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#26 Re: Terraformation » Venus » 2012-03-08 12:53:17
Hmmm. Something to do with the atmospheres rotation, perhaps? Is the atmosphere moving faster, I wonder.
Bearing in mind that it's just over an hours decrease in 160 years, so it could have already been slowing before humans started to look at it.
Or it could be aliens trying to artificially tidal lock it...
I didn't read the whole article. Did it say what causes it?
#27 Re: Civilization and Culture » Minimum Growth » 2012-03-07 20:15:39
John Creighton wrote:I think this will be more costly though.
I don't know why you think that. Raising and educating non-productive children is very costly.
So is sending people to mars. I'll reply to the rest later.
#28 Re: Civilization and Culture » Minimum Growth » 2012-03-07 13:58:59
I don't feel you've thought this through entirely.
In most things that are interesting it is impossible to think the topic through entirely.
1. As long as you have a source population, you don't need procreation to increase your population. Monastic colonies are examples of colonies that don't rely on procreation to grow. Other colonies (not such a nice example) such as the slave societies of the Caribbean grew exponentially as a result of importation of people.
I think this will be more costly though.
2. You first have to address the issue of embryo development. There is good reason to believe that one third gravity will not be conducive to good embryo development. Furthermore, pregnancy will be v. resource intentive in terms of medical equipment for an infant community.
I have no way of testing this at this time so I have to make assumptions.
3. Wouldn't it be better to simply rely on adult incomers to grow the colony to begin with, with people gradually increasing their period of stay as we learn more about one third gravity.
This would be a more costly approach in that it is money spent which is not spent to towards the direct achievement of our goals.
If we can get to the point where in situ procreation is a real option, the colony might face an issue over encouraging women to have larger families. I have suggested before that the colony might want to encourage women to have two children early on - e.g. in their early 20s, followed by two more when they are in their late 30s. You would need to have Kibbutz style child care arrangements as well I think.
That would give the four kids I suggested. I don't know much about Kibbutz. Maybe post about how it might relate to mars in another thread.
#29 Re: Civilization and Culture » Resource Allocation - What Can we learn from Carl Menger » 2012-03-07 13:53:21
Lots have been posted since I last was in the thread.
Early inhabitants would first need to focus on what it takes to repay the debt to get to Mars as I am sure that they will not be riding for free or will have had there bill paid in full. That would include the materials to make any mission possible as part of the debt. Then they will be free to go there own respective path to do more than inhabitat as they can then set forth to create what mars will need for services to earn a living with.
The model I’m assuming is they send people to mars to do science and some of those people which are sent decide to stay. If people stay it is cheaper as resources don’t need to be spent to get them home. Under such a scenario, there will be no debt to repay as they are there to do their job.
However, in the event of a larger scale colonization you scenario makes more sense but for such a scenario the cost of getting there would need to be much cheaper.
So a first order item with respect to the list is a complete lander/habitat capable to sustain life for a period of time.
So time is not a function of the listing process and that causes the confusion I have for what is a controlled gradual process is set to how we utilize the time we have once we are there.
As mentioned above I tried to break the habitat down into more bask measures of human needs. This will be useful to my analysis but may not aid yours at this time. Time plays into my analyses in that we have to optimize our needs over all time. If there is any day which our needs aren’t sufficiently met then that could be our last.
#30 Re: Civilization and Culture » Resource Allocation - What Can we learn from Carl Menger » 2012-03-07 13:44:51
John Creighton wrote:I was actually thinking of using the dollar amount to import a given quantity of good to mars as the basis for price and with this metric we can measure the size of the Martian economy.
…..
Sorry I misinterpreted you there - was in a bit of a rush earlier on.Personally I think your analysis doesn't do justice to the complexities.
It is often helpful when trying to understand something to see how we can reduce the complexities. That doesn’t mean that after such an exercise we shouldn’t go back and look at the complexities.
I think the reality is going to be much more like the early colonisation of Australia where all sorts of motives: trade, imperialism,
raw materials acquisition, criminal justice, religious proselytising, military, scientific etc were mixed up.You seem to imply that there is an exact match between the interests of the Mars inhabitants and the interests of colonisation. Not necessarily so.
