Another Antimatter Supernova Discovered
Written by Nicholos Wethington
Here's another extremely explosive supernova that can be chalked up to the production of antimatter in the core of the star: Y-155. These types of supernova explosions – which can be ten times brighter than the already spectacular explosion of a Type Ia supernova – have been theorized to exist for over forty years. About a month ago, we reported on the first observations of one of these types of supernovae, and at the American Astronomical Society super-meeting yesterday, Peter Garnavich of the University of Notre Dame presented on the observation of a second.
The star Y-155 was a whopping large star, with a mass of over 200 times that of our Sun. In these types of stars, energetic gamma rays can be created by the intense heat in the core of the star. These gamma rays in turn make pairs of electrons and positrons, or antimatter pairs. Since so much energy goes to the creation of these pairs, the pressure pushing outwards on the star weakens, and gravity swoops in to collapse the star, generating a supernova of enormous proportions.
These types of supernovae have been dubbed "pair-instability" supernovae, and once they explode, there is nothing left: in other types of supernovae, a neutron star or black hole can form out of the remnants of the star, but pair-instability supernovae explode with such force that there is nothing left where the core of the star once existed. In addition to supernova 2007bi, which we reported on in December of 2009, the supernova 2006gy is another candidate for this type of supernova.
Y-155, which lies in the constellation Cetus, was discovered as part of the Equation of State: SupErNovae trace Cosmic Expansion,"ESSENCE", search for stellar explosions. During the 6-year search, a team of international astronomers led Christopher Stubbs of Harvard University collaborated to find Type Ia supernovae as a means to measure the expansion of the Universe. These types of supernovae explode with a characteristic luminosity, making them excellent candidates to measure distances in the Universe. The team utilized the National Optical Astronomy Observatory's (NOAO) 4-m Blanco telescope in Chile.
Y-155 was discovered in November of 2007, during the last weeks of the project, using the Blanco telescope. Once the initial discovery was made, followup observations using the Keck 10-m telescope in Hawaii, the Magellan telescope in Chile, and the MMT telescope in Arizona revealed the redshifting of the light due to the expansion of the Universe to be about 80%, meaning that the star is very far away, and thus very old. Y-155 is estimated to have undergone a supernova approximately 7 billion years ago.
According to Garnavich, the team calculated the star to be generating 100 billion times the energy of the Sun at its peak. To accomplish this, it must have synthesized between 6 and 8 solar masses of nickel 56, which is what gives Type Ia supernovae their brightness. For comparison, the typical Type Ia supernova burns 0.4-0.9 solar masses of nickel 56.
Y-155 has been shown by deep imaging with the Large Binocular Telescope in Arizona to reside in a galaxy that is rather small. Smaller galaxies are usually low in heavier atoms. The gas out of which this and other types of ultra-massive stars form is relatively pristine, composed largely of hydrogen and helium. Supernova 2007bi, the first-observed pair-instability supernova, grew up in a galaxy remarkably like that of Y155.
This means that when astronomers look for other types of pair-instability supernovae, they should find more of them in smaller galaxies that existed near the beginning of the Universe, before other supernovae synthesized heavier elements and spread them around.
Source: Physorg
Filed under: Astronomy
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January 7th, 2010 at 10:12 am
You know, no idea how well a layman understands such a press release…
I sure know I as an astronomer do NOT.
The "star Y-155"… I'm sure that's a designation for the supernova as an ESSENCE transient… Does it not have a name like SN 2007xy??
A distance is given – but no redshift. 7 billion light years sounds roughly like z = 0.8 – 0.9 or so.
The energy release is in another big number unit no one in the field understands. I'm guessing it's in the 10^52 erg range.
Well, I hope an actual paper will be out soon.
January 7th, 2010 at 11:27 am
The article is interesting, but it could be written to be more science accurate.
"Gravity swoops in" ??
I was not aware gravity could swoop.
"Once they explode there is nothing left" ??
So 50% of the star was converted to anti-matter and completely annilated the other 50%%? Amazing!!
"supernovae synthesized heavier elements and spread them around" ??
Heavier elements are not synthesized. Lighter elements are fused to create the heavier ones.
January 7th, 2010 at 4:58 pm
@William Weber:
The articles at this site are not meant to be scientific papers on a particular topic. They are informational, interesting and well written. Most of the authors on this site are not professional astronomers, but like the rest of us that come here, have an interest in astronomy in particular, and science in general. You'll find that many of the commenters here do go into greater detail and offer papers to reference for the detailed science behind the articles. It's a shame that you must be so critical. I think if you continue to come to this site and read the articles offered, you'll find the writers offer a good deal of astronomy to discuss. I hope to learn something from your future posts beyond simple criticism.
January 7th, 2010 at 5:46 pm
Weber does have a point. If I consider a Gaussian surface around the star that is far from the surface I will measure a garvitational force. The star then blows up. Ignoring the rather small amount of mass in the EM energy released, the gravitational force will be the same, until the material shock wave passes my Gaussian surface.. This is the essence of the Birkoff theorem. Gravity does not disappear, but rather the source of the gravity field, which is a matter field, becomes more diffuse and spreads out.
