Nope, it's the number of protons. All atoms with the same number of protons have similar chemical properties, and that determines their place in the periodic table of elements. "Isotope" is simply Greek for "same place", so all atoms linked to the same place on the periodic table are isotopes of each other.
(I did not refer to the number of electrons because atoms can have more or less electrons than protons, which makes them ions. Atoms with the same number of protons and electrons are not electrically charged and not called ions.)
The thing that differentiates isotopes of the same element is the number of neutrons. Thus the most common form of carbon is Carbon-12, which has six protons and six neutrons, whereas Carbon-14 has six protons and eight neutrons. This makes it less stable, thus radioactive. Elemental materials have the same number of electrons (-) as protons (+), and are thus electrically neutral, but ions of an element have the same number of protons but different numbers of electrons, so they have a net positive or negative charge.
(Sorry, I appear to be repeating something that was already clarified. Carry on. )
I got that he is talking about the different isotopes of Mg such as 24Mg, 25Mg and 26Mg. That is, Mg atoms with 24, 25 and 26 neutrons in the nucleus respectively. All the Mg atoms would have 12 protons.
Sturrock's paper is saying that a ratio of 0.127 of Mg atoms with 25 neutrons to atoms of Mg with 24 neutrons and a ratio of 0.139 of Mg atoms with 26 neutrons to Mg atoms with 24 neutrons is normal. It's all about the amount of neutrons. Right? Or am I missing something?
Nolan seems to be saying in one of his samples the ratio is unusual or that there is atoms of Mg with unusual numbers of neutrons. I think.
The number used to refer to an isotope is its atomic mass: 24Mg means 12 protons + 12 neutrons; 25Mg is 12 protons+13 neutrons...and so on.
Mg stable isotopes are 24Mg, 25Mg and 26Mg, with natural abundances of 79%,10% and 11% respectively. If you take the ratio of abundances 25Mg to 24Mg, you get the value 0.127, and the ratio of abundance 26Mg to 24Mg is 0.139.
The number used to refer to an isotope is its atomic mass: 24Mg means 12 protons + 12 neutrons; 25Mg is 12 protons+13 neutrons...and so on.
Mg stable isotopes are 24Mg, 25Mg and 26Mg, with natural abundances of 79%,10% and 11% respectively. If you take the ratio of abundances 25Mg to 24Mg, you get the value 0.127, and the ratio of abundance 26Mg to 24Mg is 0.139.
Thanks again for the clarification jplaza. Would be interested in your take on all of this "weird isotopes or weird isotopic ratios" in the samples and what would constitute weird or unusual. All studies agree the samples are mostly Mg, so the isotopes are being touted as the strange thing.
Thanks again for the clarification jplaza. Would be interested in your take on all of this "weird isotopes or weird isotopic ratios" in the samples and what would constitute weird or unusual. All studies agree the samples are mostly Mg, so the isotopes are being touted as the strange thing.
I hadn't heard about these samples until this thread, and I have followed it only discontinuously...
I can comment about the two papers that came up in some posts (Sturrock and Powell), though. None of them demonstrates unusual values for the Mg isotopes abundance, so there isn't much to discuss about.
BTW, by "usual values" I mean the abundance values from IAEA (see my previous post) , since they gather the values after years of measurements, comparisons, and evaluation of data.
So what would be unusual values and what would that mean? That depends. I think there are a few steps before considering an extra-terrestrial origin.
First one, instrumentation or analysis accuracy / artifacts. In Sturrock, all samples (unknown from Ubatuba, and two from known origin), basically show the same results, but they are different to the "usual values". Take figure 2 in that paper, it shows the number of counts of each isotope, so abundance can be calculated very straight forward:
All samples are equivalent, but different to the "nominal value". IMHO, there seems to be a systematic error that has to be taken into account somehow.
On the other hand, Powell takes the same numbers and calculates something totally different to me:
I just don't know how Powell did the calculations. It should be as simple as divide the counts by the sum of all the counts. Maybe he knows about the systematic error I mention, and knows how to correct it. But to me it seems that for the ISO-A sample he just copied the nominal values from anywhere (NIST, I guess), without making any sum or division at all.