That may be the case but the colony will be much more prosperous if people go there with the intent to build a future.
Mars inhabitants might want to enjoy the creature comforts of home rather than investing in more machinery and housing so that more colonists can join them, especially if say their bank accounts back on Earth were being lined with export earnings.
By this I will presume you disposable goods as opposed to durable goods since with durable goods there is a chance that part of the value will be retained after the inhabitant passes away. One would suspect that both types will be desired and the capital used to produce disposable goods will like to a degree be durable.
However, I think it is wrong to expect a money economy to develop on Mars for several decades. The Mars money economy will be located firmly back on Earth and it will be the consortium back on Earth making the key decisions, not the Martians (I prefer Aresians for humans!).
Whether they use physical money or not is a secondary point. In prison, people trade cigarettes. It still acts as money whether or not we need to call it money. Even favors and good will serve to some degree as a medium of exchange in that people often expect some reciprocity.
#31 Civilization and Culture » Minimum Growth » 2012-03-06 13:57:55
- John Creighton
- Replies: 4
An advanced civilization can grow at a very small exponential growth rate and sill have significant growth but an initial colony has to as a minimum replace the old generation. A generation is considered to be roughly about 20 years and without new births in that time period the population will begin to stagnate. If each couple had two kids and started having kids at 20 then an initial population of 2 would grow to about 8 over a period of 80 years but if the growth rate does not exceed that the population will cease to grow as the death rate begins to match the birth rate.
Consequently an initially guess would be that between 3-4 kids per couple would be necessary to have a reasonable successful chance at growth. On a large scale initial mission 8 people, we will have a population of 8 initial people 4 generations x 4 kids per couple / 2 people per couple =126 people
Which is on average a growth of 1.6 people per year for a period of 80 years.
#32 Re: Civilization and Culture » Resource Allocation - What Can we learn from Carl Menger » 2012-03-06 13:39:18
John Creighton wrote:I was actually thinking of using the dollar amount to import a given quantity of good to mars as the basis for price and with this metric we can measure the size of the Martian economy.
I really don't think for most goods that the dollar price on Earth (if that's what you mean) will have much relevance on Mars as part of a multi-billion dollar project. I think we need to write off the initial development costs of getting people established on Mars and then get accurate amortised costs for future transit of goods on a per kg basis.
Above I said the import cost (not the dollar value on earth) and this cost includes the transportation cost. Whatever we are willing to import must to us be worth the cost for us to import it. When we are willing to utilize one of the goods (labor, materials, machinery) imported to mars to produce another good, the value of what is produced is at a minimum worth the cost of the imported resources required to make that good.
The Martians initially do science in return for the goods required to live. When such goods grow faster than they are consumed the economy grows and when the reverse happens the economy declines. If a Martian could produce some of the goods required to carry on their science by using either their free time or as surplus payments for their work then the economy grows and this growth is either though the surplus work of the initial Martians or the surplus payments of the people supporting the missing.
The value of the surpluses production would be measured in terms of how much dollar (includes shipping cost) values of earth imports a Martian is willing to exchange these goods for. Inflation indexes could be devised to consider the growth in the well being of the Martians.
#33 Re: Civilization and Culture » Resource Allocation - What Can we learn from Carl Menger » 2012-03-05 23:23:40
Yes, this sort of analysis is helpful, although I'm not sure we needed Menger to help us do it (I've posted similar analyses here before now without reading Menger!).
I've also thought of many things myself without first knowing the origin of the idea. That of course says nothing as to whether we would have thought of the same idea if we were living in the same environment as the originator of the idea. I was reading the Black Swan, and the general theme of the book is about events we never expect to happen. In part of the book he was talking to a professor who praised the book but then gave a causal explanation of what led the author to write the book. The author of the black swan, Nicholas Taleb, went on to say how the professor's statement showed he missed the point of the book. In one chapter of the book Taleb talked about our bias to find naritives to explain events and he concluded by the professor looking for a causal explination he missed this point of this chapter.