There is some confusion I think about the role of antimatter here. The star does not generate 50% of its mass as antimatter. The physics from a astrophys-101 perspective is this. Particles with mass have what we call in quantum field theory a mass-gap in their quantum field physics. It requires an energy E = E’ + 2mc^2 to generate pairs of particles, say electron-positron pairs, of mass m, and where the E’ is an additional energy required to get threshold of production. This process will not increase the energy or temperature of the core, but reduce it. The reason for this is something called the equipartition theorem in statistical mechanics. The energy of a system in a thermal distribution is E = NkT. The N here is the number of particles and k is the Boltzmann constant. Now in the production of particles we have that there are now (2 + N)kT, and if a lot of these particles, say n of them, are generated then E = NkT goes to E = (N + n)kT. This does not produce energy, for energy in the motion of particles in the hot gas is being used to generate these particle anti-particle pairs. So E remains constant here, at least in the adiabatic assumption I am employing. Well this means
NkT = (N + n)kT’
for T’ the new temperature which results from the pair production. It is then clear that T’ = TN/(N + n) < T. So the temperature decreases!
Well what happens when the temperature of the stellar core decreases? We appeal to the natural gas law pV = NkT, where if the temperature decreases then pV decreases. The pressure is what sustains the material against the gravitational force from imploding the star inwards. For the star with a mass M = rho*V (rho = density of material) the differential of gravitational pressure on a unit of material at radius r is dp = (G*rho/r^2)dr, which can be easily integrated for a constant rho, but rho may change with radius. The upshot is that V decreases which then increases the pressure, which then adjusts the temperature back up, maybe to a higher temperature. This is the origin of gravity "swooping in." This then promotes more pair production, causing more collapsing and greater pressure, causing even higher temperatures and so forth. The whole thing runs away on itself and generates this huge explosion or hypernova.
These hypernova are serious energy producers.
LC
January 7th, 2010 at 8:21 pm
This is a little confusing, but when I clear out the riff-raff at least the hypernova instability seems clear thanks to LBC model. Fast enough pair production should be an adiabatic process, which then needs to relax; LBC relaxation seems reasonable enough. (But it would gain a lot by taking out the confusing notation as N and T changes.)
@ WW:
Presumably it's the force that rips the hypernova remnants apart and scatter as the article says, not pair production as equal parts matter and anti-matter is created from the high energy radiation. In effect you don't loose mass from that, you might gain some though if some AM escapes.
It must be the gravity that "swoops in", the loss of gravitational potential energy if I understand LBC model correctly, that supplies the hypernova energy.
January 7th, 2010 at 11:15 pm
LC..
Once again, you read about things, then expand on what you've read even more. Which is normally a good thing. However, you misinterpret whatever you've read.
I have no idea why you brought up a Gaussian surface. It has nothing to do with this subject, and wouldn't be used to measure any electronic flux coming from an exploding star.
Equally confusing is your use of the equipartion theorem. You probably learned about this from reading something about super nova remnants.
Your whole description of how the star collapses is… well, I have no idea where you came up with it.
The first major point about this subject, is that the star formed in the early universe, when there weren't alot of metals. Therefore the star was mostly made of helium and hydrogen, and formed to be around 200 solar masses. Unlike stars which form today, which have much more metal, and do not become as massive.
The death of this star was the result of a process known as "pair instability".
A massive star of this size produces gamma rays which become so energetic, some of their energy is used to produce particle and anti-particle pairs. This eventually results in a drop of pressure causing the star to partially collapse under its own gravity.
During the collapse the star begins to release more energy.
The collapse compresses the core within the star creating an overpressure sufficient to begin a runaway nuclear fusion, resulting in a thermonuclear explosion.
Along with this massive release of energy, a good portion of the stars core is tranformed into nickle-56. Perhaps as much of 40-50 solar masses worth. Which we have learned from the type 1a supernova article a few days ago, the amount of nickle produced seems to attribute to the luminosity of the explosion.
Because more energy is released than the stars gravitational binding energy, it is completely disrupted. No blackhole or remnant is left behind.
January 8th, 2010 at 2:54 am
@ Aodhhan
What the heck is your motive? You hunt LBC as if there's nothing else in the world.
The thing is I don't see any flaws in LBC's arguments. He has just given a nice description what leads to the runaway-process and supported it by presenting some appropriate formulas.
On the other hand, in most cases you just claim that LBC writes non-sense, but you attempt in no way to back your claim or to correct him. You are just trolling.
So, please, do us all a favor and stop this. Or show explicitly where LBC is wrong and why.
January 8th, 2010 at 4:43 am
Mr. Flimmer,
Because the information he dishes out is incorrect.
Formulas don't support anything by themselves. In order to use a formula to support your information, you need to plug the data into the formula and produce a result. Something he has never done.
If you believe his statement about Gaussian surface, then find some reference material on it, and you'll see it is something which has no relevance to the article.
He brings up Quantum Field Theory, which is a basic mathematical and condeptual framework for comtemporary elementary physics. This subject might be a good addition if there was mention of Quantum Gravity Physics. However, that also would be going outside the topic of the article. Also, he incorrectly discusses how it works.
My time is short so I will discuss one more thing…
His formula E = E’ + 2mc^2, doesn't apply to anything on topic. Perhaps he meant E=mc^2, which would be dead on line for the subject of pair creation. He is using it to discuss the creation of 'pair production'… again his explanation is incorrect.
There is a huge contrast in my description and his. Mine is pretty much the accepted theory, and if you go through reference material you'll find I'm a lot more inline than LC is.
My point is, if someone puts out information that someone is going to learn from it, then it should be correct. Would you want your children getting information that was incorrect?
