Welcome to one of the most active flamenco sites on the Internet. Guests can read most posts but if you want to participate click here to register.
This site is dedicated to the memory of Paco de Lucía, Ron Mitchell, Guy Williams, Linda Elvira, Philip John Lee, Craig Eros, Ben Woods and David Serva who went ahead of us too soon.
We receive 12,200 visitors a month from 200 countries and 1.7 million page impressions a year. To advertise on this site please contact us.
|
|
|
RE: Black Hole eats sun
|
You are logged in as Guest
|
|
Users viewing this topic: none
|
|
Login  | |
|
  
Piwin
Posts: 3451
Joined: Feb. 9 2016
|
 RE: Black Hole eats sun (in reply to Ricardo)
|
|
|
Yeah, I guess I'm just not getting my point across, because my point is certainly not that they should overbudget.
All I'll say is to have a look at the full 22 recommendations of the report. As far as I can tell, there are only 2 that could be interpreted as "overbudgeting" (though I personally wouldn't. Corrective measures for underbudgeting are not "overbudgeting"...). They repeatedly point to problems that have nothing at all to do with "unanticipated problems", problems that stemmed from causes that were already known at the time (or that could have been known had the proper audits/analyses been performed), problems that were procedural, structural, policy-related, etc. Solve those problems and you remove a lot of the hurdles that get in the way of the project teams. Solve those problems and the project ends up cheaper, faster and easier for everyone working on it. Solve those problems and you'll be in a much better position to argue against the naysayers when the **** really hits the fan, like your example with Hubble.
Fortunately NASA didn't consider those recommendations to be wishful thinking, since they ended up implementing many of them (not sure how to handle a counterfactual like saying that requiring an 80% confidence rate and 25% contingency would have put the project on the back burner. All I can say is that they ended up implementing that recommendation, so at the very least it was within the realm of possibilities for them at that point in time). One could argue that it was too little too late, but at least it was an improvement.
https://jwst.nasa.gov/resources/JamesWebbSpaceTelescopeIndependentComprehensiveReviewPanelReport.pdf
_____________________________
"Anything you do can be fixed. What you cannot fix is the perfection of a blank page. What you cannot fix is that pristine, unsullied whiteness of a screen or a page with nothing on it—because there’s nothing there to fix."
|
|
|
|
REPORT THIS POST AS INAPPROPRIATE |
Date May 24 2022 16:45:20
 |
|
Richard Jernigan
Posts: 3245
Joined: Jan. 20 2004
From: Austin, Texas USA
|
|
RE: Black Hole eats sun (in reply to Piwin)
|
|
|
I spent 43 years working on defense contracts, mainly with the U.S. Air Force and the U.S. Navy, but also with the British Atomic Weapons Research Establishment, and the Ministries of Defense of the U.K. and another country. I also participated in the first flights of SpaceX at Kwajalein as Radar Test Director. SpaceX’s expenditure from inception to orbit was $100-million of Musk’s own money. The Kwajalein Modernization and Remoting program, to upgrade four of the planet’s most powerful and complex radars came in at a little over $200-million, from an initial estimate of $100-million. These were the smallest projects I worked on.
Others included the Strategic Defense Initiative (SDI, “Star Wars”) and every ICBM system development on our side, starting with Minuteman II. I worked on numerous proposals.
First I would observe that the James Webb Space Telescope ICRP estimate to complete was $6.5-billion. The actual cost of $10-billion was only 1.5 times over this estimate, rather than the factor of 2 overrun cited as poor planning by Piwin.
During my last 18 years I worked for three different contractors at Kwajalein Missile Range/Reagan Test Site in the Central Pacific. I was responsible for about half the technical content of two $1.5-billion proposals for staffing the range. Staffing of the missile range carried low technical and cost risk, so the contractor’s fee was low, and cost overruns were nearly zero.
On other projects, cost overruns of double the original estimates were not uncommon in some phases of the effort.
The first 25 years of my engineering career were in exploratory and advanced development of technology and systems to defeat the Soviet strategic missile defenses. For the last 15 years or so I was internationally recognized as a leader in the field, and involved in planning major projects.
