If you like Heinlein, read some of the good new stuff that he inspired. My recent favorite is Old Man's War by John Scalzi (Just won the John W. Campbell award). Inspired by Starship Troopers, but not like it.
Red Thunder is an homage to Rocket Ship Galileo by John Varley. Not as good as Scalzi, but still fun.
You may as well go for the career you really want and will be best at, because outsourcing comes to every job.
Think that a job in the food services industry wearing a polyester uniform and paper hat will save you? It won't save everyone. Next time you're in the drive-thru lane at McTacoShack(tm) yelling at the squawk box, realize that the person you're talking to doesn't have to be in the same 'Shack where your pizza is being deep-fried. Many chains already take orders at centralized locations that handle thousands of franchise operations--modern telecommunications technology makes distance irrelevant to the transmission of unintelligible speech.
I don't know if any are off-shore yet, but they will be.
So what would you rather be, an outsourced computer programmer who has can start up his own business, or an outsourced order-taker trying to find someone to pay for your skill at misunderstanding garbled speech?
Take a look at this chart showing how well CO2 correlates with the historical temperature record
And notice how the reversed scale confuses the fact that temperature rises tend to be followed by increased CO2. To the extent that correlation implies causation, it seems that high temperatures cause CO2 increases rather than the other way around.
"Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns -- the ones we don't know we don't know." - Donald Rumsfeld [quotationspage.com], February 12, 2002
Which just goes to show you that, just because you are saying a wise thing, doesn't mean that it is a wise thing to say.
The Washington press core is ordinarily a placid, docile herd. But if you say something that confuses it, they get frightened and can lash out unpredictably. Pretty soon they are asking questions about the Valerie Plame leak or Katrina.
At that point you need to distract them with a shiny object like a Supreme Court nomination.
Just a terminology thing: Gravitational potential energy is measured relative to the system dispersed out to infinity. A white dwarf has negative potential energy, and so combined with the positive energy release by fusion will diminish the energy of this Type Ia supernova, relative to what you would get if you jcoudl just ignore gravity.
The iron core of a core-collapse supernova progenitor (similar to a white dwarf in size and mass, but made of un-fusable iron) has negative gravitational energy. The 12-km radius neutron star it becomes as it collapses has a much much more negative gravitational energy, by of order -1e46 Joules (-1e53 ergs). As you'd expect, this means that there's about 1e46J of positive energy suddenly liberated. 99% of that comes out in neutrinos, which have almost no effect once they get out of the star. The remaining 1e44 ergs comes in the form of supernova light and kinetic energy of the exploding ejecta.
The non-neutrino portion of the energy of a core collapse supernova is comparable to the total energy of a Type Ia supernova (which does not produce much in the way of neutrinos).
You are right that the gravitational binding energy of a white dwarf is comparable to the fusion energy of its combustion from carbon to iron. However, comparable doesn't mean equal and if you work it out, the fusion energy dominates. The gravitational energy is negative, so it reduces the amount of available energy for the supernova (i.e. the ejecta are moving more slowly because it has to climb out of its own gravity well), but it is still energetically favorable to go from a dense chunk of carbon to an expanding diffuse cloud of iron.
No, white dwarfs do become fusion-powered supernovae, not gravity-powered. IAAA (I am an astrophysicist.)
A white dwarf becomes a Type Ia supernova when, at around 1.4 solar masses, the pressure at the center reaches the point where it can burn by fusion the carbon-nitrogen-oxygen left over from previous rounds of burning. This leads to a fusion-driven explosion that gets no net energy from gravitational collapse, leading to an expanding gas cloud that is largely hot iron-group elements.
There is another class of supernova that is gravitationally driven. Core collapse supernovae are produced when a massive star (>8 solar masses, last I heard) has burned 1.4 solar masses at its center to iron. (The 1.4 solar mass value is semi-coincidental with that in the previous paragraph, based on similar but not identical physics.) This is a gravity-powered supernova that blows the outer parts of the core away, leaving a neutron star or black hole where the core was.
There is no way for a white dwarf to become a core collapse supernova, the fusion kicks in and blows it apart before that happens.
