These are not separate beachball sized objects within the Crab Nebula. The pulses come from a beachball sized area on the pulsar within the Crab Nebula.
The magnetic field of the neutron star is so strong that it sends out radiation. The points of origin for the radiation are at the north and south magnetic poles of the neutron star. Since the neutron star rotates so fast, the radiation looks like a pulse to us. The surface locations that create those beams of radiation are small, only the size of a beach ball. And the radiation is so strong that it ionizes the atoms on the surface or just above the surface, making a little plasma cloud above the neutron star's magnetic poles.
Light travels across 12 inches in one nanosecond. (Side note: When radio astronomy technicians install optic cables, they have to measure the cables in nanosecond-light-lengths.) Since the subpulses are measured in nanoseconds, that means the beaming region on the pulsar is about that wide. A neutron star is 12 to 20km wide, and astronomers once thought the beaming region was as much as 10% of the surface area. Now, they are surprised to discover it is much smaller.
So, the question now is: what confines the neutron star's very powerful magnetic field to such a small region?
Some medical scientists believe that certain diseases are "inevitable" in that if you live long enough, you're going to get one of them. Prostate cancer is an example of one. It generally affects older men, and the older a man gets, the more likely he is to experience it.
Centuries ago, most men would never had to worry about prostate cancer. They would have died from malnutrition, beheading, or hyenas long before they age related diseases were even an issue. Now, we live long enough that we have the luxury of worrying about prostate cancer.
Besides prostate cancer, there are other age related diseases and discomforts that are far more common today than they were when my grandfather was young.
Who knows if there are other diseases waiting to be discovered by 300 year olds?
If any house was comparable to software . . .
on
Software Craftsmanship
·
· Score: 2, Interesting
... it would be the Winchester Mystery House in San Jose. It has stairs that just dead end, doors that go nowhere, and unfinished rooms. This crazy old lady uses her vast amounts of money to pay carpenters to build a house for her. So, they turned a 6 room country farmhouse into a weird, rambling mansion. That old farmhouse is still in there at the center of the mansion, surrounded by hundreds of useless rooms so you could barely recognize which rooms were original.
The carpenters had their pet projects, and some of the carpenters were obviously still in the apprentice phase. If the old lady didn't like how something turned out, she would just fire the carpenter on the spot, and hire somebody else. No wonder lots of those special projects never got finished. There was no architect, just low skill carpenters banging on nails.
I have actually worked on a software project like this. It was thoroughly unmaintainable, with much of written be people who did not understand basic software design principles. A manager fired some guy just because the software crashed when the manager used it. So, the manager had to hire somebody else to replace him. No wonder there was so much unfinished work in that software.
No design documents, no unit tests, no overall design, no modularity, and nothing was easily reused. There was no architect, just coders banging on keyboards. The core parts of the software have been rewritten so many times, and added onto so many times that you would never recognize the original code.
I am glad I don't work there anymore. It was a nightmare job for reasons besides the code.
The article demonstrates well that open source software can be used by those who want to document human rights abuses. This is good where the open source project are cryptography protocols and algorithms.
However, repressive regimes can also use the open source nature of networking protocols to spy on its own residents or limit what they can do over the internet. The repressive government just makes its own malware based upon the freely available source code.
Yes, such grpahs could have some uses. The lines in the movies and graphs represent dependencies. I recently gave a presentation to my coworkers about the importance of avoiding cyclic dependencies, and I found this much easier to do with graphs than with source code.
Nothing beats looking at the source code for really understanding the what's and why's of the software, but documentation, UML diagrams, and dependency graphs are very helpful.
Just now as I typed this message received a junk fax for "Marina, a Leading Psychic". Many people will pay for this stuff, in 2003. Not 1403! Weird.
If Marina was any good as a psychic, she would only send faxes to people gullible enough to believe what she says. Why should she waste her time and money sending faxes to skeptics like you?
I assume you are referring to the phenomenon of entangled particles when you mention the "Einstein-Podolsky-Rosen distant action paradox". There is evidence to support the "spooky action at a distance" phenomenon that troubled Einstein. The best evidence for this is the Alain Aspect experiment about entangled particles. The experiment created photons in an entangled state, and then measured their properties separately.
