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SolusLupus
2009-Aug-11, 07:21 PM
So the conversation I had with a couple of people I know on an MMORPG basically centered around fiction and stars.

The discussion centered around a fictional universe in which there are a ton of "new elements" not exactly found on the current periodic table. In my argument, I pointed out that the elements that we do know about are actually pretty clear; we also understand the process that went into creating these elements, more or less.

The point was brought up that we simply aren't sure; I brought up spectroscopy and how it can tell the chemical (and thus elemental) make-up of a star, but this was generally seen as irrelevant. The point was, that we simply don't know what's out there in the universe. In the case of Dark Matter, I would definitely agree!

However, how do we know that the periodic table is sound? How do we know that we will not run into other strange elements out there in the universe? Or are we, and should be, truly uncertain?

Note that I'm not talking about new ways of combining elements, but new elements altogether.

Also, I'm aware that all scientific statements are inductive rather than deductive, but I'm simplifying a bit by saying "how are we sure".

Amber Robot
2009-Aug-11, 07:46 PM
Well, considering that elements are made up of integer multiples of protons, there's going to be a considerable difficulty slipping any extra ones in except at the very top end. Whenever we try to create elements at the top end, they pretty rapidly decay.

SolusLupus
2009-Aug-11, 07:57 PM
Any exceptions on the elements on the top end decaying rapidly?

ShinAce
2009-Aug-11, 08:06 PM
There is an exception, called the 'island of stability'. We are still off the shore of this island in terms of creating its atoms, but the atoms themselves already have expected properties.

I do want to point out that you're talking about two different things. The periodic table of the elements represents atoms, whereas dark matter does not need to be found on the periodic table. Elementary particles have their own balance sheet.

dwnielsen
2009-Aug-11, 08:06 PM
Maybe you're talking about the island of stability? How is spectroscopy irrelevant?

SolusLupus
2009-Aug-11, 08:08 PM
The core argument on the other side was that there might be elements floating out there that we don't know about and can have no clue about until we "go out and see them".

korjik
2009-Aug-11, 08:09 PM
not really. There should be some elements around element 116 (IIRC) that should be more stable than the elements around them, but that means half-lifes in minutes instead of milli-seconds.

The structure of atoms is quite well known. Protons and Neutrons inthe nucleus with electrons around. With this structure there isnt any way there could be a new element except ones larger than currently known. When that is considered, for there to be a stable element that we dont know about, there would need to be some rather large fundamental changes in our understanding of physics.

As for the 'we dont know what is out there!' arguement, that isnt really true. We see alot of the universe, and what we can see is always the same stuff. Stars a billion light years away are the same stuff as the stars around here.

Amber Robot
2009-Aug-11, 08:09 PM
Ok, taking a quick look at the Periodic Table (http://www.webelements.com/) I find that some transuranic elements do have long lifetimes, but I'm pretty sure that they don't tend to be created naturally. For example, Curium (247Cm) has a half life of 16 million years, but was first created by bombarding plutonium with alphas.

Swift
2009-Aug-11, 08:10 PM
Any exceptions on the elements on the top end decaying rapidly?
By the "top end" I assume you mean at the high atomic weights, the trans-uranic elements.

And the answer is yes. There is the so called Island of Stability (http://www.sciencedaily.com/releases/2008/04/080406114739.htm) and there are some indications we are getting close to it. But, one of the things that is not know is, even if exists, how stable these "relatively stable" superheavy elements will be. If their half-lives are measured in seconds or even minutes, they are much more stable than the currently know elements in the 100+ atomic number range. But they still would be too unstable to do much with, or to be expected to be found in nature.

The science fiction writer Poul Anderson wrote some stories (http://en.wikipedia.org/wiki/Lodestar_(Anderson)) with these concepts in them.

Jeff Root
2009-Aug-11, 08:12 PM
Now that we have studied atoms of all the elements that exist naturally
on Earth, plus many that have been artificially constructed, and know
what they are made of and how they are put together, we are able to
define what an element is. An element is a configuration of protons,
neutrons, and electrons held together by nuclear and electric forces in
such a way as to be more or less stable.

Different elements are different because they consist of different
numbers of protons, neutrons, and electrons. We've found all the
combinations that are stable. There might be some elements which
contain large numbers of protons, neutrons, and electrons that are
somewhat stable. They will be very heavy, and their properties
can be predicted fairly well.