However, to me it is not an unreasonable conjecture that our environment influences our ideas. I have had many ideas which were not widely discussed when I originated the idea and then in about five years saw the idea reach a much wider level. Today when this happens at a very large level we might call it a meme or say the idea went viral.
Given that I am no one of significance; to me it would be egocentric to say I played a significant part in the spread of these ideas. We all play a part in the discourse of ideas. Our part is often neither essential to the propagation of the idea nor insignificant. A metaphor for this is a stone falling in water. The stone is the event which we are all reacting to and the wave is the propagation of this reaction. Each particle of water plays a part in spreading the propagation of a wave that was initiated by the drop of the stone. No one particle is essential to the propagation of the wave but without the particles the wave would not propagate.
Here is an interesting quote I read the other day:
"The Price of Generational conflict is Heavy: Intellectual Innovation Ceases among the Old, and Proceeds on Shaky Grounds Among the Young"
from Leonard Krieger: Historization and Political Engagement In Intellectual History by Malachi Haim Hacohen contained within, History And Theory Studies in the Philosophy of History pg 84. Volume 35 1996 Wesleyan University
We learn by questioning what we are taught but if we weren't taught what would there be for us to question and how then would we stimulate our minds? Returning to, The Black Swan. Nothing in the black swan from a mathematical perspective is foreign to the thinking of anyone who extensively studied statistics and mathematical modelling. From a philosophical perspective much of the ideas could be easily lifted from Bertrand Russell's, book, "The problems of Philosophy". What gave Taleb book such an in pact was both the narrative writing style which is a more effective way of communicating with non mathematical minded people and using enough examples to help make the ideas concrete. If we were to use latten terms, we would say he put the ideas, "in conreto".
Moving forward. It is great to have good ideas but I believe creativity is natural and unfortunately systematically suppressed. Great thoughts are usually not novel, but being able to put them in the context of history gives one a strong footing in any debate to follow. So much of what we think today is very old and many ideas can be traced back to Plato and Aristotle. Here is a quote for you from Bertrand's Russle's article, "How to be a man of Genius":
"If there are among my readers any young men or women who aspire to become leaders of thought in their generation, ........ A man of genius knows it all without the need of study; ............ Above all, whatever is most ancient should be dished up as the very latest thing."
http://www.personal.kent.edu/~rmuhamma/ … Genius.htm
Studying history helps to put our ideas in perspective. Knowledge of history also keeps us from becoming too naive about our ideas. History organizes our understanding of what led us to think what we do today in a chronological manner showing us the reasoning of the debate which led us to what we think today and reminds us of what has been forgotten along the way. You don't have to read Menger to have his ideas but he is a very relevant figure in history. The Austrian school of Economics tells us about our market instability. But this was known even before the Austrian Economists. Heck even Marx new it:
"In every stockjobbing swindle every one knows that some time or other the crash must come, but every one hopes that it may fall on the head of his neighbour, after he himself has caught the shower of gold and placed it in safety."
by Karl Marx.
Despite the constant mistakes of the past the snake oil salesman of the day continue to contend both that they have it all figured out and that the lessons learned from history no longer apply.
However, you don't state explicitly whether you are looking to manufacture the goods on Mars.
Yes we will manufacture on mars but it is helpful to have some analysis of how to choose what we will manufacture and how much of each good to manufacture.
We need to make a mass analysis of these goods.
I was actually thinking of using the dollar amount to import a given quantity of good to mars as the basis for price and with this metric we can measure the size of the Martian economy.
It doesn't always make sense to make goods on Mars in the first few decades of colonisation.
Does this mean you rejection Zubrin's concept of In-Situ propplent production?
For instance, what would it take to be able to manufacture medicines on Mars? The medicines will be vital - you might even say they are first order goods - but it is better to import most of them because the tonnage of manufactring equipment and skilled personnel (plus all their life support) that would be necessary to make them on Mars would be huge.
