It's a matter of definitions. According to at least one that I've read, "sci-fi" refers to "soft" science fiction, and "SF" refers to "hard" science fiction. Thus Star Trek falls under sci-fi, along with Godzilla, Babylon 5, E.T., and Stranger in a Strange Land. On the other hand, 2001, A.I., Robinson's Mars trilogy, and The Moon is a Harsh Mistress fall under SF.
Most of us think we have an intuitive understanding of the differences between hard and soft science fiction, and between science fiction and fantasy. However, everyone seems to have a different intuitive understanding! Over the years, this has led to many silly arguments within the science fiction community, reaching for illusory "precise" definitions.
Personally, I think of Star Trek as soft science fiction, since it occasionally makes an attempt to explore the technology and society of its future - a future that is extrapolated, however hamfistedly (the technobabble comes to mind:-), from our present. But that's just me.
> So yes, if you strap yourself to an ungrounded
> case, you won't zap the case cause you are at
> the same potential, but you can still zap
> external compnents you pick up.
Er, even if you strap yourself to ground, you can still zap external components you pick up, if they aren't at the same potential as ground.
The royal "we" is a substitution of "I". As the poster obviously meant "the human race" when he said "w", you appear to be quite high handed.
The poster obviously knows little physics beyond the level of intro college courses. For him to make airy, disparaging statements about the human race's knowledge of physics is more arrogant than my (admittedly abrasive) post was.
you have _NO_ idea how Gravity works. Perhaps you are confusing being able to write a formula to describe something, as knowing how it works.
If you can write down the equations for gravity, you know how gravity behaves. Contrary to the poster's insinuation that we know hardly anything about gravity, GR works very well, across a huge range of validity.
But on the other hand, we can be fairly certain that the fundamental forces of nature occur on a subatomic level.
Which, unfortunately, blows a hole in your claim that gravity will one day be manipulated the way the electromagnetic force is today. The gravitational force between two protons is on the order of 10^-36 times the electrical force. That's what people mean when they say that gravity is weak.
And, while [plasma]'s clearly affected by magnetism and electrostatic forces, it also seems to be unaffected by gravity.
Bollocks. The fact that the Sun is a sphere, and not a cloud of atoms evenly dissipated across the universe, is pretty strong evidence that plasma is affected by gravity.
Consider that, to my knowledge, we've still got no higher understanding of why two positively charged ions repel, or why a positively charged ion attracts a negatively charged ion.
Please refrain from the royal "we" in an area in which you obviously lack expertise. "Higher understanding" and "why" are loaded words; but some of us have a pretty good idea of how gravity and electromagnetism work, thank you very much.
all computations will take the same amount of time, the time it takes for an electron(or other suitable particle) to choose a spin.
That's confusingly worded. More precisely, each quantum mechanical computation of the same type will take the same time, regardless of the input. For example, if you are using a quantum mechanical computer to find a "1" in a string of "0"s, it does not matter where the "1" is located. Different types of computations will obviously take different amounts of time.
Quantum mechanics is no more than an extension of regular mechanics that is only really handy when dealing with very small particles
Depends on what you mean by extension. Insofar as quantum mechanics reduces to classical mechanics in the classical regime, sure. But the rules of quantum mechanics, and quantum mechanical intuition, are very different.
And the effects of quantum mechanics are detectable at the macro scale, through particle statistics. The fact that stars can turn into white dwarfs and neutron stars at the end of their lifetimes, some materials can be superconducters, and liquid helium is a superfluid at low temperatures, are all explained by quantum mechanics, even though they occur on the macro scale.
I dare you to try Schrodiner's equation in polar coordinates
Most undergrad quantum mechanics courses go through this when they talk about the hydrogen atom; no big deal.
but anybody can understand the concepts if they have an open mind about it.
I think you're mistaking belief for understanding. All you need to believe in quantum mechanics is an open mind, and some imagination. What you need to understand quantum mechanics is to go through the math. But it's really not difficult. There are many books that cover most of the basics of the subject, with math only slightly above high school level.
Quantum mechanics doesn't just deal with fermions - bosons are allowed too.:-)
Not to mention anyons, particles that have fractional statistics - and therefore not bosons or fermions - that can exist in 2-dimensional systems. Can't seem to dig up a useful link, though.
And don't forget dunnet, a text adventure game written entirely in elisp, and provided with GNU Emacs.
By the way, how do you get Emacs to do symbolic math?
What the ac said. Unfortuantely, the original post has now been modded up to (Score:4, Interesting), apparently on the basis that the poster claimed he is "working on a mathematics D.Phill" so his words obviously must be correct.
