> Many people think the Big Bang theory means that the universe expands
> like a conventional explosion from a sigular point. This is not correct.
Actually, it pretty much is. Although it is sometimes hard to describe
these sorts of objects and events with methaphors from our own life,
this is actually a reasonably good metaphor.
No, this is incorrect. It's a very common metaphor, to be sure; but it's a bad metaphor, insofar as the picture of what happens that it causes people to form is a bad one. It effectively communicates things which are not true.
According to every version of the Big Bang Theory I'm aware of, a crucial
component of the theory is that all the crap in the universe was extremely close
together (some would say at a 0-dimensional point, some would say just really
small --- near the size of the proton). Then, for some reason or another, the
universe just started expanding, and is pretty big now. So the conventional explosition
analogy is actually quite good.
It's quite bad, and part of the reason is illustrated in your quote above. There is an enormous difference between describing the state of the entire universe as a singularity ("a 0-dimensional point") and as a situation where stuff is compressed into a very small volume ("really small --- near the size of the proton"). Those are two extremely different cases. The first (a singularity) is what the Big Bang model, in its simplest form, would indicate; the latter is not.
The point is that the idea of some sort of really tiny pellet of supercompressed matter exploding outward implies that space already exists -- that is, that there is some sort of space that this unbelievably dense stuff is occupying, and that exists for the exploding matter to speed out into. But that's not what the Relativistic Hot Big Bang model prescribes. The expansion is not an expansion of matter flying outward through space, as an "explosion" would describe; it is an expansion of space itself. The distances between matter in the universe were increasing in the early universe not because they were moving away from each other through space, but because the space itself between them was expanding.
So I don't know where you're coming from when you say that "According to every version of the Big Bang Theory I'm aware of...", since an explosion at a single location in space is not what the theory has in mind.
For more on this, see standard GR textbooks such as:
Now, of couse, if you don't buy the Big Bang theory, then you probably don't subscribe to the "all the shit was in one small place" part of it. Ok, this is reasonable. (And I'm not talking about creationists or any bullshit like that, I mean that there is a serious academic debate in the community as to whether or not the Big Bang happened.)
No, there isn't. If you can show me some evidence for such a serious debate within the community (journal cites, for instance), I'd like to see it.
That's not to say that the cosmological community believes that there's nothing left to figure out; there's a lot to figure out. And that's not to say that the cosmological community believes, as a whole, that the Big Bang model will survive as it is without modification or supplement. But the consensus of the community is that whatever the correct description of the evolution of the Universe is, its evolution from a time when the age of the universe was about 10^-24 of what it is now and the average temperature of stuff in the univese was about a trillion degrees Kelvin, up to the present day, will look a lot like the Relativistic Hot Big Bang model.
But if you're using the words "Big Bang", then you sort of mean "conventional explosion from a singular point".
No, you don't.
Another thing I want to mention is that you claim that the universe was always infinite and it's just stretching. According to most current theory, this is not true. Most cosmologists would say that the universe is finite in size, and anyone who subscribes to the BB theory must say the universe is finite in size, since it could only have grown a finite amount in 15 (or whatever) billion years.
This, too, is incorrect. Most cosmologists wouldn't say this at all. There are numerous lines of data (the angular scale of the dominant peak in the spectrum of microwave background fluctuations probably provides the best evidence) that the large-scale geometry of the universe is not closed, and thus that the volume of the universe is not finite. You appear again to be thinking "the universe has a certain age, and it exploded from a certain point, and stuff could only have propagated out to a distance of (distance)=(expansion_rate)*(age), so therefore it's finite and that's the size." That simply isn't how the Big Bang model works.
As an aside, just because the universe is finite does not mean that we could go far enough and hit an edge. Cosmologists also believe that the universe wraps on itself in a higher dimensional way, so that we could travel in a "straight line" for an infinite amount of time without hitting and edge. For those of you who don't have the mathematics, think of a lower-dimensional analogy. Look at a guy on the surface of a sphere with finite radius (Earth e.g.) This dude can walk in a "straight line" for an infinite time, just by circling the globe.
This would be correct if the data suggested that the topology/geometry of the Universe were that it were closed. That's not what the data say, and so that's not what the community believes.
The question has also been asked in this thread: "why are we seeing light from 14 billion years ago now? Will we see 15 billion years ago in a billion years?" The answer is no. The reason we see light from 14 billion years ago is that light travels (hah) at the speed of light. So if you look at an object or region of space which is 14 billion light-years away, you will see it as it was 14 bya. The reason that,these days, we can see further "back in time" is that we can simply see further out in space. Presumably, if we could see far enough away to see far enough back in time, we would be able to observe the BB.
Not really. In principle, at any moment, you're seeing light from a range of times. Right now, for instance, you're seeing light that's one light-nanosecond old from that lamp that's a half a meter away; you're seeing light that's several light-minutes old from the sun; you're seeing light that's billions of years old from objects that are billions of light years away, and so on.
There is always a practical limit to this, however, that prevents you from seeing back to the beginning of time, whatever that means. That practical limit is referred to as the surface of last scattering. Up until when the universe was a few hundred thousand years old, the temperatures of material in the universe were so high, and the densities of this hot material in the universe were sufficiently large, that the universe was essentially opaque to light. As you look in any direction, and you look further and further away (and thus further back in time), you eventually reach a point where you simply can't see light from any further back. In fact, it is the first light you can see -- the light from this surface of last scattering -- that is the object of John Carlstrom's (hi John!) observations described in the article that spawned this topic.
I have no idea from what creationist website you're haphazardly cutting-and-pasting this stuff, but it's pretty embarassing. For you, I mean.
Criticizing a physical model plays a lot better when you have *some* basic understanding of the model itself. The description you give of the Big Bang model simply isn't an accurate one; it shows that you don't know what you're talking about. The goo you posted furthermore misquotes and misrepresents the references it cites, and makes misstatements a-plenty. I encourage you to actually take the time to learn some of the relevant physics, and then make an effort to learn what cosmologists and astrophysicists really do think, and why they think that; your screed helps you with none of those things.
>> significant noise issues
> Actually, that's the best reason I can see to put a radio telescope down
> there. Having all the array cold will decrease the thermal noise
> generated by the array itself. Even though it's an rf instrument, and
> nominally doesn't care about light, I'd expect it to do its best work in
> July.
You're absolutely right that reducing noise is the main reason for going to Antarctica, but there are still significant noise issues that have to be dealt with in the data analysis. Thermal noise from the array is not fought by going to Antarctica, though; that's fought by cooling the bolometers down to 4 Kelvin with liquid helium.