In the end… I think it is great this kid is trying to learn about physics, astronomy, etc. The problem is, he is misinterpreting, and not understanding the underlying affect.
If he truly is interested in learning, then he will look at the differences between his posts and mine, and perhaps take a second look at the information which is correct, and determine where and why he went wrong.
I'm not going to insult every readers intelligence by going into great detail about something like Gaussian Surface when it has no relavence. This is something they can look up on their own and discover it has no place here.
If you wish to believe his writing, then to each his own. In that point of view, then I've taken the time to provide an alternate point of view for someone to consider and study.
January 8th, 2010 at 5:33 am
@ Torbjorn Larsson: N is the number of particles and T is the temperature. There is another form of the gas law pV = nRT, where n = # molecules per mole and R a constant.
@ Aodhhan: Well I will say that in some sense you gave a bit of a complement by calling me a kid. When I look in the mirror the age where I was a kid looks rather distant. I have kids myself.
It is actually becoming very clear that you actually lack much understanding. For instance with E = E' + 2mc^2, the E' is necessary to generate the particle anti-particle pair of mass 2mc^2 in order to conserve the momentum 4-vector U = (-E, p_x, p_y, p_z). This is involved with the threshold energy, where with some calculation you can compute the E’. This is an elementary result of special relativity that every competent physicist knows.
A question was raised about the gravity of the exploding star. That is where the description according to Gaussian surfaces came up. There is nothing wrong with it. Watch before you leap, for it is pretty clear that in dogging me here that you are bearing yourself for everyone to see how ignorant you indeed are.
LC
January 8th, 2010 at 6:53 am
Well… if I am ignorant then I make a pretty good living from it. Yet you're so versed and educated in physics; a loss to the entire community.
To me, the entire syntax of your paragraph doesn't make sense.Nor does it make sense mathematically.
If your E' is necessary to generate the particle pare, then what is the formula solving for E'? I.e., what is the other side of the equation: E'=??????? How is this the same or different from the standard norm, that the particle pairs are created from a neutral boson colliding with atomic nuclei, causing the separation of an electron and positron (thus your pair of opposites)?
…E' is necessary to generate the particle anti particle pair of mass 2mc^2 in order to conserve momentum??? WHAT? In fact, define what E' is. This action have anything to do with the "conservation of linear momentum"?
Then explain "generate the particle pair of mass 2mc^2" I don't even get what you are saying here. Then explain how this conserves momentum, and just what momentum is being coserved?
"…to conserve the momentum 4-vector U=…" Is this some sort of result for a space time diagram? Kind of hard to understand the syntax of the sentence.
So please, almighty physics master, pitance and loss to our community. Please, educate us all and explain.
January 8th, 2010 at 7:09 am
@Aodhhan, you sound like those EU people. Hoding your incompetence behind attacking hoping that they will not discover. Pure BS.
From LBC we learn. It does not mean that he is correct but forces us to check his facts.
"I'm not going to insult every readers intelligence by going into great detail about something like Gaussian Surface when it has no relavence."
Yeah right, and now you are hoping that people are scared to ask the details of the Gaussian Surface to you. So please tell us what this Gaussian Surface is and why it has nothing to do with this article? Show us your intelligence superiority.
January 8th, 2010 at 7:44 am
@ Aodhhan: I place an additional energy E' in there and reference a threshold energy. It takes about a half to one page of calculations to work that out. If people are interested they can look this up or try to calculate it for themselves. It is similar to calculating simple theory of Compton scattering. These are rather short blog posts, not long expositories filled with explicit calculations. The fact that you "don't get what is going on here" betrays the fact you are not deeply educated in physics. This is really, and I mean REALLY, basic concepts.
LC
January 8th, 2010 at 9:14 am
Riggggght.. it would take a half a page. That has never stopped you before. You've created some very long posts. I guess I am right, you just don't know.
At least give us a reference, in which your formula relates to particle pair.
The Compton effect / Compton scattering is very close to what goes on as far as light-matter interaction.That is where the similarity ends. There are 3 basic energy phenomena for light-matter interaction: low, mid, high.
Low energy phenomena is related to the photoelectric effect. Mid-energy phenomena is related to Compton scattering. High energy phenomena relates to Pair production.
From Wikipedia: Compton scattering is a type of scattering that X-rays and gamma rays undergo in matter. The inelastic scattering off electrons in matter results in a decrease in energy (increase in wavelength) of an X-ray or gamma ray photon, called the Compton effect
Part of the energy of the X/gamma ray is transferred to a scattering electron, which recoils and is ejected from its atom, and the rest of the energy is taken by the scattered, "degraded" photon.
Compton scattering is not the major process takign place inside this topics supernova explosion, nor is it what you were going through in your explanations, at least that I could interpret. You cant have a degredation of energy and produce a supernova.
In the case of this type of supernova explosion, photons have an energy exceeding twice the rest mass of an electron (1.022 MeV for photon-nucleus pair production), photon-photon pair production may occur at 511 keV.
In simple terms… the gamma ray photons are far too energetic for compton scattering. Instead the process of "Pair production" takes place.
Per Wikipedia: Pair production refers to the creation of an elementary particle and its antiparticle, usually from a photon (or another neutral boson).
Exactly what I said earlier.