Even if you neglect M-Theory, spacetime is actually three dimensional. You subtract, not add, a dimension. Look up the Holographic Principle, for example here.
As an amusing aside, we can replace the time t with an imaginary time called the "Euclidean time", T=it. This transformation, which is known as Wick rotation, produces a Euclidean spacetime, which is helpful because we are more used to working with Euclidean geometry.
ds^2 = dT^2 + dx^2 + dy^2 + dz^2.
This is not a fashionable approach to special relativity nowadays, as it does not follow the spirit of general relativity. Instead, we define the interval using the Minskowski metric, which has a minus sign in the tt component.
But strangely enough, Wick rotation turns out to be a useful trick in performing quantum mechanical calculations using Feynman's path integral method. Roughly speaking, the action in the path integral gets transformed into a quantity called the "Euclidean Lagrangian," which is frequently much easier to sum.
Re:Nasty Little Truth About Spacetime Physics
on
The New Flatland
·
· Score: 1
Rubbish. It's appealing, and often useful, to subscribe to the relativistic notion that the world line of a particle is a static curve in spacetime. However, it's just as valid to think of time evolution as motion through time. It's absolutely a matter of semantics, because the results obtained using each picture is the same. Notwithstanding your arrogant assumption that the greatest physicists of the last century have failed to share your insight, the static spacetime picture is known to every physics undergrad.
I'm afraid your post comes off as a silly mix of conspiracy theory and pseudoscience. You may have had some physical insight, but it's buried under so much vagueness that it's impossible to tell.
...mathematically, it's not analogous to a constant of integration. It is a generalization of the field equations
It is fairly analogous, actually.
Without the cosmological constant, Einstein's field equations in index-free form are G = kT. This equation is constrained by the vanishing divergence (covariant derivative) of the energy-momentum stress tensor on the right hand side. The Einstein tensor on the left hand side is designed to have a vanishing derivative, in order to satisfy this condition. In addition, it has to reduce to Newtonian gravity in the weak field limit. We can add a cosmological constant Ag because its derivative also vanishes; if it is small enough, the weak field limit is unaffected.
This is very similar to a constant of integration. When you take the derivative of a constant, it vanishes, so the differential equation remains satisfied.
...a disregarded theory first postulated by Einstein about "negative gravity" is actually valid.
The cosmological constant, which provides a repulsion on the cosmological scale, was famously declared by Einstein to be the biggest mistake of his life. However, it has been known for many decades now that the it is a very valid part of the theory - it's not so much a fudge factor as a constant of integration.
Ironically, the official Galaxy Quest website is intended to look like a fansite, down to the inane directory ordering. It's one of the few official movie sites I've found worth visitng.
Perhaps it will one day be routine to start a computing session by dumping in some liquid nitrogen onto a yet-higher-temperature superconducting CPU.
Liquid nitrogen boils at 77K, which is already below the critical temperatures of existing high temperature superconductors. You don't really need to improve HTSC technology any further to use liquid nitrogen.
Have no fear. In Mozilla, it's possible to customize your user-agent string, in order to fool obnoxious web sites into thinking you have a different browser.
What new groundbreaking software have [the FSF] developed?... All the innovation has been coming from outside, from the people doing GNOME, GNUStep and all the rest.
That's a particularly unfortunate set of examples to use, because GNOME == GNU Network Object Modelling Environment, and GNUStep == (er...) GNUStep. Better luck next time.
Wow, what a refreshing perspective. Never before have I heard anyone say of Mozilla, "I just want a browser" every time a Mozilla article comes up.
As you probably already realize from your comment that Mozilla 0.7 is "still" too bloated, Mozilla *is* gradually getting optimized. The Mozilla team isn't diverting any resources from optimization to develop the Protozilla plugin, as you seem to imply; the plugin is a separate project at MozDev. And if the pace of improvement isn't fast enough for your taste, go contribute code instead of bitching on Slashdot.
Actually, even if electric cars ultimately derive their energy from fossil fuel-burning electrical power plant, they'll probably still be cleaner than cars with internal combustion engines. Vehicle-mounted engines sacrifice fuel-burning efficiency for portability, whereas power plants go to great lengths to burn the fuel as thoroughly as possible.
I don't have any numbers handy, but IIRC the savings are quite considerable.
Slashdot Mirror
It's a matter of definitions. According to at least one that I've read, "sci-fi" refers to "soft" science fiction, and "SF" refers to "hard" science fiction. Thus Star Trek falls under sci-fi, along with Godzilla, Babylon 5, E.T., and Stranger in a Strange Land. On the other hand, 2001, A.I., Robinson's Mars trilogy, and The Moon is a Harsh Mistress fall under SF.
