Tactical nukes indeed do get down to about that size. Some of them are "dial-a-yield."
Tactical nukes were intended for all sorts of uses. For example, the anti-aircraft batteries around the US during the early cold war had nuclear warheads in the missiles. The Navy had nuclear warheads in the anti-aircraft missiles on almost all of their combat ships. I was an aircrewman in a P-3 Orion (submarine hunter) and we carried nuclear depth charges. Submarines carried nuclear torpedos.
I believe the only reason that tactical nukes are not used in the NMD anti-missile systems is political. Although there is one other possibility (exo-atmospheric burst caused EMP), the advantages of nuclear warheads for anti-ballistic missile defense seem immense - the problems of hitting the target go away - you just need to get close. (I would love to hear from anyone who *knows* why these difficult "hit-to-kill" vehicles are being used instead of nukes, if it is not political).
As far as conventional explosives go... I once watched a demonstration (and test) at Sandia Labs (Albuquerque, NM - where they did most nuclear weapons design). They set off around 1 kiloton equivalent of high explosive a few miles from where we were watching at an Armed Forces Day demonstration. It certainly produced a very nice mushroom cloud and a heck of a bang!
As a kid, I set off a small explosive in the back yard (my parents were not amused). It was about an ounce of Sodium Chlorate mixed with Sugar and a little Sulfur, with an electrical detonator (single strand of wire shorting an extension cord). I also made a very small, but distinct, mushroom cloud:-)
Others have pointed out the problem in your physics exposition.
Let me point out that the large amount of "residual radiation" (fallout) produced by the Hiroshima bomb did not fall near Hiroshima, so there was no residual radiation in Hiroshima itself. The bomb was exploded at altitude and the radioactive components (other than the tiny amount converted to energy) was turned into extremely hot gas. That gas rose into the stratosphere and was distributed, more or less evenly, throughout the northern hemisphere.
In general, air bursts of nuclear weapons do not produce local fallout.
The Port of Chicago explosion, had it been nuclear, would have resulted in the lifting of large amounts of dust and other terrestrial material. This would have formed condensation nuclei for the radioactive material, which would have then fallen back to the ground at and within a few hundred miles of the blast. This is classic nuclear fallout for a ground burst. This would have led to significant injury and death, and the residual radiation would still be detectable (although at low levels today).
The funny thing about all the thrashing and gnashing going on here is that the same cry wasn't raised when the Clinton administration was pushing science in the other direction.
I have researcher friends eas who were afraid to cite their real views on global warming for fear of losing grants in the Gore-dominated years. There are plenty of other examples. And lets not forget the junk science used by the EPA to justify drastic interventions in our lives... junk science that has been widely debunked by responsible scientists.
Face it... government funded science will have a different *emphasis* with different administrations. The government funding of science is appropriately a political process because they are spending the taxpayers money! The US scientific establishment does a pretty good job of minimizing the ideological impacts on science, but it is still there - regardless of the ideology of the government.
One area that for years couldn't get funding - purely for political reasons - was the study of genetic contributions to behavior and learning abilities. This was because of a fear that the results might lead reinforce racism or lead to genetic predestinationism. While those fears have some validity to them, the suppression of scientific research for years was not appropriate.
The primary research the Bush administration tries to suppress is that which uses foetuses. The reason is a moral one (whether you agree with it or not) and is an attempt to avoid a perceived evil means, not to skew the results.
I started working as a programmer 35 years ago. I am still working as a programmer and software architect, and making good money, but I do worry about the threat of the export of programming jobs.
I have been a manager, director and CTO (of a 2000 person company), but I prefer technology and have been fortunate enough to do it.
One of the problems with engineering careers (including the part of software work that can truly be called engineering) is that it is done by teams. That means that individuals are too often treated as replaceable assets. This is not conducive to job security!
Another problem is that the field of software development has people ranging from tinkerers to highly schooled professionals, and all in between (in several dimensions). Thus any programmer can call himself a professional or a computer scientist, when in fact many are neither. This is very confusing to non-technical people and employers.
Simple coding from specifications is not engineering. It is a craft similar to carpentry.
Most software development is not computer science, and computer science is not even science. The field is split between mathematics and engineering, which is also confusing.
Where are the spaceships, flying cars, etc?
on
Christmas in 2050
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· Score: 5, Insightful
When I was a kid in the '50s, the futurists predicted routine space travel by now, commuting by flying automobiles, the hyrdrogen economy, copious nuclear power production, intelligent robots, oh - and the end of the world by nuclear war.
Hmmm...
And they missed the information age, microchips, the sexual revolution, the civil rights movement, the air bag in cars, AIDS, velcro and genetic engineering.
Errr... there is no longer a 1st class FCC Commercial License. Mine turned into a "General Class" a couple of decades ago. Second class also turned into a "General Class."
(for those who ask, this is a kind of license needed to be a technical person on various kinds of FCC stuff, such as two way radios and broadcast stations). The term "engineer" in broadcasting is like the term "engineer" in trains - it doesn't mean you are an engineer. I started as a broadcast "engineer" when I was in high school with a 1st class FCC License (commonly called "First Phone").
While I agree that copyright life is way too long, the argument that the copyright should not extend past the life of the artist is wrong and is equivalent to saying that the state should inherit the (house or car or bank account or whatever) of the deceased.
People are often motivated by what they may pass down to their children. If the copyright is creating a property with a finite life, that property should be controlled, after death, the same way other property of the deceased is controlled.
It all boils down to the same physics. The only way you cheat on the resolution equation is with a *moving* synthetic aperture antenna, where you can process the signals (if recorded with extremely accurate time resolution) as if the antenna were the length of the distance you moved it. I don't think that applies in this case.
A lense is mathematically equivalent to an array of traditional antennas. The same fourier equations work whether we are talking refractive optics or 10 MHz HF radio antennas!
I suspect the whole system hinges on high gain antennas on the ground, although that would require precise station keeping on the balloons (which is very energy intenstive) or tracking by the ground stations (which is an unlikely consumer technology unless the *consumer* end was using 2-D steerable phased arrays).
It will be interesting to find out just what the designers have in mind. Also interesting is why they would choose a Part-15 (unlicensed station) service.
Yes, I addressed the issue of large antennas (any lense is an antenna, of course). I think the problem is that for a lot of coverage, you need a lot of antennas, OR much limited time available for each station.
Perhaps they had in mind high gain antennas on each ground station. That would certainly help the problem by 20 dB or so.
