AM

[Erebus the Black]

Do any of you know if a primitive form of anti matter containment exists?

[Lilith]

You can contain a charged antiparticle like an antiproton or a positron in a Penning trap. Containing an uncharged antiparticle is trickier.

[Dantius]

Originally Posted By: Dong

Do any of you know if a primitive form of anti matter containment exists?

Have you been watching Angels and Demons recently?

Just curious.

[Sullust]

Have you tried an SEP field? They can be extremely effective for all types of containment.

[Niemand]

Quote:

Have you tried an SEP field? They can be extremely effective for all types of containment.

This is actually something of a misconception. Getting everyone to believe that it is someone else's problem to make sure that the antimatter doesn't fall on the floor is a very poor method indeed.

I'd guess that most of the pure antimatter on earth is kept in storage rings.

Antimatter isn't terribly uncommon, as there are sources like beta-decay producing small amounts of positrons all the time, but since they're inside ordinary matter materials they are rather ephemeral. Likewise, there's always antimatter raining down from the upper atmosphere from cosmic ray induced particle showers, but only the µ+ particles survive reach the ground, generally.

EDIT: With regard to storing neutral antimatter, it could potentially be relatively easy, at least for one specific type. Ultra-cold neutrons can be trapped relatively easily in containers of well chosen metals. (It's really weird to think of having an object with about the mass of a hydrogen atom, bouncing along through a metal pipe exactly like an absurdly tiny rubber ball, but it actually works.) Off of the top of my head it seems to me that this ought to work equivalently for antineutrons, assuming that first, you had some of them, and second that your were able to get them slowed down to ultracold energies. Of course, containing neutrons can be a little bit pointless in the long run, since when left to their own devices they just fall apart after a while.

[Goldengirl]

Originally Posted By: Dong

Do any of you know if a primitive form of anti matter containment exists?

If you find a method out, please tell me. I have all this antimatter, and no where to put it! Apparently the garbage collectors won't take it, and I don't think it's recyclable...

[Alorael at Large]

Originally Posted By: Dong

Do any of you know if a primitive form of anti matter containment exists?

Guards with sharp, heavy rocks.

—Alorael, who doesn't think it gets much more primitive than that.

[Sudanna]

After the invention of rocks? And designated security personnel? Oh, yes it can.

[Erebus the Black]

I read in a popular science bbok (it was published way before the movie) that scientists today can store AM in small vials which seemed odd, so I decided to check it with you guys.

The problem with holding AM is that you need to either contain it without letting it touch anything or contain it inside of a container made of AM which then needs to be prevented from touching anything. And, to the best of my knowledge, any system capable of containing AM is extremely large.

 

@goldenking: you need to talk to Dilbert's garbage man, I'm sure he would be willing to take it off your hands.

[Arch-Mage Solberg]

Please don't think I'm stupid or something...but...how can anti-matter be contained by anything made from matter? Do they not cancel each other out at the point they meet? Or am I thinking of Dark Matter or Dark Energy?

 

Post #494

[Nioca]

If I recall right, they only cancel out if they're the same kind of atom/particle. So antihydrogen and helium wouldn't react, but antihydrogen and hydrogen would.

[Niemand]

Quote:

Please don't think I'm stupid or something...but...how can anti-matter be contained by anything made from matter? Do they not cancel each other out at the point they meet? Or am I thinking of Dark Matter or Dark Energy?

Firstly, the general idea of most containment methods is that you don't let the antimatter being contained come into direct contact with the mechanism of the container, instead you hold it in place with electromagnetic fields produced by your normal matter container mechanism. This is the idea of the Penning trap and storage ring.

Secondly, the point made by Nioca must be taken into account. Strictly speaking, only corresponding fundamental particles can annihilate each other: electrons with positrons, up quarks with anti-up quarks, and down quarks with anti-down quarks. Antihydrogen and helium could react, because the positron of the antihydrogen can annihilate with one of the electrons of the helium, and the antiproton (u-bar u-bar d-bar, where bar denotes an antiparticle) can annihilate with one of the protons (uud) in the helium. This is all made complicated by the fact that determining how the reaction plays out depends on quantum mechanics, It's difficult to make assumptions about this, particularly since there exist particles like the neutral pion, which is a superposition of bound states of an up quark with and anti-up quark, and a down quark with an anti-down quark. (The the neutral pion is unstable, but it can exist for non-zero periods of time.)