Protons and neutrons are made of quarks. "Up" and "down" quarks.
They could be replaced by more exotic particles that are made of the
heavier "strange" and "charmed" quarks. But those heavy quarks can
only be made in very high-energy collisions, and are very unstable,
falling apart in a tiny fraction of a second. Aside from that, atoms
made from these heavier quarks would have properties very similar to
those of ordinary atoms. They would just be heavier.

You might find other particles that go together in ways different from
the ways atoms go together on Earth, but they either are astonishingly
rare at the surfaces of planets and stars and in nebulae and deep space,
or they are completely invisible, neither giving off, absorbing, reflecting,
nor refracting light. Otherwise we would see them.

-- Jeff, in Minneapolis

SolusLupus
2009-Aug-11, 08:13 PM
As for the 'we dont know what is out there!' arguement, that isnt really true. We see alot of the universe, and what we can see is always the same stuff. Stars a billion light years away are the same stuff as the stars around here.

Yes, this was a major problem I had with their argument, but they argued that we simply do not know if a star over there is the same as a star over here. I'm not sure what they knew what I meant when I mentioned spectroscopy, which would explain why they dismissed it so quickly.

Swift
2009-Aug-11, 08:21 PM
Yes, this was a major problem I had with their argument, but they argued that we simply do not know if a star over there is the same as a star over here. I'm not sure what they knew what I meant when I mentioned spectroscopy, which would explain why they dismissed it so quickly.
I generally agree with the problem you are having with the explanation.

However, if one wanted a science fiction type of hand-waving.... If I remember Poul Anderson's stories I mentioned, there was a naturally occurring source of Island of Stability elements. It was a planet orbiting a supernova remnant, at a considerable distance (think Neptune or further). When the supernova went off, it was a large gas giant, that basically got stripped down to its core. The planet's core got "painted" with a lot of the stuff from the supernova and apparently the supernova process could create transuranics.

Now, I suspect this is all based in little or no actual physics, but it is an interesting idea. And such a body would be virtually invisible to our spectroscopic techniques, as are currently most exo-solar planets.

Van Rijn
2009-Aug-11, 08:32 PM
The science fiction writer Poul Anderson wrote some stories (http://en.wikipedia.org/wiki/Lodestar_(Anderson)) with these concepts in them.


I believe Nick van Rijn was in that one. His novel Mirkheim was based on the same idea, with a battle over an exceptional world loaded with "island of stability" elements.

Swift
2009-Aug-11, 08:36 PM
I believe Nick van Rijn was in that one. His novel Mirkheim was based on the same idea, with a battle over an exceptional world loaded with "island of stability" elements.
He was. I was wondering when you would show up. :D

SolusLupus
2009-Aug-11, 08:38 PM
I may have to read these novels you guys are talking about. They sound intriguing.

Swift
2009-Aug-11, 08:59 PM
I may have to read these novels you guys are talking about. They sound intriguing.
I remember really liking them, but it has been a long time. But now I think I need to do some re-reading.

cjameshuff
2009-Aug-11, 09:27 PM
We can strip electrons off atoms one at a time due to the increasing ionization energies, and measure the charge to mass ratio of the resulting ions by sending them through a magnetic field and measuring the deflection. Combine measurements of multiple ionizations, and you can measure the possible atomic masses and the the nuclear charge of each element. The nuclear charge is always an integer multiple of the charge of a proton, the atoms of a given element all have the same nuclear charge, and only atoms of a given element have that nuclear charge.

So, we do know with great certainty that there are no gaps within the table. There's just no way to squeeze another element in there. You can't get lighter than hydrogen, so the only thing left is to add super-heavy elements on to the end...and those elements are not known for long life. The island of stability is real, but even those elements are still expected to have rather short lifetimes...the stability is relative to other superheavy elements, which tend to decay in seconds or minutes...and as others have said, they're not easy to make. There's things like positronium and dark matter, but those aren't new elements, they're different kinds of matter that don't have any place on the periodic table.

Gillianren
2009-Aug-11, 09:35 PM
The core argument on the other side was that there might be elements floating out there that we don't know about and can have no clue about until we "go out and see them".

I hate that argument so much. It's always, to me, a sign of ignorance of what we already know and how we know it.

korjik
2009-Aug-11, 09:46 PM
I generally agree with the problem you are having with the explanation.

