For those interested : Walter Lewin about the birth and death of stars

[William Gaatjes]

For those interested :
Walter Lewin in a video lecture about the birth and death of stars.

http://mitworld.mit.edu/video/158

As a sidenote :
Interesting subject Mr Lewin will mention is Jocelyn Bell.
It reminded me of other crucial figures in history : Gilles Holst and Hannes Alfven.

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

Dame Susan Jocelyn Bell Burnell, DBE, FRS, FRAS (born 15 July 1943), known as Jocelyn Bell Burnell, is a Northern Irish astrophysicist who, as a postgraduate student, discovered the first radio pulsars with her thesis supervisor Antony Hewish, for which Hewish shared the Nobel Prize in Physics with Martin Ryle. She was president of the Institute of Physics from October 2008 until October 2010, and is current interim president following the death of her successor, Marshall Stoneham, in early 2011.

The paper announcing the discovery had five authors, Hewish's name being listed first, Bell's second. Dr. Hewish was awarded the Nobel Prize, along with Dr. Ryle, without the inclusion of Bell as a co-recipient, which was controversial, and was roundly condemned by Hewish's fellow astronomer Sir Fred Hoyle.[1] The Royal Swedish Academy of Sciences, in their press release announcing the 1974 Nobel Prize in Physics,[2] cited Ryle and Hewish for their pioneering work in radio-astrophysics, with particular mention of Ryle's work on aperture-synthesis technique, and Hewish's decisive role in the discovery of pulsars. Dr. Iosif Shklovsky, recipient of the 1972 Bruce Medal, had sought out Bell at the 1970 International Astronomical Union's General Assembly, to tell her "Miss Bell, you have made the greatest astronomical discovery of the twentieth century."[3]

Bell Burnell seems to have no bitterness over not sharing in the Nobel Prize, despite the fact that it was she, having built the four acre radio telescope over two years, who initially recorded and then noticed the anomaly, reviewing 96 feet of paper data per night, and, as she confirmed in the Beautiful Minds programme, had to be persistent in recording and reporting it in the face of scorn from Hewish, who was initially insistent the anomaly was due to interference. She also referred in the programme to meetings held by Hewish and Ryle which she should have been invited to, but was not. After Ryle and Hewish had concocted a 'little green man' intelligent life theory to explain the initial single pulse, further persistent recording and study of the data on Bell Burnell's own initiative revealed the presence of other similar pulses, finally leading to the explanation of them as Pulsars.[16] In an after-dinner speech made in 1977, she had the following to say on the matter (Bell Burnell, J. (1977). "After-dinner speech"):
There are several comments that I would like to make on this: First, demarcation disputes between supervisor and student are always difficult, probably impossible to resolve. Secondly, it is the supervisor who has the final responsibility for the success or failure of the project. We hear of cases where a supervisor blames his student for a failure, but we know that it is largely the fault of the supervisor. It seems only fair to me that he should benefit from the successes, too. Thirdly, I believe it would demean Nobel Prizes if they were awarded to research students, except in very exceptional cases, and I do not believe this is one of them. Finally, I am not myself upset about it -- after all, I am in good company, am I not!

 

[William Gaatjes]

This is interesting : Every once in a while i as an amateur stumble upon something i did not know but it sure is fascinating. It is not new news. The theory is at least 11 years old.
When most people mention the energy source of the sun, it is always mentioned that at the core of the sun fusion takes place. But this theory is about that the core of our sun is a very solid iron core that is falling apart at the subatomic level. Fusion does take place but not at the core. Very violent nuclear reactions take place at the core. I do not understand much of it, but if i understand it correctly, it seems that the higher elements are broken apart by complicated intermediate steps which involves neutrons and the end result is protons and electrons as can be found in the solar wind. Standard model is used here.


A better explanation :

http://news.mst.edu/2003/03/research_suggests_neutron_repu.html

Research by an undergraduate chemistry student at the University of Missouri-Rolla may shed new light on where the Sun gets its energy.

The research, published in the Journal of Fusion Energy, confirms that neutron repulsion is an energy source on the Sun, and may in fact be the major source of energy for most solar power.

The study shows that neutron emission from the Sun may release up to three times as much energy as hydrogen fusion. The paper also supports a UMR chemistry professor's claims that the Sun may have formed from the collapsed core of a supernova.