My silly suggestion about ultracold anti-neutrons is based on the fact that the reflection of (normal) ultracold neutrons from metal surfaces arises from funny quantum mechanical effects; essentially the neutron bounces off of the combined string force potential of the surface. This might not work equivalently for antineutrons, but I don't happen to know of a specific reason that it wouldn't.

Keep in mind that talking about materials 'touching' or 'meeting' doesn't necessarily make sense microscopically, after all, atoms are mostly empty space, and so, by extension are molecules and all larger material structures.

Quote:

Or am I thinking of Dark Matter or Dark Energy?

Dark matter pretty much refers, in its most general sense, to anything that isn't a star. In this interpretation the Earth is dark matter because an astronomer in another galaxy wouldn't be able to see it at all. Dark matter is believed to exist because various large structures in the universe (galaxies, galaxy clusters, and so forth) move as though they have or are under the influence of more gravity than can be explained by all of the bright, visible matter astronomers can see. Therefore there must be some other matter that is present which is 'dark' since it can't be seen. More recently people have come to the conclusion that dark matter is likely to be in exotic forms (non-baryonic dark matter), such as fundamental particles which have not yet been detected on earth.

Dark energy is weirder still, and it's name is arguably not the least bit descriptive. Basically the universe is growing faster than anyone expected, so they made up a name for the (unknown) mechanism causing it. Since they had given the name 'dark matter' to the unknown matter causing the previously mentioned gravitational anomalies, they gave it a similar name, but since it clearly wasn't (as sort of ordinary) matter (since that would tend to make the universe contract), they called it 'dark energy'.

[nikki.]

So could somebody explain this thread to somebody with only a secondary-school education in physics, please?

 

For instance, how can you have an "anti-particle" of a particular element?

[A less presumptuous name.]

Originally Posted By: Niemand

Antimatter isn't terribly uncommon, as there are sources like beta-decay producing small amounts of positrons all the time, but since they're inside ordinary matter materials they are rather ephemeral.

I've always wondered how one would distinguish between positron emission and electron capture. They have the same end result, do they not?

[Niemand]

Quote:

how can you have an "anti-particle" of a particular element?

Atoms are of course composed from electrons, protons, and neutrons. Each proton is made up of two up quarks and a down quark, while each neutron is two down quarks and an up quark. The antiparticle of the electron is called the positron, because it is exactly the same, except for having a positive electric charge. Likewise, the two types of quarks mentioned above each have an antiparticle which has the same mass but opposite charge (the charge of the up quark is +2/3, so the charge of the anti-up quark is -2/3).

So to 'form' (in the thought experiment sense) any 'anti-element', take a normal atom of that element, then swap out each electron for a positron and each quark for its anti-quark. You may note that in doing so you have also formed anti-protons and anti-neutrons, since you have put together sets of quarks to form particles with the same masses, but opposite charges as the protons and neutrons.

EDIT:

Quote:

I've always wondered how one would distinguish between positron emission and electron capture. They have the same end result, do they not?

No they don't. Keep in mind that a positron is not the same thing as the lack of an electron!

In positron emission, one of the up quarks in the nucleus of an atom turns into a down quark (via the weak interaction) and emits a W+ boson in the process. The W+ then splits into a positron and an electron anti-neutrino, both of which then generally escape the atom.

In electron capture, an up quark in the nucleus exchanges a W- boson with an electron, and as a result the up quark becomes a down quark, and the electron becomes and electron neutrino, which escapes.

So, in one case a positron and an anti-neutrino come out and the charge of the nucleus increases, while in the other case only a neutrino comes out and the charge of the nucleus decreases.

[Arch-Mage Solberg]

Thank you Niemand for your explanations. They are pretty informative. I don't claim to be a brainiac. There are some things I know, some I just know about and others I have no clue. This falls into the area that I just know about. I am a vapid History and Science channel fanatic. I have seen a few episodes about matter and anti-matter. I have also seen episodes about Dark Matter. Dark Energy is something I know only by name. I understood a little about what they were talking about, but not fully.

 

Post #497

[Slawbug]

Originally Posted By: Arch-Mage Solberg

I am a vapid History and Science channel fanatic.

Do you mean avid?

[nikki.]

Thanks. I think I got my head around that. So these "anti-elements" are what we call anti-matter? How do they react with other elements, anti- or not, and in what way is/could that beneficial to us?

