The shock front hit a pre-solar cloud with the mass of our Sun, containing dust, water, carbon monoxide, and molecular hydrogen, and the temperature even reached as high as 1000 degrees Kelvin (726 degrees Celsius). After it cooled, the cloud collapsed and thus the solar system was formed
For several decades, scientists thought that the solar system was formed as a result of a shock wave from a stellar explosion - a supernova - which caused the collapse of a dense gas cloud that contracted to form the sun and the planets. But accurate models of this formation process only work under the premise that the temperature during the violent event remained constant.
Now, astrophysicists at the Carnegie Institution for Space Magnetism have shown for the first time that a supernova could well have caused the formation of the Solar System under the more realistic premise of rapid heating and cooling.
The results, published in the Astrophysical Journal in October, resolved the great controversy.
"Since the 70s, we have had chemical evidence from meteorites that points in the direction of the idea that a supernova caused the formation of the solar system," notes Alan Boss, one of the Carnegie research leaders. "But the devil is in the details. Until now, scientists have not been able to propose a plausible scenario in which the collapse creates the system at the same time that new isotopes are formed from the supernova and thrown into the collapse cloud."
Short-lived radioactive isotopes - remnants of elements with the same number of protons, but a different number of neutrons - found in ancient meteorites decay in a process that takes millions of years and turn into other elements (also known as daughter elements). Finding daughter elements in primitive meteorites implies that the short-lived parent isotopes were formed only about a million years before the meteorites themselves were formed. "One of the parent isotopes, iron-60, can only be produced in large quantities in the powerful nuclear fusion reactors inside massive or evolved stars," explained Boss. "Iron-60 decays to nickel-60, and nickel-60 is found in primitive meteorites. So we know where and when the parent isotope was formed, but not how it got here."
Previous models by Boss and a former colleague in the Department of Magnetism for Prudence Foster showed that the isotope could have settled into the pre-solar cloud if a shock wave from a supernova explosion slowed to 10 to 40 kilometers per second, and the cloud and wave had a constant temperature of about 263 degrees Celsius ( 10 degrees above absolute zero). "These models didn't work if the material was heated by compression or cooled by radiation, and this problem left serious doubts in the community about the possibility that a supernova shock started these events four million years ago," commented Harry Vanhalle, who found the negative result in his doctoral research at the Harvard Center -Smithsonian for Astrophysics in 1997.
Using adaptive hydrodynamics software, FLASH 2.5, designed to handle shock wave fronts, as well as an improved cooling law, the Carnegie researchers considered several scenarios. In all models, the shock front hit a presolar cloud with the mass of our Sun, containing dust, water, carbon monoxide, and molecular hydrogen, and the temperature reached as high as 1000 Kelvin (726 degrees Celsius). In the absence of cooling, the cloud did not collapse. But with the improved cooling law, they found that after 100,000 years the pre-solar cloud was a thousand times denser, and that heat from the shock front was quickly lost, leaving only a thin layer with temperatures close to 1000 Kelvin (726 degrees Celsius). After 160,000 years, the center of the cloud collapsed a million times denser, forming the early sun. The researchers found that the isotopes from the front of the shock wave mixed within the early sun in a manner consistent with their origin in a supernova.
"This is the first time they have created an accurate model for a supernova scenario that causes the formation of the solar system," says Boss. "We started with a small bang, 9 billion years after the big bang."
This research was supported in part by NASA's Solar System Research Headquarters and Planetary Geology and Geophysical Programs and in part by NASA's Astrobiology Institute.
23 תגובות
Higgs:
Let me remind you that there are no proofs in science - there are only refutations.
Failure to converge indicates an error.
This is the purpose of the experiment.
Tell me what is the purpose of your proposal not to do such experiments?
Michael
The convergence will indicate the solution of the system, but who will indicate that the system reflects the fiscal reality.
Higgs:
I repeat. Here we are not talking about something similar to the Riemann hypothesis and nothing similar to it.
Here it is a system of differential equations that constitute the theory, in language terms that describe the assumptions regarding the situation before the formation of the solar system and in a simulation that divides time into short segments as much as the power of calculation allows and follows the approximate movement (according to the equations) of the various components of the system.