Y-155 is a "Pair-instability supernova"
According to Wikipedia: A pair instability supernova occurs when pair production, the production of free electrons and positrons in the collision between atomic nuclei and energetic gamma rays, reduces thermal pressure inside a supermassive star's core. This pressure drop leads to a partial collapse, then greatly accelerated burning in a runaway thermonuclear explosion which blows the star completely apart without leaving a black hole remnant behind
Wow, imagine that… almost word for word on what I said earlier. (not to mention the article itself).
At no time was compton scattering talked about. In no reference about this type of supernova explosion could I find anything related to compton scattering… and nowhere does it talk about compton scattering and supernovas. Because in short… compton scattering causes a decrease of energy, exactly opposite of what takes place.
Further down the page, Wikipedia even goes into the process of the core being transformed into Nickle-56. Also explaining stellar behavior of different solar mass stars in pair instability conditions.
Now, if you can't follow what is written, and what Wikipedia says (or any other reference on the subject), then there really isn't any hope for you in the short term. Perhaps a good tutor would help.
January 8th, 2010 at 9:20 am
I just said the calculation was similar to a Compton scattering calculation.
LC
January 8th, 2010 at 9:28 am
@Aodhhan
"At no time was compton scattering talked about. In no reference about this type of supernova explosion could I find anything related to compton scattering…"
Have you actually understood what LBC wrote?
"It is ****SIMILAR**** to calculating simple theory of Compton scattering.
But aparently you have a need of wikipedia to copy and paste Aodhhan
January 8th, 2010 at 9:36 am
Aodhhan,
are you kidding us? In fact, you must, otherwise I cannot believe what I read here.
What kind of human being are you that you didn't see that "Compton scattering" was an example.
This means that the calculation of E' (used before) is rather simple, and it takes about half a page to do so. Just LIKE the calculation of the Compton effect. LBC gave the Compton effect as an EXAMPLE of a rather easy calculation, NOT as a process that decreases the supernova energy. There was not any word of him that could have led to such a conclusion! What do you want?
Are you just searching for some words here and then just start to shout some stuff at us, although the words explicitly had nothing to do with the topic?
And what is wrong with E=E'+2mc^2?
Assume m is the rest mass of an electron. Then it is also the mass of the positron. Right? The rest mass of the electron is therefore E_e=m*c^2 and the rest mass of the positron is E_p=m*c^2. So the least energy that is necessary in order to produce a pair of an electron and a proton is E=E_e+E_p=2*m*c^2. Correct?
The problem is, a pair produced by this energy (which would be indeed 1022 keV) would be at rest, and thus annihilate immediately. This not the energy loss process that is needed here.
In fact, we need a little bit of additional energy, let's name it E'. This additional energy will go into the kinetic energy of the created pair. They can now actually move, and thus they can survive for a time that is greater than 0.
So, the energy that is needed here is
E=2*m*c^2+E'.
A pair created from the energy E can survive for a brief period of time, but this period, as short as it may be, is enough to reduce the radiation pressure of the star's core significantly; especially when many pairs are produced simultaneously.
What is wrong with this argument?
January 8th, 2010 at 9:38 am
Ooops, it should read:
"So the least energy that is necessary in order to produce a pair of an electron and a POSITRON is…."
January 8th, 2010 at 9:56 am
@DrFlimmer
Indeed, creating a base pair is not enough, they would instantaneous annihilate since they would collide with each other again.
The additional energy is needed so they can be sent of in space avoiding meeting each other. Until it bumps into another anti-particle.
January 8th, 2010 at 10:11 am
I have a silly question.
Why is it called anti-matter supernova?
My first thought was that it was a star composed of anti-matter. But this is not what the article says.
If I understand correctly the star gets so warm that the the generated gamma rays energy becomes matter-anti-matter so the star somehow cools because of this converting energy in mass so it collapses since it cannot keep its shape. The mass including the matter-anti-matter focusses in the core and a supernova gets triggered.
The confusing part is how is it possible that the anti-matter survives long enough so that the star can collapse. Should it not bump into another particle that converts back to energy so the enery is back?
Or do the anti-matter particles get somehow ejected into space away from normal particles?
January 8th, 2010 at 10:16 am
Of course the full relativistic momentum invariant is
m^2 = E^2 – p^2,
with c = 1, which one needs to really work with.
This little affair is a bit unnerving, for who ever this individual is has targeted me almost exclusively. It started in late December, but this week it ramped up. This makes me suspect this goes beyond physics, but that this individual is somebody who I have known, or know, who has some sort of cyber-vendetta against me. I should blow this off, but then again I can’t let these just go easily. Name calling can have its effect if it is not dealt with.
LC
January 8th, 2010 at 10:21 am
DrFlimmer,
Wow. What you wrote made complete sense. I cannot judge on it's correctness though. I has been years since my undergrad science years and I have not meddled in physics since
As for the Aodhhan fellow, he seems to have some background in physics but I'm guessing that he got stuck along the way and did not advance. Just a hunch. His belligerent attacks are completely out of left field and no need for that tone of voice.
January 8th, 2010 at 10:51 am
@ ND
Thanks, although my explanation was the easy one, and LBC is right that "normally" one has to include the full relativistic equations. But for the sake of argument, mine was enough, I think.
@ Olaf
The name is just due to the fact that anti-matter is involved at all, which is normally not the case. Indeed, you are right, the positron will be annihilated almost the same moment it was produced. But, the "almost" is long enough.