Most of us think we have an intuitive understanding of the differences between hard and soft science fiction, and between science fiction and fantasy. However, everyone seems to have a different intuitive understanding! Over the years, this has led to many silly arguments within the science fiction community, reaching for illusory "precise" definitions.
Personally, I think of Star Trek as soft science fiction, since it occasionally makes an attempt to explore the technology and society of its future - a future that is extrapolated, however hamfistedly (the technobabble comes to mind :-), from our present. But that's just me.
no, that would be GNU/Gnome/Linux
When you expand Gnome/Linux, you get (GNU Network Object Modelling Environment)/Linux. Putting another GNU in front is redundant.
> So yes, if you strap yourself to an ungrounded
> case, you won't zap the case cause you are at
> the same potential, but you can still zap
> external compnents you pick up.
Er, even if you strap yourself to ground, you can still zap external components you pick up, if they aren't at the same potential as ground.
The royal "we" is a substitution of "I". As the poster obviously meant "the human race" when he said "w", you appear to be quite high handed.
The poster obviously knows little physics beyond the level of intro college courses. For him to make airy, disparaging statements about the human race's knowledge of physics is more arrogant than my (admittedly abrasive) post was.
you have _NO_ idea how Gravity works. Perhaps you are confusing being able to write a formula to describe something, as knowing how it works.
If you can write down the equations for gravity, you know how gravity behaves. Contrary to the poster's insinuation that we know hardly anything about gravity, GR works very well, across a huge range of validity.
But on the other hand, we can be fairly certain that the fundamental forces of nature occur on a subatomic level.
Which, unfortunately, blows a hole in your claim that gravity will one day be manipulated the way the electromagnetic force is today. The gravitational force between two protons is on the order of 10^-36 times the electrical force. That's what people mean when they say that gravity is weak.
And, while [plasma]'s clearly affected by magnetism and electrostatic forces, it also seems to be unaffected by gravity.
Bollocks. The fact that the Sun is a sphere, and not a cloud of atoms evenly dissipated across the universe, is pretty strong evidence that plasma is affected by gravity.
Consider that, to my knowledge, we've still got no higher understanding of why two positively charged ions repel, or why a positively charged ion attracts a negatively charged ion.
Please refrain from the royal "we" in an area in which you obviously lack expertise. "Higher understanding" and "why" are loaded words; but some of us have a pretty good idea of how gravity and electromagnetism work, thank you very much.
How low we sink for the sake of karma. I mean, ripping off the poor Anonymous Cowards? Hah.
all computations will take the same amount of time, the time it takes for an electron(or other suitable particle) to choose a spin.
That's confusingly worded. More precisely, each quantum mechanical computation of the same type will take the same time, regardless of the input. For example, if you are using a quantum mechanical computer to find a "1" in a string of "0"s, it does not matter where the "1" is located. Different types of computations will obviously take different amounts of time.
Quantum mechanics is no more than an extension of regular mechanics that is only really handy when dealing with very small particles
Depends on what you mean by extension. Insofar as quantum mechanics reduces to classical mechanics in the classical regime, sure. But the rules of quantum mechanics, and quantum mechanical intuition, are very different.
And the effects of quantum mechanics are detectable at the macro scale, through particle statistics. The fact that stars can turn into white dwarfs and neutron stars at the end of their lifetimes, some materials can be superconducters, and liquid helium is a superfluid at low temperatures, are all explained by quantum mechanics, even though they occur on the macro scale.
I dare you to try Schrodiner's equation in polar coordinates
Most undergrad quantum mechanics courses go through this when they talk about the hydrogen atom; no big deal.
but anybody can understand the concepts if they have an open mind about it.
I think you're mistaking belief for understanding. All you need to believe in quantum mechanics is an open mind, and some imagination. What you need to understand quantum mechanics is to go through the math. But it's really not difficult. There are many books that cover most of the basics of the subject, with math only slightly above high school level.
Quantum mechanics doesn't just deal with fermions - bosons are allowed too. :-)
Not to mention anyons, particles that have fractional statistics - and therefore not bosons or fermions - that can exist in 2-dimensional systems. Can't seem to dig up a useful link, though.
I believe the link you need is HotBits: Genuine random numbers, generated by radioactive decay. If memory serves, it was featured on Slashdot some time ago.
And don't forget dunnet, a text adventure game written entirely in elisp, and provided with GNU Emacs. By the way, how do you get Emacs to do symbolic math?
By your definition, all of cryptography is "security by obscurity."