OTOH, there is no solid evidence to support ESP or UFOs. Just anecdotal stories which can not be verified later.
Sure it seems that the "spooky action at a distance" is just as freaky as ESP, but there is a well-known, repeatable experiment which supports the entanglement of quantum particles. No repeatable experiment has ever supported ESP, although there have been numerous attempts. I am not saying that ESP does not exist, just that no scientifically valid experiment has supported it.
Carl Sagan's rule that: "Extraordinary claims require extraordinary evidence" applies to both entangled particles and ESP. Using this rule, we can accept the measured phenomenon of entangled particles, and reject claims about ESP.
BTW, I agree with you entirely that religion is invalid when these rules are applied to it. So are superstitions, metaphysical claptrap, and other spiritual beliefs. Let's just demote all that to plain old wishful-thinking.
A 3 day trip up the cable inside a small elevator is enough to make anybody go crazy. They have to give us some choices for entertainment on the way up - including an internet connection. Somebody is going to do nothing but surf the net for those 3 days while being cooped up in a small room.
Re:Spread the Cost (was: Moore's Law)
on
The Space Elevator
·
· Score: 1
There is one very obvious use for carbon nanotubes here on Earth: computer chips. Carbon nanotubes are semiconductors. (It depends upon the chirality of the twist of the tube whether that tube is an insulator or semiconductor.) Excess electrons flow nicely along the carbon nanotubes.
Physcists would have to find a way to cheaply mass produce carbon nanotubes in bulk before the tubes start showing up in household electronics. Now having said that, let me add a qualifier: the carbon nanotubes likely to be used for computer chips are going to be a lot shorter than the ones used for a space elevator. The real question is: Can we find a way to cheaply mass produce very long tubes?
The weight of the cable is part of the whole equation, but so is the weight and position of the anchoring satellite. The satellite would be above geosynchronous orbit along with much of the cable. That part of the cable and the satellite would be balanced by the part of the cable below geosynchronous orbit.
So, yes the lower part of the cable does pull on the satellite and the upper part of the cable.
> At one point during an RAF competition I was told by my other members > of my flight, who knew of my dislike for football to 'just stay out > of the way'
Do you mean Royal Air Force? Must have been cool to have a high school flight team. Alas, my high school could not afford any fighter planes for the athletic department.
There's a reason why the show's initials are BS. When I saw it as a child, I thought then that it was lame. However, I know a college friend who actually liked it. Can't imagine why.
Why did the script writers name the home planet of humanity Kobol? If I ever grew up on a planet named Kobol, I'd leave ASAP, and wouldn't even mention it on my resume. I would find my way to something better like Perl or C++.
Apparently, the managers do have a very different way of thinking about free (as in price) software than you. A lot of people just don't understand how using free software can save them money.
But, there may be more to their rejection than what they think of free software. The managers may have other issues such as: Will they replace a lot of existing software at their customer sites with all this great new software you have in mind? Will they have to retrain their customers, their sales people, and their customer-support staff to use the new stuff? Will there be a whole new set of bugs to fix in any software they build on top of the open source products?
Believe, I have advocated using open-source products to various employers. Sometimes they were really interested, and understood that there are some high quality open source programs. But if they had to replace existing stuff, then they also had a lot of other questions to ask. (Other managers were just mentally filtered out any sentences containing the words "open source" or "free software".)
Collective Ownership vs Individual Ownership
on
Open Code Has Fewer Bugs
·
· Score: 2, Insightful
The old saying about "many eyes makes all bugs shallow" is true even for propeietary code. I have been working on proprietary software for most of my career. My own opinion is that software made by companies with collective ownership policies is of better quality than software made by companies which allow for individual ownership.
At some places where I worked, some people just "owned" some of the source code and for whatever reason, nobody else was allowed to touch it (or sometimes even see it if the boss owned the code). Anybody else who wrote anything dependent upon that often found a lot of bugs in that code, and just had to wait until so-and-so got around to fixing it. Some of eventually wrote a replacement for that whole component, and obsoleted the original.
At some places where I worked, and at where I am now, the rule is that we all own the code collectively. Sure, there are some people that better understand some parts of the code than others, but nobody tells anybody that some code is off limits. It is easy to just go in to some section of code, fix the bug, and move on.