On a "particle physics scale" 10^-16 s is sometimes referred to as being long, so you get a clue.
The critical point here is, that uncountable pairs are produced at the same time, and the short moment, when there is, say, no radiation left over, 'cause it's all in the particles, in that brief moment gravity "takes over" and the star collapses.
The reproduced radiation by the annihilation is probably one point why there is "nothing left" from this supernova. The radiation pressure that suddenly builds up again, is maybe responsible to tear the star apart. But I'm no expert here, and this is just a guess!
January 8th, 2010 at 11:05 am
I am thinking does the mass increases of the star when all gamma rays are converted into matter/anti matter? Or is it equal since the the Gamma rays originates from disappearing matter that gets converted into gamma rays.
DrFlimmer, 10^-16 is long but not nearly long enough for gravity to take over and collapse a star. The mass would only move during this 10^-16 seconds. So I guess the pairs get created and annihilated all the time but the numerous creations add up all those 10^-16 seconds so in the end you do get the collapse.
Just like juggling, the ball is only a fractions of a second in your hand, all the rest of the time it is in the air. The creation of the base pairs are most of the time in the matter/anti matter par than in the gamma ray state.
January 8th, 2010 at 11:12 am
First of all, it isn't Compton Scattering which causes the explosion of a star.Therefore it has no relevence.
In basic terms.. you cannot get enough energy. You might as well use just about any formula which uses e and E.
In compton scattering, a photon is scattering an electron. When this is done it results in a decrease of energy to the photon….recoil, recoil, recoil!
In Pair production a photon is scattering an atomic nucleus, resulting in the release of an electron and positron… thus teh beginning of the wild things I talked about earlier.
Now, which do you think requires more energy, and consequently creates more energy?
Once again.. Compton scatters electrons;
Pair Production scatters atomic nuclei.
Your assumption about m as the rest mass of an electron and positron is a bit humorous. Since when talking about an electron and a positron, you are discussing tada: PAIR PRODUCTION! See why it is funny?
Compton Scattering has nothing to do with positrons.. and vice-versa!!!
Rest mass energy applies in pair production, as there must be enough rest mass energy of the two particles to allow both energy and momentum to be conserved.
So, did I pass your little test, or are you of the same odd thinking as LC?
At my own peril and risk… the following link should enlighten you quite a bit about Compton Scattering, and at least provide you with some answers and formulas. It will also challenge you to really understand it.
http://www.astro.umd.edu/~miller/teaching/astr601/lecture14.pdf
…this is my last post on this subject. Because if you are still in disagreement, then you are too stubborn to learn the correct answers…. and too selfish to admit you are wrong.
January 8th, 2010 at 11:19 am
Think of it this way. The thermal energy of a substance is Q = cT, where c is a heat capacity. Now the heat capacity increases as the number of modes or molecules increases in a unit volume. With the generation of matter-antimatter pairs some of the heat energy goes into generating more particles. This increases the heat capacity. Now if the energy involved in generating e-e^+ pair is not too much, and electrons are 1/500 or so the mass of protons which makes this a safe assumption, then the total heat energy remains the same. So you get
c'T' = cT,
and thus T' = (c/c')T. Now since c' > c this makes T' < T. So the temperature drops, even though the heat energy remains approximately the same. Now use natural gas law and you see the pressure decreases. Gravity now can squash the star further, which again elevates the temperature higher, generating more e-e^+ pairs, increasing the heat capacity and … .
This is a sort of iterative way of looking at it, related to something called an adiabatic process. The material has an equation of state with isotherms and isobars and this can be examined as a single thermodynamic cycle which sums over little units of volume bounded by isotherms and isobars.
LC
January 8th, 2010 at 11:28 am
@ Aodhhan: the energy equivalent of the e-e^+ pair is 2mc^2. I presume you did see the two (2), for the two particles. I said, and this appears to have escaped your attention, the calculation was similar to Compton scattering. I did not say it was the same! The calculation is rather simiilar — similar logic. I don't need a treatise on Compton scattering. I can work out Feynman diagrams for this in Quantum Electrodynamics with the Dirac electron.
LC
January 8th, 2010 at 2:27 pm
Why is Aodhhan still concentrating on something LBC never said? LBC never claimed that there is Compton scattering?
January 8th, 2010 at 3:42 pm
Okay, this Aodhhan guy is annoying. A Google search with a few guesses brought up this page: http://forums.channelregister.co.uk/user/19958/. A few style similarities make me think it may be the same person, but I'm not sure, and his word is probably not trustworthy either way.
Still, LBC, if it helps you figure out who he is and if you know them, awesome.
January 8th, 2010 at 3:48 pm
I conjecture that he has some mental difficulties. His hammering away like this and this insistence about Compton scatter has an almost autistic quality to it. I get a certain sense that he is younger, but if he is older this could be a signature of dementia. He clearly has nowhere the physics knowledge he claims, and his "solutions" to things he claims we, oh woe to us pea-brains, would not believe, so he can't release it This is a classic signature of a crank, and somebody who thinks they are far more competent at something than they really are. It is a form of severe cognitive dissonance.
Well he claims he will not post on this topic. I wish he would not post on any topic. Good riddance to bad rubbish if that happens.