Silly, you don't have a right to enforce the content of a site you browse(including pop-ups or drop-downs or other obnoxious tings)!
Of course, you have a right to do whatever you want to avoid seeing their popups (untell the DMCA gets even worse:-(), but you don't have a right to prevent them from trying to display them!
If you don't enjoy popups and don't want to install a blocker, DON'T GO TO THEIR SITES or INSTALL A POPUP BLOCKER!.
Isn't this similar to what folks always say to those who want to block pr0n? If you don't want to see it, DON'T LOOK!
Wi-Fi only has a few channels. These balloons, at high altitude, are going to be in range of literally tens of thousands of wi-fi emitters, not to mention 2.4GHz (and presumably 5GHz) cordless phones. Microwave ovens also operate on this spectrum - how many little leaks will there be. Remember, this is on Part-15 spectrum (at least in the US) where *anyone* can set up as many transmitters as they want!
Even with steerable phased array antennas, the interference problem seems insurmountable in urban areas. You would need a WHOLE LOT of great big antennas (many meters - don't have time to do the detailed calcs) and even then many areas are unlikely to work.
Either something is being left unsaid, or.. I smell a possible scam.
Does anyone have information that would contradict this interference argument?
Sigh... the old slippery slope argument rears its slipper head again...
Laws already exist, all over the place, regarding the internet and things you do with this. There will be more as the internet gets more important to the economies of the world.
The creation of an anti-spam law does not "open the floodgates" - the slippery slope argument simply holds no water. The world, including the world of laws, does not work on absolutes. Everything ultimately ends up a compromise, because in human behavior there are few clear boundaries. Thus the government becomes inserted in almost all kinds of behavior at the extremes, and lots of other behavior at the norm.
Since PCB's are relatively harmless, and their carinogenicity in people has been well tested and found to be unmeasurable, this whole thing about the Hudson is basically a way to waste lost of taxpayer dollars, screw up the river, screw up GE, and fatten the wallets of some rich trial lawyers. Electrical workers, including those at GE, have had PCB exposures vastly higher than you can ever get from river water, and their cancer risk is at or below normal.
One amusing phenomenon is the number of rich liberals who live along the upper Hudson - folks who are happy to impose ultrastrict environmental rules on everyone else - who object to this project because it will mess up the river for a long time/
I read that paper some time ago. I just read it again. It contradicts *nothing* that I have said.
If you believe otherwise, I would suggest you extract the specific assertion and make it here.
The paper is about how smart networks can increase the bit rate per area per megaherz. This is not exactly black magic. Cell technology is a primitive (and in some cases, not so primitive) example of the principle.
As I said before, "open spectrum" and "software defined radios" (or more apropos to that paper, smart radios) do not remove the issues of interference.
They are simply clever ways of dealing with the issue that *improve* spectrum usage. They do it through a number of techniques - but ultimately there are three principles:
1) Time/Frequency multiplexing - using intelligence to make it more effective than past systems. This includes spread spectrum (already used in cellular), ultra-wideband techniques (a special form of spread spectrum), collision avoidance (chosing a temporarily available frequency), and various levels of local cooperation.
2) Area multiplexing - the cellular principle, but with more flexibility and intelligence. Basically one reduces the power of the radio because one is talking to a more local resource.
3) Relaying through the network to avoid long haul transmissions - something amateur radio packet networks have been doing for decades.
NONE of these techniques eliminates the problem of interference. NONE of these techniques relies on any new physical or computational principle which magically makes the problem go away.
ALL of these techniques are already in use at one level or another, and all still boil down to the same fundamental issues: signal-to-noise ratio limits the channel carrying capacity (as is pointed out in the paper that *you* referenced). These techniques simply provide for the re-use of channels in space and time - and nothing more.
Put another way... old fashioned spectral regulation uses fixed frequencies with guard bands and power limits (and other limitations more technical) to avoid interference. Open Spectrum (a movement of which that paper is a part) uses smart radios to achieve the same effect, resulting in a significant increase in spectral efficiency (in fact, potentially a vast increase). Those techniques may actually *increase* the total amount of man-made radio noise, as seen from a distance (say - a space based military radar or a radio telescope).
Finally, it is important to recognize that Open Spectrum has several dimensions: technical, political and economic. Many of the proponents of open spectrum are more informed on the latter two issues than the former.
Open spectrum does *not* reduce, for example, government regulation. What it does is use highly detailed and technical regulation in a general fashion to produce a spectral space where individual regulation (station licensing) is not required. THAT is a significant improvement economically and politically. In other words, it regulates the characteristics of radios, rather than the users of those radios. This exists today in some areas - for example your don't need a license to use a cell phone, but the cell phone *does* need an FCC approval (on very detailed technical grounds) before it can be legally sold or used.
In the technical area, Open Spectrum (in many variants) replaces one set of problems with another, and hopefully in the process produces more value to spectrum users. The problems it removes are guard bands and individual stations licensing.
The problems it adds include increased radio complexity; more difficult testibility; more system robustness at the cost of typically less predictable for a single station; hidden station issues; tolerance of defective radios (which may violate the protocols); tolerance of intentional "commons" hogs (see citizen band radio for an example) ; difficulty in interference prediction ; individual system failure if stations *happen* to get too close together.
All of these can be dealt with, and will be.
Just don't tell me that the radio interference has magically vanished because of this stuff. It hasn't, and it won't.
Re:fear mongering
on
DOD vs. 802.11b
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· Score: 3, Informative
What a load of.... ahistorical disinformation!
It was not clear what was happening at first. There were no fighters that could intercept in time - some were launched but didn't get there fast eough.
The fact that Washington might come under attack was not immediately obvious. In fact, nobody knew it was terrorism until the SECOND plane hit the WTC. By that time, the third plane was getting close to hitting (it was also flying low, with the transponder turned off, and was very hard to track on civilian radar). And most people don't realize that the US normally had ZERO armed fighters aloft, and only a few on standby alert for the entire east coast.
As far as the flight over PA... the crash was witnessed. It was not a military attack. The debris was not scattered over a wide area, but rather confined to the small area typical of high speed flight into the ground at a high angle.
The president wanted to return to DC. His advisors wisely suggested he do otherwise until the magnitude of the threat could be determined. It was some time before it was determined that there were no more rogue aircraft up there.