"Neutron emission in the core of the Sun may trigger a series of reactions that collectively produce the Sun's luminosity and an outpouring of protons and neutrinos from its surface," writes Erin Miller of of Weskan, Kan., a sophomore chemistry major at UMR. Miller co-authored the paper, titled "Neutron Repulsion Confirmed As Energy Source," with Dr. Oliver Manuel, professor of chemistry at UMR, and Aditya Katragada, a graduate student in UMR's chemistry department.

A neutron is one of the fundamental particles that makes up matter. Neutrons act like tiny bar magnets, which can repel one another as do the like ends of two magnets. In their paper, Miller and her colleagues examine the properties of all 2,850 known nuclides (atoms) "to see how the potential energy from interactions between neutrons in the nucleus compares with that generated by the well-known repulsive interactions between positive charges in the nucleus."

The researchers found that the interactions between neutrons "increase the potential energy" and, comparing the energy to that created by positive charges, determined that neutron repulsion "may represent a major source of energy if the Sun formed on the collapsed core of a supernova and neutron-emission from its core triggers a series of reactions that generate luminosity, solar neutrinos, and an outflow of hydrogen in the solar wind."

The fraction of mass converted to energy through neutron repulsion is greater than for uranium fission or hydrogen fusion, the next greatest known sources of energy," says Manuel, who is a nuclear chemist. He adds that neutron repulsion generates more than half of the Sun's energy.

The notion that the Sun formed on the collapsed core of a supernova was introduced by Manuel in earlier papers. Manuel believes a supernova rocked our area of the Milky Way galaxy some five billion years ago, giving birth to all the heavenly bodies that populate the solar system. But the theory goes against the widely-held belief among astrophysicists that the sun and planets were formed 4.5 billion years ago in a relatively ambiguous cloud of interstellar dust.

The paper is dedicated to James-Alan Holt Powers of Richland, Mo., a former UMR nuclear engineering student who died unexpectedly in 2001. He was from Dixon, Mo., and is called in the paper "a student of exceptional talent who entered this university on his 14th birthday from home-schooling" and "was captivated by the information contained in the cradle of the nuclides," one portion of the research discussed in the paper. He died soon after his 17th birthday.

The origin of our solar system.

Main website :
http://www.omatumr.com/index.html


Some important names :
William A Fowler.
http://www.osti.gov/accomplishments/fowler.html

Abstracts in pdf.

http://www.griffith.edu.au/conference/ics2007/pdf/ICS176.pdf


http://www.omatumr.com/abstracts2005/The_Suns_Origin.pdf

 

[William Gaatjes]

To be honest, i had not fully seen the lecture yet. Now i had time to view it and there is something that made me wonder. At time 45.31 in the lecture, Mr Lewin shows a picture of supernova 1987A. This photograph is if i am correct taken with use of the Hubble telescope.

Here is the picture :

The smaller ring seems obvious as matter that is blast away. But the two larger fainter rings, remind me of the explanation of O Manuel and group, primarily the middle picture.
The difference is that the SN1987A supernova is rotated almost 105 degrees clockwise.
But it seems striking. Is it coincidence ? If it is the same, this is the birth of a new solar system perhaps ? Is what we see a rapidly expanding bipolar nebula ?

Here is the wiki :
http://en.wikipedia.org/wiki/SN_1987A

And a larger complete picture :

 

[William Gaatjes]

At time 01:01:23 Mr Lewin explains about binary star systems with 1 normal star(donor) and 1 neutron star(accretor). I was thinking that since the neutron star should have a very large magnetic field, should it not influence the donor star with that magnetic field ? If we look at the CME from our own sun and how this CME matter is guided by the magnetic field lines, then we can safely assume something similar must happen there as well.

A picture of our sun :

A larger picture (NASA /SOHO)

Since we know that a lot of the solar wind is accumulated at the magnetic field lines of our earth (for example Birkeland Currents and amazing situations as described by Hannes Alfven), we can safely assume that this might also happen with a neutron star. It has a very strong gravity field but what is perhaps more important is that it also has an enormous magnetic field. Then perhaps the in the binary star system, by the donor produced solar wind and CME(should be violent and perhaps released only towards the neutron star) is captured by the neutron star and manipulated .

Particles with high speed and strong magnetic fields, that makes me think of this :

It is similar to cyclotron radiation, but generated by the acceleration of ultrarelativistic (i.e., moving near the speed of light) charged particles through magnetic fields. This may be achieved artificially in synchrotrons or storage rings, or naturally by fast electrons moving through magnetic fields in space. The radiation produced may range over the entire electromagnetic spectrum, from radio waves to infrared light, visible light, ultraviolet light, X-rays, and gamma rays. It is distinguished by its characteristic polarization and spectrum.