[Student of Trinity]

Electron capture is like receiving a payment; positron emission is like issuing an invoice. If everyone paid every debt instantly, there would be no difference, but as a matter of fact banknotes and bills circulate independently of one another. Some people manage to collect a lot of banknotes, while others find that bills accumulate. But electrons and positrons are a monetarist's dream: there is no analog for electrons of the government's ability to print more money.

 

The effect on your bottom line is the same, though. That is, the nuclear charge decreases in both electron capture and positron emission; Niemand must have mixed up some W± somewhere. The difference is simply that in one case there is one more positron out there, while in the other there is one less electron. In both cases there is a neutrino emitted, not an antin-neutrino. (Lepton number is conserved.)

 

Does antimatter mean anti-elements? Well, in principle; but in fact the concept of an element isn't really very relevant to antimatter. Elements mean atoms, or at least nuclei. Electrons and quarks are not elements, just as bricks are not buildings. And although in principle antiparticles could clump together into anti-nuclei and anti-atoms, in fact they just don't.

 

There just isn't much antimatter around. Nobody really knows why, since anti-matter and matter seem to be completely symmetrical, but everything we've seen in the universe is overwhelmingly matter rather than antimatter. So to have antimatter atoms, the elementary antiparticles that compose the atoms have to be produced first. Whether they are produced naturally or artificially, enormous concentrations of energy are needed.

 

But then, in comparison to the energy needed to produce positrons and anti-protons, the binding energy of an atom is negligible. Producing anti-hydrogen is kind of like trying to roast a marshmallow with a hand grenade. It's tricky; it won't just happen naturally. You have to catch some anti-protons out of a powerful particle accelerator, catch some positrons out of another accelerator, then slow them both down and bring them gently together, so that they stick together as an atom of anti-hydrogen.

 

This also means that it is NOT safe to bring anti-hydrogen into contact with helium. The anti-hydrogen's single positron and single anti-proton will simply have a choice of which helium electron and proton with which to annihilate. And the anti-proton could happily annihilate with either of the two helium neutrons as well; the explosion would simply have to emit an electron or something, to conserve electric charge. On the other hand, while matter-antimatter annihilation releases something like a thousand times more energy even than nuclear fusion, the annihilation of a single anti-atom wouldn't even boil a mist droplet. Even when 100% of Mc^2 is turned into energy, the mass of a single atom is just too small to amount to much.

 

So there are no uses for antimatter atoms, because they are not naturally occurring. We've only ever made a few, as pure research, and they're long gone now. If we ever did gain the capability to produce large amounts of antimatter, it might be a good way of storing energy, but it would not be an energy source. We would not get any more energy out than we had put in to create the antimatter. Maybe it would be a sort of expensive synthetic fuel, suitable for starships or something.

[Dantius]

Originally Posted By: Nikki, but edited a little by me

1. So these "anti-elements" are what we call anti-matter?
2. How do they react with other elements, anti- or not?
3. In what way is/could that beneficial to us?

From my understanding:

1. Yes.

2. If they encounter their element, they produce a violently unstable reaction. I believe it's about comparable to a nuclear blast, but with no long-term effects like radiation.

3. In a nutshell, they don't. They're useless for energy or power generation, because they require ridiculous amounts of energy to make and store, they're far too cumbersome for weapons or military uses because of the problem of downsizing the containment unit to a manageable size, and there are no medical applications. I heard someone once propose use in long-range space travel, but since when are we launching manned crafts beyond Earth orbit (also it was probably pop-sci blather given who I heard it from)?

Apparently they give insight into what happened in the first few picoseconds of the Big Bang when there were roughly equal potions of matter and ant-matter, but then they annihilated each other and created the universe or something. Ask a astrophysicist about it, or read the Wikipedia article if you're more curious.

tldr; cool stuff for learning about the universe but has no practical applications.

[Kelandon]

Originally Posted By: Dantius

I believe it's about comparable to a nuclear blast, but with no long-term effects like radiation.

Well, sort of. In a conventional nuclear explosion, some energy is released. That energy comes from the difference in mass between the original material and whatever is produced. So if you're doing hydrogen fusion, you're taking some hydrogen atoms, smacking them together, and making helium. The hydrogen weighed more than the helium, though, which means that some of the mass that was in the hydrogen got converted into energy in the reaction. For most nuclear reactions, the percentage of the mass that gets converted into energy is relatively small. (I believe the number for hydrogen-to-helium is less than 1%.)