If Clinton had been president, he would have sent a few more cruise missiles up the rear of a few more camels, and then gone crying to the United Nations. Oh, and he would have blown up a pharmaceutical factory somewhere. It was Clinton who failed to take Al Queda seriously in the first place - missing opportunities to capture Bin Laden. Furthermore, Clinton's "impeachment war" was widely recognized throughout the world as a phony war meant to distract from political embarassment. As such, it further inflamed the Arab world when they saw a US President willing to kill Arabs for his own personal gain!
Oh, btw... the order WAS given to shoot down the PA flight if it came into striking range of a major target.
Would that this be true! But it is not. Check out Shannon's laws.
The way you separate signals from noise is ultimately by integration. The longer you integrate, the lower the signal to noise ratio you can tolerate. BUT... that limits the information rate - I can pull one bit per second out of pretty deep noise - either by coherently integrating for a while, or by sending it in a very narrow band way and using very narrow filters (which equates to long integration - there ain't no free lunch).
Any modulation scheme and data recovery scheme you come up with boils down to this same limit. This even applies to ultra-wideband technology, which is, at low signal levels, no different than spread spectrum.
All that speedy processors ultimately do is perform the same functions that analog systems can do now. They just do it vastly less expensively (for certain algorithms - say phase linear sharp filters) and with more precision (in almost all cases). But even the act of converting into the digital domain reduces the signal to noise ratio through quantization noise.
If you don't believe that there is a fundamental limit, I suggest you propose an algorithm for extracting the information. Let's use a simple modulation scheme and here we go:
The signal at the receiver is at a level of -174dBm (decibels referenced to 1 milliwatt).
The receiver is operating at 273 degrees Kelvin with the standard input impedance of 50 ohms resistive.
The modulation scheme is simple phase shift keying (a 1 = phase 0, 0 = phase 180).
Well... actually I was considering synthetic aperture radar, which reduces the physical antenna size requirements (to zero in the case of scatterometry).
Re:Other problems as well
on
DOD vs. 802.11b
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· Score: 3, Informative
The problem isn't "high-speed tower-hopping."
The problem is that the signal from one cell phone at altitude hits many cell towers at once, interfering with other callers.
The word "cellular" means that the system uses small areas called cells. The primary reason for for this article is to allow the same frequencies to be used in multiple separate cells at the same time, by different users. From an airplane, all of those cells are hit at once.
Cellular architecture is one method of improving spectrum efficiency, and was mandated by the FCC for that reason.
Neither software defined radio nor the Open Spectrum initiative renders interference problems obsolete. Saying otherwise is about as meaningful as saying that modern computing repeals the 2nd Law of Thermodynamics!
Radios of any sort increase the energy in the bandwidth that they use. This is true whether they are narrowband traditional radios or ultramodern, cellularized, spread spectrum or ultra-wideband radios of the future.
Any radio receiver has to pull its desired signal out of the ambient noise. That noise consists of natural noise (thermal noise, spherics, astronomical sources, etc) and man-made noise (either noise-like signals or coherent signals). Many radio systems must operate close to the theoretical edge of practicality. The military and reconnaisance organizations especially need to operate with very small noise margins - their ability to do so is one of their advantages.
Increasing the ambient signal levels do degrate the capabilities of these systems. That is trivially proven.
Open Spectrum is an approach to improve bandwidth sharing. That is all it is - it is not a magic panacea that somehow makes interference vanish. Software Defined Radio is simply processing radio signals in software. It also doesn't change the underlying physics.
Consider the issue of radar... radar operates with an inverse-fourth law (the radar equation). The return signal is inversely proportional to the fourth power of the range. Normal radio operates by an inverse square law. Thus radar is especially vulnerable to interference.
To put a little numeracy in here... let's look at a 5GHz space based radar. Assume it outputs 1000 watts peak power (power is very expensive in orbit, you know) from an altitude of 150 miles. Assume the antenna shapes this to 100,000 watts effective radiated power (ERP).
By the time this reaches the earth, it is about 1E-7 watts per square meter. Assume the radar wants to image an area of 100 meters. This is 1E-3 watts or 1 milliwatt. A *single* WiFi stations puts out 10s of milliwatts. Thus if you have one WiFi per 100 square meters, you will have ambient "noise" of 20-30 decibells above the radar signal.
So, this is not a trivial issue. Of course, coherent integration can overcome much higher SNR's, but only at a cost (it requires much more time per resolution area, reducing the overall capability of the system).
In other words, there ain't no free lunch.
The Pentagon has the services of the best experts around to advise it on issues like this. Discounting their objections out of hand is arguing from either ignorance or opinion, not science or engineering. Determining whether their objections are appropriate in this case is a matter for analyses far more complex than will appear on slashdot, and in some cases, probably will require access to very sensitive classified information.
Haven't you heard of aflatoxins? Almost all cases of liver cancer in the US (other than those caused by alcoholism) are caused by aflatoxins - most commonly found in peanut butter.
Moderate amounts of alcohol appear to have a number of beneficial health effects - drink *some*.
Computer programming causes chronic nerve cell migration in the brain - avoid it.
(all right, I made that up... but I'll bet it is true - maybe harmful, maybe beneficial:-)
Face it... there ain't no way to guarantee that you are living well into your 120s or 130s.
But if it makes you feel better to believe so... go ahead.
Re:Age Explorer is a Elderly-discriminating Machin
on
Old Age Simulator
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· Score: 5, Insightful
Contrary to the fantasies of the young, much of how you feel as you age depends on luck and genetics, not lifestyle. Lifestyle certainly counts, but we don't even know what is best. For example, exercise a lot and if you aren't lucky and careful, you will have *more* arthritis as you age. Eat well and when you get old you may discover that what was thought was eating well was no longer the best.
I had the misfortune to contract an intestinal infection relatively young. It triggered an autoimmune disorder that has caused me trouble for over 20 years. Lifestyle had nothing to do with it! Now I am an old fart with arthritis (and not from overexercising I guarantee you!). Friends of mine who were in took care of themselves are dead from various causes (cancer, stroke, etc).
People want to believe they are immortal and in control of things. I see this the most in pilots (which I used to be) as they analyze how *they* wouldn't make the stupid mistakes that just killed one of their peers. The cult of exercise is a similar psychological phenomenon. A lot of people believe, deep down, that if they exercise well and eat the right stuff (and maybe avoid pesticides or power plants, or wear tin hats when the UFOs fly over), they will live forever... or at least long enough that they need not consider their mortality. I think this is one reason that people have such extreme emotional reactions to certain kinds of risk - such as nuclear power or trace chemical contaminants.