It converges to the desired result if and only if the known laws of nature indeed lead the system from the opening state to the desired end state in the desired (recommended) period of time (the one available to the process in reality).
As soon as there is no convergence of this kind, it can be concluded with certainty that:
or the assumed opening conditions are incorrect
Or that the laws of nature that were "triggered" are wrong
In other words - this is an experiment to examine theories exactly according to the best scientific tradition.
Michael
I do not dispute in any way the professional ability of the software engineers, I am sure that the guys are talented.
However, regarding this type of simulation, I will give an example from the mathematical field.
Imagine doing a simulation for the exact housing of the prime numbers or the Riemann hypothesis.
As long as you don't know the legality mechanism behind it, the result can be anything.
Of course, on the other hand, you can start calculating and they have already done it, but I mean that the simulation knows how to go to the infinite domain, but there is currently no direct computational solution for that.
Higgs
I understand that in known systems such as pilot and weather it is possible to correct the simulation until it behaves like in reality.
But the solar system is also a known result, someone did the experiment and if we don't get it at the end of the simulation it means that something in the variables is wrong. Something like reverse engineering of nature but on a computer. After having the source code we try to run it and see if we get the same results.
It's not that we're trying to simulate the accelerator in Zern where we really don't know what the result is and any simulation can be suited to the wishes of the researchers' hearts. That's where the real experiment should be done.
Higgs:
And I assure you that they have enough programmers who are competent enough and with enough experience and your theory simply fails the experimental test.
Michael
From my many years of knowledge of the field, I know how easy it is to navigate the desired result of such simulations. There are many guys who sit in research institutes, get a nice salary, write software like this and nice articles and everyone is happy. It's very nice and I applaud that there will be more like this. But are simulations science. In my opinion, no, because these are simulations and there is no possibility of checking the physical expression they are meant to represent. Which is not the case when it comes to the plane or the weather.
I have nothing against researchers of this kind, I absolutely applaud them, all in all I tried to share my little experience with software systems of this kind. If you were personally offended by this, I apologize.
I still believe that it is impossible to engage in any scientific profession only through simulation without the possibility of testing the thing itself in real experience.
Higgs:
seriously?
You want to tell me that they didn't have a good plan all these years that would result in the desired result?
I'm sorry but it doesn't seem serious to me.
Systems of this type are also used today to predict the climate and they do it quite well.
The number of parameters that can be played with is not so great and not every "game" is legal.
By the way - I have no idea what you are trying to achieve with your words.
Do you want them not to investigate the issue just because we don't have the ability to create a solar system in the lab? Or is your whole intention to say that everyone is not serious and only you are?
for everyone
An hour ago I came back from a busy day at work. I understand that Carnegie Hall was looking for me. Tell them I'm already home.
Besides, it was a tiring day with interesting phone calls. Even, you won't believe it, Avi Blizovsky, the cute manager of our website, called me. I warned him about the article I was about to write and he went on alert.
After coffee I will start responding
bye for now
Sabdarmish Yehuda
point
Sorry if I spoke freely. Any good programmer with enough experience and mathematical knowledge can write a simulation program that will present in a very graphical way any theory that comes to his mind.
And no one will argue with the result or check the correctness of the simulation because there is also no practical way to do it with this kind of data. Building a simulation software for an airplane of a certain model and checking its correctness may cost a large number of man-years. whereas here it is a speculation that is presented through the running of this complex code that represents linear and micro processes on a cosmic scale. There are not enough human years to verify the integrity of such a thing. There is no doubt that the guy who wrote the algorithms and implemented them is a good software engineer, but this is no more scientific work than writing a new computer game.
And for me, science is any raising of this or that speculation and an attempt to verify or disprove it and in the city to expand the initial point of view.
Serious gray cell.
The problem is that in all organizations of this kind there are too many intrigues and waste of energy, too little
Real.
But, of course, as a gray cell, laughing, sad, screaming, genius, senstori...etc.
The internal choice is in your hand..when you find it.
Hugin
Higgs, there is a wide range between truth and eye work.
Simulations must make certain assumptions. in the form of parameters and the operations on them. And this is called the model. No one claimed otherwise. You are just fooling.
And, what is this: "What you and other commenters are producing here is science"? Who even produces science here? It's a fool and it's an idiot. What science is produced here anyway?