We could consider medicine a basic need which can't be reduced into more basic needs. I will leave it open the best way to think about medicine when planning for a mission, base, outputst or civilization. I do agree though that much of the medicine need will intially be importated.
What we need to aim for on Mars is a basic scaled down industrial infrastructure (using scaled down machines - lathes, furnaces, presses etc). We also need to aim for a stripped down economy. There's no need to use paper on Mars. People can use their imported lightweight laptops for writing. There's no need to have separate batteries and electric motors for different machines - you can swap the motors and batteries as the need arises.
Sounds reasonable. Standardization helps make goods more substitutable and hence helps us better prepare for our future needs. Moving along. In order to know which pieces of equipment we should bring first to mars I would ask how does each of these suggestions you made provide for current or anticipated needs of future people in space. They all sound reasonable and I hope for a better analysis to follow.
Rather than try and procude a range of materials - lots of different polymers and so on - it will be better to concentrate on a few basic materials e.g. glass, basalt/fibre glass, bamboo, iron and steel and adapt our products to those materials.
I'm in total agreement her but only to a point that each good helps to fullfill our needs. It makes no sence to devote any more resources to the production of such goods then is utalizable, and what can be utilized depends on what complementry goods are availableble. The necessary complementry goods would include labor and machanery as well as raw inputs.
#34 Re: Civilization and Culture » Resource Allocation - What Can we learn from Carl Menger » 2012-03-05 13:54:56
Thanks for the subject as I understand thou when we go to Mars which is not directly livable for man that some of the second order list moves to the first as a result of destination. That said thou many on the second and even the third are related for the expansion or direct result of colonization/ settlement of man's extended stay.
I’ve considered that and while it makes sense to say something like a life support is a basic need and therefore a first order good; part of what a life support system does can be broken down into the production of goods which constitute our basic needs.
We need so much oxygen, we need so much water, we need so much food over a given period of time. Part of the function of the life support system is to produce these basic inputs to sustain our life from human waste. Heat is perhaps slightly trickier in that we don’t have a direct need for heat or cold since the amount of heat we either take from our environment or give to our environment is dependent on temperature.
However, we could consider heat as an input to maintain shelter which is a basic need. So we can take shelter as a first order good and consider both the structure and the heater second order goods which we need to combine to provide shelter. That is a shelter is produced as a result of combining a given amount of heat with a given amount of structure, and a given amount of breathable air.
Shelter is maintained by the life support system which produces the part of the air in the shelter we consume.
The goal here is to reduce that amount of things which are considered first order goods or basic needs, so the value of all other goods can be measured in terms of how they can be used to obtain the first order goods that we need.
While it is true we all value things differently we all have similar basic needs. As a consequence if we build a metric based upon the satisfaction of these basic needs it is more likely to model something which correlates to some degree to our wants as we must all want these things to a certain degree in order to survive. What this is, is essentially a reductionist version of utility where instead of trying to capture everything that motivates us we try to express our motivation as best we can in terms of some of our most basic needs.
#35 Civilization and Culture » Resource Allocation - What Can we learn from Carl Menger » 2012-03-04 14:08:46
- John Creighton
- Replies: 15
Carl Menger in his book, "Principles of Economics" [1] talks about orders of goods. 1st order goods are those which directly satisfy our basic needs such as food and shelter. 2nd order goods are goods used to obtain 1st order goods. For instance we can't eat a, bow and arrow. However, we can use a, bow and arrow, to achieve first order goods though hunting. Third order goods are the goods required to produce second order goods. For instance we may use wood to make a, hunting bow.
Menger criticises Adam Smith for making specialization of labour the central factor of human progress. Menger lived during an Era of economics called, "The Marginal Revolution". One idea which came out of the marginal revolution was that of Marginal cost. Marginal, cost could be used to argue the diminishing marginal return of complexity/specialization [2] but more importantly Menger stressed the significance of higher order goods (A.K.A invention) for the progress of civilization.
Menger also talked about how higher order goods were complementary. For instance if one had insufficient cotton to utilize all their sewing machines, then each sewing machine would be less useful for the satisfaction of human needs and hence less valuable. In order to produce a lower order good from a higher order good you need the right complementary goods of that order.