These experiments are attempting to detect variations in the microwave background at the level of fractions of millikelvin; cooling down to the ambient temperature, even in Antarctica, would not come close to addressing their thermal noise issues.
Depending on the frequencies used in their
observations, atmospheric molecular lines are
a source of noise (e.g. from water vapor); since Antarctica is basically the biggest desert in the world, water vapor and other such lines are less of an issue there. More significantly, though, and again depending on frequency, galactic synchrotron radiation and emission from interstellar dust provide the largest noise sources.
> so how exactly will this telescope pinpoint "dark matter"
> any more than any other telescope? I mean, you don't really
> even know what you are looking for. Is it just that there
> is more night time to use it in, or is this just the only way
> they could sell this project.
Neither.
First of all, as an aside, when trying to learn about dark matter, there are some telescopes which are more useful than others; it depends on what you're trying to do. For example, attempting to map the dark matter distribution using weak gravitational lensing requires a telescope with a very wide field-of-view as well as excellent "seeing". The Hubble Space Telescope fails the first of those two conditions, while the Canada-France-Hawaii Telescope on Mauna Kea has traditionally been an excellent telescope for such work.
But second, and more importantly, your question is off-base. The purpose of this telescope is not to investigate dark matter, but rather what's (unfortunately, imho) being referred to these days as "dark energy." If you were to talk to an old astronomer or a specialist in general relativity, they'd refer to it as "a cosmological constant" instead; if you were to speak with a particle theorist, they'd call it "vacuum energy density." The point here is to try to learn something about the energy density of empty space. That's a bizarre notion, I know; but there are particle physics reasons why you might think that such a thing wouldn't be zero, and astronomical observations that argue that we've already seen that it isn't zero. But those observations have been hard to do; there's a fair number of them, from different approaches, and they're generally quite consistent with each other, but it's still possible that they're wrong. And with something as counterintuitive as this, one would like the evidence to be still much stronger than it currently is. The observations this microwave telescope will do should come at this question from yet another angle, and with a fairly high degree of precision. And we'll see.
To learn more about this work and to develop the background that would satisfy your curiosity, I suggest taking the time to do some research, e.g. by checking out the websites for the principles involved in this project.
There's also some excellent cosmological primers available on the web that go over some of this stuff; see e.g. Ned Wright's cosmology tutorial (here and especially here) as well as Wayne Hu's Introduction to the Cosmic Microwave Background.
To go through your concerns one by one:
1. The U.S., in concert with other nations, already maintains an extensive set of scientific facilities in Antarctica, in the form of permanent bases at the South Pole and at McMurdo Sound and Palmer Station. These facilities are manned and operated year-round. Their purpose is to provide logistical support for the scores of short- and long-term scientific projects that take place in Antarctica, such as the one described in this article. In other words, the issue of logistical support for such a project in Antarctica really isn't an issue; an entire organizational/logistical apparatus has been running for many years to provide this capability for science as a whole, and they'll only be one of many projects each year that will take advantage of it.
2. There is already a significant amount of observational evidence for the presence of what's referred to here as "dark energy." One hint of the presence of such an energy component to the Universe comes from trying to reconcile two observations: the first is that cosmic microwave background data indicates that the large-scale geometry of space is flat; the second is that the matter density of the universe (both in baryons, or normal matter, and in unknown dark matter, not to be confused with "dark energy"), measured via a broad variety of techniques, can only provide about 20% of the mass-energy density required to make the large-scale geometry be as flat as is observed. What's the other 80%? If it can't be matter of some sort, then what is it? When this is combined with recent observations that the expansion of the universe is accelerating -- something only possible if such a "dark energy" component to the mass-energy density of the universe is present -- one is forced to take this possibility seriously. (there's a lot more to be said about this issue, but only if someone cares)
3. The telescope will not solely look at one spot on the sky.
4. Lighting is not really an issue; this is not a visible light telescope, but rather a microwave telescope. There are significant noise issues that will have to be confronted in the data analysis, but not really from day vs. night problems.
The Taleban were no more to do with the Sept 11 attacks than the people of Scotland were to do with Lockerbie. Their only obligation to Osama bin Laden is that he is a brother Moslem and the Qu'ran says if you take in a guest, you are responsible for protecting him.
You can't be serious. Are you actually suggesting that the Taliban had no idea whatsoever that bin Laden and his merry band of pranksters hadn't set up a plethora of terrorist training camps, hadn't been using them to train terrorists, and hadn't been dispatching the students abroad to commit terrorism? Because if they did, then their guilt extends beyond your statement.
And the US simply didn't recognise the Taleban as a functioning government. They never tried to depose them before the current invasion.
That's correct -- the US didn't recognize the Taliban as Afghanistan's legitimate government. Nor, for that matter, did the country from which you're posting. Nor did the UN. Nor did any other countries on the entire planet, except for Pakistan and the United Arab Emirates. The US, Great Britain, etc., didn't attack the legitimate government; they supported the legitimate government -- whom they did recognize -- in its ongoing civil war.
> The Taliban only offered to extradite OBL to > another country operating under Sharia (i.e. > Muslim religious) law. The only other country > that is fully operating under Sharia is Iran.
Or the US client state, Saudi Arabia.
Oh, please. First of all, while it's certainly the case that in certain specific ways, the U.S.-Saudi relationship is close, it is utterly absurd to refer to Saudi Arabia as a U.S. client state. If that were true, one would expect the Saudi government to defer to the U.S. more often, especially on issues of extreme importance to the U.S. government. Instead, they rarely do, especially with regards to the topic currently of greatest interest to the U.S. government -- investigations of terrorism. They have not cooperated with the FBI in its investigations of the Saudi Sept. 11 terrorists. They refused to allow U.S. investigators to even speak to those arrested by Saudi authorities for the Khobar Towers bombing, under any terms or circumstances at all. Efforts to shut down money-laundering pathways which have led through Saudi Arabia have been met by stone walls. Client state, indeed.
Secondly, while the legal and penal systems in Saudia Arabia can certainly be extreme in their severity, it is incorrect to refer to them as an implementation of Sharia. In fact, the fact that it isn't has been given as one of bin Laden's gripes against the Saudi ruling family. The implication of your response above -- that if the U.S. had simply coughed up their evidence to the Taliban, they would have been perfectly happy to turn him over to the Saudis -- is patently absurd. Both bin Laden and the Taliban had stated that they consider the official Saudi government as an impediment to be overthrown, as they see it wrong for such a corrupt entity to control the land of Mecca and Medina . ..but the Taliban would have turned over bin Laden to the Saudi government? Be serious.