> Patches are expensive, difficult and their need may have killed people. > Therefore, serious testing has to have happened before a true release.
Car makers hate recalls much more than consumers do, but AFAIK, they have always been forced into it. Ford was forced to deal with Pintos that blew up every time they were rear-ended. It was internally documented that Ford/Firestone knew about the problems with tires on SUVs years before they were forced to replace the tires.
If they had done some serious testing before release, then maybe Seymour Cray would never have died because his SUV flipped over due to a bad tire.
The Highlift Systems FAQ says the US military will probably have to protect it. Which might mean fighter planes based off carriers flying around the ribbon to prevent any other aircraft or any ships from getting too close.
Yes, it would generate power, but perhaps that power can be used to lift objects off the Earth. I hope the ribbon can withstand the differences in electrical potential. (The US-Italian space tether failed because electrical flow along the tether burned through the insulator, and broke the tether.)
Riding down the ribbon would also generate power since gravity would convert potential energy to kinetic energy. Which means the cost of raising something off the Earth could be far more than the cost of sending something down to Earth. (A one-way passenger ticket down might be cheap.)
Carbon nanotubes may have a longitudinal tensile strength of 200 Gigapascals, but what about the strength of the transverse bonds connecting one carbon tube to the tube next to it? Those transverse bonds may not need to withstand 200 Gigapascals of force, but they still have to be damn strong. A split in a wooden board can travel the length of the entire board. Would a split in the space elevator ribbon cause the whole ribbon to become a series of parallel threads?
Of course Microsoft will use this as a way to get some $ out of every M$ email user. Until people switch and find some other free way to send email. I doubt it will end spam, but it may drive people away from using M$ tools.
Solar panels appear to be a better investment than 6% APR tax free. If your business has an electricity budget of several $K per year, than take the following info and plug it into a spreadsheet.
Scenario 1: Buy solar panels for $55K. * Saves $3300 per year in electrical costs. * Power generation drops by.0081 per year. (They are rated to produce 85% of their peak power after 20 years.) * Electrical costs go up by 3% per year. * Take the yearly electrical cost savings and invest it at 6% per year. * Pay 20% of any interest on that investment each year. * Pay $2K per 10 years for solar equipment maintanence.
Scenario 2: Invest $55K conservatively at 6%. * Pay 20% of any interest on that investment each year. * Yearly earnings are reinvested at 6%.
The results are surprising after 30 years. Scenario 1 ends up with $263K in the bank. Scenario 2 ends up with only $224K in the bank. Buying solar panels is better than a 6% APR investment.
Solar panels win since there is no tax on money saved because you spend less for your electricity bills. So, let's see what the results are if we remove the tax on interest to give the investment-only scenario a better chance. The results still favor the solar panels: Scenario 1 gets $320K after 30 years. Scenario 2 gets $316K after 30 years.
Dark Energy Sucks because it exerts a negative pressure on the universe. (There's a neat article about positive and negative pressure in the most recent Scientific American - including stuff about dark energy and the cosmos.)
Anything with a negative pressure sucks. Anything with a positive pressure blows.
Relying on some function, class, library, component, what-have-you as a black box can reduce performance. It helps to have a little grey knowledge of how that function or class behaves, especially if that function takes anything more than constant time to do its thing.
For example, consider some function that gives you an answer, but always takes linear time. If you keep calling it repeatedly that means it now takes way more than linear time.
After a while, almost every C or C++ programmer has seen something like this:
strcat( buffer, "apple " );
strcat( buffer, "banana " );
strcat( buffer, "cherry " );
Each time strcat() is called, it traverses the entire buffer before it adds the second string. So, now those 3 functions calls are taking O(n^2) instead of just O(n). Put those 3 functions calls above into a loop, and they require O( n * n * m ) where m is the number of loop iterations. And then if that loop is inside a function that gets called repeatedly, the performance gets even worse. That is probably the most common example I see of people treating a function as a black box.
Many new programmers do things like that and unwittingly force other programmers into making expensive function calls. Just recently I fixed a cleanup routine that suddenly went from taking linear time to cubic time to finish. A coworker found a function that removed 1 item from a container, so she used it thinking of it as a black box. But, that function not only deleted 1 item at a time, but also sorted the remaining items using bubble sort - which takes O(n^2) time. After her change, the cleanup function was now much slower. No wonder it now took 10,000 times as long to cleanup a container of 100 items! The fix was to go through the container once, and not calling that other function - which needed some fixing of its own.