CIA estimated that the USSR spent over 100-billion rubles on strategic missile defense. The penetration aids on the Minuteman II missile system cost about $200-million to defeat the Soviet defense, 1969 dollars.
The technology and systems development projects typically consisted of three phases: exploratory and advanced development, development of manufacturing processes and test, and production for deployment. During exploratory and advanced development various design concepts are explored. One concept is selected for detailed design and development. Hardware is built, tested and refined. This first stage carries the most technological risk: design ideas turn out not to work, unforeseen problems arise. This stage experiences the greatest cost and schedule overruns. But exploratory and advanced development cost much less than production, so the advanced development overruns are a small fraction of overall system cost.
The JWST is a one-off. Actual hardware fabrication was a much smaller fraction of the cost than production for an operationasl military system. The exploratory and advanced development overruns were nearly half of the eventual total system cost, by no means unusual in a project for extensive development of novel technology.
RNJ
|
|
|
|
REPORT THIS POST AS INAPPROPRIATE |
Date May 24 2022 17:55:49
|
|
Piwin
Posts: 3451
Joined: Feb. 9 2016
|
|
RE: Black Hole eats sun (in reply to Richard Jernigan)
|
|
|
quote:
the actual cost of $10-billion was only 1.5 times over this estimate
Just to clarify, the factor 2 was in reference to the JWST baseline in the confirmation review (which I believe is right after the round of PDRs, end of phase B, in NASA world? If I'm correct about that, then personally I think at PDR you should be able to give a solid ballpark estimate of the costs). That figure was around $5.1 billion, and later revised upwards following the ICRP recommendations. I did get the year wrong though, since the estimate comes from 2008, not 2009.
What I'm mostly arguing against is the line of thought that lumps everything into unforeseeable problems and says you can't expect any financial accountability at all in research projects. I don't think it's wise to communicate that way about these projects, especially when there are those who would like to scrap them altogether. Of course, internally they do take these problems seriously, and the fact that there even was an ICRP (and that its recommendations were followed) is proof enough.
After a quick glance at articles of the time, I think the ICRP chair, John Casani, struck the right chord. His message to the outside world was 1. It's hard to get these complicated projects right, and 2. there were faults in the previous budget and we're doing X, Y and Z to correct them. Saying 1. without 2. is in my opinion a mistake. Investors, whether private corporations or taxpayers, will expect some degree of accountability. Dismissing that expectation of accountability on the grounds that it's scientific research just won't fly. And if we persist in telling people that science=0 financial accountability, then there are some interesting scientific projects in the future that may quite literally not fly...
On a separate note, I would have loved to be a fly on the wall in some of the places you've worked. With my former work in languages, I had the opportunity to sit in on a variety of meetings related to space projects (ESA, CNES, Ariane, Thales, etc.). Hence some basic familiarity with what is involved in the budgeting process and with just how tense discussions on planning and financing can get. Unfortunately it was mostly in office rooms rather than on-site locations. When I was offered an assignment in Kourou (which paid surprisingly little but was appealing just to be able to see a bit of the action up close), it was unfortunately at a time where I was struggling with a crippling fear of flying, so I declined. By the time I had worked my way back up to being able to handle longer flights, I had already changed careers.
_____________________________
"Anything you do can be fixed. What you cannot fix is the perfection of a blank page. What you cannot fix is that pristine, unsullied whiteness of a screen or a page with nothing on it—because there’s nothing there to fix."
|
|
|
|
REPORT THIS POST AS INAPPROPRIATE |
Date May 24 2022 21:10:01
|
|
Richard Jernigan
Posts: 3245
Joined: Jan. 20 2004
From: Austin, Texas USA
|
|
RE: Black Hole eats sun (in reply to Piwin)
|
|
|
Piwin-
I confess to being both sarcastic, and imprecise. I did not intend seriously to question your criticism of the JWST cost overrun. I just meant to point out the ICRP’s inability to predict the final cost much more accurately than the NASA budgeteers they criticized.