There is no doubt that moderate exercise is better than no exercise, and that overweight is worse than not being overweight. Beyond that, it's far less clear what to do. Probably the most important determinant, for someone in our prosperous society, is what parents they chose.
For man rated cost-to-orbit, the Saturn V was and would be lower cost per pound than the Shuttle is.
The shuttle was a dishonest trick by NASA - it has never delivered anywhere close to the promised mission rate or cost per pound to orbit. In order to justify the shuttle, NASA had to promise that it would carry out all launch-to-orbit missions, and forced all other government agencies to rely on it.
The shuttle is an engineering kludge. It resembles the worst legacy system any coder has ever had to deal with. The idea of resuable vehicles sounds great, but there are alternatives, as Bob Truax (former head of Navy space program, Project Private Enterprise, Truax Engineering - see http://www.freespeaker.org/technology/greatmambo.h tml , http://www.astronautix.com/lvfam/truax.htm)
When Challenger blew up, the US was unable to launch important reconnaisance satellites for many months. For this reason, they are now launched by expendable vehicles developed for that purpose.
Of course, NASA isn't all to blame. Congress and the American people got tired of space. Once we had landed on the moon, the public mostly was not interested in more space expenditures. On top of that, the economic conditions of the 70s were terrible, and the political conditions were worse.
NASA did understand one thing: public relations is often more important than substance in acquiring funds. They seem to have forgotten that. An exciting, even risky manned mission would draw more public interest and support than all the science missions put together.
I started carrying it when gangs, who do not give a hoot about gun registration or gun laws, started carjacking people - often killing them in the process. They also started randomly shooting people in cars (in my town - these are not urban legends - I monitor the police scanner from time to time).
I hope I never have to use the gun in self defense AGAIN. But I have fired a gun in self defense before, and I am sure it prevented me from being badly beaten or killed (by people who had just put one of my friends in the hospital). Like most defensive uses of guns, there were no injuries.
The right to keep and bear arms derives from the doctrine of natural rights, which also forms the basis of the US constitution. The "militia" clause gives a justification for the right, but does not in itself restrict the right. The constitution does not say "You have the right to keep and bear arms in a militia." It says...
(paraphrased to make my point clear)
[MILITIAS ARE GOOD] [PEOPLE HAVE A RIGHT TO KEEP AND BEAR ARMS]
It does not say that people have a right to keep and bear arms only if they are in a militia. The milita clause is given as an explanation, not a restriction - specifically:
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.
Notice that this right is more expressly pronounced than in the first amendment. The First Amendment (held so sacred by slashdotters and the gun grabbers) simply limits the powers of congress (Congress shall make no law...).
Furthermore, the constitutions of the individual states often have even stronger gun rights in them. Keep in mind that for those states to be admitted to the union, their constitutions had to be approved by the national government.
Hence there is a clear and strong argument to be made for the rights of individuals to have firearms. It isn't an absolute right any more than free speech is (ownership of nuclear weapons is not ok any more than the classic crying fire in a crowded theater).
Additionally, there are practical arguments for the keeping of weapons by non-criminals (who have them anyway - now very common in Britain, the highest crime rate country in the western world) and non-psychotics. Firearms are an equalizer. They allow a small or elderly person to defend themselves against the strong or the gang. There are numerous cases (about 1 a year here in the Phoenix area) where the elderly drive off, wound or kill intruders into their homes.
As far as the statistical arguments go... the most important point is that they are only meaningful if you choose to ignore (or disagree with) the constitutional protections on keeping and arming bears... errr bearing arms. Utilitarian arguments should not overcome rights - that is the entire principle of having a constitution in the first place!
The statistics, of course, prove all sorts of things and prove nothing. It is obvious that having firearms around means that more people will be shot. It is also obvious that having bicycles means that more children will be run over. So if you are going utilitarian, relative utility is important.
More children are killed by swimming pools than by firearms. There is no right to have a swimming pool and the utility value is relatively small.
Most victims of firearm violence are killed by criminals, and nobody has yet put forward a proposal that can effectively disarm criminals!
Why should business in particular be singled out as the only interest that is prohibited from participating in our political system?
Businesses represent other people - namely their stockholders and (in some areas) their employees.
If you are going to deny the right to businesses, how about zillionaire Hollywood actresses whose only qualification is big b00bs?
How about trade unions?
How about pro or anti abortion groups?
How about the NRA?
How about the trial lawyers? If businesses don't balance the influence of trial lawyers, pretty soon we won't have any businesses operating in our country!
I think the whole approach to dealing with campaign financing is idiotic. We are restricting the rights of various parts of our society to speak their position (through advertising or direct contributions), with the limits arbitrarily set depending on what deals can be cut in congress. This is corruption way beyond what corporations or trial lawyers can buy!
WAKE UP, FOLKS! The purpose of campaign finance reform is to keep incumbents in office! It works well. Since the post-Watergate campaign "reforms", incumbency has been greatly strengthened. It is rare that a challenger wins in a national political race. The new reforms will make it even harder.
The way to combat those forces who you think have too much power is to organize to achieve equivalent power, not to arbitrarily create complex restrictions.
I wonder how many of those who complain about the power of big corporations actually contribute to organizations which counter them? After all, there are many anti-corporate groups which have vast power - the environmentalist groups being the most significant (the trial lawyers are more powerful, but they just want to take the money, not change policy in any other way).
It is a well known fact that America is controlled by corporations
More like a favorite myth of the left.
America is controlled by those people who actually go out and vote. Politicians who want those votes are forced, by stupid campaign finance laws among other things, to rely on corporations and other powerful interest groups to get their message out. More accurately, because of the laziness of the voters, they need to spend the money to put out propaganda since the voters allow themselves to be subject to it.
Some of the most powerful organizations in American political power today are *not* profit making corporations (which is no doubt what you meant by corporations). Instead, they are other special interest groups.
These groups include:
Huge trade unions - especially the teacher and government employee unions. In fact, the democratic party is almost dominated by the those unions. These unions, unlike corporations, have the ability to enact a tax on their members to pay for their lobbying. Legally, members can opt out of this tax, but practically it is very hard. Often the unions advocate causes that go against the values and interests of their members.
Trial Lawyers - as individuals and groups. This is another very large contributor to the democratic party. The part of the Democrats not owned by the trade unions is mostly owned by the trial lawyers. These lawyers are a form of predatory private economic interest, but a rarely condemned by those who attack Microsoft or other economic groups that actually produce something of value. The lawyers need government clout to prevent reform of the tort laws which, along with totally junk science, are used to extort hundreds of billions of dollars from productive corporations in class action suits.