What the ac said. Unfortuantely, the original post has now been modded up to (Score:4, Interesting), apparently on the basis that the poster claimed he is "working on a mathematics D.Phill" so his words obviously must be correct.
Even if you neglect M-Theory, spacetime is actually three dimensional. You subtract, not add, a dimension. Look up the Holographic Principle, for example here.
As an amusing aside, we can replace the time t with an imaginary time called the "Euclidean time", T=it. This transformation, which is known as Wick rotation, produces a Euclidean spacetime, which is helpful because we are more used to working with Euclidean geometry.
This is not a fashionable approach to special relativity nowadays, as it does not follow the spirit of general relativity. Instead, we define the interval using the Minskowski metric, which has a minus sign in the tt component.
But strangely enough, Wick rotation turns out to be a useful trick in performing quantum mechanical calculations using Feynman's path integral method. Roughly speaking, the action in the path integral gets transformed into a quantity called the "Euclidean Lagrangian," which is frequently much easier to sum.
Rubbish. It's appealing, and often useful, to subscribe to the relativistic notion that the world line of a particle is a static curve in spacetime. However, it's just as valid to think of time evolution as motion through time. It's absolutely a matter of semantics, because the results obtained using each picture is the same. Notwithstanding your arrogant assumption that the greatest physicists of the last century have failed to share your insight, the static spacetime picture is known to every physics undergrad.
I'm afraid your post comes off as a silly mix of conspiracy theory and pseudoscience. You may have had some physical insight, but it's buried under so much vagueness that it's impossible to tell.
It is fairly analogous, actually.
Without the cosmological constant, Einstein's field equations in index-free form are G = kT. This equation is constrained by the vanishing divergence (covariant derivative) of the energy-momentum stress tensor on the right hand side. The Einstein tensor on the left hand side is designed to have a vanishing derivative, in order to satisfy this condition. In addition, it has to reduce to Newtonian gravity in the weak field limit. We can add a cosmological constant Ag because its derivative also vanishes; if it is small enough, the weak field limit is unaffected.
This is very similar to a constant of integration. When you take the derivative of a constant, it vanishes, so the differential equation remains satisfied.
The cosmological constant, which provides a repulsion on the cosmological scale, was famously declared by Einstein to be the biggest mistake of his life. However, it has been known for many decades now that the it is a very valid part of the theory - it's not so much a fudge factor as a constant of integration.
Ironically, the official Galaxy Quest website is intended to look like a fansite, down to the inane directory ordering. It's one of the few official movie sites I've found worth visitng.
Perhaps it will one day be routine to start a computing session by dumping in some liquid nitrogen onto a yet-higher-temperature superconducting CPU.
Liquid nitrogen boils at 77K, which is already below the critical temperatures of existing high temperature superconductors. You don't really need to improve HTSC technology any further to use liquid nitrogen.
Have no fear. In Mozilla, it's possible to customize your user-agent string, in order to fool obnoxious web sites into thinking you have a different browser.
You'll have to edit prefs.js or user.js in your Mozilla home directory. According to http://mozilla.org/unix/customizing.html, the relevant preference is:
user_pref("general.useragent.override", "Mozilla/5.0 (X11; U; Linux 2.2.16-22smp i686; en-US; m18) Gecko/20010110 Netscape6/6.5");
It's actually in the preferences ui.
Edit->Preferences->Appearance->Show Tooltips
Unfortunately, doing this also disables the displaying of title attributes as tooltips. There's a bugzilla entry about this.
What new groundbreaking software have [the FSF] developed?... All the innovation has been coming from outside, from the people doing GNOME, GNUStep and all the rest.
That's a particularly unfortunate set of examples to use, because GNOME == GNU Network Object Modelling Environment, and GNUStep == (er...) GNUStep. Better luck next time.
Wow, what a refreshing perspective. Never before have I heard anyone say of Mozilla, "I just want a browser" every time a Mozilla article comes up.
As you probably already realize from your comment that Mozilla 0.7 is "still" too bloated, Mozilla *is* gradually getting optimized. The Mozilla team isn't diverting any resources from optimization to develop the Protozilla plugin, as you seem to imply; the plugin is a separate project at MozDev. And if the pace of improvement isn't fast enough for your taste, go contribute code instead of bitching on Slashdot.
Actually, even if electric cars ultimately derive their energy from fossil fuel-burning electrical power plant, they'll probably still be cleaner than cars with internal combustion engines. Vehicle-mounted engines sacrifice fuel-burning efficiency for portability, whereas power plants go to great lengths to burn the fuel as thoroughly as possible.
I don't have any numbers handy, but IIRC the savings are quite considerable.