On the other hand, in an antimatter reaction, it's 100%. You take an electron and a positron and smack 'em together, you get complete conversion from mass to energy out of the reaction. This means that if you were somehow to take some hydrogen and make it do nuclear fusion, and then right next to it take an equal amount of hydrogen and antihydrogen and collide them, you'd get obscenely more energy from the antimatter reaction. So in a certain sense, antimatter/matter collisions release vastly more energy than traditional fission or fusion reactions.

(EDIT: Oh yeah. That energy typically comes out as gamma rays, which means you DO get all of the harmful radiation as in a conventional nuclear bomb.)

The problem, as noted above, is that antimatter is — for mysterious reasons — not terribly common around the universe, at least not in forms larger than a particle or two. This is probably a good thing, because if there were large chunks of antimatter floating around, and if they hit us, well, boom. But it does present a puzzle. I don't think we know of any way of producing matter without producing an equal amount of antimatter, but somehow, at some point, the universe must have, or else it must have hid all the antimatter where we can't see it. Neither possibility makes a great deal of sense to us right now.

[Arch-Mage Solberg]

Originally Posted By: CRISIS on INFINITE SLARTIES

Originally Posted By: Arch-Mage Solberg

I am a vapid History and Science channel fanatic.

Do you mean avid?

Yes...very bad choice of words.

Kind of advanced thinking going on here, huh?

Post #498

[Sarachim]

Originally Posted By: Dantius

Originally Posted By: Nikki, but edited a little by me

2. How do they react with other elements, anti- or not?

2. If they encounter their element, they produce a violently unstable reaction.

This is not quite right. First, as explained above, antimatter elements could theoretically exist but have never actually been observed, because antimatter isn't very common and thus does not conglomerate into atoms. Second, if you did have elemental antimatter, it would be able to annihilate with any matter, not just the corresponding matter element. The subatomic particles (protons, neutrons, electrons and their antimatter equivalents) are what have to be opposites.

[Niemand]

Originally Posted By: Student of Trinity

Niemand must have mixed up some W± somewhere. The difference is simply that in one case there is one more positron out there, while in the other there is one less electron. In both cases there is a neutrino emitted, not an anti-neutrino. (Lepton number is conserved.)

Gah. I should've taken the time to draw out the diagrams, as it should definitely be a neutrino emitted in both cases.

Either that, or if neutrinos are Majorana fermions and the \nu_e is the \bar{\nu_e} so I'm right anyway. Now I just need the neutrinoless double beta decay experiments (besides the Klapdor-Kleingrothaus interpretation of the Heidelberg-Moscow data) to see something and vindicate me.

Originally Posted By: Sarachim

First, as explained above, antimatter elements could theoretically exist but have never actually been observed

They have been observed, although not in nature; several experiments have produced antihydrogen. Not anything like enough for a bomb, but enough to determine that it was present and, I think, to examine some of its properties.

[A less presumptuous name.]

Niemand and SoT - Thanks for trying to explain, but I guess my previous education in the subject (about 30 minutes of discussion during the "nuclear" section of AP Chemistry) isn't enough to fully understand. I know more because of Wikipedia, and I understand that the underlying mechanism is different. I always just assumed that the released positron would hit an electron on the way out, and short of monitoring the decay as it happened, there would be no way to tell which had occurred.

[Erebus the Black]

1. But the Anti particles do appear naturally, even if for split seconds and in trace amounts (1 every Avogadro number for example), true?

2. you don't need elements to cause annihilation, you can use positrons and con-tons (a word play on pro and con, prbly never got in to use because it sounds too much like quantum) for annihilation?

3. if so wouldn't it be possible to place a satellite close to the sun with a net, like a Busard scoop (if the scoop actually scoops them into a chamber, (different subject) which it has to if you want to use the CNO reaction for propulsion without wasting fuel), and trap (according to mass and charge) positrons in one containment field and con-tons in another and then use them to bombard simple matter (hydrogen1) in order to receive the resulting energy?