Powerful ideological lobbies. In the case of the democratic party, these include:
Emily's list - an organization that contributes large amounts of money to radically "pro-choice" candidates.
Hollywood actors
National Organization for Women (NOW)
National Abortion Rights Aliance? (NARAL)
NAACP and other black organizations
Sierra Club, Greenpeace, and other rich environmental groups (which then receive huge grants from the government)
In the case of the republican party, they include:
NRA - National Rifle Association
Right to Life Groups
But ultimately, the power resides in the voters. Only when they allow their votes to be bought with advertising, rather than looking at the issues, do the corporations, lawyers, unions, and ideological groups gain such clout.
Slashdot Mirror
Tactical nukes indeed do get down to about that size. Some of them are "dial-a-yield."
:-)
Tactical nukes were intended for all sorts of uses. For example, the anti-aircraft batteries around the US during the early cold war had nuclear warheads in the missiles. The Navy had nuclear warheads in the anti-aircraft missiles on almost all of their combat ships. I was an aircrewman in a P-3 Orion (submarine hunter) and we carried nuclear depth charges. Submarines carried nuclear torpedos.
I believe the only reason that tactical nukes are not used in the NMD anti-missile systems is political. Although there is one other possibility (exo-atmospheric burst caused EMP), the advantages of nuclear warheads for anti-ballistic missile defense seem immense - the problems of hitting the target go away - you just need to get close. (I would love to hear from anyone who *knows* why these difficult "hit-to-kill" vehicles are being used instead of nukes, if it is not political).
As far as conventional explosives go... I once watched a demonstration (and test) at Sandia Labs (Albuquerque, NM - where they did most nuclear weapons design). They set off around 1 kiloton equivalent of high explosive a few miles from where we were watching at an Armed Forces Day demonstration. It certainly produced a very nice mushroom cloud and a heck of a bang!
As a kid, I set off a small explosive in the back yard (my parents were not amused). It was about an ounce of Sodium Chlorate mixed with Sugar and a little Sulfur, with an electrical detonator (single strand of wire shorting an extension cord). I also made a very small, but distinct, mushroom cloud
For more info on nukes, see This Site.
Others have pointed out the problem in your physics exposition.
Let me point out that the large amount of "residual radiation" (fallout) produced by the Hiroshima bomb did not fall near Hiroshima, so there was no residual radiation in Hiroshima itself. The bomb was exploded at altitude and the radioactive components (other than the tiny amount converted to energy) was turned into extremely hot gas. That gas rose into the stratosphere and was distributed, more or less evenly, throughout the northern hemisphere.
In general, air bursts of nuclear weapons do not produce local fallout.
The Port of Chicago explosion, had it been nuclear, would have resulted in the lifting of large amounts of dust and other terrestrial material. This would have formed condensation nuclei for the radioactive material, which would have then fallen back to the ground at and within a few hundred miles of the blast. This is classic nuclear fallout for a ground burst. This would have led to significant injury and death, and the residual radiation would still be detectable (although at low levels today).
The funny thing about all the thrashing and gnashing going on here is that the same cry wasn't raised when the Clinton administration was pushing science in the other direction.
I have researcher friends eas who were afraid to cite their real views on global warming for fear of losing grants in the Gore-dominated years. There are plenty of other examples. And lets not forget the junk science used by the EPA to justify drastic interventions in our lives... junk science that has been widely debunked by responsible scientists.
Face it... government funded science will have a different *emphasis* with different administrations. The government funding of science is appropriately a political process because they are spending the taxpayers money! The US scientific establishment does a pretty good job of minimizing the ideological impacts on science, but it is still there - regardless of the ideology of the government.
One area that for years couldn't get funding - purely for political reasons - was the study of genetic contributions to behavior and learning abilities. This was because of a fear that the results might lead reinforce racism or lead to genetic predestinationism. While those fears have some validity to them, the suppression of scientific research for years was not appropriate.
The primary research the Bush administration tries to suppress is that which uses foetuses. The reason is a moral one (whether you agree with it or not) and is an attempt to avoid a perceived evil means, not to skew the results.
I started working as a programmer 35 years ago. I am still working as a programmer and software architect, and making good money, but I do worry about the threat of the export of programming jobs.
I have been a manager, director and CTO (of a 2000 person company), but I prefer technology and have been fortunate enough to do it.
One of the problems with engineering careers (including the part of software work that can truly be called engineering) is that it is done by teams. That means that individuals are too often treated as replaceable assets. This is not conducive to job security!
Another problem is that the field of software development has people ranging from tinkerers to highly schooled professionals, and all in between (in several dimensions). Thus any programmer can call himself a professional or a computer scientist, when in fact many are neither. This is very confusing to non-technical people and employers.
Simple coding from specifications is not engineering. It is a craft similar to carpentry.
Most software development is not computer science, and computer science is not even science. The field is split between mathematics and engineering, which is also confusing.
When I was a kid in the '50s, the futurists predicted routine space travel by now, commuting by flying automobiles, the hyrdrogen economy, copious nuclear power production, intelligent robots, oh - and the end of the world by nuclear war.
Hmmm...
And they missed the information age, microchips, the sexual revolution, the civil rights movement, the air bag in cars, AIDS, velcro and genetic engineering.
So much for futurists.
Errr... there is no longer a 1st class FCC Commercial License. Mine turned into a "General Class" a couple of decades ago. Second class also turned into a "General Class."
(for those who ask, this is a kind of license needed to be a technical person on various kinds of FCC stuff, such as two way radios and broadcast stations). The term "engineer" in broadcasting is like the term "engineer" in trains - it doesn't mean you are an engineer. I started as a broadcast "engineer" when I was in high school with a 1st class FCC License (commonly called "First Phone").
While I agree that copyright life is way too long, the argument that the copyright should not extend past the life of the artist is wrong and is equivalent to saying that the state should inherit the (house or car or bank account or whatever) of the deceased.
People are often motivated by what they may pass down to their children. If the copyright is creating a property with a finite life, that property should be controlled, after death, the same way other property of the deceased is controlled.
It all boils down to the same physics. The only way you cheat on the resolution equation is with a *moving* synthetic aperture antenna, where you can process the signals (if recorded with extremely accurate time resolution) as if the antenna were the length of the distance you moved it. I don't think that applies in this case.
A lense is mathematically equivalent to an array of traditional antennas. The same fourier equations work whether we are talking refractive optics or 10 MHz HF radio antennas!