(even assuming the Saudis would take him, since they refused once in the past -- oh, wait, that couldn't have happened, they're a client state, I forgot)
> The US government did not help to establish > the Taliban. And please do not attempt to > say "But they gave them $43 million last > year!" because they didn't. That $43 million > was grain, medicine, and aid to the people > of Afghanistan who were starving due to > famine.
Sure they did, the US government funded, trained and equipped the organization that would later become the Taleban during the Soviet occupation.
More silliness. Your statement is the logical equivalent of saying that the UK (through Lawrence of Arabia) funded, trained, and equipped the folks that later became Hizbollah during World War I.
Yes, the U.S. provided military aid to the muhjahedeen fighting the Soviet occupation. Yes, a small fraction of those folks, well after the U.S. was gone, organized the core of the Taliban. The jump from there to suggesting that the U.S. "helped establish the Taliban" suggests a fairly bizarre approach to interpreting history.
I think you misinterpreted his response.
I read Alan Cox's "Why pray do you need a commercial DVD to DVD copier?" *not* as saying "what earthly use could you have for one?", but rather as responding to the poster's assertion that the DMCA is effective at stopping piracy, and its effectiveness is demonstrated by the fact that DVD-to-DVD copiers are not commercially available. Alan Cox's reply, quoted above, was to say `you don't need such a copier to commit piracy, so this consequence of the DMCA is not much evidence of its effectiveness at stopping piracy.'
That's my read, anyway.
The majority of important legislation passed by Congress is in the form of "riders," which are attached to politically popular bills dealing with substantially different subject matter.
Reading each of the proposed laws listed, I was able to find a couple of paragraphs to support everything the original poster mentioned.
If that's the case, then I'm sure you'd have no problem providing links to such text in question on the House or Thomas-LOC websites?
I look forward to seeing it, since I don't think you can. I've read the text of the bills in question, back through the 103rd Congress, and saw no such content as you describe. Yes, riders routinely get attached to bills -- but that happens on the floor, not in committee. This year's HR 4239, for example, has been
referred to the Ways and Means Committee
(and hasn't even been considered by it yet!); the previous Congress' HR 4239 was
referred to the House Subcommittee on Health and Environment and died there; and so on.
It is fortuitous that we have an astute reader like b.foster among us who will read the many pages of obfuscation in the laws going through Congress and distill the things that interest the tech community. Your time would better be spent writing your congressman than posting misinformed replies on Slashdot.
Like I say, I may be mistaken, maybe they don't use unique ID's for the bill numbers,
They don't, which is why Googling on H.R. numbers isn't the most effective way of searching this stuff.
Take the first one, for example: HR 4239, which the parent of this subthread claims "makes it a felony to distribute any kind of sexually explicit material to a user who does not register with a government-sanctioned age verification service (like AdultCheck)." You Googled and found that HR 4239 appeared to be a bill "To revise the banking and bankruptcy insolvency laws with respect to the termination and netting of financial contracts." In actuality, what you found was HR4239 from the 105th Congress (1997-1998). Using the House of Representatives database, one learns that:
- In the 104th Congress (1995-1996), HR4239 was a bill "To provide for the licensing of commercial space reentry vehicles and reentry sites, and for other purposes."
- In the 106th Congress (1999-2000), HR4239 was a bill "To amend title XVIII of the Social Security Act to stabilize indirect graduate medical education payments."
- And in the 107th Congress (2001-2002), HR4239 is a bill "To extend the temporary suspension of duty on (unbelievably long chemical compound name omitted)."
Still unanswered, of course, is the question of what the original poster was talking about in his/her claims about HR4239, or indeed any of the four bills mentioned. I checked all four HR numbers back through the 103rd Congress, and found nothing like anything he/she listed.
The bogus refs give the impression that this person chooses to persuade through misinformation. The spoilers in the.sig don't suggest a very thoughtful person either. Perhaps the original poster will clear this up?
This was a very limited ruling, and the government is still barred from enforcing the law.
This isn't much of a news story...
I think the real story is in the fact that eight out of nine justices asserted that a law regulating content on the net which relied upon local community standards was not overbroad -- that is, that those who wish to obey such laws must cater to the community standards of every place in the U.S. or risk prosecution.
Whether the COPA itself is ultimately upheld or struck down, this statement about the sort of content restrictions of which the Court would approve with is kinda scary, IMHO.
Islam's interaction with other religions has always been with its followers holding a sword to the followers of the other religion's necks.
I can't tell whether you're thinking of the Crusades, when all those horrible Muslims kept marching deep into Europe over and over with a stated intention of killing as many Christians as possible to "liberate" their holy land, or Britain and France in the first half of the 20th Century, when all those Muslims colonized Britain and France and treated their residents brutally until after World War II.
What? Backwards? What about a history class? Huh?
Other religions like Christianity, Judaism, Buddhism, Wicca and probably a lot more allow for secular coexistance and equal rights. They allow for freedom and tolerance. They make it easy to believe and yet be a rational human being.
Hmmm. I'm a research scientist and educator by training and profession. I've never had any problems with Muslims, or Jews, directly. I and my associates in my field have, however, had lots of problems from Christians. These have ranged from being told in a shopping center parking lot that I was going to hell for working on cosmology and "believing" in the Big Bang, to the Tennessee state legislature, acting with biblical justification, passing a law that teachers in Tennessee could go to jail for teaching that evolution is an accepted paradigm of the scientific community (thank heavens for a gubernatorial veto).
Not that I think that such problems with intolerant Christians tar all Christians or the entire faith; but when you make absurd blanket statements about all of Islam, and then simulataneously make blanket statements that Christians are tolerant and encourage reason, I don't know whether to laugh or cry.
The reason the media got so quiet on Enron is because the Bush Administration did nothing to help bail them out, while there is an incredible amount of evidence of Enron getting special favors from the CLINTON Administration.
The Media is just protecting their boy Clinton.
HTH
with the irrational obsession. HAND. And watch out for the black helicopters.
Laws are statements that are held to be true and inviolable, within certain constraints, such as the velocity/scale ones I mentioned earlier.