Now what I think Menger gives us is a philosophy of planning. We must consider what are the most basic needs for a; Space mission, base, outputs or civilization, and then ask what goods of the next order can most efficiently satisfy these lower order needs.
Some first order needs we may identify for surviving in space are fuel, shelter, food, oxygen, water.
-- (side note: If wanted to inject Maslo into the discussion we might also consider higher level needs (as opposed to higher order) and consider psychological needs but lets start at least at first with the most basic needs.)
-- Second order goods might include:
1) transportation systems to cheaply import goods
2) life support systems (mechanical or biological) to recycle water and oxygen
3) materials to expand shelters (brick, inflatable's, burrowing equipment)
4) drilling equipment to extract water
5) air processing equipment to extract fuel and water from the air.
6) tools to make shelter.
7) hydrogen to make fuel (hydrogen can be both a first and a second order good as it can be used directly for fuel or turned into methane to produce more food)
8) refrigeration and other methods of preserving food.
--Third order goods might include
1) A 3D printer to make tools and parts necessary to repair equipment.
2) Digging equipment to extract stuff to make the raw materials to build food and shelter.
3) Seismic equipment to explore for resources.
4) Transportation equipment to transport resources
5) electrolysis equipment to extract hydrogen from water.
6) Tools and spare parts needed to maintain second order goods.
Now to a point everything discussed so far seems as it should be obvious but without explicitly looking at our needs through this thought process it is easy to miss-allocate our resources.
In advanced economies such as ours, planning does not need to be as central organized as it does in more primative societies. The better a free market economy functions the better price will be as a signal as to the relative value of goods for the purposes of satisfying the needs of a society. In a primitive space mission\outputs or civilization the information given by price does not give us more information about the best allocation of resources then we are able to obtain through planning because the complexity is small enough to fully model the problem and their does not exist enough aggregate information in price to surpass our imperfect ability to anticipate our needs.
Consequently one might presume that in such situations we should plan for our needs. What Menger gives is a criteria to plan in that, we must prioritize our planning so that before worrying about higher order goods, we must have sufficient quantities of the lower order goods to satisfy our needs. Additionally Menger reminds us that the value of a higher order good also depends on having enough of the complementary goods to utilize the good. For instance we can dig up all the dirt we want but if we lack the resources to turn that good into Iron, then the marginal benefit of digging up more dirt quickly decreases to a point of becoming of negative value as we are both wearing out our digging equipment and expending valuable fuel.
Menger was the catalyst for what is now known as the Austrian School of economics [4] and this school often focussed on the non mathematical aspects of economics. It wasn't that they did not consider mathematical approaches valuable it was that by narrowly focussing on quantitative aspects we misallocate the resources we use to study an issue. Mathematics can obscure an issue, take an overlay narrow approach in considering the causes in order to get to a workable model, and give us too much confidence in causal relationships by the miss use of statistics.
That said in another thread I will formulate the above in a mathematical manner. In this thread I would like to deal solely with conceptual issues and discuss how a mission, outputs or civilization should prioritize their needs by breaking down goods into various orders and consider the cost of obtain each good of each order.
--------------------
Refferences
[1] Carl Menger - Principles of Economics (1871) [3], http://mises.org/books/mengerprinciples.pdf
[2] Clay Shirky - The Collapse of Complex Business Models - http://www.shirky.com/weblog/2010/04/th … ss-models/
[3] Wikipedia - Principles of Economics, http://en.wikipedia.org/wiki/Principles_of_Economics
[4] Wikipedia, Puecursors to the Austrian School of Economics, http://en.wikipedia.org/wiki/Austrian_School#Precursors
#36 Not So Free Chat » Bring Back Free Chat » 2012-03-04 12:14:22
- John Creighton
- Replies: 3
Given the form is slow again I see no reason why we shouldn't bring back free chat again. Well, it was a source of disagreement it was also a source of very energetic posting.
#37 Meta New Mars » Wiki » 2012-03-04 12:11:34
- John Creighton
- Replies: 19
What is the chances of the wiki coming back? Is all the old data still available?