The 'Physics Essays' journal that is mentioned in TFA has this to say about its peer review process:
Articles submitted for publication will be reviewed by scientific peers. Realizing the interchangeable roles of authors and reviewers, the positive aspect of the reviewing process will be retained by providing the authors with the reviewers' comments. Authors should judge which part of the reviewers' suggestions are appropriate to improve the quality of his or her paper. The editor, who is responsible for the Journal, will allow a large degree of freedom to the authors in this process.
So basically the article is reviewed by peers, but if the review says 'this is garbage from beginning to end', it still can get published.
There is a simple way to aim mirrors that you learn about in Boy Scouts.
Use a double-sided mirror with a hole in the center of it. Get the mirror in approximately the right position so that you can see the target through the hole, and in the backside reflection you can see on the ground where the Sun shines through the hole.
Tilt the mirror so that the sunlit point on the ground is (in the backside reflection) at the location of the hole, and so that you are still looking at the target through the hole.
If you draw it, remembering how mirrors reflect equal angles incidence and reflection, you can see that this shines the sunlight right at your target.
Easier to draw than describe, and easier to do than draw.
In the US, our government has allocated $223 million for a 6300 foot long, 200 foot high (~2 km, 60 meter) bridge Not too far out of line when you scale down the Italian bridge.
They are going to put it between Ketchican, Alaska (population 14500) and Gravina Island (population 50).
Sicilians may have invented organized crime, but the US Congress has perfected it.
HOWEVER, the linear velocity of an inner orbit is slower than the linear velocity of an outer orbit.
Actually, the linear velocity for an inner orbit is faster than for an outer orbit, on average. Earth is going 30 km/s around the Sun, while Mercury varies between 39 km/s (at its farthest to the Sun) and 59 km/s (at its closest).
However, if a probe similar to Messenger were in an orbit that gets as far out as Earth, and as close in as Mercury, then it would be going much slower than Earth at Earth's distance, and much faster than Mercury at Mercury's distance.
So to go from travelling alongside Earth to travelling alongside Mercury, without any of those fancy gravity assists, you would
a) Fire your rockets against your direction of motion, to slow down from your circular Earthlike orbit
b) Wait half an orbit as you swoop down to reach the distance of Mercury
c) Again fire your rockets against your direction of motion, to slow down to the speed of Mercury's orbit.
But the graity assists make it easier (in terms of how much rocket you have to carry--harder in terms of calculating the orbit).
This new technique is neat because it works at smaller applied magnetic fields, of order a few Gauss (Earth's field is ~1/3 - 1/2 Gauss). This means you don't need big bulky claustrophobic expensive helium-cooled superconducting electromagnets, but can use simpler, cheaper coils.
Basically, you get injected with a bunch of small particles of magnetite, which magnetically saturate at low fields. If you hit an unsaturated particle with a varying magnetic field, its magnetization varies and it gives a signal that can be detected by a readout coil. When the particle is saturated by a few Gauss field, then additional field variation doesn't change the magnetization, and so there isn't much signal out.
By scanning an applied semi-static few-Gauss field, with a gradient so that the field is zero in some region, you can differentially look for signal in the zero region. By scanning this zero region around the body, you can cover the entire body region by region and so build up a 3-D image of where the magnetite particles are.
(This is assuming that this is the same technique as was reported in Nature a few weeks ago.)
He reports only an ISP only in the low 200s, this is not efficent enought to get to orbit.
TFA is unavailable due to slashdotting, but low 200's will get you ~5km/s with a 90% mass ratio. It's plenty for sub-orbital work, and useful for the first stage if you're not trying for Single Stage To Orbit.
Top Industries 2004 RACE: TEXAS DISTRICT 6 Joe Barton (R)* Oil & Gas $224,398 Electric Utilities $221,951 Health Professionals $205,650 Pharmaceuticals/Health Products $151,276 TV/Movies/Music $93,500
Alan Moore (creator of the comic) has publicly disavowed any connection with the film, had his name taken off the credits, and, as a result of some suit using his name in related publicity, severed other ties to the media conglomerate involved.
The problem with defending the purity of the English language is that English is about as pure as a cribhouse whore. We don't just borrow words; on occasion, English has pursued other languages down alleyways to beat them unconscious and riffle their pockets for new vocabulary.