It's correct that for a relationship to be asserted as a "law," those doing so have a high degree of personal confidence that it provides an accurate description of the relation between the observables contained within. In that sense, they are "held to be true," just as I hold that conservation of momentum is "true." I very very strongly think it's right. But that's not the same thing as "proven." I can believe that a physical law is inviolable; but I cannot possibly show that it's inviolable, since to do so would require testing that law in the infinity of possible circumstances. So "held to be true/inviolable" is a social statement about we scientists, rather than a statement of scientific fact.
Saying that you cannot "logically assert with 100% confidence that it cannot happen" may indeed be logical but it adds nothing to a debate about whether a law holds true or not. It would be scientific to say "I assert this cannot happen because...". This is how science moves forward, not by arguing about logic.
I disagree strongly. In regard to your last point, I'll simply say that in my job (as an astrophysicist), I've worked with hundreds of other researchers, all of whom have done a decent job of moving the field forward through the process of putting forward theories and either falsifying them or accumulating evidence in their favor, while understanding that the theories in question are never proven to be true.
You originally asserted that when a theory is proven, it becomes a law. The reply that "in fact, a law is not a theory which has been proven to be true, especially since theories are never proven to be true in science" is not just some silly philosophical statement or dispute about a fine point of logic, but has crucial importance. I mentioned that it's a quite common misconception; that misconception has tangible negative ramifications.
As an example of the importance of the common misconception of which we speak. ..in the U.S., we frequently hear people who are uneducated about the fact that scientific theories are never proven true refer to the theory of evolution with "it's just a theory! It hasn't been proven to be true!" Strictly speaking, this is correct -- the theory of evolution has not been proven to be true. But this is a scientifically uninteresting point to make, because it never will be proven to be true, because no scientific theories are ever proven to be true. Similarly, gravity is `just a theory'; the theory of gravity has not been proven to be true, either. We put stock in our scientific theories not because they are ever proven true, but simply because we have accumulated a compelling degree of evidence in their favor.
Once a hypothesis has some experimental grounding, it becomes a theory. Once that theory has been proven it becomes a law.
No. This is probably the single most common misconception about physical science; but a misconception it is.
A physical "law" is not a "theory that has been proven". The word "law", in physical science, is used to describe relations between independently observable properties of systems that have been detected through experimentation or observation. Thus we have Newton's Law of Gravitation, which relates an external observable property of an object (the force upon it) to intrinsic but observable properties of that object (its mass, the masses of other objects, and the distances between them); this is a physical law even though, strictly speaking, it isn't true (as we now know that it provides only an approximation, which holds reasonably well over certain domains of length and mass scale).
The fact is that theories are never proven to be true in science. A theory can be falsified, but can never be proven true. This is because no matter how much evidence you have collected in favor of a theory, it is always imaginable that tomorrow, someone will observe some phenomenon that contradicts it. We have tons and tons of evidence supporting conservation of momemtum in systems isolated from external forces; but no matter how much evidence we have, it is logically impossible for me to guarantee that tomorrow someone won't do a robust experiment that shows violation of conservation of momentum. I'll bet all the money in the world that won't happen, I'm confident it won't happen; but I cannot logically assert with 100% confidence that it cannot happen. You can never say with logical certainty what will happen in an experiment until you do the experiment; and because of this, scientific theories are not proven true. Instead of being "proven to be true," scientific theories are "supported by the weight of accumulated evidence"; it is the degree to which that accumulates evidence is convincing that determines the statue of the theory it supports.
In the US, it's not really the government's job to deal with religions unless they're a threat to something - they've ignored the big religions for this long, why not ignore Scientology?
Because they are a "threat to something,"
and the Federal Government has known it for quite
some time, having spent millions to put various heads of the Co$ behind bars.
How is what they do different than what Christianity and Islam do?
While there are frequent horrific actions performed in the U.S. by adherents or even senior authorities of Christianity and Islam (e.g. the recent revelations about Cardinal Bernard Law in Boston), I am not aware of large-scale illegal operations authorized and performed by heads of those respective churches. As just one example, this Time Magazine article notes massive wiretapping and burglary operations aimed at Federal agencies, for which a large number of top-level authorities of the Co$ (including Hubbard's wife) were sent to prison.
> Well, Christians don't try to subvert the legal process to their own ends,
> at least not in an organized way.
That's silly. Of course they do. There are many different shades of Christianity, but the evangelical crowd would be quite happy to see the United States become a Christian nation, and frequently espouse their wish for laws that would establish this. More frequently than not, their tactics are just as unethical as the Scientologists are. From stealth candidates [ifas.org] to pushing for so-called "intelligent design" [world-of-dawkins.com] theories, they are well versed in using the political system to achieve religious ends.
Read up on the rise and fall of the Christian Coalition for more information on this.
And you may wish to read up on the history of the Co$ as well. See, for instance, this Time magazine article. While it's true that other religious organizations have been known to use the legal process to further their ends, I don't think it's sane to compare the two, at least in the U.S. I would not be at all surprised if the number of lawsuits filed in the U.S. by the Co$ and its related organizations within the last ten years were larger than all lawsuits filed by all.other recognized religious organizations in the U.S. added together.
If however there exists a mechanism for conversion somehow from matter to anti matter (there is no fundamental reason why not, is there? (really, i dont know), even if it goes via some exotic scheme) then the source of your energy becomes other matter. You simply have a VAST supply of irreplenishible energy, and you consume it in the process.
Unfortunately, you can't make antimatter that way.
It's true that somehow switching a proton into an antiproton would not violate the requirement of
conservation of mass-energy, so on first pass you might think you'd be OK with E=mc^2. But mass-energy isn't the only conserved quantity in the Universe. Another conserved quantity, for instance, is electric charge. I can't directly create an antiproton out of a proton because conservation of electric charge is violated thereby -- the system went from +1 to -1, for a net change of -2 electric charge in the Universe.
Yet another conserved quantity is called "baryon number", which basically counts the number of quarks (+1) and antiquarks (-1). A proton (three quarks) simply somehow "switching" to an antiproton (three antiquarks) would violate conservation of baryon number.
In fact, what this tells you is that not only can't you get antiprotons in a 1-1 exchange for the energy you put in, but it's actually much worse than that, since you need energy to create
other particles that will keep the books balanced as far as electric charge, baryon number, etc.,
are concerned. Typically, in order to produce an antiproton, you've gotta also produce a new proton with it. This means that not only am I not getting in antimatter mass all the energy I'm putting in, I'm actually getting somewhat less than half.