What is implied from the article is as if the creation mechanism of the sun is unique and different from the creation mechanisms of other sun-like (main series) stars.
In other words, the model is general for all star-like stars
Sun and only the wording specifically refers to "our" sun
In order to perhaps be more attractive. If that's the case
So how does the new model explain the formation of stars
The ancients, before the formation of the first supernovae?
Michael
This is software with thousands of parameters and millions of variables. This dynamic calculation process is so easily biased enough that a butterfly gets stuck in someone's hair when it is done to bias the results.
Talk to people who wrote such programs.
This is not science but a graphic game. In the same way, the computer can produce music and poetry, but it would never know how to make coffee according to your taste if you tell it to add a little sugar and a lot of milk.
Michael - you spoke well!
The esteemed respondents here, including myself, would not be accepted into any scientific workplace on the specific subject - neither in Israel nor in the world - not to mention publication in respectable newspapers.
And it is better for Yehuda to stick to his pension - not to be dissolved by today's financial instruments...
But he can give nice scientific lectures as part of "Culture for the People" - and I'm really not joking or trying to insult.
And Hugin, etc.: the award of I.G. Nobel for this year you missed - there is another chance for next year, but not in the sciences. in philosophy!!!
In short: how easy it is to criticize real scientists and scientific works that are published in important and mostly well-reviewed newspapers...
And if you've noticed, I myself usually deal with people in my reactions and almost never with issues. Sorry - and I confess: I do not, unfortunately, have sufficient knowledge and education in the subjects of physics and space.
But people I know well..
Hugin:
If so - then so and so...
But it is not so and therefore it is also not correct to conclude that so and so.
If Yehuda could get a salary for his "science", his financial situation would be better.
He himself would jump at the bargain.
The fact that he does not work at the Carnegie Institution is not the result of the hand of chance or my witchcraft.
Higgs:
You have exaggerated.
Even in this article it is easy to see that your accusations are false accusations.
After all, the models didn't give what their developers wanted until recently and people didn't see it as proof of their claim but rather proof of a problem - either in the claim or in the model.
These models are not created in a vacuum (although they deal with events within it). They implement within themselves the behavior on a small scale as studied and studied in detail. It's not just that supercomputers are needed to perform these simulations.
Another exaggeration is of course to call what Yehuda does on the site "science".
Is it to blow up theories that have been disproved for a long time and stick to them against all the evidence and with a fervor that only religion can give is science?
Is it science to dismiss other theories for which there are many confirmations, in vain and without a shred of experimental proof or logical reasoning?
In general - scientific work that almost does not happen here on the site.
Most of what happens here are comments on the scientists' work.
Some of the responses are more learned and some less so, but only a tiny handful of them can boast the title of "science" and even that - with limited responsibility, since it is only a theory and not an experiment.
If so, then it is better not to be enslaved to any establishment.
Not equal, not equal, not equal> In the name: the true inner freedom. Life in its wonders.
That's it, I said again.
Hugin
Sabdarmish Yehuda
What you and other commenters are producing here is science at least on the scale of the Carnegie Institution and the kind of "scientists" behind "theories" such as the current article. The only difference is that nobody pays you a salary for it. However, if you start receiving a salary from this type of institute, you will be sure that they will no longer treat your theories with disdain and will also translate them into other languages.
I think the title "little bang" that came to describe a super nova explosion, is misleading! A super nova is an explosion, during which it is completely different from a reduced big bang.
It's just grabbing a title that has nothing behind it. The solar system did not form from a small bang. point.
Good signature
Sabdarmish Yehuda
point
Those in the field know, I assume you have never written simulation software for fast computers
Sorry for the too free comparison, meaning any theory that creates a picture that fits someone's private belief.
This is psychology not physics. Check how psychological experiments are conducted in order to confirm this direction. For students as for professionals, the end justifies the means.
The programs on their rules are written and analyzed in the best way in terms of the results that will fit the pre-determined presentation.
higgs,
What is the connection? The simulations assume certain simplified situations.
And what are "theories about creationism", there is no such theory.
These simulation software like psychological simulation software fulfill the worldviews and beliefs of their creators. After all, no one has really tested their reliability under controlled conditions.
That's why the theories that seem to come out of these simulations are no less shaky than theories about creationism. These are not proof of anything.