login. The e-mail address is provided to give the website the location of a reasonably secure version of your public key, so they can validate the challenge packet.
If you change e-mail hosts, you simply give the new host your original public key. (Which will probably be an automagic one click option by the time this system goes public, given that stupid-ease-of-use is its purpose.) Now when you sign in, your browser sends the signed challenge packet, and the new location of your old public key.
(And since there will be people who want a more pseudonymous identity, and since the system is open source, there will invariably be a bunch of geeks setting up a bunch of servers to host public keys for people like you, and/or server-ware you can host yourself. Then your broswer gives that pseudo-email location instead of a real e-mail address.)
Slashdot Mirror
Now we know how that got its name.
If he had nothing to hide, why was he so nervous? The system works!
The Euro/Aus scanners don't show the direct image. It is processed to separate the "normal" (clothes and body) from "abnormal" (weapons), and then displays the "abnormal" against a generic silhouette. The idea is that the scanners will be easier to introduce into countries with stronger privacy laws/culture than the US. However, it seems to be fooled by variations in bodies and clothing.
TSA systems have human operators interpret the images directly. They quickly get used to ghosting and artifacts and stop issuing false positives. However, tests (official and otherwise) show that they also fail to detect actual weapons.
some of us would start playing with legos again
Every time an American says "legos", Denmark dies a little inside.
No, brother, we... have... Meccano.
WTF? Former students can't be friends either? I keep contact with several former teachers.
"...unless it is available to school administrators and the child's legal custodian, physical custodian, or legal guardian."
Once you're over 18, it can't apply to you.
Somebody should.
Arrested? He should get his own TV show!
What is the fascination with making animals glow?
It's a quick and dirty way to test whether the inserted gene is being expressed in all tissues.
Step two is to attach your desired test gene to the bioluminescent gene. Now you can see where the test gene is being expressed. That removes the doubt from a failure to get the expected result; is it because the experimental treatment doesn't work properly, or because the gene isn't active in the desired tissue? Failure+glow means the treatment failed. Failure+no-glow means a problem with the insertion.
(IANAB, IANYB.)
Don't forget base jumping from the tower.
And since we now have all these tourists and adventurers, lets stick a revolving hotel at the top.
Don't be so quick to give up. The chimney effect works just as well in reverse. If you cool the air at the top of a tall chimney, say by misting a small amount of water, it will become denser than the air beneath and "fall" down the chimney (become more dense as it does so, displacing the air at the bottom.) Apparently the amount of water needed is quite small compared to the volume of cool air displaced. And like the solar tower, the taller the chimney, the stronger the effect.
(I'm not saying it is worth either the water or the cost of a double-tower, I'm just saying it's a genuine effect.)
Under rational decision making, money already spent should not have any influence over forward looking financial decisions. The argument that "we've spend $X billions already which will go to waste" is fallacious logic.
While I agree with your description of the sunk-cost fallacy, I disagree that "money already should not have any influence" on funding decisions. Past performance is a predictor of future performance. SpaceX reportedly spent about $600m on two rockets and a capsule. I'm not just playing fanboi, it just sets the current known limits of what is physically possible. NASA spent $9b (according to the congressman) on a program that failed to deliver a single launcher, in spite of taking the supposed "cheaper" path of reusing existing shuttle technology. That suggests, in the future, that any argument about "Proven Technology" is bullshit. Similarly, any program that using the same system of contracting and NASA design, will probably also fail. OTOH, even if we double SpaceX development budget to $1.2b, then for the $9b spent on Constellation, NASA could have issued seven $1.2b contracts for seven alternative launchers/capsules, payable on first launch. Pick the best three launchers for the next round of funding.
FTFA: "Instead, NASA was directed to pursue a riskier course, diverting billions of dollars to a group of companies– most devoid of experience in manned space vehicles"
Ah, Republicans, all for market solutions, as long as the money goes to the your preferred part of the market.
(Even better, they're blaming Obama for wasting $9b on the ridiculous Constellation.)
"Single point of failure" is an engineering term. A system can have any number of them.
Posting to undo accidental downmod.
the two full-rotation sets already scheduled (and I presume completed) during approach, [...] The main issue is that they're not releasing the pictures they have -- particularly the full-rotation sets mentioned above,
Thanks for the details. I didn't realise they had the images I wanted, and just weren't releasing them. At least if the probe dies, or the camera fails, or some other disaster, there will be some data available. What's left is just my nerd-rage-impatience.
One Froggy Evening, if anyone was wondering.