LC
January 8th, 2010 at 4:03 pm
Couldn't resist the irony, from "Faster-Than-Light Pulsar Phenomena" 1-7-10 8:37pm Aodhhan:
"I really don't care if you think I'm a quack or not. One thing is for sure… anything I post is my work, not words cut and pasted from a searched site, or something poorly paraphrased from some site, where the work is done by someone else. Anything I post is well written and easily understood." Nuff said.
I come to UT to learn, discuss and gain perspective on a wide range of astronomical topics. I value commentary from a wide range of people with different backgrounds and knowledge above and beyond the press release basics on a thread. I would hope that any potential poster at this site would not be put off on commenting because of being repeatedly slammed by an anonymous individual. People can disagree without being disagreeable.
January 8th, 2010 at 4:10 pm
I agree LBC, I also thought about autism in Aodhhan.
You apparently say things that does not fit his view of thinking. An Autistic person would freak about such a thing.
The weird thing is that he ignores all the rest of us.
LBC keep up the good work, I do not always understand it all because it is a bit too abstract but it is very informative. It is very interesting to see the formula's in action too.
January 8th, 2010 at 4:25 pm
@LBC:
I wouldn't give this fool another thought. I realize that can be difficult when the attacks become so personal, but like a schoolyard bully, paying them any attention simply stokes further attacks. I find it telling that jokers like this(and Anaconda) are rarely agreed with by the posters on this site that I respect for their knowledge. They are simply lone wolves on the prairie howling into the wind because noone with any sense will pay them any attention. I for one continue to learn from your posts, although with no science background some of it is a bit over my head.
January 8th, 2010 at 5:06 pm
The whole thing was a bit weird, for he kept coming after me. At first I thought he was a physicist with real objections, but that pretty quickly became falsified. I wondered for a while whether this was somebody I know. I wondered if this guy was local and might cause trouble. I don't have any serious enemies that I know of, but then again you never know about that guy you spilled coffee on at a Starbucks last yere — that did not happen BTW.
Popisfizzy posted a UK link, which might mean he resides over there. So maybe there is the problem. I have experience with Britain, and my commentary is that the English are drowning themselves in alcohol — they drink way too much. Alcohol induced dementia?
LC
January 8th, 2010 at 10:35 pm
LBC…
The fact you weren't covering the positron in any of your formulas, should have been the dead give-away for you to realize you were off track.. Especially when you recognized there were a pair of particles.
My problem with you, is people come here to see what is new, and also learn a bit in the process.
Its amazing, that you.. who doesn't have any formal physics training can seemingly know everything about the topic and spew out information as if you've taught it for 3 decades.
However, 70 percent of the time, you use the right words… you just don't use them in the correct context. Which plainly displays you have no idea what you are talking about.
The other 30 percent of the time, you get your cut and paste correct from some website… I'm sure.
The topic here is a perfect example. You were so far off, it was rediculous. What is really hilarious is every time I challenged you to explain yourself, you came up with something else. which seemed realy odd.
Although you did hang onto the thermal dynamic formula for quite a bit. However, you don't seem to understand, that your formula didn't apply in this case. You basically tried to interpolate the formula into a thermonuclear process.
I'm a cosmologist who teaches physics, and I also do consulting part-time with a major aerospace company contracted to the US Air Force.
You still need to learn, that something that works for one thing, doesn't always easily transfer to something else. Even when your logic tells you it should. I.e. the fusion cycle on the sun, isn't the exact cycle which happens in a nuclear reactor, or even with laser fusion.
BTW.. I looked at the link posted. I am not the Aodhhan posting there. I'm squarely in the United States, and do not participate in any website originating in the UK.
I honestly don't care if you believe me or not. However, if you post incorrect information I'm going to challenge it. If I ask a question, I expect an explanation and references… not more formulas and babble.
January 9th, 2010 at 2:32 am
I, for one, am going to believe the guy who has been published and has several books.
And who is being non-anonymous.
On a scientific newsite.
Which is rather well-known.
And posts on another, even better-known website dedicated to science, which is undoubtedly viewed and scrutinized by professionals, whose readership has overlap with this one.
Instead of, you know, the random anonymous guy not making sense.
Just sayin'.
January 9th, 2010 at 5:10 am
@ Aodhhan
Well, dude, if my English is too bad that you can't understand it, then I'm sorry. I thought I was making myself clear enough, but obviously I did not.
For your information, my Master's thesis (that is currently under construction) deals with the inverse Compton effect. Next to this point, the Compton effect is one of THE classical examples a student has to deal with during his studies. The Compton effect is well known to me, thanks!
And, believe it or not, nobody here disputed that the Compton effect has no real role in the this specific supernova process. That's the point.
No, I don't see why this is funny. Electrons and positrons are basically the same. They have just the opposite sign when it comes to their charge. Everything else is the same, so is the mass!
And Compton scattering applies to positron just as it does to electrons. Because the Compton effect does not rely on the charge, just on the mass. That's also the reason why the Compton effect with other particles is negligible. They are just too heavy for the photon to give them a good slap.
Normally, I can admit rather quickly that I was wrong, when I've been proven wrong. I have no problem with that. The thing is, I don't see your point — so, I can't admit my mistake wherever that might have occurred.
January 9th, 2010 at 5:38 am
I doubt that Aodhhan has a great depth of understanding in physics. On the UT blog article on the emission of radiation by a pulsar source faster than light
http://www.universetoday.com/2010/01/06/faster-than-light-pulsar-phenomena/#more-49646
on January 7th, 2010 at 8:37 pm he wrote:
If you imagine this entire system as a wheel, and at the hub of the wheel is the millisecond pulsar, traveling near the speed of light. Think of the radio waves as the curved spokes of the entire system. As they move towards the end of the wheel they are accelerated. Induced by the magnetic waves, they collect to become the outside circumfrance [sic] of the wheel.