#38 Re: Science, Technology, and Astronomy » Scientists Propose Test Of String Theory Based On » 2008-02-02 01:10:25
ScienceDaily (Feb. 1, 2008) — Ancient light absorbed by neutral hydrogen atoms could be used to test certain predictions of string theory, say cosmologists at the University of Illinois. Making the measurements, however, would require a gigantic array of radio telescopes to be built on Earth, in space or on the moon.
String theory -- a theory whose fundamental building blocks are tiny one-dimensional filaments called strings -- is the leading contender for a "theory of everything." Such a theory would unify all four fundamental forces of nature (the strong and weak nuclear forces, electromagnetism, and gravity). But finding ways to test string theory has been difficult.
Now, cosmologists at the U. of I. say absorption features in the 21-centimeter spectrum of neutral hydrogen atoms could be used for such a test.
"High-redshift, 21-centimeter observations provide a rare observational window in which to test string theory, constrain its parameters and show whether or not it makes sense to embed a type of inflation -- called brane inflation -- into string theory," said Benjamin Wandelt, a professor of physics and of astronomy at the U. of I.....
#39 Re: Unmanned probes » Wielding a Cost-Cutting Ax, and Often, at NASA » 2008-01-03 13:20:15
To finance President Bush’s exploration initiative to return humans to the Moon, while also financing space shuttle operations and a shuttle replacement out of the agency’s approximately $16 billion annual budget, science program money is being held to about a 1 percent increase per year for four years.
As usual the NYT can't resist a subtle jab at Bush by implying that science at NASA is paying for his "exploration initiative" (confusion with SEI from several years ago?) by twisting the truth. Exploration got less than requested in the 2008 budget at $3.8B (requested $3.9B) whereas science got far more in total at $5.6B and more than requested ($5.5B).
That’s unfortunate. I dream of a world where journalist get the facts right. Why are they called journalist anyeay, they don’t work for a journal. I think they should be called tabloidist. lol
#40 Re: Unmanned probes » Wielding a Cost-Cutting Ax, and Often, at NASA » 2008-01-01 13:56:51
WASHINGTON — In Washington, it almost seems radical — completing government projects at their original budgeted cost.
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Enlarge This Image
Bill AerospaceA Kepler mirror inspection.
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NASAOne project S. Alan Stern reined in was the Kepler mission to launch a planet-hunting telescope.
Yet at NASA, the new director of the space science division appears to be making headway at doing just that, creating some anguish among researchers and contractors along the way.
In his eight months on the job, the director, S. Alan Stern, has turned back almost a half-dozen requests for more money from projects experiencing cost overruns, he said. That has forced mission leaders to trim parts of their projects, streamline procedures or find other sources of financing.
Dr. Stern, an astrophysicist and planetary scientist, became associate administrator for NASA’s Science Mission Directorate in April. In an appearance before Congress the next month, he outlined a tough plan for keeping missions on budget and holding leaders responsible: better cost-estimating tools to more realistically price missions, more experience for scientists running projects, and new studies to better understand and reduce technology risks.
NASA devotes about $5.4 billion a year to its science program, divided among specialties like astrophysics, earth science and planetary exploration. To finance President Bush’s exploration initiative to return humans to the Moon, while also financing space shuttle operations and a shuttle replacement out of the agency’s approximately $16 billion annual budget, science program money is being held to about a 1 percent increase per year for four years.
Factoring in inflation and the loss of what had been anticipated financing increases, space experts say this amounts to a loss for NASA science of about $3 billion over that period. For Dr. Stern, that means doing more with less.
One of the first targets in his effort to attack cost overruns was the Kepler mission, a project started in 2001 to launch a planet-hunting telescope. Because of management problems, technical issues and other difficulties, the price tag went up and the launching date slipped from the original 2006 target.
In 2006, NASA resolved itself to a 20 percent cost overrun, which raised the price to $550 million, and accepted a 2008 launching time. Then the Kepler team came to Dr. Stern last spring with a request for an additional $42 million.