The antiproton production at Fermilab described in the article, for instance, bombards nuclei with high energy protons. Antiprotons come off of this, but so do protons and muons and antineutrinos and lots of other crap. The incident protons ("incident" = "coming in and whacking something else") have to have enough kinetic energy to create not only the mass of the antiproton, but the mass of another proton as well, to conserve all the conserved quantum numbers like electric charge, baryon number, etc.
This sounds pretty grim as far as using antimatter as an energy source, but that's only because we commonly have a misconception of antimatter as some "miracle energy source." It wouldn't be.
What it would be is portable and convenient,
Slashdot Mirror
> Many people think the Big Bang theory means that the universe expands
> like a conventional explosion from a sigular point. This is not correct.
Actually, it pretty much is. Although it is sometimes hard to describe these sorts of objects and events with methaphors from our own life, this is actually a reasonably good metaphor.
No, this is incorrect. It's a very common metaphor, to be sure; but it's a bad metaphor, insofar as the picture of what happens that it causes people to form is a bad one. It effectively communicates things which are not true.
According to every version of the Big Bang Theory I'm aware of, a crucial component of the theory is that all the crap in the universe was extremely close together (some would say at a 0-dimensional point, some would say just really small --- near the size of the proton). Then, for some reason or another, the universe just started expanding, and is pretty big now. So the conventional explosition
analogy is actually quite good.
It's quite bad, and part of the reason is illustrated in your quote above. There is an enormous difference between describing the state of the entire universe as a singularity ("a 0-dimensional point") and as a situation where stuff is compressed into a very small volume ("really small --- near the size of the proton"). Those are two extremely different cases. The first (a singularity) is what the Big Bang model, in its simplest form, would indicate; the latter is not.
The point is that the idea of some sort of really tiny pellet of supercompressed matter exploding outward implies that space already exists -- that is, that there is some sort of space that this unbelievably dense stuff is occupying, and that exists for the exploding matter to speed out into. But that's not what the Relativistic Hot Big Bang model prescribes. The expansion is not an expansion of matter flying outward through space, as an "explosion" would describe; it is an expansion of space itself. The distances between matter in the universe were increasing in the early universe not because they were moving away from each other through space, but because the space itself between them was expanding.
So I don't know where you're coming from when you say that "According to every version of the Big Bang Theory I'm aware of...", since an explosion at a single location in space is not what the theory has in mind.
For more on this, see standard GR textbooks such as:
Gravitation and Cosmology by Stephen Weinberg
Gravitation by Misner, Thorne and Wheeler
Or see standard cosmology texts such as:
The Early Universe by Kolb and Turner
Cosmological Physics by John Peacock
Now, of couse, if you don't buy the Big Bang theory, then you probably don't subscribe to the "all the shit was in one small place" part of it. Ok, this is reasonable. (And I'm not talking about creationists or any bullshit like that, I mean that there is a serious academic debate in the community as to whether or not the Big Bang happened.)
No, there isn't. If you can show me some evidence for such a serious debate within the community (journal cites, for instance), I'd like to see it.
That's not to say that the cosmological community believes that there's nothing left to figure out; there's a lot to figure out. And that's not to say that the cosmological community believes, as a whole, that the Big Bang model will survive as it is without modification or supplement. But the consensus of the community is that whatever the correct description of the evolution of the Universe is, its evolution from a time when the age of the universe was about 10^-24 of what it is now and the average temperature of stuff in the univese was about a trillion degrees Kelvin, up to the present day, will look a lot like the Relativistic Hot Big Bang model.
But if you're using the words "Big Bang", then you sort of mean "conventional explosion from a singular point".
No, you don't.
Another thing I want to mention is that you claim that the universe was always infinite and it's just stretching. According to most current theory, this is not true. Most cosmologists would say that the universe is finite in size, and anyone who subscribes to the BB theory must say the universe is finite in size, since it could only have grown a finite amount in 15 (or whatever) billion years.
This, too, is incorrect. Most cosmologists wouldn't say this at all. There are numerous lines of data (the angular scale of the dominant peak in the spectrum of microwave background fluctuations probably provides the best evidence) that the large-scale geometry of the universe is not closed, and thus that the volume of the universe is not finite. You appear again to be thinking "the universe has a certain age, and it exploded from a certain point, and stuff could only have propagated out to a distance of (distance)=(expansion_rate)*(age), so therefore it's finite and that's the size." That simply isn't how the Big Bang model works.
As an aside, just because the universe is finite does not mean that we could go far enough and hit an edge. Cosmologists also believe that the universe wraps on itself in a higher dimensional way, so that we could travel in a "straight line" for an infinite amount of time without hitting and edge. For those of you who don't have the mathematics, think of a lower-dimensional analogy. Look at a guy on the surface of a sphere with finite radius (Earth e.g.) This dude can walk in a "straight line" for an infinite time, just by circling the globe.
This would be correct if the data suggested that the topology/geometry of the Universe were that it were closed. That's not what the data say, and so that's not what the community believes.
The question has also been asked in this thread: "why are we seeing light from 14 billion years ago now? Will we see 15 billion years ago in a billion years?" The answer is no. The reason we see light from 14 billion years ago is that light travels (hah) at the speed of light. So if you look at an object or region of space which is 14 billion light-years away, you will see it as it was 14 bya. The reason that,these days, we can see further "back in time" is that we can simply see further out in space. Presumably, if we could see far enough away to see far enough back in time, we would be able to observe the BB.
Not really. In principle, at any moment, you're seeing light from a range of times. Right now, for instance, you're seeing light that's one light-nanosecond old from that lamp that's a half a meter away; you're seeing light that's several light-minutes old from the sun; you're seeing light that's billions of years old from objects that are billions of light years away, and so on. There is always a practical limit to this, however, that prevents you from seeing back to the beginning of time, whatever that means. That practical limit is referred to as the surface of last scattering. Up until when the universe was a few hundred thousand years old, the temperatures of material in the universe were so high, and the densities of this hot material in the universe were sufficiently large, that the universe was essentially opaque to light. As you look in any direction, and you look further and further away (and thus further back in time), you eventually reach a point where you simply can't see light from any further back. In fact, it is the first light you can see -- the light from this surface of last scattering -- that is the object of John Carlstrom's (hi John!) observations described in the article that spawned this topic.
I have no idea from what creationist website you're haphazardly cutting-and-pasting this stuff, but it's pretty embarassing. For you, I mean.