Have you ever wondered why some programs are slow no matter how fast your CPU gets? Ever wonder why some of the most complex software take so much time? My guess is that there are so many layers of inefficient functions calling other inefficient functions.
One reason I like the STL is that it has complexity guarantees. The definition of the STL tells you that some functions will take constant time always, while other take linear time at worst. Any implementation of the STL must match (or beat) those guarantees. So, you never have to worry about calling an STL function and wonder if its implementation will take 10,000 times as long as another implementation. I think of the complexity guarantees as some grey knowledge about the STL, so I can treat it as black box otherwise.
As a courtesy (or warning) to other programmers who have to develop on top of my code, I often say how complex a function is. Such as whether it takes constant time or logarithmic time for an input of a given size. That little piece of grey knowledge allows them to decide how they want to use the function.
When I read the review of this, I could not even want to watch it. The plot stinks. The premise has so many contrivances that I can't just suspend disbelief.
This Picard clone grows up in a Romulan slave mine and ends up becoming the leader of Romulus? Would any self-respecting Romulan ever accept a former slave, or a human as their leader? It is far more likely that the clone would never get out of slavery.
This just has no credibility as a plot device. Since politics in the ST reality is just a mirror of today's geopolitics, just try this idea and see if you could believe it. Imagine some nation like China making a clone of a caucasian US Navy captain, and put him to work hauling dirt. Then when the Chinese leadership gets decimated, they have this caucasian clone take over. Name one person who would buy this for a minute!
Give me a break, Berman! Not even the Raelians believe anything that stupid!
I just learned about the Mt Stromlo fire here on Slashdot. My spouse was collaborating remotely with a friend doing research there. (My spouse is safe here in the US, friend was at Mt Stromlo, and have no idea about his safety.) Some news websites says the observatory staff had only 20 minutes warning before the firestorm came up the hill through the pine trees. I hope he got out in time, since there is only one road in or out of the observatory grounds.
Slashdot Mirror
These are not separate beachball sized objects within the Crab Nebula. The pulses come from a beachball sized area on the pulsar within the Crab Nebula.
The magnetic field of the neutron star is so strong that it sends out radiation. The points of origin for the radiation are at the north and south magnetic poles of the neutron star. Since the neutron star rotates so fast, the radiation looks like a pulse to us. The surface locations that create those beams of radiation are small, only the size of a beach ball. And the radiation is so strong that it ionizes the atoms on the surface or just above the surface, making a little plasma cloud above the neutron star's magnetic poles.
Light travels across 12 inches in one nanosecond. (Side note: When radio astronomy technicians install optic cables, they have to measure the cables in nanosecond-light-lengths.) Since the subpulses are measured in nanoseconds, that means the beaming region on the pulsar is about that wide. A neutron star is 12 to 20km wide, and astronomers once thought the beaming region was as much as 10% of the surface area. Now, they are surprised to discover it is much smaller.
So, the question now is: what confines the neutron star's very powerful magnetic field to such a small region?
Some medical scientists believe that certain diseases are "inevitable" in that if you live long enough, you're going to get one of them. Prostate cancer is an example of one. It generally affects older men, and the older a man gets, the more likely he is to experience it.
Centuries ago, most men would never had to worry about prostate cancer. They would have died from malnutrition, beheading, or hyenas long before they age related diseases were even an issue. Now, we live long enough that we have the luxury of worrying about prostate cancer.
Besides prostate cancer, there are other age related diseases and discomforts that are far more common today than they were when my grandfather was young.
Who knows if there are other diseases waiting to be discovered by 300 year olds?
... it would be the Winchester Mystery House in San Jose. It has stairs that just dead end, doors that go nowhere, and unfinished rooms. This crazy old lady uses her vast amounts of money to pay carpenters to build a house for her. So, they turned a 6 room country farmhouse into a weird, rambling mansion. That old farmhouse is still in there at the center of the mansion, surrounded by hundreds of useless rooms so you could barely recognize which rooms were original.