Under the U.S. Department of Defense contracting regulations of the late 20th century, the Preliminary Design Review reported upon the detailed design of the concept selected at the Conceptual Design Review. This design formed the baseline for physical testing. Up to this point the work had been almost entirely theoretical. The revolting developments began to happen when the preliminary design was built and physically tested. Unacceptable test results required analysis and redesign. Some reserves of time and money would be included in the original plan to accommodate analysis and redesign. The greatest cost and schedule uncertainty occurs after Preliminary Design Review, and before Final Design Review.
In my experience, more experienced organizations produced more accurate initial cost and schedule estimates. For example, before undertaking the Trident ICBM program, Lockheed Missiles and Space Company had executed development and production of Polaris and Poseidon. Raytheon had many successful radar technology and system development programs before their efficient and prompt production of the radar system for the present U.S. ICBM defense. These companies had a reputation for accurate cost estimates and on-time delivery. But the cited programs were incremental technology developments, not great leaps forward. These companies also had reputations as expensive and risk averse.
On the other hand, General Electric Reentry Systems Division had a solid record of developing ICBM reentry vehicles.
There were moderate cost and schedule overruns, but the technology was revolutionary. Improved accuracy enabled smaller warhead yields, smaller reentry vehicles, and the development of ICBMS carrying multiple independently targeted reentry vehicles.
But GE performed miserably on a contract for lightweight, subscale reentry vehicle decoys, which in my estimation required only moderate technological innovation. The brilliant innovators in reentry vehicle design had retired or moved on. GE was ill equipped in the art and science of decoy evaluation, and failed to bring in subcontractors with the requisite experience. And they made amateurish mistakes in design and test.
A few years ago Larisa and I visited the U.S. Space and Rocket Center in Huntsville, Alabama, which commemorates the development of the Saturn 5 moon rocket. The hardware on display is immense and impressive. I pointed out what I considered the most impressive display of all, a summary of the program plan. It was extremely risky, with little or no slack for redesign and retest. I said to Larisa, whose mother was an aeronautical engineer in the USSR, “This, and the amount of money thrown at it, is what impressed the Russians.”
“Aside from the money, why was the U.S.A. able to do it?”
“Von Braun and the Peenemunde brain trust made sure to surrender to us instead of being captured by the Soviets. We made sure they had enough earlier support to develop the ability to do this. It was a tour de force, but it was built on incremental development. As you know, the Soviets gained an initial lead in the space race, but lost it to catastrophic test failures and redesign delays.”
I know nothing about space telescope design and development, but NASA has repeatedly touted the JWST as revolutionary in both design and capability. The development of accurate cost and schedule eluded both the original NASA/ industry team and ICRP’s panel of outside experts. I can offer no diagnosis.
RNJ
|
|
|
|
REPORT THIS POST AS INAPPROPRIATE |
Date May 24 2022 23:35:08
|
|
Richard Jernigan
Posts: 3245
Joined: Jan. 20 2004
From: Austin, Texas USA
|
|
RE: Black Hole eats sun (in reply to Ricardo)
|
|
|
quote:
ORIGINAL: Ricardo
quote:
No. The Wikipedia article claims that ablation of about 3/4 of the tamper material is the most efficient case. I don’t understand why 3/4 is most efficient.
Right, so only 1/4 of it is squeezing in on the spark plug…so after fusion occurs, that 1/4 left over might fission, but since it is separated from the other 3/4, is that small amount enough fission to account for 50% of the descructive force??? That is what had me scratching my head.
Two thermonuclear devices whose effects (not design) I frequently studied were the 300 kiloton warheads of some U.S. ICBMs and the estimated 1 megaton warheads of Soviet exoatmospheric interceptors.
Fissioning uranium produces about 17 kilotons of energy per kilogram of uranium. A little arithmetic gives 35kg for the pre-ablation mass of the tamper of the U.S. warhead, 59kg for the Soviet.
Uranium density is about 19 grams/cubic centimeter. This requires 1,858 cubic centimeters of uranium for the 300 kt warhead, 3096 cc for the 1 megaton device. To give a feel for the size, this amount of uranium would fit in a cube 4.76 inches on a side for the smaller warhead, 5.74 inches for the larger, pre-ablation.