[Lilith]

Originally Posted By: Prick of a needle

1. But the Anti particles do appear naturally, even if for split seconds and in trace amounts (1 every Avogadro number for example), true?
2. you don't need elements to cause annihilation, you can use positrons and con-tons (a word play on pro and con, prbly never got in to use because it sounds too much like quantum) for annihilation?
3. if so wouldn't it be possible to place a satellite close to the sun with a net, like a Busard scoop (if the scoop actually scoops them into a chamber, (different subject) which it has to if you want to use the CNO reaction for propulsion without wasting fuel), and trap (according to mass and charge) positrons in one containment field and con-tons in another and then use them to bombard simple matter (hydrogen1) in order to receive the resulting energy?

what

[waterplant]

Originally Posted By: Dantius

Apparently they give insight into what happened in the first few picoseconds of the Big Bang when there were roughly equal potions of matter and ant-matter, but then they annihilated each other and created the universe or something.

Apparently not. If this occurred then there would be nothing (this is where the mystery lies).
Perhaps what was created from the big bang was smaller than matter (energy?) and this product plus it's counterpart came together to form what we know as matter i.e. matter and anti-matter exist as the same entity and are in the process of annihilating each other.

Or maybe anti-matter isn't here - meaning that it doesn't exist in this space/time where matter exists (or at least not yet).

Philosophically speaking anything can only exist in relation to it's opposite.

[Ephesos]

Originally Posted By: waterplant

Philosophically speaking anything can only exist in relation to it's opposite.

Then what, pray tell, is the opposite of a giraffe?

[Niemand]

Originally Posted By: waterplant

Apparently not. If this occurred then there would be nothing (this is where the mystery lies).

No, there wouldn't be nothing; that's not what annihilation means in this context. When two particles annihilate, they still have to produce something else, in order to obey various conservation laws, like those for momentum and energy.

Originally Posted By: waterplant

Perhaps what was created from the big bang was smaller than matter (energy?) and this product plus it's counterpart came together to form what we know as matter i.e. matter and anti-matter exist as the same entity and are in the process of annihilating each other.

After some consideration I cannot figure out what you intend this to mean. What does 'smaller than matter' mean?

Perhaps you're suggesting that there are more fundamental building blocks of the particles which we currently identify as fundamental? This is possible, and is sort of what string theory is supposed to be about (bearing in mind that I know literally nothing about string theory in any useful detail), but at the moment we have no actual evidence for any smaller substructure beyond what has already been identified.

As for "matter and anti-matter exist as the same entity and are in the process of annihilating each other", this is, in a literal sense, not true, since (most) antiparticles differ observably from their counterparts. For example, one can distinguish electrons from positrons quite easily by pushing them through a magnetic field, and seeing that they deflect in opposite directions. One could however, argue that matter and anti-matter are both subtypes of something more general, which is certainly reasonable.

Originally Posted By: waterplant

Or maybe anti-matter isn't here - meaning that it doesn't exist in this space/time where matter exists (or at least not yet).

This is manifestly not the case, since antimatter is observed all the time, just only in minute quantities and persisting only for short periods of time.

Originally Posted By: waterplant

Philosophically speaking anything can only exist in relation to it's opposite.

This sort of idea, which I'm frankly sounds to me like gibberish, is what makes me tend to ignore philosophy as being more trouble than it's worth. Anyway, as Ephesos points out, the concept of an opposite does not seem to be well defined for macroscopic objects (possibly because macroscopic objects are arguably not thoroughly defined?), but even within the realm of particle physics where we can be quite precise about what is an particle, and what is its opposite, taking this to mean its anti-particle, this statement still doesn't seem to mean much. Keep in mind that not all particles have distinct anti-particles; the photon is its own anti-particle, for example, and the neutrinos might be their own as well.

Originally Posted By: Prink of a needle

3. if so wouldn't it be possible to place a satellite close to the sun with a net, like a Busard scoop (if the scoop actually scoops them into a chamber, (different subject) which it has to if you want to use the CNO reaction for propulsion without wasting fuel), and trap (according to mass and charge) positrons in one containment field and con-tons in another and then use them to bombard simple matter (hydrogen1) in order to receive the resulting energy?

I should really just leave this to Thuryl's handling, but I cannot resist objecting: Why would the sun be a useful source of anti-protons? (It does produce positrons, but they don't, to my knowledge, escape the core.) What does the CNO cycle have to do with antimatter? The sun shines primarily due to the proton-proton chain anyway, as i understand it.

[nikki.]

Originally Posted By: Ephesos

Originally Posted By: waterplant

Philosophically speaking anything can only exist in relation to it's opposite.

Then what, pray tell, is the opposite of a giraffe?

An empty space in the shape of a giraffe.