If you discard experimental or calculation innacuracies, then you can think about how the isotopes were able to change their abundances.
Sturrock points out he was told that:
When magnesium is heated, it tends to lose the lighter isotopes preferentially: the change in the abundance ratio 26 Mg/24Mg should be twice the change in 25Mg/24Mg.
So I depending on the "history" of the sample, the Mg abundances can vary (but how much? I don't know)
Also, you can think about that the change could be made on purpose. Changing the isotopes abundance is common in nuclear technology. The best example being Uranium. Natural Uranium has 99.3% of 238U and 0.7% of 235U, but it is enriched to 3-5% to be used as nuclear fuel (or 80-90% to produce a nuclear bomb). Helium most abundant isotope is 4He (99.998%), but neutron detectors are built using pure 3He. So the point in this case is that you enrich with an specific isotope to take advantage of nuclear interactions. I don't know if Mg is used in any nuclear application, but changing a minor isotope in a few tenths of percent, won't really make much difference.
Then you can think about natural causes for changing the abundances. If a material is hit by neutrons or cosmic rays (we are constantly being hit by these), it may undergo a nuclear reaction, which usually are isotope-dependent (that is, Mg24 could have a reaction that Mg25 and Mg26 do not). However, I think you would need a very high dose of irradiation to significantly change the abundances.
There may be other possibilities I am missing, but then you may start speculation about the material coming from outside Earth.
Nice find! I was busy reading through how various P&W engines were built. What's interesting is it's a logical thought. We have a piece of Mg supposedly form Ubatuba in 1957 and we have a known plane crash in the same area and time. Yet, Sturrock nor any of the other researchers that I can find ever consider the plane a possible source for the Mg. They're too busy looking for UFOs.
Well, the connection would be enough for any conspiracy theorist to believe in.
We know that it's just a hypothesis at this point, a possibility that should be checked out.
But it is a possible answer to the question of how a piece of magnesium ends up in the jungle.
The naming conventions don't seem to follow the one created for the samples by Sturrock:
3 Since there had been no systematic tracking of specimens in the APRO files, it was convenient to adopt a new system of coding the various specimens when they were transferred from APRO to Stanford University. Specimens received from APRO were numbered SU-A, SU-B, etc. If a specimen was subdivided, its parts were coded SU-Ia, SU-Ib, etc.
I'm just curious, the piece in the back of the "B" sample looks really tiny. Maybe like Craig described his sliver he took off the sample he was using:
He returned the sample he tested in the '60s to the Lorenzens. If that included the sample and the sliver he took off and tested, then the sample was loaned out and lost, maybe the sliver stayed with the collection.
@jplaza, if that little sliver had been subjected to Neutron Activation Analysis, would the it now have different isotopes of Mg in it?
Why do ufologists take fuzzy pictures even when it's of a sample in the lab? Must be something going on with their cameras...
(didn't we have a cartoon on that in the humor thread?)
I noticed this news report on Avi Loeb's researches on the first 'interstellar' meteor. It describes his explorations in the Pacific Ocean and states that he has completed the explorations and taken the materials discovered back to Harvard for further analysis.
If I understand the report correctly, the materials discovered consist only of the 50 or so 'spherules' brought up by a magnetic 'sled', as discussed earlier in this thread. He seems confident that these derive from the 'interstellar' meteor, though I don't see his reasons for confidence, given that small spherules of cosmic origin are widely found in ocean sediments. He is quoted as believing
they either have interstellar origins, or have been made by an advanced extraterrestrial civilization.
He is also quoted as believing [note that this does not necessarily use his own words] that
the tiny objects, about half a millimetre in size, are most likely made from a steel-titanium alloy that is much stronger than the iron found in regular meteors.
His earlier report mentioned iron, magnesium and titanium in the spherules, but I suppose 'steel-titanium alloy' sounds more like the products of advanced technology!
I note that the news report does not seem to mention the so-called 'wire' discovered shortly before the 'spherules'. (See #4 above.) Perhaps Loeb is no longer confident of its extraterrestrial origins.