Criticizing a physical model plays a lot better when you have *some* basic understanding of the model itself. The description you give of the Big Bang model simply isn't an accurate one; it shows that you don't know what you're talking about. The goo you posted furthermore misquotes and misrepresents the references it cites, and makes misstatements a-plenty. I encourage you to actually take the time to learn some of the relevant physics, and then make an effort to learn what cosmologists and astrophysicists really do think, and why they think that; your screed helps you with none of those things.
>> significant noise issues
> Actually, that's the best reason I can see to put a radio telescope down
> there. Having all the array cold will decrease the thermal noise
> generated by the array itself. Even though it's an rf instrument, and
> nominally doesn't care about light, I'd expect it to do its best work in
> July.
You're absolutely right that reducing noise is the main reason for going to Antarctica, but there are still significant noise issues that have to be dealt with in the data analysis. Thermal noise from the array is not fought by going to Antarctica, though; that's fought by cooling the bolometers down to 4 Kelvin with liquid helium. These experiments are attempting to detect variations in the microwave background at the level of fractions of millikelvin; cooling down to the ambient temperature, even in Antarctica, would not come close to addressing their thermal noise issues.
Depending on the frequencies used in their observations, atmospheric molecular lines are a source of noise (e.g. from water vapor); since Antarctica is basically the biggest desert in the world, water vapor and other such lines are less of an issue there. More significantly, though, and again depending on frequency, galactic synchrotron radiation and emission from interstellar dust provide the largest noise sources.
> so how exactly will this telescope pinpoint "dark matter"
> any more than any other telescope? I mean, you don't really
> even know what you are looking for. Is it just that there
> is more night time to use it in, or is this just the only way
> they could sell this project.
Neither.
First of all, as an aside, when trying to learn about dark matter, there are some telescopes which are more useful than others; it depends on what you're trying to do. For example, attempting to map the dark matter distribution using weak gravitational lensing requires a telescope with a very wide field-of-view as well as excellent "seeing". The Hubble Space Telescope fails the first of those two conditions, while the Canada-France-Hawaii Telescope on Mauna Kea has traditionally been an excellent telescope for such work.
But second, and more importantly, your question is off-base. The purpose of this telescope is not to investigate dark matter, but rather what's (unfortunately, imho) being referred to these days as "dark energy." If you were to talk to an old astronomer or a specialist in general relativity, they'd refer to it as "a cosmological constant" instead; if you were to speak with a particle theorist, they'd call it "vacuum energy density." The point here is to try to learn something about the energy density of empty space. That's a bizarre notion, I know; but there are particle physics reasons why you might think that such a thing wouldn't be zero, and astronomical observations that argue that we've already seen that it isn't zero. But those observations have been hard to do; there's a fair number of them, from different approaches, and they're generally quite consistent with each other, but it's still possible that they're wrong. And with something as counterintuitive as this, one would like the evidence to be still much stronger than it currently is. The observations this microwave telescope will do should come at this question from yet another angle, and with a fairly high degree of precision. And we'll see.
To learn more about this work and to develop the background that would satisfy your curiosity, I suggest taking the time to do some research, e.g. by checking out the websites for the principles involved in this project. There's also some excellent cosmological primers available on the web that go over some of this stuff; see e.g. Ned Wright's cosmology tutorial (here and especially here) as well as Wayne Hu's Introduction to the Cosmic Microwave Background.
To go through your concerns one by one:
1. The U.S., in concert with other nations, already maintains an extensive set of scientific facilities in Antarctica, in the form of permanent bases at the South Pole and at McMurdo Sound and Palmer Station. These facilities are manned and operated year-round. Their purpose is to provide logistical support for the scores of short- and long-term scientific projects that take place in Antarctica, such as the one described in this article. In other words, the issue of logistical support for such a project in Antarctica really isn't an issue; an entire organizational/logistical apparatus has been running for many years to provide this capability for science as a whole, and they'll only be one of many projects each year that will take advantage of it.
2. There is already a significant amount of observational evidence for the presence of what's referred to here as "dark energy." One hint of the presence of such an energy component to the Universe comes from trying to reconcile two observations: the first is that cosmic microwave background data indicates that the large-scale geometry of space is flat; the second is that the matter density of the universe (both in baryons, or normal matter, and in unknown dark matter, not to be confused with "dark energy"), measured via a broad variety of techniques, can only provide about 20% of the mass-energy density required to make the large-scale geometry be as flat as is observed. What's the other 80%? If it can't be matter of some sort, then what is it? When this is combined with recent observations that the expansion of the universe is accelerating -- something only possible if such a "dark energy" component to the mass-energy density of the universe is present -- one is forced to take this possibility seriously. (there's a lot more to be said about this issue, but only if someone cares)
3. The telescope will not solely look at one spot on the sky.
4. Lighting is not really an issue; this is not a visible light telescope, but rather a microwave telescope. There are significant noise issues that will have to be confronted in the data analysis, but not really from day vs. night problems.
You can't be serious. Are you actually suggesting that the Taliban had no idea whatsoever that bin Laden and his merry band of pranksters hadn't set up a plethora of terrorist training camps, hadn't been using them to train terrorists, and hadn't been dispatching the students abroad to commit terrorism? Because if they did, then their guilt extends beyond your statement.
And the US simply didn't recognise the Taleban as a functioning government. They never tried to depose them before the current invasion.
That's correct -- the US didn't recognize the Taliban as Afghanistan's legitimate government. Nor, for that matter, did the country from which you're posting. Nor did the UN. Nor did any other countries on the entire planet, except for Pakistan and the United Arab Emirates. The US, Great Britain, etc., didn't attack the legitimate government; they supported the legitimate government -- whom they did recognize -- in its ongoing civil war.
> The Taliban only offered to extradite OBL to
> another country operating under Sharia (i.e.
> Muslim religious) law. The only other country
> that is fully operating under Sharia is Iran.
Or the US client state, Saudi Arabia.
Oh, please. First of all, while it's certainly the case that in certain specific ways, the U.S.-Saudi relationship is close, it is utterly absurd to refer to Saudi Arabia as a U.S. client state. If that were true, one would expect the Saudi government to defer to the U.S. more often, especially on issues of extreme importance to the U.S. government. Instead, they rarely do, especially with regards to the topic currently of greatest interest to the U.S. government -- investigations of terrorism. They have not cooperated with the FBI in its investigations of the Saudi Sept. 11 terrorists. They refused to allow U.S. investigators to even speak to those arrested by Saudi authorities for the Khobar Towers bombing, under any terms or circumstances at all. Efforts to shut down money-laundering pathways which have led through Saudi Arabia have been met by stone walls. Client state, indeed.