So if the pulsar is the hub, moving near the speed of light, the end of the wheel will be moving much faster. In excess of the speed of light [sic].
Since it is commonly known… on a wheel, the outside edge is moving much faster, with the same amount of force than the hub providing the energy. [end quote]
I seriously doubt that somebody who teaches cosmology would write such rubbish. This is something you might expect from a sophomore student.
There are some faster than light cases in general relativity. In the de Sitter cosmology there is a frame dragging effect so that galaxies beyond the cosmological event horizon r = sqrt{3/Lambda}. Lambda = cosmological constant. You get z > 1 redshift of galaxies and the accelerated expansion of space is dragging matter “faster than light.” This is also seen in the Kerr-Penrose frame dragging around rotating black holes. In these cases space can geometriodynamically, to use Wheeler’s term, evolve this way. This does not occur for a pulsar or neutron star, for there needs to be an event horizon.
Compton scattering is on a Feynman graph tree level just one process in a whole set of processes involving how the quantized electromagnetic field interacts with the Dirac electron. The Dirac electron has its pair from the Dirac sea of negative energy states, which with enough energy emerges as the positron. So Compton scattering with the anti-electron is functionally identical to Compton scattering, and it is called I think called Babha-Babha (sp?) scattering.
LC
January 9th, 2010 at 12:19 pm
@Lawrence B. Crowell
I forgot to let you know I've purchased and read your book 'Can Star Systems Be Explored' . I enjoyed the book and the way you describe real-life situations when needed to emphasize the important points and themes of your book.The real-life situations simplified and made understanding your book far easier for people like me not as knowledgeable in physics but still eventually I am able to understand the physics involved in space travel !!! Your book answered many questions/problems lacking in books I've previously read about space travel!!!!!
In this thread, I do not understand why so-and so is attacking you as you do know what you are talking about and reading your posts on many threads over the last few years tells me you know what you are talking about without any reservations!!!!
Take care
January 9th, 2010 at 1:43 pm
Thanks. It is written on a bout a junior level of understanding of physics. This Aodhhan fellow does seem to have some exposure to physics, but his discussions of it are incoherent.
LC
January 9th, 2010 at 4:32 pm
If you think I did such a poor job of explaining it in a fashion most people would understand, then you do better. Lets see just how well you understand it and if you can interpret it to an audience which is not versed in science. This means no cut and pasting other peoples work.
January 9th, 2010 at 4:51 pm
@Aodhhan
"I'm a cosmologist who teaches physics, and I also do consulting part-time with a major aerospace company contracted to the US Air Force."
Again big words but I do not see any proof so far about these claims. You keep on using fuzzy words pretending to know it all but give zero evidence of why we should believe such a claim.
January 9th, 2010 at 6:03 pm
@Lawrence B. Crowell
I am lucky to be able to retire at 55yo 3 years ago as a Network System Administrator for the State of California and did not require I knew that much about Physics like you do. I can now have plenty of time to be a serious amateur astronomer and go to SW Australia
in Dec-Feb every other year to check out the southern skies. I'm always open to learning and doing new things about astronomy and I find these forums and many other sites very informative. I like how you and other very knowledgebles post comments and clarify many interesting science matters
January 9th, 2010 at 6:41 pm
@ LBC:
Thanks, I got that. If you read my comment again then this unfortunate trolling business has stopped taking your time, you will see that I just meant that the ambiguity is confusing at first read, meant as suggestion in kind.
January 9th, 2010 at 8:21 pm
Thanks to all. I think the demon's voice is getting a bit dimmer in recent days. The real problem is that people like him tend to get into elected office. He missed that mark, thank goodnessl.
LC
January 9th, 2010 at 10:07 pm
Yes, I didn't think you could do better.
It is so nice to see a friend or two and probably a second and third login name of yours makes comments to support yourself. LOL
Yet, none of the individuals who are experts do.
January 9th, 2010 at 11:34 pm
Aodhhan,
You've got issues dude. You mentioned that we would not believe your credentials, now we know why you said that.
January 10th, 2010 at 5:04 am
Aodhhan has issues of some sort. This is obsessive, suggesting some sort of OCD problem, or the insistence over Compton scattering might reflect some autistic disorder. He must have skipped his Ritalin pills as a kid. I think he has some exposure to physics, but not much depth. The biggest thing I can judge is that he most likely needs therapy.
LC
January 10th, 2010 at 9:41 am
@ Aodhhan
You clearly are a real dope. I mean you say nothing substantial and still target one person in your posts, article after article. Clearly it is you who seemingly knows nothing about science (let alone cosmology!). An example of this same peculiar behaviour was the December 23rd, 2009 UT article "Blue Stragglers Can Be Either Vampires or Stellar Bad-Boys", where you said;
If this is how you think science and the scientific method works, clearly you know nothing about the subject. (Let alone anything about cosmology, as you claim you do)
[Research, here? Eh, on a blog site? You have got to be kidding me!']