I noticed this news report on Avi Loeb's researches on the first 'interstellar' meteor. It describes his explorations in the Pacific Ocean and states that he has completed the explorations and taken the materials discovered back to Harvard for further analysis.
Interesting (as Loeb himself says) that the radiometric age of the supposed extra-solar system spherules (or rather the materials in them, such as uranium) is
of order the age of the universe (14 billion years)
If I understand correctly, in nature uranium is only produced in very high-energy stellar events like supernova explosions or mergers of neutron stars, so it couldn't be produced before stars themselves, at least a few hundred million years after the Big Bang. But 'of the order the age of the universe' is a rather loose phrase which could strictly include anything more than a few billions of years old. However, Loeb himself contrasts it with the age of the solar system (~5 billion years) so he must mean something older than that.
I don't know how reliable radiometric dating is for objects like cosmic spherules. In dating igneous rocks like granite, the underlying assumption is that the mineral components of the rock were formed when the rock cooled from a molten state and have stayed largely intact since then. On this assumption the date of formation of the rock can be estimated from the relative proportions of (say) uranium and lead in the rock, as uranium decays to lead at a predictable rate. This underlying assumption is not obviously valid for cosmic spherules formed when objects 'burn up' in the atmosphere.
Claims of 'non human origin' are laughable given that there probably isn't a scientist or metalurgist in the world who is aware of every single manufacturing technique that exists. There are probably thousands of bizarre patents locked away in draws, that only the manufacturer is aware of or would even know of as they are the only ones making a particular product. Long before claims of 'non human origin' are made, every single patent in existence needs to be reviewed...and I doubt anyone has done that.
As Avi Loeb has reported that some of his cosmic spherules contain a 'steel titanium alloy', I was interested to find a historical study of the use of titanium in human technology.
At first sight titanium might seem a good candidate for the 'reverse engineering' of ETI artifacts like crashed spacecraft. Titanium is an abundant material (more common than carbon in the earth's crust) with remarkable and useful chemical and physical properties. Yet little titanium was produced until the 1950s, when production suddenly and dramatically increased, and titanium came to be extensively used in military aerospace projects, following large-scale investment by the US Government. We might suspect that crashed UFOs (at Roswell or elsewhere) were found to contain large amounts of titanium, and the Government decided 'aha, we must make more use of this wonder material before the Russkies do!)
The historical study suggests a more mundane but still exciting story. Titanium turns out to be an exceptionally difficult material to extract and work with, and practical applications (other than titanium dioxide as a white pigment in paint) were long delayed. The study traces the development of titanium from its discovery by an English clergyman in 1790 to its use in modern aerospace. By 1938 the problem of extracting pure titanium had been largely solved, but there was not much interest in it until in 1940 the US Bureau of Mines got involved. It might be thought that this was a response to military needs, but according to the study 'its work was delayed by the war', so it does not seem that it was given a high priority for military reasons. Work continued after the War, and by the late 1940s the military was taking a keen interest in its potential as a strong but relatively lightweight material. It began to be hyped in the press as a 'wonder metal', but turned out to be very difficult to work with. Only great persistence, and Government funding, overcame the technical problems, and by the late 1950s it was coming into widespread use, notably in the Lockheed A-12 and its successors. The study is here:
This doesn't after all seem like a good case for reverse engineering from crashed UFOs. Much of the groundbreaking work was done by independent researchers or commercial companies before the military became involved, and before the 'flying saucer' craze began. It might still be thought that discovery of crashed vehicles containing titanium could have given research fresh impetus, since it would have shown that use of titanium is at least possible , but the onus would be on the advocates of such a theory to find more direct evidence to prove it
As Avi Loeb has reported that some of his cosmic spherules contain a 'steel titanium alloy', I was interested to find a historical study of the use of titanium in human technology.
At first sight titanium might seem a good candidate for the 'reverse engineering' of ETI artifacts like crashed spacecraft. Titanium is an abundant material (more common than carbon in the earth's crust) with remarkable and useful chemical and physical properties. Yet little titanium was produced until the 1950s, when production suddenly and dramatically increased, and titanium came to be extensively used in military aerospace projects, following large-scale investment by the US Government. We might suspect that crashed UFOs (at Roswell or elsewhere) were found to contain large amounts of titanium, and the Government decided 'aha, we must make more use of this wonder material before the Russkies do!)