Secondly, while the legal and penal systems in Saudia Arabia can certainly be extreme in their severity, it is incorrect to refer to them as an implementation of Sharia. In fact, the fact that it isn't has been given as one of bin Laden's gripes against the Saudi ruling family. The implication of your response above -- that if the U.S. had simply coughed up their evidence to the Taliban, they would have been perfectly happy to turn him over to the Saudis -- is patently absurd. Both bin Laden and the Taliban had stated that they consider the official Saudi government as an impediment to be overthrown, as they see it wrong for such a corrupt entity to control the land of Mecca and Medina . . .but the Taliban would have turned over bin Laden to the Saudi government? Be serious.
(even assuming the Saudis would take him, since they refused once in the past -- oh, wait, that couldn't have happened, they're a client state, I forgot)
> The US government did not help to establish
> the Taliban. And please do not attempt to
> say "But they gave them $43 million last
> year!" because they didn't. That $43 million
> was grain, medicine, and aid to the people
> of Afghanistan who were starving due to
> famine.
Sure they did, the US government funded, trained and equipped the organization that would later become the Taleban during the Soviet occupation.
More silliness. Your statement is the logical equivalent of saying that the UK (through Lawrence of Arabia) funded, trained, and equipped the folks that later became Hizbollah during World War I. Yes, the U.S. provided military aid to the muhjahedeen fighting the Soviet occupation. Yes, a small fraction of those folks, well after the U.S. was gone, organized the core of the Taliban. The jump from there to suggesting that the U.S. "helped establish the Taliban" suggests a fairly bizarre approach to interpreting history.
I think you misinterpreted his response. I read Alan Cox's "Why pray do you need a commercial DVD to DVD copier?" *not* as saying "what earthly use could you have for one?", but rather as responding to the poster's assertion that the DMCA is effective at stopping piracy, and its effectiveness is demonstrated by the fact that DVD-to-DVD copiers are not commercially available. Alan Cox's reply, quoted above, was to say `you don't need such a copier to commit piracy, so this consequence of the DMCA is not much evidence of its effectiveness at stopping piracy.' That's my read, anyway.
Reading each of the proposed laws listed, I was able to find a couple of paragraphs to support everything the original poster mentioned.
If that's the case, then I'm sure you'd have no problem providing links to such text in question on the House or Thomas-LOC websites?
I look forward to seeing it, since I don't think you can. I've read the text of the bills in question, back through the 103rd Congress, and saw no such content as you describe. Yes, riders routinely get attached to bills -- but that happens on the floor, not in committee. This year's HR 4239, for example, has been referred to the Ways and Means Committee (and hasn't even been considered by it yet!); the previous Congress' HR 4239 was referred to the House Subcommittee on Health and Environment and died there; and so on.
It is fortuitous that we have an astute reader like b.foster among us who will read the many pages of obfuscation in the laws going through Congress and distill the things that interest the tech community. Your time would better be spent writing your congressman than posting misinformed replies on Slashdot.
I smell sock puppet.
They don't, which is why Googling on H.R. numbers isn't the most effective way of searching this stuff.
Take the first one, for example: HR 4239, which the parent of this subthread claims "makes it a felony to distribute any kind of sexually explicit material to a user who does not register with a government-sanctioned age verification service (like AdultCheck)." You Googled and found that HR 4239 appeared to be a bill "To revise the banking and bankruptcy insolvency laws with respect to the termination and netting of financial contracts." In actuality, what you found was HR4239 from the 105th Congress (1997-1998). Using the House of Representatives database, one learns that:
- In the 104th Congress (1995-1996), HR4239 was a bill "To provide for the licensing of commercial space reentry vehicles and reentry sites, and for other purposes."
- In the 106th Congress (1999-2000), HR4239 was a bill "To amend title XVIII of the Social Security Act to stabilize indirect graduate medical education payments."
- And in the 107th Congress (2001-2002), HR4239 is a bill "To extend the temporary suspension of duty on (unbelievably long chemical compound name omitted)."
Still unanswered, of course, is the question of what the original poster was talking about in his/her claims about HR4239, or indeed any of the four bills mentioned. I checked all four HR numbers back through the 103rd Congress, and found nothing like anything he/she listed.
The bogus refs give the impression that this person chooses to persuade through misinformation. The spoilers in the .sig don't suggest a very thoughtful person either. Perhaps the original poster will clear this up?
This isn't much of a news story...
I think the real story is in the fact that eight out of nine justices asserted that a law regulating content on the net which relied upon local community standards was not overbroad -- that is, that those who wish to obey such laws must cater to the community standards of every place in the U.S. or risk prosecution. Whether the COPA itself is ultimately upheld or struck down, this statement about the sort of content restrictions of which the Court would approve with is kinda scary, IMHO.
Islam's interaction with other religions has always been with its followers holding a sword to the followers of the other religion's necks.
I can't tell whether you're thinking of the Crusades, when all those horrible Muslims kept marching deep into Europe over and over with a stated intention of killing as many Christians as possible to "liberate" their holy land, or Britain and France in the first half of the 20th Century, when all those Muslims colonized Britain and France and treated their residents brutally until after World War II.
What? Backwards? What about a history class? Huh?
Other religions like Christianity, Judaism, Buddhism, Wicca and probably a lot more allow for secular coexistance and equal rights. They allow for freedom and tolerance. They make it easy to believe and yet be a rational human being.
Hmmm. I'm a research scientist and educator by training and profession. I've never had any problems with Muslims, or Jews, directly. I and my associates in my field have, however, had lots of problems from Christians. These have ranged from being told in a shopping center parking lot that I was going to hell for working on cosmology and "believing" in the Big Bang, to the Tennessee state legislature, acting with biblical justification, passing a law that teachers in Tennessee could go to jail for teaching that evolution is an accepted paradigm of the scientific community (thank heavens for a gubernatorial veto).
Not that I think that such problems with intolerant Christians tar all Christians or the entire faith; but when you make absurd blanket statements about all of Islam, and then simulataneously make blanket statements that Christians are tolerant and encourage reason, I don't know whether to laugh or cry.
The reason the media got so quiet on Enron is because the Bush Administration did nothing to help bail them out, while there is an incredible amount of evidence of Enron getting special favors from the CLINTON Administration.
The Media is just protecting their boy Clinton.
HTH with the irrational obsession. HAND. And watch out for the black helicopters.