“Four times they came for more money and four times we told them ‘no,’” Dr. Stern said.
After Dr. Stern’s team threatened to open the project to new bids so other researchers could take it over using the equipment that had already been built, the Kepler group came up with a solution. Among other measures, the duration of the four-year mission was cut by six months and preflight testing was scaled back.
“When they came to believe I was serious and had my boss’s backing,” Dr. Stern said, “they took it seriously. They quickly found a way to erase that bill.”
Dr. Stern, 50, came to NASA from the Southwest Research Institute in Boulder, Colo., where he directed the Space Science and Engineering Division. His hard line on cost overruns has been one of the first signs of change noticed by researchers and many outsiders. So far, he said, his team has rolled back cost overruns in almost a half-dozen projects, sending out word that this is now standard procedure.
“I admire what he’s doing,” said Dr. Lennard A. Fisk, professor of space science at the University of Michigan and chairman of the Space Studies Board at the National Academy of Sciences. Dr. Fisk, who headed NASA’s science directorate in the 1980s, said true reform required a cultural change at the agency in how it runs programs. And a director must be consistent, he said, to convince people of the seriousness of the effort.
“In the beginning, he has to be hard-nosed with everybody,” Dr. Fisk said. “The first one he blinks on could be a problem. He has to maintain his credibility.”
Dr. Stern said that when he took the job, he told the NASA administrator, Michael D. Griffin, that he planned personnel and policy changes in his division to make the most of a stagnant budget while continuing to sponsor world-leading space science. He noted the appointment of Dr. John C. Mather, a Nobel laureate, to the vacant post of chief scientist in the directorate as a sign that science, not just launching spacecraft, would be the chief focus.
“We’re just not walking around swinging the ax,” Dr. Stern said. “We have a very new team that, I hope, is changing the way we do business.”
#41 Re: Interplanetary transportation » Mass Drivers » 2007-12-01 16:46:07
All this and much more has been discussed here previously, please try to find and add to existing topics. There are plenty of interesting ideas and excellent comments available. It's perfectly ok to bring dead topics back to life!
I'm sure it's been discussed there but I didn't notice it skimming though it. I prefer focused topics. The topics you listed are general.
#42 Re: Interplanetary transportation » Mass Drivers » 2007-12-01 00:16:28
I'm not sure if anyone is interested but:
orbinal velocity7.8 km/s = 7800 m/s
A=dv/dt=dv/dx dx/dt=dv/dx v
a dx=v dv
a delta X = ½ (V2^2-V1^2)
delta X = ½ (V^2)/a=0.5*(7800^2/(9.80665*10))
=310197.67198788577138982221247827 m
=310 km
Thus forgetting engineering problems like friction energy stability and such you would need a 310 km track to accelerate something to orbital velocity if you are accelerating at 10 gees. Perhaps 100 km would be enough to replace a first stage but it is apparent that any kind of flinging device is going to be massive and very expensive if the G forces are not too excessive.
http://en.wikipedia.org/wiki/Gravitational_acceleration
http://en.wikipedia.org/wiki/Orbital_speed
http://www.onlineconversion.com/speed_common.htm
#43 Re: Interplanetary transportation » Mass Drivers » 2007-11-29 13:41:38
Anyway, someone in another thread mentioned 1 km as the largest conservable radius of a mass driver. The cost of such a device should beyond practical but if such a device could be built out of rigid materials then as the thing starts to pick up speed a tether could extend the radius further. I think that a tether could extended the radius 10 times beyond the length of the rigid part of the arm. Also as mentioned in another thread, even at 10 km we are still talking 100 gees.
http://www.newmars.com/forums/viewtopic … 6&start=40
I can’t imagine the friction forces and the effect such a device would have on local wind patterns. I think that linear acceleration would make more sense as an alternative to a first state. I haven’t worked out though how long a track you would need to get a reasonable boost at 9 gees of acceleration. Maybe I’ll work it out tonight.