The carpenters had their pet projects, and some of the carpenters were obviously still in the apprentice phase. If the old lady didn't like how something turned out, she would just fire the carpenter on the spot, and hire somebody else. No wonder lots of those special projects never got finished. There was no architect, just low skill carpenters banging on nails.
I have actually worked on a software project like this. It was thoroughly unmaintainable, with much of written be people who did not understand basic software design principles. A manager fired some guy just because the software crashed when the manager used it. So, the manager had to hire somebody else to replace him. No wonder there was so much unfinished work in that software.
No design documents, no unit tests, no overall design, no modularity, and nothing was easily reused. There was no architect, just coders banging on keyboards. The core parts of the software have been rewritten so many times, and added onto so many times that you would never recognize the original code.
I am glad I don't work there anymore. It was a nightmare job for reasons besides the code.
The article demonstrates well that open source software can be used by those who want to document human rights abuses. This is good where the open source project are cryptography protocols and algorithms.
However, repressive regimes can also use the open source nature of networking protocols to spy on its own residents or limit what they can do over the internet. The repressive government just makes its own malware based upon the freely available source code.
Yes, such grpahs could have some uses. The lines in the movies and graphs represent dependencies. I recently gave a presentation to my coworkers about the importance of avoiding cyclic dependencies, and I found this much easier to do with graphs than with source code.
Nothing beats looking at the source code for really understanding the what's and why's of the software, but documentation, UML diagrams, and dependency graphs are very helpful.
Just now as I typed this message received a junk fax for "Marina, a Leading Psychic". Many people will pay for this stuff, in 2003. Not 1403! Weird.
If Marina was any good as a psychic, she would only send faxes to people gullible enough to believe what she says. Why should she waste her time and money sending faxes to skeptics like you?
I assume you are referring to the phenomenon of entangled particles when you mention the "Einstein-Podolsky-Rosen distant action paradox". There is evidence to support the "spooky action at a distance" phenomenon that troubled Einstein. The best evidence for this is the Alain Aspect experiment about entangled particles. The experiment created photons in an entangled state, and then measured their properties separately.
OTOH, there is no solid evidence to support ESP or UFOs. Just anecdotal stories which can not be verified later.
Sure it seems that the "spooky action at a distance" is just as freaky as ESP, but there is a well-known, repeatable experiment which supports the entanglement of quantum particles. No repeatable experiment has ever supported ESP, although there have been numerous attempts. I am not saying that ESP does not exist, just that no scientifically valid experiment has supported it.
Carl Sagan's rule that: "Extraordinary claims require extraordinary evidence" applies to both entangled particles and ESP. Using this rule, we can accept the measured phenomenon of entangled particles, and reject claims about ESP.
BTW, I agree with you entirely that religion is invalid when these rules are applied to it. So are superstitions, metaphysical claptrap, and other spiritual beliefs. Let's just demote all that to plain old wishful-thinking.
A 3 day trip up the cable inside a small elevator is enough to make anybody go crazy. They have to give us some choices for entertainment on the way up - including an internet connection. Somebody is going to do nothing but surf the net for those 3 days while being cooped up in a small room.
There is one very obvious use for carbon nanotubes here on Earth: computer chips. Carbon nanotubes are semiconductors. (It depends upon the chirality of the twist of the tube whether that tube is an insulator or semiconductor.) Excess electrons flow nicely along the carbon nanotubes.
Physcists would have to find a way to cheaply mass produce carbon nanotubes in bulk before the tubes start showing up in household electronics. Now having said that, let me add a qualifier: the carbon nanotubes likely to be used for computer chips are going to be a lot shorter than the ones used for a space elevator. The real question is: Can we find a way to cheaply mass produce very long tubes?
The weight of the cable is part of the whole equation, but so is the weight and position of the anchoring satellite. The satellite would be above geosynchronous orbit along with much of the cable. That part of the cable and the satellite would be balanced by the part of the cable below geosynchronous orbit. So, yes the lower part of the cable does pull on the satellite and the upper part of the cable.
> At one point during an RAF competition I was told by my other members
> of my flight, who knew of my dislike for football to 'just stay out
> of the way'
Do you mean Royal Air Force? Must have been cool to have a high school flight team. Alas, my high school could not afford any fighter planes for the athletic department.