I suspect the whole system hinges on high gain antennas on the ground, although that would require precise station keeping on the balloons (which is very energy intenstive) or tracking by the ground stations (which is an unlikely consumer technology unless the *consumer* end was using 2-D steerable phased arrays).
It will be interesting to find out just what the designers have in mind. Also interesting is why they would choose a Part-15 (unlicensed station) service.
Yes, I addressed the issue of large antennas (any lense is an antenna, of course). I think the problem is that for a lot of coverage, you need a lot of antennas, OR much limited time available for each station.
Perhaps they had in mind high gain antennas on each ground station. That would certainly help the problem by 20 dB or so.
Silly, you don't have a right to enforce the content of a site you browse(including pop-ups or drop-downs or other obnoxious tings)!
:-(), but you don't have a right to prevent them from trying to display them!
Of course, you have a right to do whatever you want to avoid seeing their popups (untell the DMCA gets even worse
If you don't enjoy popups and don't want to install a blocker, DON'T GO TO THEIR SITES or INSTALL A POPUP BLOCKER!.
Isn't this similar to what folks always say to those who want to block pr0n? If you don't want to see it, DON'T LOOK!
Wi-Fi only has a few channels. These balloons, at high altitude, are going to be in range of literally tens of thousands of wi-fi emitters, not to mention 2.4GHz (and presumably 5GHz) cordless phones. Microwave ovens also operate on this spectrum - how many little leaks will there be. Remember, this is on Part-15 spectrum (at least in the US) where *anyone* can set up as many transmitters as they want!
Even with steerable phased array antennas, the interference problem seems insurmountable in urban areas. You would need a WHOLE LOT of great big antennas (many meters - don't have time to do the detailed calcs) and even then many areas are unlikely to work.
Either something is being left unsaid, or.. I smell a possible scam.
Does anyone have information that would contradict this interference argument?
Sigh... the old slippery slope argument rears its slipper head again...
Laws already exist, all over the place, regarding the internet and things you do with this. There will be more as the internet gets more important to the economies of the world.
The creation of an anti-spam law does not "open the floodgates" - the slippery slope argument simply holds no water. The world, including the world of laws, does not work on absolutes. Everything ultimately ends up a compromise, because in human behavior there are few clear boundaries. Thus the government becomes inserted in almost all kinds of behavior at the extremes, and lots of other behavior at the norm.
Since PCB's are relatively harmless, and their carinogenicity in people has been well tested and found to be unmeasurable, this whole thing about the Hudson is basically a way to waste lost of taxpayer dollars, screw up the river, screw up GE, and fatten the wallets of some rich trial lawyers. Electrical workers, including those at GE, have had PCB exposures vastly higher than you can ever get from river water, and their cancer risk is at or below normal.
One amusing phenomenon is the number of rich liberals who live along the upper Hudson - folks who are happy to impose ultrastrict environmental rules on everyone else - who object to this project because it will mess up the river for a long time/
I read that paper some time ago. I just read it again. It contradicts *nothing* that I have said.
If you believe otherwise, I would suggest you extract the specific assertion and make it here.
The paper is about how smart networks can increase the bit rate per area per megaherz. This is not exactly black magic. Cell technology is a primitive (and in some cases, not so primitive) example of the principle.
As I said before, "open spectrum" and "software defined radios" (or more apropos to that paper, smart radios) do not remove the issues of interference.
They are simply clever ways of dealing with the issue that *improve* spectrum usage. They do it through a number of techniques - but ultimately there are three principles:
1) Time/Frequency multiplexing - using intelligence to make it more effective than past systems. This includes spread spectrum (already used in cellular), ultra-wideband techniques (a special form of spread spectrum), collision avoidance (chosing a temporarily available frequency), and various levels of local cooperation.
2) Area multiplexing - the cellular principle, but with more flexibility and intelligence. Basically one reduces the power of the radio because one is talking to a more local resource.
3) Relaying through the network to avoid long haul transmissions - something amateur radio packet networks have been doing for decades.
NONE of these techniques eliminates the problem of interference. NONE of these techniques relies on any new physical or computational principle which magically makes the problem go away.
ALL of these techniques are already in use at one level or another, and all still boil down to the same fundamental issues: signal-to-noise ratio limits the channel carrying capacity (as is pointed out in the paper that *you* referenced). These techniques simply provide for the re-use of channels in space and time - and nothing more.
Put another way... old fashioned spectral regulation uses fixed frequencies with guard bands and power limits (and other limitations more technical) to avoid interference. Open Spectrum (a movement of which that paper is a part) uses smart radios to achieve the same effect, resulting in a significant increase in spectral efficiency (in fact, potentially a vast increase). Those techniques may actually *increase* the total amount of man-made radio noise, as seen from a distance (say - a space based military radar or a radio telescope).
Finally, it is important to recognize that Open Spectrum has several dimensions: technical, political and economic. Many of the proponents of open spectrum are more informed on the latter two issues than the former.
Open spectrum does *not* reduce, for example, government regulation. What it does is use highly detailed and technical regulation in a general fashion to produce a spectral space where individual regulation (station licensing) is not required. THAT is a significant improvement economically and politically. In other words, it regulates the characteristics of radios, rather than the users of those radios. This exists today in some areas - for example your don't need a license to use a cell phone, but the cell phone *does* need an FCC approval (on very detailed technical grounds) before it can be legally sold or used.
In the technical area, Open Spectrum (in many variants) replaces one set of problems with another, and hopefully in the process produces more value to spectrum users. The problems it removes are guard bands and individual stations licensing.
The problems it adds include increased radio complexity; more difficult testibility; more system robustness at the cost of typically less predictable for a single station; hidden station issues; tolerance of defective radios (which may violate the protocols); tolerance of intentional "commons" hogs (see citizen band radio for an example) ; difficulty in interference prediction ; individual system failure if stations *happen* to get too close together.
All of these can be dealt with, and will be.
Just don't tell me that the radio interference has magically vanished because of this stuff. It hasn't, and it won't.
What a load of .... ahistorical disinformation!
It was not clear what was happening at first. There were no fighters that could intercept in time - some were launched but didn't get there fast eough.
The fact that Washington might come under attack was not immediately obvious. In fact, nobody knew it was terrorism until the SECOND plane hit the WTC. By that time, the third plane was getting close to hitting (it was also flying low, with the transponder turned off, and was very hard to track on civilian radar). And most people don't realize that the US normally had ZERO armed fighters aloft, and only a few on standby alert for the entire east coast.