#44 Re: Interplanetary transportation » Space Elevator or Scramjet? » 2007-11-28 14:22:35
An enormous amount of energy is needed to accelerate an object to 8km/sec, 1 kg would need 0.5*1*8000^2 or 3.2*10^7 Joules. It's about 100 times the energy needed to lift it to 32 km (1*32000*9.8 J)
If this is a mass driver it will need a long vacuum pipe with associated coils, vacuum pumps, shutters etc etc. To keep the structure to a feasible length, say 100m, it would need to accelerate the package in 0.025 secs at 200,000 G thus needing 800 kW of power assuming no losses due to friction. This device has to be suspended at 32 km together with its power supply and a collection system to receive and load the payload. Anyone want to bid for the contract?
I find the idea interesting from a technical point of view but I agree the economics aren’t there. All I need to do is consider how hard it is to justify the cost of a high speed train between two cities to see how dubious the economics would be for the device which is being proposed.
#45 Re: Interplanetary transportation » Space Elevator or Scramjet? » 2007-11-28 13:14:34
I’m sure the cost and technical challenges and cost would be immense but if an object is accelerated 32 km and released 32 km above the ground as Antius suggested then would the G forces really be that large?
#46 Re: Science, Technology, and Astronomy » Google Sky » 2007-11-25 15:54:38
I was looking at Google Sky the other day, zooming in here, there, and everywhere, and kept finding Unnamed Galaxies. Either Google hasn't bothered to name the Galaxies (they're the bigges objects in the known universe, you'd think they'd be named) or they haven't been discovered yet.
On a side note you can get pretty good pics of stars.
My guess is that they are identified. Weather they are given a name or a number I’m not sure. I don’t know which extraterrestrial objects are assigned names.
#47 Re: Human missions » Earths Oceans Explored - but why not colonized » 2007-11-24 00:12:31
No light? And land reclamation must have its limits. You also lose that river or lake.
Build upwards then
Actually that will probably be what will happen. Did you know in Japan that they are building a building that is almost a completely contained city. I still think though that the idea of living under water with the fishes is somewhat romantic even if it isn't good for the health.
#48 Re: Human missions » Earths Oceans Explored - but why not colonized » 2007-11-22 13:10:36
Who said it would cost millions and who said it would be really deep down in the ocean? Who said it would be in the ocean anyway? You could colonise rivers and have tunnels leading to them.
Why not just live underground?
#49 Re: Interplanetary transportation » Northrop Grumman Lunar Lander Challenge » 2007-08-23 00:36:30
Armadillo Aerospace - July 14, 2007 notes
It took me an appallingly long time to get the 3-axis attitude values from the GPS into the correct reference frame for the existing flight control software. It was frustrating having to leave the box and antennas propped up at different angles out in the middle of the parking lot while working on the software inside, but the worst part was that I felt that I had gone through every possible orientations of the quaternion output before I finally just switched over to the Euler angle output and eventually got it working. I’m supposed to be good at all that 3D math. Sigh
New module design - tethered test flights - (mpg video 2:26 mins 20 MB download)
That's kind of amusing 
#50 Re: Science, Technology, and Astronomy » A renaissance for space solar power? » 2007-08-21 08:50:31
I found this interesting:
This document ...
http://spacesolarpower.files.wordpress. … _f2391.doc
... referenced in that post contains all the latest advances - 4300 W/kg thin film solar, Landis' integrated solid state laser, solar sail type 5 g/m^2 mass loading. Very nice.
This is exactly where they need to be going on this. These have to be gossamer structures. Launch costs will kill anything else.
I'll look at it later. Anyway, is it worth 80 cents per killowat hour? I suppose logistically supplying gas or batteries could be hard but in terms of cost I think it would be much cheaper to just ship fuel to a generator. Anyway, at 1 billion dollar revenue per year that would be about a 10 billion dollar system at 10% a rate of return (which is reasonable). Do we think it would cost more or less then 10 billion to produce a 1.5 MW system? HOw much power does the international space station produce? Would this system be much cheaper per killowhat produced then the international space station? If they could build a 1.5 MW system for 1 billion dollars then they'd be laughing.