There's a reason why the show's initials are BS. When I saw it as a child, I thought then that it was lame. However, I know a college friend who actually liked it. Can't imagine why.
Why did the script writers name the home planet of humanity Kobol? If I ever grew up on a planet named Kobol, I'd leave ASAP, and wouldn't even mention it on my resume. I would find my way to something better like Perl or C++.
Yeah, but considering how poorly Watson treated Rosalind Franklin, would any woman be interested in dating him?
Apparently, the managers do have a very different way of thinking about free (as in price) software than you. A lot of people just don't understand how using free software can save them money.
But, there may be more to their rejection than what they think of free software. The managers may have other issues such as:
Will they replace a lot of existing software at their customer sites with all this great new software you have in mind?
Will they have to retrain their customers, their sales people, and their customer-support staff to use the new stuff?
Will there be a whole new set of bugs to fix in any software they build on top of the open source products?
Believe, I have advocated using open-source products to various employers. Sometimes they were really interested, and understood that there are some high quality open source programs. But if they had to replace existing stuff, then they also had a lot of other questions to ask. (Other managers were just mentally filtered out any sentences containing the words "open source" or "free software".)
The old saying about "many eyes makes all bugs shallow" is true even for propeietary code. I have been working on proprietary software for most of my career. My own opinion is that software made by companies with collective ownership policies is of better quality than software made by companies which allow for individual ownership.
At some places where I worked, some people just "owned" some of the source code and for whatever reason, nobody else was allowed to touch it (or sometimes even see it if the boss owned the code). Anybody else who wrote anything dependent upon that often found a lot of bugs in that code, and just had to wait until so-and-so got around to fixing it. Some of eventually wrote a replacement for that whole component, and obsoleted the original.
At some places where I worked, and at where I am now, the rule is that we all own the code collectively. Sure, there are some people that better understand some parts of the code than others, but nobody tells anybody that some code is off limits. It is easy to just go in to some section of code, fix the bug, and move on.
> Patches are expensive, difficult and their need may have killed people.
> Therefore, serious testing has to have happened before a true release.
Car makers hate recalls much more than consumers do, but AFAIK, they have always been forced into it. Ford was forced to deal with Pintos that blew up every time they were rear-ended. It was internally documented that Ford/Firestone knew about the problems with tires on SUVs years before they were forced to replace the tires.
If they had done some serious testing before release, then maybe Seymour Cray would never have died because his SUV flipped over due to a bad tire.
The Highlift Systems FAQ says the US military will probably have to protect it. Which might mean fighter planes based off carriers flying around the ribbon to prevent any other aircraft or any ships from getting too close.
Yes, it would generate power, but perhaps that power can be used to lift objects off the Earth. I hope the ribbon can withstand the differences in electrical potential. (The US-Italian space tether failed because electrical flow along the tether burned through the insulator, and broke the tether.)
Riding down the ribbon would also generate power since gravity would convert potential energy to kinetic energy. Which means the cost of raising something off the Earth could be far more than the cost of sending something down to Earth. (A one-way passenger ticket down might be cheap.)
Carbon nanotubes may have a longitudinal tensile strength of 200 Gigapascals, but what about the strength of the transverse bonds connecting one carbon tube to the tube next to it? Those transverse bonds may not need to withstand 200 Gigapascals of force, but they still have to be damn strong. A split in a wooden board can travel the length of the entire board. Would a split in the space elevator ribbon cause the whole ribbon to become a series of parallel threads?
Of course Microsoft will use this as a way to get some $ out of every M$ email user. Until people switch and find some other free way to send email. I doubt it will end spam, but it may drive people away from using M$ tools.
Solar panels appear to be a better investment than 6% APR tax free. If your business has an electricity budget of several $K per year, than take the following info and plug it into a spreadsheet.
.0081 per year. (They are rated to produce 85% of their peak power after 20 years.)
Scenario 1: Buy solar panels for $55K.
* Saves $3300 per year in electrical costs.
* Power generation drops by
* Electrical costs go up by 3% per year.
* Take the yearly electrical cost savings and invest it at 6% per year.
* Pay 20% of any interest on that investment each year.
* Pay $2K per 10 years for solar equipment maintanence.