The fission of these relatively small amounts of uranium is driven by neutrons from the fusion reaction, not by critical mass uranium neutrons as in the explosive-compressed trigger.
I have no practical experience with this subject, so someone should at least check my arithmetic.
RNJ
|
|
|
|
REPORT THIS POST AS INAPPROPRIATE |
Date May 31 2022 18:01:16
|
|
BarkellWH
Posts: 3358
Joined: Jul. 12 2009
From: Washington, DC
|
|
RE: Black Hole eats sun (in reply to Piwin)
|
|
|
quote:
Seriously... 10bn dollars just for some slightly better PC wallpaper. Geez... Just kidding of course. Mind-boggling images. Can't help but feel excited, and small.
Agreed Piwin. How can one look at those images taken by the James Webb Space Telescope, seeing the universe as it was more than 13 billion years ago, and not be excited. The universe is estimated to be 13.8 billion years old, so what we are seeing is very close to the singularity known as the Big Bang and the beginning of space-time. Amazing!
As exciting as I find these images and what they represent, I am equally excited that this enterprise represents mankind's continuing quest for knowledge of the unknown. From the earliest exploration of Asia and the Americas by the Portuguese and Spanish down to the present-day and the JWST exploration of the earliest evidence of the universe's beginning, the quest continues. It is what makes us human, in my opinion.
Bill
_____________________________
And the end of the fight is a tombstone white,
With the name of the late deceased,
And the epitaph drear, "A fool lies here,
Who tried to hustle the East."
--Rudyard Kipling
|
|
|
|
REPORT THIS POST AS INAPPROPRIATE |
Date Jul. 12 2022 18:14:22
|
|
BarkellWH
Posts: 3358
Joined: Jul. 12 2009
From: Washington, DC
|
|
RE: Black Hole eats sun (in reply to mark indigo)
|
|
|
quote:
for "exploration" of Asia and America you could substitute "exploitation". The Portuguese and Spanish were hardly motivated by a quest for "knowledge of the unknown" as the lands they "discovered" weren't unknown to the people that already lived there.... Certainly Columbus was looking for a quick route to India (hence "west indies") to make money from the spice trade, and the Portuguese were also looking for a sea route to India for the same reason, having already established a lucrative slave trade in west Africa even before Vasco de Gama and the "discovery" of Brazil.
It is common knowledge that Columbus was searching for a Westward route to India and the spice trade. Neither Columbus, nor the Spanish, nor the Portuguese were on purely scientific expeditions to enhance geographic knowledge, and I did not suggest that they were. Nevertheless, that exploitation of people and resources were involved does not detract from the discoveries they made and the knowledge they brought back to Europe. Historically, the exploitation of people and resources has been a driving force of exploration. They are hardly mutually exclusive, and it certainly did increase knowledge of the unknown at the time, which was necessary for the success of the enterprise.
The Indians who came from Siberia across the Bering land bridge settled in what we call North America. But they contributed nothing to knowledge. Columbus made careful note of how he got to the New World, its inhabitants, the flora and fauna, and he paved the way for future exploits. In short, Columbus made the New World available to Europe and increased mankind's understanding of the known world. That is the nature of discovery.
The Indians did not explore and discover Europe or any other region, and they had no idea of their place in the World's geography. Theirs was a static, unchanging view of their known world, largely determined by tradition and myth One often hears the trite phrase that one cannot "discover" a land where people already live, but "discovery" requires that the knowledge obtained be transmitted and used for the enhancement of knowledge and further exploration.
Columbus was a master mariner and captain. He made four voyages to the New World, and in fact did discover it when he first made landfall in San Salvador in today’s Bahamas. He landed in several areas, including Honduras in Central America. There is some evidence that Leif Erikson landed earlier in Newfoundland, but he did nothing to increase knowledge, which Columbus did, and which is the true result of discovery. And Columbus did it without the benefit of knowing how to determine longitude, a process that wouldn't be available with accuracy until the sea chronometer was developed in the 18th century.