It's correct that for a relationship to be asserted as a "law," those doing so have a high degree of personal confidence that it provides an accurate description of the relation between the observables contained within. In that sense, they are "held to be true," just as I hold that conservation of momentum is "true." I very very strongly think it's right. But that's not the same thing as "proven." I can believe that a physical law is inviolable; but I cannot possibly show that it's inviolable, since to do so would require testing that law in the infinity of possible circumstances. So "held to be true/inviolable" is a social statement about we scientists, rather than a statement of scientific fact.
Saying that you cannot "logically assert with 100% confidence that it cannot happen" may indeed be logical but it adds nothing to a debate about whether a law holds true or not. It would be scientific to say "I assert this cannot happen because...". This is how science moves forward, not by arguing about logic.
I disagree strongly. In regard to your last point, I'll simply say that in my job (as an astrophysicist), I've worked with hundreds of other researchers, all of whom have done a decent job of moving the field forward through the process of putting forward theories and either falsifying them or accumulating evidence in their favor, while understanding that the theories in question are never proven to be true.
You originally asserted that when a theory is proven, it becomes a law. The reply that "in fact, a law is not a theory which has been proven to be true, especially since theories are never proven to be true in science" is not just some silly philosophical statement or dispute about a fine point of logic, but has crucial importance. I mentioned that it's a quite common misconception; that misconception has tangible negative ramifications.
As an example of the importance of the common misconception of which we speak. . .in the U.S., we frequently hear people who are uneducated about the fact that scientific theories are never proven true refer to the theory of evolution with "it's just a theory! It hasn't been proven to be true!" Strictly speaking, this is correct -- the theory of evolution has not been proven to be true. But this is a scientifically uninteresting point to make, because it never will be proven to be true, because no scientific theories are ever proven to be true. Similarly, gravity is `just a theory'; the theory of gravity has not been proven to be true, either. We put stock in our scientific theories not because they are ever proven true, but simply because we have accumulated a compelling degree of evidence in their favor.
No. This is probably the single most common misconception about physical science; but a misconception it is.
A physical "law" is not a "theory that has been proven". The word "law", in physical science, is used to describe relations between independently observable properties of systems that have been detected through experimentation or observation. Thus we have Newton's Law of Gravitation, which relates an external observable property of an object (the force upon it) to intrinsic but observable properties of that object (its mass, the masses of other objects, and the distances between them); this is a physical law even though, strictly speaking, it isn't true (as we now know that it provides only an approximation, which holds reasonably well over certain domains of length and mass scale).
The fact is that theories are never proven to be true in science. A theory can be falsified, but can never be proven true. This is because no matter how much evidence you have collected in favor of a theory, it is always imaginable that tomorrow, someone will observe some phenomenon that contradicts it. We have tons and tons of evidence supporting conservation of momemtum in systems isolated from external forces; but no matter how much evidence we have, it is logically impossible for me to guarantee that tomorrow someone won't do a robust experiment that shows violation of conservation of momentum. I'll bet all the money in the world that won't happen, I'm confident it won't happen; but I cannot logically assert with 100% confidence that it cannot happen. You can never say with logical certainty what will happen in an experiment until you do the experiment; and because of this, scientific theories are not proven true. Instead of being "proven to be true," scientific theories are "supported by the weight of accumulated evidence"; it is the degree to which that accumulates evidence is convincing that determines the statue of the theory it supports.
Because they are a "threat to something," and the Federal Government has known it for quite some time, having spent millions to put various heads of the Co$ behind bars.
How is what they do different than what Christianity and Islam do?
While there are frequent horrific actions performed in the U.S. by adherents or even senior authorities of Christianity and Islam (e.g. the recent revelations about Cardinal Bernard Law in Boston), I am not aware of large-scale illegal operations authorized and performed by heads of those respective churches. As just one example, this Time Magazine article notes massive wiretapping and burglary operations aimed at Federal agencies, for which a large number of top-level authorities of the Co$ (including Hubbard's wife) were sent to prison.
> at least not in an organized way.
That's silly. Of course they do. There are many different shades of Christianity, but the evangelical crowd would be quite happy to see the United States become a Christian nation, and frequently espouse their wish for laws that would establish this. More frequently than not, their tactics are just as unethical as the Scientologists are. From stealth candidates [ifas.org] to pushing for so-called "intelligent design" [world-of-dawkins.com] theories, they are well versed in using the political system to achieve religious ends.
Read up on the rise and fall of the Christian Coalition for more information on this.
And you may wish to read up on the history of the Co$ as well. See, for instance, this Time magazine article. While it's true that other religious organizations have been known to use the legal process to further their ends, I don't think it's sane to compare the two, at least in the U.S. I would not be at all surprised if the number of lawsuits filed in the U.S. by the Co$ and its related organizations within the last ten years were larger than all lawsuits filed by all.other recognized religious organizations in the U.S. added together.
Unfortunately, you can't make antimatter that way.
It's true that somehow switching a proton into an antiproton would not violate the requirement of conservation of mass-energy, so on first pass you might think you'd be OK with E=mc^2. But mass-energy isn't the only conserved quantity in the Universe. Another conserved quantity, for instance, is electric charge. I can't directly create an antiproton out of a proton because conservation of electric charge is violated thereby -- the system went from +1 to -1, for a net change of -2 electric charge in the Universe. Yet another conserved quantity is called "baryon number", which basically counts the number of quarks (+1) and antiquarks (-1). A proton (three quarks) simply somehow "switching" to an antiproton (three antiquarks) would violate conservation of baryon number.
In fact, what this tells you is that not only can't you get antiprotons in a 1-1 exchange for the energy you put in, but it's actually much worse than that, since you need energy to create other particles that will keep the books balanced as far as electric charge, baryon number, etc., are concerned. Typically, in order to produce an antiproton, you've gotta also produce a new proton with it. This means that not only am I not getting in antimatter mass all the energy I'm putting in, I'm actually getting somewhat less than half. The antiproton production at Fermilab described in the article, for instance, bombards nuclei with high energy protons. Antiprotons come off of this, but so do protons and muons and antineutrinos and lots of other crap. The incident protons ("incident" = "coming in and whacking something else") have to have enough kinetic energy to create not only the mass of the antiproton, but the mass of another proton as well, to conserve all the conserved quantum numbers like electric charge, baryon number, etc.
This sounds pretty grim as far as using antimatter as an energy source, but that's only because we commonly have a misconception of antimatter as some "miracle energy source." It wouldn't be. What it would be is portable and convenient,