[waterplant]

Originally Posted By: Ephesos

Originally Posted By: waterplant

Philosophically speaking anything can only exist in relation to it's opposite.

Then what, pray tell, is the opposite of a giraffe?

An anti-giraffe.

Niemand, just because you regard philosophy as gibberish doesn't mean it actually is (ok it is in your version of the world but maybe that's because you haven't tried to understand it).

To say what is is fine, especially if you have evidence, but to automatically dismiss an idea without said evidence (of disproof) is not sound scientific practice.

[Dintiradan]

We should be glad anti-giraffes are so rare. The last time a giraffe and an anti-giraffe collided, this happened. Were a herd of each to collide, we'd lose all of Africa.

[Niemand]

Quote:

just because you regard philosophy as gibberish doesn't mean it actually is.

It was deliberate that I spoke about how the statement sounded to me, rather than making a general claim about the statement itself. I now wish that I hadn't edited out the parts of my original sentence which referred to my deferring attempts to understand philosophical ideas, on the grounds that doing so looks like it will take a lot of effort, rather than deciding never to consider them. Also, ignoring is not the same as dismissing (as false); there are vast amounts of microbiology research which I ignore because understanding them would require substantial investment in learning microbiology, but which I do not hold to be false. This is the same as my approach to most philosophy; I don't claim that it is wrong, merely that I haven't read it, and won't be doing so right away (or possibly ever, although to a degree I would like to get around to it).

Quote:

To say what is is fine, especially if you have evidence, but to automatically dismiss an idea without said evidence (of disproof) is not sound scientific practice.

Firstly, in arguing with your idea, I did not claim that it was false (which could require disproof), but instead objected that it wasn't clear whether the statement had a meaning which could be assessed to be true or not. Furthermore, I did not go so far as to say it was meaningless, but pointed to some examples which seemed to show that its meaning was unclear (Eph's opposite giraffe, or the self-conjugate photon). As I see it, the burden of proof is currently on you to argue that your statement has a definite meaning in the face of these examples. Then we can worry about whether you need to prove that it is true (which you did assert), or I need to prove that it is false (which I did not assert, but might choose to once the statement's meaning is established). Otherwise, at the moment I treat the statement as having no meaning, and so I have made no judgement about its truthfulness.

As an analogy, if I asserted that zabogleebs are always trunglish, I wouldn't be surprised if you neither agreed with me nor disagreed and presented an example of a zabogleeb which is not trunglish. The sensible response is to demand that I specify what I mean by zabogleebs and trunglish if I expect anyone to care about what I'm saying.

[Slawbug]

I have less patience than Niemand and I'm just going to say it's baloney. Prove it, or it's baloney, because it sounds like baloney.

[waterplant]

Niemand, if your assertion was sincere then I would listen to what you had to say if only to get an insight into your radical state of mind.

 

Concepts often predate proof, often by centuries.

 

Originally Posted By: CRISIS on INFINITE SLARTIES

I have less patience than Niemand and I'm just going to say it's baloney. Prove it, or it's baloney, because it sounds like baloney.

 

'A little nonsense now and then is treasured by the wisest men' (& women I presume).

Willy Wonka

[Slawbug]

Originally Posted By: waterplant

Concepts often predate proof, often by centuries.

That's true. So we can enumerate the categories of things that lack proof as follows:

(1) True concepts whose proof has not yet arrived
(2) Untrue concepts whose proof will never arrive

Since the second category is rather gargantuously larger than the first, that assertion doesn't really help support any unproven concept. Should we be open to a baloney concept someday being proven? Absolutely. Should we kowtow to it in the meantime? Nope.

[waterplant]

Agreed. Leaving unproven concepts open for discussion (criticism being an essential part of this process) may be a good way forward.

 

 

btw I believe that humans are still way off establishing even the fundamentals of what is. Some of the most bizarre sounding ideas have, and will continue to become, 'common' knowledge.

[Dantius]

Originally Posted By: waterplant

Agreed. Leaving unproven concepts open for discussion (criticism being an essential part of this process) may be a good way forward.

Oh cool, so yo- no wait, I see where this is going. This is going to turn into another attempt to critique science, isn't it?

[Sullust]

Originally Posted By: CRISIS on INFINITE SLARTIES

Originally Posted By: waterplant

Concepts often predate proof, often by centuries.