However, if one wanted a science fiction type of hand-waving.... If I remember Poul Anderson's stories I mentioned, there was a naturally occurring source of Island of Stability elements. It was a planet orbiting a supernova remnant, at a considerable distance (think Neptune or further). When the supernova went off, it was a large gas giant, that basically got stripped down to its core. The planet's core got "painted" with a lot of the stuff from the supernova and apparently the supernova process could create transuranics.

Now, I suspect this is all based in little or no actual physics, but it is an interesting idea. And such a body would be virtually invisible to our spectroscopic techniques, as are currently most exo-solar planets.

http://en.wikipedia.org/wiki/Supernova_nucleosynthesis

It does have some basis in physics

stutefish
2009-Aug-11, 10:06 PM
Lonewulf, are they arguing that there might be an element somewhere within the bounds of the current periodic table--say, between Carbon and Silicon--that we just haven't seen yet?

Or are they arguing that there might be an element somewhere beyond the upper boundary of the periodic table that we haven't seen yet?

SolusLupus
2009-Aug-11, 10:21 PM
Actually, the overall lines of their argument were that, in general, we don't know what's out there because we haven't seen it with our own eyes. But in this specific sense, they were arguing that we do not know if the stars out there are totally different than our own sun, or that we do not know if those stars may very well have produced different elements than what we are familiar with.

Timothy Reed
2009-Aug-11, 10:30 PM
Samuel R. Delany's 1968 novel "Nova" used the plot device of increasingly stable superheavy elements as the atomic number increased beyond 300. The trans-three-hundred elements, collectively known as Illyrion, were generated in the cores of stars and were a valuable resource used for power and space travel. The story focuses on a Moby Dick-like quest to capture large quantities of Illyrion as a star goes nova rather than mine trace quantities from planetary sources.

Eta C
2009-Aug-12, 12:38 AM
Actually, the overall lines of their argument were that, in general, we don't know what's out there because we haven't seen it with our own eyes. But in this specific sense, they were arguing that we do not know if the stars out there are totally different than our own sun, or that we do not know if those stars may very well have produced different elements than what we are familiar with.

Have they ever looked at the sky at night? Then they've seen it with their own eyes. Astronomers & physicists have as well through telescopes and other instruments. All of the stars we've observed behave in similar ways. The absorbtion spectra (and emission spectra) of every star observed (and the number is huge) behave in the same way as the sun does. All of these can be explained by the known periodic table of elements. I agree with Gillian. Arguments like these ignore all that we do know and the conclusions that we can draw from it.

01101001
2009-Aug-12, 12:52 AM
Like my kid asking what other ways a 4x4 blue Lego block can possibly be connected to a 4x4 red one.

That's it, kid. You've exhaustively explored the solution space.

It's another step toward adulthood.

Amber Robot
2009-Aug-12, 01:07 AM
Actually, the overall lines of their argument were that, in general, we don't know what's out there because we haven't seen it with our own eyes. But in this specific sense, they were arguing that we do not know if the stars out there are totally different than our own sun, or that we do not know if those stars may very well have produced different elements than what we are familiar with.

Do these same people wonder if the people on the TV can see them. I mean, if we can see them, why can't they see us??:confused:

aastrotech
2009-Aug-12, 01:55 AM
Like my kid asking what other ways a 4x4 blue Lego block can possibly be connected to a 4x4 red one.

That's it, kid. You've exhaustively explored the solution space.

It's another step toward adulthood.

That's probably where they were coming from. But they were also possibly looking to "the local geek" to entertain them with more imaginative speculations. Such as maybe weak/strong/unusual circumstance interaction between baryonic and nonbaryonic (dark) matter. Though they probably didn't know thats what they were looking for beyond entertainment from the local geek.

Like the kid who is really looking to dad for more imaginative suggestions for lego blocks than "exhausting the solution space for connecting a 4x4 blue Lego block to a 4x4 red one". He just doesn't know what to ask for. Even a kid intuits that there's more to lego blocks (and more to dad) than that. He's right about legos. He's not neccessarily right about dad.

That's another step toward adulthood too.

Delvo
2009-Aug-12, 03:43 AM
In a way, it's a valid and even insightful question, recognizing the possibility of "unkown unknowns" as opposed to "known unknowns". The only problem is that this just doesn't happen to be a context in which such thinking is applicable, because too much of the subject is known and rather little is unknown.