It rubs the lotion on its skin It does this when it's told It rubs the lotion on its skin Or else it gets the hose And when it's done there's one more thing A simple little task, it's: Put the fucking lotion in the basket.
Slashdot Mirror
If you like Heinlein, read some of the good new stuff that he inspired. My recent favorite is Old Man's War by John Scalzi (Just won the John W. Campbell award). Inspired by Starship Troopers, but not like it.
Red Thunder is an homage to Rocket Ship Galileo by John Varley. Not as good as Scalzi, but still fun.
We have to wait for it to reach the tipping point first.
Yes, that's what you traditionally do if you're in Greek Hentai. Or hang yourself.
You may as well go for the career you really want and will be best at, because outsourcing comes to every job.
Think that a job in the food services industry wearing a polyester uniform and paper hat will save you? It won't save everyone. Next time you're in the drive-thru lane at McTacoShack(tm) yelling at the squawk box, realize that the person you're talking to doesn't have to be in the same 'Shack where your pizza is being deep-fried. Many chains already take orders at centralized locations that handle thousands of franchise operations--modern telecommunications technology makes distance irrelevant to the transmission of unintelligible speech.
I don't know if any are off-shore yet, but they will be.
So what would you rather be, an outsourced computer programmer who has can start up his own business, or an outsourced order-taker trying to find someone to pay for your skill at misunderstanding garbled speech?
And notice how the reversed scale confuses the fact that temperature rises tend to be followed by increased CO2. To the extent that correlation implies causation, it seems that high temperatures cause CO2 increases rather than the other way around.
The classic Jack Chick tract Who Will Be Eaten First.
Which just goes to show you that, just because you are saying a wise thing, doesn't mean that it is a wise thing to say.
The Washington press core is ordinarily a placid, docile herd. But if you say something that confuses it, they get frightened and can lash out unpredictably. Pretty soon they are asking questions about the Valerie Plame leak or Katrina.
At that point you need to distract them with a shiny object like a Supreme Court nomination.
Just a terminology thing: Gravitational potential energy is measured relative to the system dispersed out to infinity. A white dwarf has negative potential energy, and so combined with the positive energy release by fusion will diminish the energy of this Type Ia supernova, relative to what you would get if you jcoudl just ignore gravity.
The iron core of a core-collapse supernova progenitor (similar to a white dwarf in size and mass, but made of un-fusable iron) has negative gravitational energy. The 12-km radius neutron star it becomes as it collapses has a much much more negative gravitational energy, by of order -1e46 Joules (-1e53 ergs). As you'd expect, this means that there's about 1e46J of positive energy suddenly liberated. 99% of that comes out in neutrinos, which have almost no effect once they get out of the star. The remaining 1e44 ergs comes in the form of supernova light and kinetic energy of the exploding ejecta.
The non-neutrino portion of the energy of a core collapse supernova is comparable to the total energy of a Type Ia supernova (which does not produce much in the way of neutrinos).
You are right that the gravitational binding energy of a white dwarf is comparable to the fusion energy of its combustion from carbon to iron. However, comparable doesn't mean equal and if you work it out, the fusion energy dominates. The gravitational energy is negative, so it reduces the amount of available energy for the supernova (i.e. the ejecta are moving more slowly because it has to climb out of its own gravity well), but it is still energetically favorable to go from a dense chunk of carbon to an expanding diffuse cloud of iron.
No, white dwarfs do become fusion-powered supernovae, not gravity-powered. IAAA (I am an astrophysicist.)
A white dwarf becomes a Type Ia supernova when, at around 1.4 solar masses, the pressure at the center reaches the point where it can burn by fusion the carbon-nitrogen-oxygen left over from previous rounds of burning. This leads to a fusion-driven explosion that gets no net energy from gravitational collapse, leading to an expanding gas cloud that is largely hot iron-group elements.
There is another class of supernova that is gravitationally driven. Core collapse supernovae are produced when a massive star (>8 solar masses, last I heard) has burned 1.4 solar masses at its center to iron. (The 1.4 solar mass value is semi-coincidental with that in the previous paragraph, based on similar but not identical physics.) This is a gravity-powered supernova that blows the outer parts of the core away, leaving a neutron star or black hole where the core was.
There is no way for a white dwarf to become a core collapse supernova, the fusion kicks in and blows it apart before that happens.