That's true. So we can enumerate the categories of things that lack proof as follows:

(1) True concepts whose proof has not yet arrived
(2) Untrue concepts whose proof will never arrive

Since the second category is rather gargantuously larger than the first, that assertion doesn't really help support any unproven concept. Should we be open to a baloney concept someday being proven? Absolutely. Should we kowtow to it in the meantime? Nope.

There are concepts that are not necessarily untrue; however, no proof of them will ever arrive.

[waterplant]

Gödel's Incompleteness Theorem is a good example.

[Lilith]

hi. let's not fight.

 

let us stipulate for the time being that the general claim that "nothing can exist without its opposite" is a bit too broad to be meaningfully assessed. there is, however, a symmetry between the production of particles and antiparticles under all conditions we have observed, and it is not clear how that symmetry was broken in order to produce a universe containing lots of matter and almost no antimatter.

 

ok peace out.

[Dikiyoba]

Originally Posted By: Dintiradan

We should be glad anti-giraffes are so rare. The last time a giraffe and an anti-giraffe collided, this happened. Were a herd of each to collide, we'd lose all of Africa.

Dikiyoba's initial thought was to suggest the effarig, but you have clearly already won the debate.

[Alorael at Large]

Originally Posted By: Prick of a needle

(Proposal for annihilation-fueled energy!)

Beta decay is probably the best source of "free" antiparticles, but it's not really feasible to set up beta scoops, and in any case the energy costs of setting up some kind of particle catcher and storage would be far greater than the potential energy gains from annihilating those particles.

There is plenty of garbage philosophy, but there's also stuff in the field that's rigorous. Whether it's useful is another question entirely, but at the very least there are ideas that hold together well and don't contradict anything that's obviously axiomatic. Like, say, reality.

However, when philosophy starts going head to head with empirical observations, you get ugly thing like the science wars. Basically, philosophers have no justification for making claims about the nature of the universe on a physical level. They can do it, but they're not going to be taken seriously by any actual scientists or anyone who understands science.

—Alorael, who must also note that, physically speaking, nothing can exist with its opposite for certain values of "with," as an excess of "withness" leads to annihilation.

[Student of Trinity]

My limited experience of talking with actual professional philosophers is that they are particularly good at identifying baloney. In fact the biggest problem with philosophy seems to me to be that it's much better at critiquing things than at constructing anything. Philosophers seem to be like cooks who have wicked sharp knives but nothing in the fridge. So philosophy as a discipline does have its problems, but baloney is something else.

[Goldengirl]

If I can offer a little bit of clarification on the philosophical idea that seems so desperately to need clarifying. The conceptual history of that statement comes from the nature of how we view ontology; in order to understand something in a specific context, we need to have an antithesis with which to compare it.

 

Take, for example, a world in which everything is the same shade of blue. The concepts in relation to color, such as the color wheel, don't really have a meaning in this world; it's only when there are different colors, or shades and hues, even, that color can have a meaning.

 

So, we cannot really begin to describe what something is until we also have an opposite of it, so to speak. Although, it doesn't really have to be the opposite, merely different.

[Alorael at Large]

You cannot have a thing without having something different from that thing is a little bit less ringing, though. Especially when what it boils down to is that any thing (or quality) indistinguishable from another thing (or quality) is in fact the same thing (or quality). And philosophers don't even unanimously agree on that.

 

—Alorael, who finds it even stranger with description as the problem. He finds it much easier to describe something that is the same as something else than something entirely different. "That giraffe-prime? It's just like a giraffe, except... no, it's just like a giraffe."

[A less presumptuous name.]

This is off topic, but it's a physics question and doesn't really merit its own thread:

 

Today in physics, we started learning about force (exciting, right!). So, we were asked if, in a frictionless vacuum, applying force perpendicular to the direction of a moving object would a) increase it's speed, decrease it's speed, c) make it turn, or d) do nothing.

 

I figured that both a and c were right. Clearly the object will start to move in a new direction, making c correct. However, my physics teacher said that as it begins to move in the new direction, it will lose speed in the original direction. I fail to see how this happens. Can anyone clarify?

[waterplant]

If the perpendicular force has a greater velocity than the object then it would increase in speed (see billiards).

 

It shouldn't turn but continue in a straight line in a new direction.

[waterplant]

btw

 

Originally Posted By: Lilith

hi. let's not fight.

 

 

 

ok peace out.

 

Two people looking into the same hole from different sides may clash heads occasionally. It's not my intention to fight with anybody.

 

Peaced out.