...Such as maybe weak/strong/unusual circumstance interaction between baryonic and nonbaryonic (dark) matter.Other possibilities do come to my mind: matter based on quarks in pairs, quadruplets, hexes, or such instead of trios; matter based on quarks other than the up & down and/or leptons other than the electron (imagine a cluster of charms, stranges, and muons in the exact counter part arrangements to our carbon & oxygen atoms; would they still combine to form a c-s-µ equivalent to carbon dioxide?); whole atoms, molecules, or planets of antimatter (antiprotons, antineutrons, positrons); matter with various degrees or types of quantum entanglement or coherency, like Bose-Einstein condensates...

However, this broadening of the scope of the question doesn't help much; it still lies mostly in the realm of known answers, whether because we know why it wouldn't work or because we've already seen it and know what it's like. But there are a few things in there that even the latest science can't answer, like why antimatter is so uncommon and whether it would really be such a perfect mirror of normal matter on complex large scales or not.

WayneFrancis
2009-Aug-12, 04:03 AM
Actually, the overall lines of their argument were that, in general, we don't know what's out there because we haven't seen it with our own eyes. But in this specific sense, they were arguing that we do not know if the stars out there are totally different than our own sun, or that we do not know if those stars may very well have produced different elements than what we are familiar with.

Well this just shows they are very ignorant of physics. When you talk about the elements the science is about as sound as you can get. It isn't as complicated as lets say molecules and things like protein folding.

The periodic table is a definition of Atoms. Atoms are defined by the number of protons they have. Protons are baryons that interact with all 4 forces (Gravity, Electromagnetic, Weak and Strong forces). Protons have a very definite charge due to the 3 quarks that they are made up of. There has never been a test that goes against the standard model when it comes to the basic physics of atoms.

So carbon is defined by having 6 protons. It doesn't matter how many electrons or neutrons it has. It is still carbon. We can even predict attributes of the other isotopes of carbon very well along with the isotopes. An isotope is defined by the number of neutrons it has.

Atoms don't interact long term with other types of matter besides electrons. IE a photon, neutrino, etc don't "attach" themselves to a atom giving it different qualities. Generally speaking any interaction causes a immediate change in the atom that results in some other type of atom.

With that definition claiming that an atom on some other star with 6 protons would be something other then carbon is just pure ignorance about the science. It is literally like saying "You don't know there aren't invisible pink unicorns on that star just making it look the way it does."

As it has been said before, everywhere we look in the universe we see signs that the baryonic matter acts the same not only everywhere we look but, since light is of finite speed, every "when" we look.

So from them if they don't understand spectroscopy then point them to the wiki, try to explain it yourself or give up and realise they are just wilfully ignorant. I understand where they are coming from because when I was 6 I had similar thoughts brought on by sci-fi. By junior high though I understood enough about physics to understand why my old ideas would not hold up.

WayneFrancis
2009-Aug-12, 04:08 AM
Do these same people wonder if the people on the TV can see them. I mean, if we can see them, why can't they see us??:confused:

I believed this when I was 4. I remember thinking that people where actually in there. Then again I didn't really think that cartoons where not real. Man my parents never had the types of conversations I've had with my son when he was 4. I had a talk to him about how you shouldn't do the stuff you do in GTA3 in real life and he looked at me with that look of disgust and said "Dad! It's just a game!" I don't think my parents talked to me much when I was a child...that could be a good thing :)

chornedsnorkack
2009-Aug-12, 03:47 PM
What do you think could be the names of quark elements?

I mean, we have not been able to synthesize quarks. This is hard because of quark confinement - separating coloured particles takes more energy than creating quark-antiquark pair that neutralizes the colours to white.

But if colour is conserved, and electric charge certainly is conserved, what are you going to do with a free quark which has no mate in the entire Universe? You cannot neutralize a quark. A free up quark is charge +2/3... add an electron, and you get an ion with charge -1/3. An ion whose spectroscopic properties can be predicted from quantum mechanic and electromagnetism (with a small uncertainty due to unknown rest mass of a free up quark) - and whose chemical properties are strictly predictable from first principles.

If you dissolve some up quarks in water and apply electric current, will the up quark go to cathode (charge +2/3) or anode (quark plus electron give charge -1/3)?