The historical study suggests a more mundane but still exciting story. Titanium turns out to be an exceptionally difficult material to extract and work with, and practical applications (other than titanium dioxide as a white pigment in paint) were long delayed. The study traces the development of titanium from its discovery by an English clergyman in 1790 to its use in modern aerospace. By 1938 the problem of extracting pure titanium had been largely solved, but there was not much interest in it until in 1940 the US Bureau of Mines got involved. It might be thought that this was a response to military needs, but according to the study 'its work was delayed by the war', so it does not seem that it was given a high priority for military reasons. Work continued after the War, and by the late 1940s the military was taking a keen interest in its potential as a strong but relatively lightweight material. It began to be hyped in the press as a 'wonder metal', but turned out to be very difficult to work with. Only great persistence, and Government funding, overcame the technical problems, and by the late 1950s it was coming into widespread use, notably in the Lockheed A-12 and its successors. The study is here:
This doesn't after all seem like a good case for reverse engineering from crashed UFOs. Much of the groundbreaking work was done by independent researchers or commercial companies before the military became involved, and before the 'flying saucer' craze began. It might still be thought that discovery of crashed vehicles containing titanium could have given research fresh impetus, since it would have shown that use of titanium is at least possible , but the onus would be on the advocates of such a theory to find more direct evidence to prove it
Although most texts say that steel is a man made alloy, and steel titanium alloy would be even more so, given the vast array of conditions that exist out there I personally would not find it that surprising if 'man made' materials could be cooked up on some exoplanet.
Following up on Loeb's Globes, here is an interview with one of the guys pushing back on his claims of intergalactic origin and the likelihood that Loeb's team mange to find pieces related to a specific meteor, or possible alien prob (bold by me):
"It's been known for a century that if you take a magnetic rake and run it over the ocean floor, you will pull up extraterrestrial spherules,"Peter Brown, a meteorite specialist at the University of Western Ontario in Canada, told Live Science. Such debris has accumulated worldwide on the seafloor over millions of years from meteors dropping tiny bits of molten metal as they pass overhead, Brown added. Factoring in shifting ocean currents and sedimentary movements, "it essentially would be impossible to say that this particular spherule comes from a particular event."
Brown also recently co-authored a paper calling into question IM1's interstellar pedigree. The claim that the meteor came from outside our solar system is based on its ridiculous speed upon entering our atmosphere. However, Brown said, "particularly at higher speeds, the U.S. government sensors tend to overestimate speeds." A lower speed would also account for the object's unusual brightness profile, which didn't match what would be expected for a metallic meteor moving at over 100,000 mph (160,000 km/h), Brown said.
Brown doesn't say any of it is impossible, just not likely:
Of course, this doesn't mean the meteorite isn't from another star system — just that it doesn't have to be. To date, there have been no confirmed interstellar meteorite impacts on Earth, though Brown himself has spent 20 years searching for one.
As for the possibility that this is evidence of extraterrestrial technology, most of the scientific community is skeptical. "That would be an extremely cool result," Brown said. "But I don't see any evidence that would necessarily back you into such an extreme hypothesis."
Readers may like to note that Avi Loeb's expedition is causing an international (not interstellar) incident. Allegedly the materials in question were recovered from waters in the jurisdiction of Papua New Guinea. The Government of PNG say that permission should have been sought for the expedition and for removal of material ('rare objects') from the sea floor. The row may even scupper a recent defense deal between PNG and the USA. Some are saying that Loeb's team should face criminal charges.
I base this on a paywalled article in today's UK Times. A Google News search should turn up other sources.
However, George Penua Polon, deputy administrator of Manus Province, has now come out and demanded answers as to why and how the fragments were removed.
"We've been cheated," he told the Sunday Times. "They came here, no one knew about it and now they've gone. What have they found? Does it have value? Do we have rights over it? If it's scientific research, how are our scientific institutions going to benefit?"
Rob McCallum, an experienced ocean explorer, claimed that Loeb's team had applied for a marine science research permit. However, he said that this doesn't cover objects from space.