Yet here is a different story, different person, and still the same belligerent attitude in the same wanton and ill-informed manner.This is the same dumb attempt to try and qualify for some kind of quote misplaced superiority, or lack thereof. Target the one with the best knowledge in the group, and try and bury them by attacking and discrediting them – in the very vain attempt to appear as "some kind of equal". I.e. You always counter claim the person is "ignorant"
As to some of mental disorder? Nah, don't quite believe it! More like disappointment that others might just know more than him, and that his self-centred ego is hurting because he knows he can do nothing about it.
However, in the end I think I was quite right when I said; "Sounds more like sour grapes to me!"
January 10th, 2010 at 4:46 pm
I have issues? LOL
Who is the one making personal attacks?
Who is the one who cannot come up with a better solution?
Who is the one who didn't understand the subject?
Who is the one who cuts and paste or makes comments which are totally outside the subject?
Like… your comment about the "Scientific Method". That definitely has nothing to do with making comments. Never would someone apply the "Scientific Method" in a blog.
Another example where you use a word, phrase, or action yet do not use it correctly.
Every time you speak, you just dig a deeper hole.
January 10th, 2010 at 5:49 pm
Your right. You a bigger jackass than I thought.
You know nothing.
January 10th, 2010 at 5:57 pm
@aodhhan
Perhaps you should read Superbright Supernova First Observed of Antimatter Variety before you actually make wild comments like you previous one.
January 10th, 2010 at 6:31 pm
The avXiv paper for this article is Supernova 2007bi as a pair-instability explosion by Gal-Yan, et.al.
As to Aodhhan comment;
This is quite wrong. The nickel mass at the core according to the paper is between 3.7 and 7.4 Solar Masses. If we were to believe you, this is about 40% of the whole stellar mass, when in actuality, the predicted percentage is about 5%-10% (So much for a "good proportion."
Also Ni56 is more associated with the light-curve decay and the brightness of the observed emission lines than "luminosity of the explosion" (whatever that means).
Perhaps you should read the sources instead of quoting dubious sources like Wikipedia?
January 10th, 2010 at 6:54 pm
@ Hon. Salacious B. Crumb:
Good catch on the Nickle 56 thing. This guy actually got this from another UT blog article which mentions this. I didn't bother chasing it down to nail his butt with it. I figured already this guy is a wacko If you are so interested you might chase it down.
It is interested you mention sour grapes, for Aesop's tales are basically observations about cognitive dissonance. He was a psychologist before Freud. Take a look at
http://en.wikipedia.org/wiki/Cognitive_dissonance
The problem is that some people get caught in cognitive dissonace. Mind you we all have these experiences, which can stem from unfortunate emotional experiences to really intellectual questions. Most normal people put these in perspective, and if the problem is sufficiently profound we might call up reason to think about it. Some people get caught in these situations with highly negative emotional content. This continues and they can't address ordinary life without seeing everything around them as some sort of personal assault. So they "counter attack," against everybody, which makes everyone else avoid the guy. Aodhhan is the sort you meet at a party and quickly try to get away from. We have all met these types.
Aohhan is one of the many millions, about 1/4 of people out there, who suffer from mild psychiatric disorders
LC
January 10th, 2010 at 8:26 pm
Yes, that was an error. Probably meant to put in a different scale when I was editing and didn't catch it. Obviously from the scale, I didn't mean it.
At least I can admit an error.
Very good job of catching it.
January 11th, 2010 at 8:15 am
@ Aodhhan
Actually from the meagre amount you have post there are even more errors than I care to mention.
Also you said;
Yet when someone does then you say to me;
So which is it? Why so blatantly contradict yourself?
It seems to me that all information (relevant or not), is unacceptable unless it meets your narrow little worldview,
As for;
Then why say it? Really. Who would make such an obvious mistake? It appears these values you quote were taken from somewhere else, so why didn't you paraphrase it as a quote or give the actual source? (Your thoughts or are they just taken from someone else?)
Clear you will happily wildly criticise and condemn others when you have no idea of what you are taking about yourself!
In a nutshell. All needless hypocrisy just to support your own ego.
January 11th, 2010 at 10:01 am
Oh, come on. This is getting silly. Just like those awful long discussions with "The Snake".
Don't feed the trolls; indeed, this is correct.
January 11th, 2010 at 10:38 am
I agree with DrFlimmer, Aodhhan sounds like a EU-activist. only good in pseudo science and for the rest zero knowledge of real science.
Just ignore him, and back to real interesting stuff LBC.
January 11th, 2010 at 2:40 pm
I dont really like the use of the term "Antimatter Supernova" in the article, as it is a misnomer. Afaik "pair instability supernova" are an accepted term.
January 11th, 2010 at 3:32 pm
Excalibur,
Yes but which works better for public outreach and movies?
Anti-Mater Supernova cahptahn off the starboard, we can get some antimatter with the probe otherwise we'll crash into the planet!
or
Pair instability supernova? Is that like a marriage gone really really bad?
January 11th, 2010 at 3:33 pm
At least Anacond did not claim to be a scientist at his day job.
January 12th, 2010 at 1:37 am
But he claimed to know better, which was/is the critical point. Btw: We should've made a party last week. It's been about one year ago that Snakeman showed up first on BA….. Happy new year
January 12th, 2010 at 6:37 am
Yes cheers! I had a little brandy last night
January 12th, 2010 at 11:47 am
ND,
The problem comes when the public outreach causes more confusion than it explains.
"Antimatter supernova" = a star made of antimatter explodes…