SolusLupus
2009-Aug-12, 03:56 PM
On a slightly related note, what are the chances that we would find strange new metals floating out in space? That's actually where the conversation originally started at its very core; the varying metal ores listed in the science fiction game that are not like any metals we know about today. They're base metals, not man-manufactured alloys; what are the chances of that?

korjik
2009-Aug-12, 04:07 PM
On a slightly related note, what are the chances that we would find strange new metals floating out in space? That's actually where the conversation originally started at its very core; the varying metal ores listed in the science fiction game that are not like any metals we know about today. They're base metals, not man-manufactured alloys; what are the chances of that?

Considering that there is alot of research into differing alloys and metals, I would have to say it is pretty low.

SolusLupus
2009-Aug-12, 04:11 PM
Just as I thought.

Jeff Root
2009-Aug-12, 04:43 PM
... we have not been able to synthesize quarks. This is hard because
of quark confinement - separating coloured particles takes more energy
than creating quark-antiquark pair that neutralizes the colours to white.

But if colour is conserved, and electric charge certainly is conserved,
what are you going to do with a free quark which has no mate in the
entire Universe? You cannot neutralize a quark. ...
I may misunderstand what you are asking, but I'd speculate that
if you managed to produce a free quark, it would very quickly find a
hadron to join up with, which would then split into a pair of mesons.

-- Jeff, in Minneapolis

Jeff Root
2009-Aug-12, 04:55 PM
On new metals: Can anyone say what the most recently-developed alloys
are that are significantly different from anything that previously existed?
My guess is that new processes for making alloys are now usually more
significant than new alloys themselves. So the usefulness of an alloy may
have been worked out in the 1930's, but it wasn't until the 1990's that
someone developed a means of making it cheaply enough for general use.
Or whatever.

-- Jeff, in Minneapolis

chornedsnorkack
2009-Aug-12, 05:25 PM
I may misunderstand what you are asking, but I'd speculate that
if you managed to produce a free quark, it would very quickly find a
hadron to join up with, which would then split into a pair of mesons.


"Mesons" are hadrons. They are white. And have integer charges. And consist of a quark and antiquark.

Say you produce a free, red, up quark. Charge +2/3.

It will electrostatically repel any proton and any nucleus. It may have strong attraction to them - who knows? It might have strong repulsion instead.

Suppose that it finds a neutron to pair up with. Neutron is three quarks and no antiquarks. One up and two down. One red, one green, one blue.

Then we have four quarks, two up and two down. Two reds, one green, one blue.

There is no way they could split to two mesons.

What IS the lowest energy configuration for a free quark in presence of available nucleons? Might be that the up quark simply repels the neutronm. Might be that they stick together, as one particle/nucleus, charge +2/3. Or might be that they promptly split to two... what? How do you call a coloured assembly of several quarks? It is neither a free quark nor a white hadron (meson or baryon).

matthewota
2009-Aug-12, 05:33 PM
Is there a periodic table of subatomic particles yet? Or is it still a disorganized zoo?

Swift
2009-Aug-12, 06:01 PM
On new metals: Can anyone say what the most recently-developed alloys
are that are significantly different from anything that previously existed?
My guess is that new processes for making alloys are now usually more
significant than new alloys themselves. So the usefulness of an alloy may
have been worked out in the 1930's, but it wasn't until the 1990's that
someone developed a means of making it cheaply enough for general use.
Or whatever.

-- Jeff, in Minneapolis
An interesting, and difficult question, and I would say the answer is yes. ;)

Often, half the challenge with a new composition is finding a method to produce it, particularly at the production scale, so it is often difficult to seperate the compositional challenges from the process challlenges.

One example is preparing alloys from metals that are immiscible when molten, and one proposal for solving that is microgravity processing, though other ideas have been proposed. Many of these have been tested at the lab scale, but have been difficult to scale up.

Other examples are amorphous metals (http://en.wikipedia.org/wiki/Amorphous_metal), where the challenges were both in the processing and in finding compositions (these are being scaled up to production scales) and Quasicrystalline materials (http://en.wikipedia.org/wiki/Quasicrystal), where the initial big challenge was recognizing that this material could even exist.

cjameshuff
2009-Aug-12, 06:04 PM
Is there a periodic table of subatomic particles yet? Or is it still a disorganized zoo?

That's a false dichotomy. There isn't necessarily a periodicity to arrange things in a table by...that does not mean that there's no organization, only that different methods of organization must be used.