As far as the flight over PA... the crash was witnessed. It was not a military attack. The debris was not scattered over a wide area, but rather confined to the small area typical of high speed flight into the ground at a high angle.
The president wanted to return to DC. His advisors wisely suggested he do otherwise until the magnitude of the threat could be determined. It was some time before it was determined that there were no more rogue aircraft up there.
If Clinton had been president, he would have sent a few more cruise missiles up the rear of a few more camels, and then gone crying to the United Nations. Oh, and he would have blown up a pharmaceutical factory somewhere. It was Clinton who failed to take Al Queda seriously in the first place - missing opportunities to capture Bin Laden. Furthermore, Clinton's "impeachment war" was widely recognized throughout the world as a phony war meant to distract from political embarassment. As such, it further inflamed the Arab world when they saw a US President willing to kill Arabs for his own personal gain!
Oh, btw... the order WAS given to shoot down the PA flight if it came into striking range of a major target.
Would that this be true! But it is not. Check out Shannon's laws.
The way you separate signals from noise is ultimately by integration. The longer you integrate, the lower the signal to noise ratio you can tolerate. BUT... that limits the information rate - I can pull one bit per second out of pretty deep noise - either by coherently integrating for a while, or by sending it in a very narrow band way and using very narrow filters (which equates to long integration - there ain't no free lunch).
Any modulation scheme and data recovery scheme you come up with boils down to this same limit. This even applies to ultra-wideband technology, which is, at low signal levels, no different than spread spectrum.
All that speedy processors ultimately do is perform the same functions that analog systems can do now. They just do it vastly less expensively (for certain algorithms - say phase linear sharp filters) and with more precision (in almost all cases). But even the act of converting into the digital domain reduces the signal to noise ratio through quantization noise.
If you don't believe that there is a fundamental limit, I suggest you propose an algorithm for extracting the information. Let's use a simple modulation scheme and here we go:
The signal at the receiver is at a level of -174dBm (decibels referenced to 1 milliwatt).
The receiver is operating at 273 degrees Kelvin
with the standard input impedance of 50 ohms resistive.
The modulation scheme is simple phase shift keying (a 1 = phase 0, 0 = phase 180).
The modulation rate is 100kbps.
Go for it!
Well... actually I was considering synthetic aperture radar, which reduces the physical antenna size requirements (to zero in the case of scatterometry).
The problem isn't "high-speed tower-hopping."
The problem is that the signal from one cell phone at altitude hits many cell towers at once, interfering with other callers.
The word "cellular" means that the system uses small areas called cells. The primary reason for for this article is to allow the same frequencies to be used in multiple separate cells at the same time, by different users. From an airplane, all of those cells are hit at once.
Cellular architecture is one method of improving spectrum efficiency, and was mandated by the FCC for that reason.
Baloney yourself!
Neither software defined radio nor the Open Spectrum initiative renders interference problems obsolete. Saying otherwise is about as meaningful as saying that modern computing repeals the 2nd Law of Thermodynamics!
Radios of any sort increase the energy in the bandwidth that they use. This is true whether they are narrowband traditional radios or ultramodern, cellularized, spread spectrum or ultra-wideband radios of the future.
Any radio receiver has to pull its desired signal out of the ambient noise. That noise consists of natural noise (thermal noise, spherics, astronomical sources, etc) and man-made noise (either noise-like signals or coherent signals). Many radio systems must operate close to the theoretical edge of practicality. The military and reconnaisance organizations especially need to operate with very small noise margins - their ability to do so is one of their advantages.
Increasing the ambient signal levels do degrate the capabilities of these systems. That is trivially proven.
Open Spectrum is an approach to improve bandwidth sharing. That is all it is - it is not a magic panacea that somehow makes interference vanish. Software Defined Radio is simply processing radio signals in software. It also doesn't change the underlying physics.
Consider the issue of radar... radar operates with an inverse-fourth law (the radar equation). The return signal is inversely proportional to the fourth power of the range. Normal radio operates by an inverse square law. Thus radar is especially vulnerable to interference.
To put a little numeracy in here... let's look at a 5GHz space based radar. Assume it outputs 1000 watts peak power (power is very expensive in orbit, you know) from an altitude of 150 miles. Assume the antenna shapes this to 100,000 watts effective radiated power (ERP).
By the time this reaches the earth, it is about 1E-7 watts per square meter. Assume the radar wants to image an area of 100 meters. This is 1E-3 watts or 1 milliwatt. A *single* WiFi stations puts out 10s of milliwatts. Thus if you have one WiFi per 100 square meters, you will have ambient "noise" of 20-30 decibells above the radar signal.
So, this is not a trivial issue. Of course, coherent integration can overcome much higher SNR's, but only at a cost (it requires much more time per resolution area, reducing the overall capability of the system).
In other words, there ain't no free lunch.
The Pentagon has the services of the best experts around to advise it on issues like this. Discounting their objections out of hand is arguing from either ignorance or opinion, not science or engineering. Determining whether their objections are appropriate in this case is a matter for analyses far more complex than will appear on slashdot, and in some cases, probably will require access to very sensitive classified information.
Apple slices with peanut butter?
:-)
Haven't you heard of aflatoxins? Almost all cases of liver cancer in the US (other than those caused by alcoholism) are caused by aflatoxins - most commonly found in peanut butter.
Moderate amounts of alcohol appear to have a number of beneficial health effects - drink *some*.
Computer programming causes chronic nerve cell migration in the brain - avoid it.
(all right, I made that up... but I'll bet it is true - maybe harmful, maybe beneficial
Face it... there ain't no way to guarantee that you are living well into your 120s or 130s.
But if it makes you feel better to believe so... go ahead.
Contrary to the fantasies of the young, much of how you feel as you age depends on luck and genetics, not lifestyle. Lifestyle certainly counts, but we don't even know what is best. For example, exercise a lot and if you aren't lucky and careful, you will have *more* arthritis as you age. Eat well and when you get old you may discover that what was thought was eating well was no longer the best.
I had the misfortune to contract an intestinal infection relatively young. It triggered an autoimmune disorder that has caused me trouble for over 20 years. Lifestyle had nothing to do with it! Now I am an old fart with arthritis (and not from overexercising I guarantee you!). Friends of mine who were in took care of themselves are dead from various causes (cancer, stroke, etc).