Regarding the Indians, they were doing to themselves what Columbus and the Spanish after him did to them. Do not think the Indians were just a group of pastoral people picking daisies. The Mexica (Aztecs) ran an empire in which they required tribute and thousands of sacrificial victims. In fact, Cortes did not conquer the Mexica with his 600 Spaniards alone. He formed an alliance with the Tlaxcalan Indians, who were subjugated by the Mexica, and some 20,000 Tlaxcalans accompanied him to Tenochtitlan to defeat the Mexica.
In what is today the US, the Pueblo Indians of the Southwest were attacked and pillaged by the Apache and Navajo. They built their cliff dwellings to escape other Indians' raiding and pillaging. The Comanche raided other Indians and made slaves of many of their captives. The point of all this is not to justify the Spanish (and Portuguese) conquests in the Americas, but to demonstrate that the Indians were no better in their dealings with each other.
Distance traveled does not determine morality. Whether the Mexica conquered, demanded tribute, slaves, and sacrificial victims of a neighboring tribe; or Columbus and later Spanish (and Portuguese) explorers conquered, made slaves of, and mistreated the Indians and exploited the resources they encountered after crossing the Atlantic is irrelevant. Both acts are equally morally wrong if they are to be judged by today's standards.
Bill
_____________________________
And the end of the fight is a tombstone white,
With the name of the late deceased,
And the epitaph drear, "A fool lies here,
Who tried to hustle the East."
--Rudyard Kipling
|
|
|
|
REPORT THIS POST AS INAPPROPRIATE |
Date Jul. 16 2022 17:22:23
|
|
Piwin
Posts: 3451
Joined: Feb. 9 2016
|
|
RE: Black Hole eats sun (in reply to BarkellWH)
|
|
|
quote:
It is what makes us human, in my opinion.
Some years ago, I probably would've said language is our defining feature. Nowadays I'm not so sure. Or at least, I'm not so sure it is embedded in our genetic code and that there is what Pinker called a "language instinct". The more I look into it, the more the supporting evidence seems tenuous to me, and the more the arguments against seem to carry weight. Nowadays I lean more towards what Chater and Mortensen are calling "the language game" (the eponymous book is worth the read, if only for how rich it is in interesting anecdotes and factoids). They see language as a "community-wide game of charades, where each new game builds on those that have gone before". The sense in which biology defines language would then only be that in which it naturally constrains what kind of language game we can play. Put another way, they argue that languages have adapted to how our brains work, not the other way around. There's no definitive answer of course, but if I had to bet money on it today, that's what I'd bet it on.
What it is that makes us human would for me be perhaps some combination of our social nature and a strong leaning towards creativity, towards taking bits and pieces of knowledge and recombining them into something new. But who knows. We seem to be pretty bad at recognizing and understanding forms of intelligent life other than our own. Not just in how we think of non-human animals, but also in how we relate to extinct branches of intelligent life that were very close to humanity, like Neanderthals. Makes me wonder whether we would be able to recognize extraterrestrial intelligence even if one day we saw it staring right back at us. IMHO a stronger definition of what makes us human would have to be in contrast to what is not human, and since we're not all that good at recognizing non-human intelligence, we're perhaps not all that well equipped to define what it is that makes us human either.
_____________________________
"Anything you do can be fixed. What you cannot fix is the perfection of a blank page. What you cannot fix is that pristine, unsullied whiteness of a screen or a page with nothing on it—because there’s nothing there to fix."
|
|
|
|
REPORT THIS POST AS INAPPROPRIATE |
Date Jul. 17 2022 15:35:06
|
|
 New Messages |
 No New Messages |
 Hot Topic w/ New Messages |
 Hot Topic w/o New Messages |
 Locked w/ New Messages |
 Locked w/o New Messages |
|
Post New Thread
Reply to Message
Post New Poll
Submit Vote
Delete My Own Post
Delete My Own Thread
Rate Posts
|
|
|
Forum Software powered by ASP Playground Advanced Edition 2.0.5
Copyright © 2000 - 2003 ASPPlayground.NET |
0.09375 secs.
|
Printable Version