Scenario 2: Invest $55K conservatively at 6%.
* Pay 20% of any interest on that investment each year.
* Yearly earnings are reinvested at 6%.
The results are surprising after 30 years.
Scenario 1 ends up with $263K in the bank.
Scenario 2 ends up with only $224K in the bank.
Buying solar panels is better than a 6% APR investment.
Solar panels win since there is no tax on money saved because you spend less for your electricity bills. So, let's see what the results are if we remove the tax on interest to give the investment-only scenario a better chance. The results still favor the solar panels:
Scenario 1 gets $320K after 30 years.
Scenario 2 gets $316K after 30 years.
Dark Energy Sucks because it exerts a negative pressure on the universe. (There's a neat article about positive and negative pressure in the most recent Scientific American - including stuff about dark energy and the cosmos.)
Anything with a negative pressure sucks.
Anything with a positive pressure blows.
Relying on some function, class, library, component, what-have-you as a black box can reduce performance. It helps to have a little grey knowledge of how that function or class behaves, especially if that function takes anything more than constant time to do its thing.
For example, consider some function that gives you an answer, but always takes linear time. If you keep calling it repeatedly that means it now takes way more than linear time.
After a while, almost every C or C++ programmer has seen something like this:
strcat( buffer, "apple " );
strcat( buffer, "banana " );
strcat( buffer, "cherry " );
Each time strcat() is called, it traverses the entire buffer before it adds the second string. So, now those 3 functions calls are taking O(n^2) instead of just O(n). Put those 3 functions calls above into a loop, and they require O( n * n * m ) where m is the number of loop iterations. And then if that loop is inside a function that gets called repeatedly, the performance gets even worse. That is probably the most common example I see of people treating a function as a black box.
Many new programmers do things like that and unwittingly force other programmers into making expensive function calls. Just recently I fixed a cleanup routine that suddenly went from taking linear time to cubic time to finish. A coworker found a function that removed 1 item from a container, so she used it thinking of it as a black box. But, that function not only deleted 1 item at a time, but also sorted the remaining items using bubble sort - which takes O(n^2) time. After her change, the cleanup function was now much slower. No wonder it now took 10,000 times as long to cleanup a container of 100 items! The fix was to go through the container once, and not calling that other function - which needed some fixing of its own.
Have you ever wondered why some programs are slow no matter how fast your CPU gets? Ever wonder why some of the most complex software take so much time? My guess is that there are so many layers of inefficient functions calling other inefficient functions.
One reason I like the STL is that it has complexity guarantees. The definition of the STL tells you that some functions will take constant time always, while other take linear time at worst. Any implementation of the STL must match (or beat) those guarantees. So, you never have to worry about calling an STL function and wonder if its implementation will take 10,000 times as long as another implementation. I think of the complexity guarantees as some grey knowledge about the STL, so I can treat it as black box otherwise.
As a courtesy (or warning) to other programmers who have to develop on top of my code, I often say how complex a function is. Such as whether it takes constant time or logarithmic time for an input of a given size. That little piece of grey knowledge allows them to decide how they want to use the function.
When I read the review of this, I could not even want to watch it. The plot stinks. The premise has so many contrivances that I can't just suspend disbelief.
This Picard clone grows up in a Romulan slave mine and ends up becoming the leader of Romulus? Would any self-respecting Romulan ever accept a former slave, or a human as their leader? It is far more likely that the clone would never get out of slavery.
This just has no credibility as a plot device. Since politics in the ST reality is just a mirror of today's geopolitics, just try this idea and see if you could believe it. Imagine some nation like China making a clone of a caucasian US Navy captain, and put him to work hauling dirt. Then when the Chinese leadership gets decimated, they have this caucasian clone take over. Name one person who would buy this for a minute!
Give me a break, Berman! Not even the Raelians believe anything that stupid!
I just learned about the Mt Stromlo fire here on Slashdot. My spouse was collaborating remotely with a friend doing research there. (My spouse is safe here in the US, friend was at Mt Stromlo, and have no idea about his safety.) Some news websites says the observatory staff had only 20 minutes warning before the firestorm came up the hill through the pine trees. I hope he got out in time, since there is only one road in or out of the observatory grounds.