Delvo
2009-Aug-12, 07:08 PM
Is there a periodic table of subatomic particles yet? Or is it still a disorganized zoo?Sometime within the last year or two, Garret Lisi proposed one that included both matter and force particles such as photons, including gravitons (the existence of which has been in doubt). It's just in multiple dimensions instead of two (so there are also multiple "diagonals" along which you can look through it, instead of just the two diagonals in the table of the elements, down-left and down-right). And, like the periodic table of the elements as originally made by Mendeleėv, it has gaps which might be testable: spots in the geometrical arrangement where you can predict that something should be and you can estimate what its traits are, but it hasn't been seen yet, but at least the "table" gives you an idea of what you're looking for.

I've heard nothing about Lisi's multi-dimensional arrangement of the fundamental particles since its original publication. Presumably, it's being examined by other physicists to determine its theoretical/mathematical validity.

Chacal
2009-Aug-12, 07:15 PM
Actually, the overall lines of their argument were that, in general, we don't know what's out there because we haven't seen it with our own eyes.

Are you sure they are breathing? Air being invisible and all...


The periodic table is a wonderful tool: after the elements known at the time it was designed (circa 1869) were arranged into it according to its rules, you could even predict some of the potential properties of the elements still not on the table (there were holes). Elements like Fluorine, Helium (and all the other Noble Gases), Gallium, Germanium, Scandium and others which were discovered only after the table was defined. Take the Noble Gases, for example. By their electronic structure, they should be inert (because they have full orbitals, with no 'holes' or 'free electrons'). Because of that, they shouldn't associate even with themselves (in crystals or molecules), so these elements should be gases (because crystals and large molecules — even made of a single kind of atom — are heavy). Lo and behold: Noble (they don't associate) Gases.

Chacal
2009-Aug-12, 07:48 PM
On a slightly related note, what are the chances that we would find strange new metals floating out in space? That's actually where the conversation originally started at its very core; the varying metal ores listed in the science fiction game that are not like any metals we know about today. They're base metals, not man-manufactured alloys; what are the chances of that?

An ore is one thing, a metal is another, an alloy is yet a third.

Ores are mixtures of pure metals with impurities (especially for 'noble' metals, such as gold) or mixtures of metallic salts with or without impurities (For example, Wikipedia says "Bauxite is the most important aluminium ore. It consists largely of the minerals gibbsite Al(OH)3, boehmite γ-AlO(OH), and diaspore α-AlO(OH), together with the iron oxides goethite and hematite, the clay mineral kaolinite and small amounts of anatase TiO2.")

Different ores in space? Very likely, as there would have been different formation conditions.

Different alloys? Could be, but the chances of an ore being a ready-made, useful alloy are very slim. How many metals can be mined on Earth that are ready for use? Like you shovel the ore off the ground and smelt it? Very few.

Different metals? Just floating about? Extremely unlikely, and only if the elements in the 'stability island' happen to be metals AND those metals are useful for anything (they may be too heavy but weak, they may be too radioactive but not easily fissionable, they may be too reactive, they may be nonconductive, they may be all liquids, for all we know). For example, what's Scandium good for?

astromark
2009-Aug-12, 07:56 PM
The periodic table does not have gaps. We start at H and wonder on through to who knows what... and that's the truth of it for the masses. Me. Those high end big numbers elements that seem to have a shorter life than the small end tighter elements... BUT would one of you most learned people please spare me the time to tell me what, where and how does dark mater fit into this subject. We know its there, we can not see it. But it has mass. What prey tell ? ( knowing that I will be told its not the same thing ) Why ? There seems to be so many gaps in our view... Take a deep breath and be gentle...mark.

Jeff Root
2009-Aug-12, 09:09 PM
Mark,

No.

Sorry.

I'd be happy to spare the time but your guess is about as good as anyone
else's, at the moment.

The gaps in the table of elements have been filled. Sorry again. It's too
late for you to apply.

And careful with that pi! It's getting awful close.

-- Jeff, in Minneapolis

Swift
2009-Aug-13, 06:27 PM
On a slightly related note, what are the chances that we would find strange new metals floating out in space? That's actually where the conversation originally started at its very core; the varying metal ores listed in the science fiction game that are not like any metals we know about today. They're base metals, not man-manufactured alloys; what are the chances of that?
Given this conversation, I thought people might be interested in this from BBC.com (http://news.bbc.co.uk/2/hi/science/nature/8194292.stm):

By slamming materials together, scientists have made a mineral that is found naturally only in meteorites and the deep layers of Earth's mantle.