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

 

[William Gaatjes]

I just watched this great lecture about particles that carry charge and magnetic fields. Much topics are covered and such as the Lorentz factor.
http://en.wikipedia.org/wiki/Lorentz_factor

Since Mr Lewin always uses on the site experiments to show you how it works, you will be able to easily follow it.

It is from MIT (OPENCOURSEWARE) and presented by Walter Lewin.
Lecture 13, moving charges in b fields. Sounds complicated, but just watch it. If you are not being able to follow, just start from lecture 1 and all will fall into place if you are really interested. However, you will have questions that the lectures do not answer, you will have to search for answers to those questions.

http://ocw.mit.edu/courses/physics/...ctures/lecture-13-moving-charges-in-b-fields/

Why this lecture ? I mentioned the cyclotron in the post above. And this topic will be explained. Now the interesting part will be when the particles according to calculation (very high energy) should move faster then the speed of light in a vacuum but this of course cannot be. Thus the lorentz factor is used to adjust the calculation.

I may be wrong about this, but here the interesting story begins about how electrons can generate EM waves ? And how perhaps other particles can produce novel effects and radiation. If i am right, i am understanding it( yay for the amateurs).

EDIT:
I forgot to mention that also a very good and simple explanation about mass spectrometers is given.

 

[Ghiedo27]

Any time to accelerate a charge you get EM radiation. Or are you implying something else?

As a side note, this link has a nicely condensed overview of EM wave production.

 

[William Gaatjes]

Any time to accelerate a charge you get EM radiation. Or are you implying something else?

As a side note, this link has a nicely condensed overview of EM wave production.

Great is it not. ^_^
IMHO :
You give it more energy, and for a short moment ripples appear. Ripples like a soliton. Em radiation.

There is something that puzzles me.
I wonder if the calculations keep track of different states at different times or just integrate all events into a single event.

 

[William Gaatjes]

Any time to accelerate a charge you get EM radiation. Or are you implying something else?

As a side note, this link has a nicely condensed overview of EM wave production.

Acceleration of a charge in a magnetic field. Yep. But also deceleration ?
It explains at least nicely why a sinusoidal movement is ideal. There is always acceleration and deceleration in a sinusoidal movement. And at a repetition rate linked to the frequency.

 

[Ghiedo27]

You lost me. Any time you accelerate a charge you generate a magnetic field, yes? And deceleration is just acceleration in a negative direction (which is only negative in relation to the coordinates you have chosen). Maybe this is just over my head.

 

[William Gaatjes]

You lost me. Any time you accelerate a charge you generate a magnetic field, yes? And deceleration is just acceleration in a negative direction (which is only negative in relation to the coordinates you have chosen). Maybe this is just over my head.

I am confused now myself also.
I thought i understood it.
Charges such as an electron, accelerating or decelerating produce EM radiation.
But charges moving i assume at constant speed also produce EM radiation when deflected by a magnetic field.

And then there is the issue of the electron moving very slowly( nowhere near the speed of light in vacuum or close to the speed of light in vacuum.

I think i need sleep.

 

[Sunny129]

I am confused now myself...Charges such as an electron, accelerating or decelerating produce EM radiation.
But charges moving i assume at constant speed also produce EM radiation when deflected by a magnetic field.

you're overlooking the fact that not all bodies that move with a constant speed are non-accelerating bodies. recall that by definition, acceleration is a change in velocity, and that by definition, velocity is a speed AND a direction. a change in either (or both) component(s) of velocity results in an acceleration. so if a charge is moving at a constant speed while being deflected by a magnetic field, it is moving at a constant speed but changing direction at the same time, and is therefore accelerating. so it is still the acceleration of the charge that causes it to emit EM radiation.

 

[William Gaatjes]

you're overlooking the fact that not all bodies that move with a constant speed are non-accelerating bodies. recall that by definition, acceleration is a change in velocity, and that by definition, velocity is a speed AND a direction. a change in either (or both) component(s) of velocity results in an acceleration. so if a charge is moving at a constant speed while being deflected by a magnetic field, it is moving at a constant speed but changing direction at the same time, and is therefore accelerating. so it is still the acceleration of the charge that causes it to emit EM radiation.