So basically the article is reviewed by peers, but if the review says 'this is garbage from beginning to end', it still can get published.
There is a simple way to aim mirrors that you learn about in Boy Scouts.
Use a double-sided mirror with a hole in the center of it. Get the mirror in approximately the right position so that you can see the target through the hole, and in the backside reflection you can see on the ground where the Sun shines through the hole.
Tilt the mirror so that the sunlit point on the ground is (in the backside reflection) at the location of the hole, and so that you are still looking at the target through the hole.
If you draw it, remembering how mirrors reflect equal angles incidence and reflection, you can see that this shines the sunlight right at your target.
Easier to draw than describe, and easier to do than draw.
In the US, our government has allocated $223 million for a 6300 foot long, 200 foot high (~2 km, 60 meter) bridge Not too far out of line when you scale down the Italian bridge.
They are going to put it between Ketchican, Alaska (population 14500) and Gravina Island (population 50).
Sicilians may have invented organized crime, but the US Congress has perfected it.
Actually, the linear velocity for an inner orbit is faster than for an outer orbit, on average. Earth is going 30 km/s around the Sun, while Mercury varies between 39 km/s (at its farthest to the Sun) and 59 km/s (at its closest).
However, if a probe similar to Messenger were in an orbit that gets as far out as Earth, and as close in as Mercury, then it would be going much slower than Earth at Earth's distance, and much faster than Mercury at Mercury's distance.
So to go from travelling alongside Earth to travelling alongside Mercury, without any of those fancy gravity assists, you would
a) Fire your rockets against your direction of motion, to slow down from your circular Earthlike orbit
b) Wait half an orbit as you swoop down to reach the distance of Mercury
c) Again fire your rockets against your direction of motion, to slow down to the speed of Mercury's orbit.
But the graity assists make it easier (in terms of how much rocket you have to carry--harder in terms of calculating the orbit).
This new technique is neat because it works at smaller applied magnetic fields, of order a few Gauss (Earth's field is ~1/3 - 1/2 Gauss). This means you don't need big bulky claustrophobic expensive helium-cooled superconducting electromagnets, but can use simpler, cheaper coils.
Basically, you get injected with a bunch of small particles of magnetite, which magnetically saturate at low fields. If you hit an unsaturated particle with a varying magnetic field, its magnetization varies and it gives a signal that can be detected by a readout coil. When the particle is saturated by a few Gauss field, then additional field variation doesn't change the magnetization, and so there isn't much signal out.
By scanning an applied semi-static few-Gauss field, with a gradient so that the field is zero in some region, you can differentially look for signal in the zero region. By scanning this zero region around the body, you can cover the entire body region by region and so build up a 3-D image of where the magnetite particles are.
(This is assuming that this is the same technique as was reported in Nature a few weeks ago.)
He reports only an ISP only in the low 200s, this is not efficent enought to get to orbit.
TFA is unavailable due to slashdotting, but low 200's will get you ~5km/s with a 90% mass ratio. It's plenty for sub-orbital work, and useful for the first stage if you're not trying for Single Stage To Orbit.
The shuttle SRBs have an ISP of 273 seconds.
http://opensecrets.org/races/indus.asp?ID=TX06&cy
Alan Moore (creator of the comic) has publicly disavowed any connection with the film, had his name taken off the credits, and, as a result of some suit using his name in related publicity, severed other ties to the media conglomerate involved.
Read more about it.
But yes, buy the comic. It's good. While you're at it, pick up 'Watchmen', also by Moore. (The movie of which is currently 'in turnaround'.)
Sounds great, but I don't have any intel machines.
Can you run it under Virtual PC on the G5?
I'm glad the gamma-ray bursts are directed into space.
Although the outward going flashes (first detected by CGRO a decade ago) are much stronger, there are also lighting-generated X-rays seen on the ground.
Bluetooth is an available option, and there are already programs that will let you control bluetooth macs with your bluetooth phone.
Let us not forget that he also built Evil Knievel's Sky Cycle in the 70's.
No, Robert Truax did the Sky Cycle. But both Rutan and Truax are amazing.
The first step in dealing with dyslexia is admitting that you have it.
Denial is not just a park in Alaska.