Wadsleyite (http://en.wikipedia.org/wiki/Wadsleyite) is apparently a magnesium silicate.

trinitree88
2009-Aug-13, 07:11 PM
Is there a periodic table of subatomic particles yet? Or is it still a disorganized zoo?

Mattewota. Yes, it's called the Standard Model. Try:http://en.wikipedia.org/wiki/Standard_Model

and Lonewolf, you are right on the money in speaking of spectroscopy. A new element ought to have a unique fingerprint in the electromagnetic line spectra world....and it ought to be calculable from first principles using modified versions of Bohr's original insight into the hydrogen atom's spectrum. Since it's not a two body problem, technically there's no solution to a multiple-body problem, including 3-body, but I believe perturbation theory makes pretty accurate approximations, here. pete

There are no missing members of the baryons, mesons, or hyperons. Whether we find a Higgs remains to be seen, and the entire physics community does not follow heavy Higgs rationale, though it is mainstream.


As for seeing new elements...they should then show up in cosmic ray emulsions, cloud chambers, wire chambers, calorimeters in particle detector labs, which in a magnetic field cause their trails to curve if they are charged, enabling a charge/mass ratio to be determined. They don't show up though.To the best of my reading knowledge, no unknown cosmic ray has ever shown up, though somebody else in the forum may have an anecdotal incident or a paper that says otherwise. pete SEE:http://en.wikipedia.org/wiki/Cosmic_ray

also see:http://hyperphysics.phy-astr.gsu.edu/hbase/HFrame.html

chornedsnorkack
2009-Aug-13, 07:25 PM
Mattewota. Yes, it's called the Standard Model. Try:http://en.wikipedia.org/wiki/Standard_Model

There are no missing members of the baryons, mesons, or hyperons.
There are. But we would not expect to see them all. Note that hyperons are baryons; we can predict the existence of a lot of hyperons that we have never seen, but this is statistically not odd at all.



As for seeing new elements...they should then show up in cosmic ray emulsions, cloud chambers, wire chambers, calorimeters in particle detector labs, which in a magnetic field cause their trails to curve if they are charged, enabling a charge/mass ratio to be determined. They don't show up though.To the best of my reading knowledge, no unknown cosmic ray has ever shown up, though somebody else in the forum may have an anecdotal incident or a paper that says otherwise. pete SEE:http://en.wikipedia.org/wiki/Cosmic_ray

So what? Has plutonium 244 ever been found in cosmic rays?

trinitree88
2009-Aug-13, 07:43 PM
There are. But we would not expect to see them all. Note that hyperons are baryons; we can predict the existence of a lot of hyperons that we have never seen, but this is statistically not odd at all.


So what? Has plutonium 244 ever been found in cosmic rays?

chornedsnorkack. Yep, it has...SEE:http://cat.inist.fr/?aModele=afficheN&cpsidt=17298907

and I'm curious, which hyperon is still missing? pete


see:http://en.wikipedia.org/wiki/Hyperon

chornedsnorkack
2009-Aug-13, 08:07 PM
chornedsnorkack. Yep, it has...SEE:http://cat.inist.fr/?aModele=afficheN&cpsidt=17298907

No. Its decay results were found in meteorites, not cosmic rays. Meteorites also contain decay results of a bunch of other long-lived isotopes.

But curium 247 has been sought in meteorites, unsuccessfully. Which suggests that if nature contained modest amounts of superheavy elements with half-life of 10+ million years, we should not find them either.


and I'm curious, which hyperon is still missing? pete


see:http://en.wikipedia.org/wiki/Hyperon

Ah yes. All strange particles are found if hyperons only refer to strange particles.

Doubly charmed baryons have been predicted, but not confirmed. Triply charmed baryon is missing. As are doubly and triply beautiful baryons.

Swift
2009-Aug-13, 08:10 PM
Doubly charmed baryons have been predicted, but not confirmed. Triply charmed baryon is missing. As are doubly and triply beautiful baryons.
Well that's strange. :p

Van Rijn
2009-Aug-13, 08:51 PM
Well that's strange. :p

You might like this:

Discovery of a strangely beautiful baryon (http://irfu.cea.fr/Sap/Phocea/Vie_des_labos/Seminaires/index.php?id_type=2&type=2&y=2007&id=1590)


Three months ago the DZero experiment at the Tevatron collider, the most powerful particle accelerator machine currently operating, announced the discovery of the first baryon containing quarks from all three known generations of matter. This particle, the Xi_b (aka Cascade b), is make of a "beauty" quark, a "down" quark, and a "strange" quark, all combined together to create a strangely beautiful baryon.