When the ion drive isn't running, there is plenty of power. There's no reason to not gather as much data as possible. After all, if something went bung during insertion (when the probe was out of comms with Earth) it would be the only data they have. Given the detail in the last image (from ten days ago), what prevented them from at least getting a full surface sequence?
Other NASA probes take images from distant approach, trying to milk as much data as they can before the arrive, as well as PR for the mission. I can't find an explanation of why the Dawn team have been so reticent to image their target. It doesn't bode well for the rest of the mission.
I'm annoyed by the lack of images from the Dawn team. Compared to other NASA probes, they've really skimped on the public images. (Every week or so they've posted a single image from the low-res navigation imager. Not even a complete sequence of Vesta's surface (it rotates every 5 hours, so not exactly difficult.)) I hope that isn't going to set the standard for the entire mission.
(They have an excuse for the insertion burn, but not during coasting.)
I think I just had a small stroke while typing that.
Masturbation does seem to be a common part of this thread.
And, because they don't get the reference, assume it's racist.
It's true, I think I read somewhere that for every penny that is invested in NASA, there's a full dollar that is returned
Decades ago, some organisation worked out that every dollar spent by the government produced $7 in GDP. This somehow got picked up by NASA promoting science-writers as "Every dollar invested in NASA has returned $7 to the country!" (And now, apparently, that has been exaggerated further, into pennies for dollars.) It's crap though.
Also crap is...
I don't know what Obama was thinking...
Obama requested an increase in NASA's budget. Republican dominated congress cut it. You seem to be blaming the wrong side.
Bit late, but hopefully you have notification turned on...
I've actually thought about having them go through the early arithmetic videos a bit this summer as review, rather than just doing the occasional practice problems
Don't do that. Even the practice problems. If your kids really are brighter than average, then do not pre-study material they'll be covering in normal classes, or else when they encounter it in normal classes they'll be bored out of their minds. If they are smart, they specifically don't need to study the same material twice.
If you want to push them further than the school is, go wider, not deeper. Ie, instead of pre-studying what the school is going to cover, teach them things the school won't cover. (Especially if they've shown an interest in something obscure.)
And it is 20+ year old technology. Things have advanced significantly since Hubble was designed.
Rubbish. Tube with mirrors. Everything out of date is electronic, much of which they had already updated to upgrade Hubble itself. Had they been able to try riskier upgrades on proven Hubble-clones over the last 20 years, Webb wouldn't be such a gamble. (The folding mirror gimmick was first proposed ten or fifteen years ago as a Hubble upgrade.)
I know common sense says that building just one complex system is much quicker and cheaper than doing several partial systems and the full design. One is cheaper than five, right? But history has shown us otherwise. Your first one is always the worst, so keep it simple. Learning your craft, a bit at a time, ends up saving you time and money. What I don't understand is why NASA keeps forgetting the lesson, it used to be their primary operating principle, one mission, one problem.
You are aware of course that Hubble shoehorned a bunch of new technology in and came in about 2-3X over budget. You did know that right?
[Sigh] You think that somehow argues against my point? The lesson isn't "well, shucks, that's just how things work", the lesson is "don't do that again". How many times do you need to burn your hand on the pot before you figure out you're holding it wrong?
Webb, like Hubble before it, pushes the boundaries of science and engineering.
Webb may never fly. Hell of a design flaw.
For twenty years, we could have been testing the specific technologies, the multi-segmented mirror, the heat-shield, the cryo-cameras, the robo-spectrometer, etc, on working 'scopes. Webb would just be the "next generation"; that would be it's novel problem, integration of the proven technologies in a new chassis. If it works, it then becomes the proven base model for the next series of incremental developments which seed the next generation.
[SpaceX vs Constellation] You are presuming they are pursuing the same goal.
Putting humans on Mars?
I think it is a real bad design error to use an e-mail address as a login. What happens if you change your provider? Do you log in with your new (thus unknown) e-mail address? Or do you want to send the lost password to the no longer existing one?
It's not using an e-mail address as a login. It's using a private-key signed challenge packet as a login. The e-mail address is provided to give the website the location of a reasonably secure version of your public key, so they can validate the challenge packet.
If you change e-mail hosts, you simply give the new host your original public key. (Which will probably be an automagic one click option by the time this system goes public, given that stupid-ease-of-use is its purpose.) Now when you sign in, your browser sends the signed challenge packet, and the new location of your old public key.
(And since there will be people who want a more pseudonymous identity, and since the system is open source, there will invariably be a bunch of geeks setting up a bunch of servers to host public keys for people like you, and/or server-ware you can host yourself. Then your broswer gives that pseudo-email location instead of a real e-mail address.)