"This is a unique project," he said. "It aims to locate, retrieve and study material that literally fell from the sky. Current permitting procedures focus on the extraction of existing biological or geological material, which this is not. This research recovered grains of sand that are from outside of the area/PNG/Earth and have no known economic or commercial value."
A senior official from the immigration department claimed that there may be a legal question to answer for prof Loeb and his tea with regards to how they retrieved the IM1 fragment.
They told the outlet: "It may be illegal, hence, those scientists can be charged criminally."
Speaking to UNILAD, prof Loeb said: "We have been engaged with PNG for eight months and have an agreement with the University of Technology (PNG) to study and share the results of this unique astrophysical project. We look forward to continuing to work with the relevant PNG authorities as they may so determine."
I'm pretty sure that meteorites are "geological material", and the fact that they didn't originate where they ended up is true for a large amount of geology.
Note that McCallum states that the team had applied for a permit, not that they had received one.
I'd say, until someone puts them up on ebay. "Genuine exterrestrial material retrieved from the seafloor", a unique item like that should fetch a pretty penny.
It's kinda taking magnet fishing (-> youtube) to the next level.
“There are about 850 spoken languages in Papua, the most linguistically diverse place on Earth,” Prof Loeb wrote on Medium. “Yet, if the expedition recovers a gadget with an extraterrestrial inscription, we will add a new language to this site.”
Enthusiasm and optimism can be wonderful, and there's no reason for scientists to conform to some stereotype of an emotionally cool, straight-laced model of reserve.
But I think Avi Loeb is starting to blur the line between optimism for his originally-stated goal (recovering parts of a meteorite which might be of interstellar origin) and support for unlikely fringe theories with little scientific basis.
There is no real reason to connect the possible finding of meteoritic fragments of possible interstellar origin with an increased chance of finding alien artefacts.
"It's been known for a century that if you take a magnetic rake and run it over the ocean floor, you will pull up extraterrestrial spherules,"Peter Brown, a meteorite specialist at the University of Western Ontario in Canada, told Live Science. , "it essentially would be impossible to say that this particular spherule comes from a particular event."
My (perhaps cynical) suspicion is that any materials found with "interesting" characteristics (e.g. relatively high titanium content) will be described as having been part of an "interstellar object", but more conventional materials won't be.
If this is so, we could have an interstellar object built to order- and an (admittedly slim) opportunity to study the real composition of a meteorite possibly of interstellar origin will be lost, a loss to science.
A loss to science driven by a deliberate selection bias. Maybe we already see evidence of this in Loeb's interest in the piece of wire that was retrieved; if you find a piece of wire on the seabed- wherever you find it- the default theory must be that it's a piece of wire with terrestrial origins.
Incidentally, high-titanium content spherules of debated origin are already known,
YDB spherules with diameter <50 μm averaged 5.0 wt% TiO2, or 35× higher, and 26 of those had average TiO2 of 41 wt% (range: 12–70 wt%),
The authors studied spherules from widespread locations and conclude that they originated from a Younger Dryas impact event.
The possibility of such an event, with global consequences, is much contested and not widely accepted.
Whatever the accuracy of their conclusions, the author's descriptions of spherules with a wide range of size, chemical composition and colours demonstrates that spherules perhaps similar to those described by Avi Loeb are already known.
A number of different origins are listed (clearly some are not likely explanations for Loeb's spherules),
It is widely accepted that spherules form during cosmic impacts, and spherules also form as ablation products from the influx of meteorites and cosmic dust. However, not all terrestrial spherules are cosmic in origin...spherules and glass can be produced by continental volcanism, hydro volcanism, metamorphism, lightning strikes, and coal seam fires. In addition, detrital magnetite and quartz grains are frequently rounded from wind and water action and may appear spherulitic, as can authigenic framboids, all of which are common in sediments. Spherules... can also be produced anthropogenically, especially by coal-fired powerplants and smelters... numerous spherules... have been produced in atomic explosions
(Edited for brevity, citation numbers removed; original text viewable on link or in attached PDF).
The authors do not discuss the destruction of an alien spacecraft as a possible origin of titanium-rich spherules.
)