People want to believe they are immortal and in control of things. I see this the most in pilots (which I used to be) as they analyze how *they* wouldn't make the stupid mistakes that just killed one of their peers. The cult of exercise is a similar psychological phenomenon. A lot of people believe, deep down, that if they exercise well and eat the right stuff (and maybe avoid pesticides or power plants, or wear tin hats when the UFOs fly over), they will live forever... or at least long enough that they need not consider their mortality. I think this is one reason that people have such extreme emotional reactions to certain kinds of risk - such as nuclear power or trace chemical contaminants.
There is no doubt that moderate exercise is better than no exercise, and that overweight is worse than not being overweight. Beyond that, it's far less clear what to do. Probably the most important determinant, for someone in our prosperous society, is what parents they chose.
For man rated cost-to-orbit, the Saturn V was and would be lower cost per pound than the Shuttle is.
h tml , http://www.astronautix.com/lvfam/truax.htm)
The shuttle was a dishonest trick by NASA - it has never delivered anywhere close to the promised mission rate or cost per pound to orbit. In order to justify the shuttle, NASA had to promise that it would carry out all launch-to-orbit missions, and forced all other government agencies to rely on it.
The shuttle is an engineering kludge. It resembles the worst legacy system any coder has ever had to deal with. The idea of resuable vehicles sounds great, but there are alternatives, as Bob Truax (former head of Navy space program, Project Private Enterprise, Truax
Engineering - see http://www.freespeaker.org/technology/greatmambo.
When Challenger blew up, the US was unable to launch important reconnaisance satellites for many months. For this reason, they are now launched by expendable vehicles developed for that purpose.
Of course, NASA isn't all to blame. Congress and the American people got tired of space. Once we had landed on the moon, the public mostly was not interested in more space expenditures. On top of that, the economic conditions of the 70s were terrible, and the political conditions were worse.
NASA did understand one thing: public relations is often more important than substance in acquiring funds. They seem to have forgotten that. An exciting, even risky manned mission would draw more public interest and support than all the science missions put together.
I too carry a gun - in my car.
I started carrying it when gangs, who do not give a hoot about gun registration or gun laws, started carjacking people - often killing them in the process. They also started randomly shooting people in cars (in my town - these are not urban legends - I monitor the police scanner from time to time).
I hope I never have to use the gun in self defense AGAIN. But I have fired a gun in self defense before, and I am sure it prevented me from being badly beaten or killed (by people who had just put one of my friends in the hospital). Like most defensive uses of guns, there were no injuries.
The right to keep and bear arms derives from the doctrine of natural rights, which also forms the basis of the US constitution. The "militia" clause gives a justification for the right, but does not in itself restrict the right. The constitution does not say "You have the right to keep and bear arms in a militia." It says...
(paraphrased to make my point clear)
[MILITIAS ARE GOOD] [PEOPLE HAVE A RIGHT TO KEEP AND BEAR ARMS]
It does not say that people have a right to keep and bear arms only if they are in a militia. The milita clause is given as an explanation, not a restriction - specifically:
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.
Notice that this right is more expressly pronounced than in the first amendment. The First Amendment (held so sacred by slashdotters and the gun grabbers) simply limits the powers of congress (Congress shall make no law...).
Furthermore, the constitutions of the individual states often have even stronger gun rights in them. Keep in mind that for those states to be admitted to the union, their constitutions had to be approved by the national government.
Hence there is a clear and strong argument to be made for the rights of individuals to have firearms. It isn't an absolute right any more than free speech is (ownership of nuclear weapons is not ok any more than the classic crying fire in a crowded theater).
Additionally, there are practical arguments for the keeping of weapons by non-criminals (who have them anyway - now very common in Britain, the highest crime rate country in the western world) and non-psychotics. Firearms are an equalizer. They allow a small or elderly person to defend themselves against the strong or the gang. There are numerous cases (about 1 a year here in the Phoenix area) where the elderly drive off, wound or kill intruders into their homes.
As far as the statistical arguments go... the most important point is that they are only meaningful if you choose to ignore (or disagree with) the constitutional protections on keeping and arming bears... errr bearing arms. Utilitarian arguments should not overcome rights - that is the entire principle of having a constitution in the first place!
The statistics, of course, prove all sorts of things and prove nothing. It is obvious that having firearms around means that more people will be shot. It is also obvious that having bicycles means that more children will be run over. So if you are going utilitarian, relative utility is important.
More children are killed by swimming pools than by firearms. There is no right to have a swimming pool and the utility value is relatively small.
Most victims of firearm violence are killed by criminals, and nobody has yet put forward a proposal that can effectively disarm criminals!
Why should business in particular be singled out as the only interest that is prohibited from participating in our political system?
Businesses represent other people - namely their stockholders and (in some areas) their employees.
If you are going to deny the right to businesses, how about zillionaire Hollywood actresses whose only qualification is big b00bs?
How about trade unions?
How about pro or anti abortion groups?
How about the NRA?
How about the trial lawyers? If businesses don't balance the influence of trial lawyers, pretty soon we won't have any businesses operating in our country!
I think the whole approach to dealing with campaign financing is idiotic. We are restricting the rights of various parts of our society to speak their position (through advertising or direct contributions), with the limits arbitrarily set depending on what deals can be cut in congress. This is corruption way beyond what corporations or trial lawyers can buy!
WAKE UP, FOLKS! The purpose of campaign finance reform is to keep incumbents in office! It works well. Since the post-Watergate campaign "reforms", incumbency has been greatly strengthened. It is rare that a challenger wins in a national political race. The new reforms will make it even harder.
The way to combat those forces who you think have too much power is to organize to achieve equivalent power, not to arbitrarily create complex restrictions.
I wonder how many of those who complain about the power of big corporations actually contribute to organizations which counter them? After all, there are many anti-corporate groups which have vast power - the environmentalist groups being the most significant (the trial lawyers are more powerful, but they just want to take the money, not change policy in any other way).
More like a favorite myth of the left.
America is controlled by those people who actually go out and vote. Politicians who want those votes are forced, by stupid campaign finance laws among other things, to rely on corporations and other powerful interest groups to get their message out. More accurately, because of the laziness of the voters, they need to spend the money to put out propaganda since the voters allow themselves to be subject to it.
Some of the most powerful organizations in American political power today are *not* profit making corporations (which is no doubt what you meant by corporations). Instead, they are other special interest groups.
These groups include:
In the case of the republican party, they include:
NRA - National Rifle Association
Right to Life Groups
But ultimately, the power resides in the voters. Only when they allow their votes to be bought with advertising, rather than looking at the issues, do the corporations, lawyers, unions, and ideological groups gain such clout.