:rolleyes:

WayneFrancis
2009-Aug-14, 06:17 AM
Sometime within the last year or two, Garret Lisi proposed one that included both matter and force particles such as photons, including gravitons (the existence of which has been in doubt). It's just in multiple dimensions instead of two (so there are also multiple "diagonals" along which you can look through it, instead of just the two diagonals in the table of the elements, down-left and down-right). And, like the periodic table of the elements as originally made by Mendeleėv, it has gaps which might be testable: spots in the geometrical arrangement where you can predict that something should be and you can estimate what its traits are, but it hasn't been seen yet, but at least the "table" gives you an idea of what you're looking for.

I've heard nothing about Lisi's multi-dimensional arrangement of the fundamental particles since its original publication. Presumably, it's being examined by other physicists to determine its theoretical/mathematical validity.

He's got a talk on TED which is a good primer on the idea.

http://www.ted.com/index.php/talks/garrett_lisi_on_his_theory_of_everything.html

WayneFrancis
2009-Aug-14, 07:15 AM
you might like this:

discovery of a strangely beautiful baryon (http://irfu.cea.fr/sap/phocea/vie_des_labos/seminaires/index.php?id_type=2&type=2&y=2007&id=1590)



:rolleyes:

wooo - cool!

Swift
2009-Aug-14, 02:12 PM
Is there a periodic table of subatomic particles yet? Or is it still a disorganized zoo?
I happened upon this poster-style view (http://www.pha.jhu.edu/~dfehling/particle.gif) of the Standard Model, that seems to be a good summary.

trinitree88
2009-Aug-14, 02:17 PM
No. Its decay results were found in meteorites, not cosmic rays. Meteorites also contain decay results of a bunch of other long-lived isotopes.

But curium 247 has been sought in meteorites, unsuccessfully. Which suggests that if nature contained modest amounts of superheavy elements with half-life of 10+ million years, we should not find them either.


Ah yes. All strange particles are found if hyperons only refer to strange particles.

Doubly charmed baryons have been predicted, but not confirmed. Triply charmed baryon is missing. As are doubly and triply beautiful baryons.


chornedsnorkack. Ok, you are of course correct on my oversight on the continued filling of the second and third familys...I was thinking only in the first. Kudos.
However, as the meteorite in question, could have been struck by the plutonium-244 as a cosmic ray, which then decayed in situ...I don't think that that possibility can be entirely excluded. It doesn't necessarily mean the Pu-244 was primordial in the meteorite's parent body. pete

Jeff Root
2009-Aug-14, 08:00 PM
It doesn't necessarily mean the Pu-244 was primordial in the meteorite's
parent body.
That should be reasonably easy to determine, shouldn't it?

-- Jeff, in Minneapolis

trinitree88
2009-Aug-17, 03:31 PM
That should be reasonably easy to determine, shouldn't it?

-- Jeff, in Minneapolis

Jeff. I think it would depend on the physical location of the decay trail. If it's near the edge, it could've impacted, then decayed. I don't know the acid etching technology well enough to be definitive. It just seems to me that single action mechanisms for physical processes become more convoluted as we learn more about them. Let me know if you have a more definitive result. Thanks. pete

NorthernBoy
2009-Aug-17, 04:04 PM
I may misunderstand what you are asking, but I'd speculate that
if you managed to produce a free quark, it would very quickly find a
hadron to join up with, which would then split into a pair of mesons.

-- Jeff, in Minneapolis

This is a "what if" that does not make sense, so speculation which follows from it means little. Quark confinement does not allow free quarks at the energy scales at which hadrons exist. At higher energy scales (where asymptotic freedom pertains), then there is no reason that the quark would join with a set of quarks which themselves were colour neutral, and they most certainly could not create two mesons.

mugaliens
2009-Aug-18, 07:18 PM
One of the more intriguing things I've run across in recent years is the display of the periodic table of the elements in 3D, commonly known as the Alexander Arrangement of the Elements. This Q&A (http://allperiodictables.com/aptpages/aaeDetail_9_3D.html) explains why it's so useful.

This site (http://www.mpcfaculty.net/ron_rinehart/periodic.htm) contains many different representations of the periodic table, including 3D as well as spiral.