You are right. IIRC It is as simple as turning around a corner with sufficient speed. Forces act upon you. Was that not inertia ? Everything wants to keep moving in the same direction ?

 

[Sunny129]

You are right. IIRC It is as simple as turning around a corner with sufficient speed. Forces act upon you. Was that not inertia ? Everything wants to keep moving in the same direction ?

yes, that's the basic idea. inertia is an object's tendency to maintain a constant velocity (constant speed AND constant direction), whether that velocity is zero or non-zero, unless acted upon by a force. in the case of a charge moving through a magnetic field, a magnetic force is applied to the charge, thus causing it to change direction. in the case of our planet, a gravitational force is applied to our planet (by the sun), again causing it to change direction. this form of acceleration is known as centripetal acceleration, as it implies acceleration induced by a change in direction, and not necessarily a change in speed.

 

[Ghiedo27]

If you really want to up the brain implosion factor, consider an electron in orbit. Continuously accelerating, only puts out EM radiation when it moves to a lower orbit.

 

[William Gaatjes]

If you really want to up the brain implosion factor, consider an electron in orbit. Continuously accelerating, only puts out EM radiation when it moves to a lower orbit.

Orbits are not the way. Try my avatar. It is a "picture" taken from an electron. (Not really, it is a laser diffraction IIRC.)
Electrons are not really orbiting in my view. I always believed it more to be volumetric spherical waves. 3D. It is more difficult to keep track of everything but it gives more bliss when you can glance it for just a few seconds.

 

[Ghiedo27]

Regardless of which side of wave-particle duality you're on there is motion. And if they do move, then there has to be acceleration so they don't just fly off of the nucleus. Even as a standing wave any portion other than the nodes has to be a moving charge, yes?

 

[Sunny129]

Regardless of which side of wave-particle duality you're on there is motion. And if they do move, then there has to be acceleration so they don't just fly off of the nucleus. Even as a standing wave any portion other than the nodes has to be a moving charge, yes?

i don't know...are you absolutely sure there is motion? there is certainly a change in position, but does that absolutely imply motion? even at the quantum level? even if one is of the "waves are particles" opinion, it is still generally accepted that electrons do not orbit the nucleus in the same sense that the planets orbit the sun. if electrons do not orbit the nucleus (and consequently do not experience centripetal acceleration), then how do they exist without being massively attracted to, and accelerated radially toward, the positively charged nucleus? and how do they manage to "exist" in this way without creating EM radiation?

i'm not sure that this paradox has been explained by anything other than quantum theories themselves. for instance, some quantum theorists believe that electrons can exist at a particular location about the nucleus of an atom at any given instant, and then reappear at another location the very next instant. whether or not some arbitrary length of time passes between the disappearance of an electron at one location and the reappearance of the same electron at another location, i don't know. the passage of time would of course imply motion, even if we didn't actually see the electron move from one location to another. and intuition tells us that an object can't just instantaneously move from one location to another. but we can't just rely on intuition here for the same reason we can't rely on intuition with relativity theory - your intuition can often mislead you. as hard as it may be to imagine, some very strange things can happen at the quantum level. and while everything in my experience tells me that objects cannot traverse distances instantaneously, i wouldn't just eliminate it from being a possibility in the quantum world. besides, an electron is far from an ordinary "object."

i'm not saying i firmly support the theory. i'm as skeptical as the next theorist...heck, i don't even know how accurately i recalled the theory. but i'm not sure how else to explain how an electron bound to a nucleus only emits EM radiation when it jumps down to a lower energy level, and not during its stay at any particular energy level.

 

[William Gaatjes]

When having always interesting discussions with my friend and colleague,
we where wondering about something.

Gravitational redshift , pulsars and the very strong magnetic field of neutron stars.

A bit of explanation behind the theory :
A pulsar is a neutron star that rotates very fast and produces a more or less focused beam of EM radiation. IIRC, usually this is hard x rays but i am not sure. IIRC, gravitational redshift is the effect that when an electromagnetic wave, is produced on a body with a strong gravitational field, that to an weakens in strength over distance. This weakening of the gravitational field means that the electromagnetic wave increases in wavelength. The EM wave becomes red shifted.

See picture :

Wiki for full explanation. For a better explanation, please google or ask an expert in the field.
http://en.wikipedia.org/wiki/Gravitational_redshift


Here is the question :
Since the EM waves of a pulsar originated on the surface of the neutronstar, and since the neutron star has an immense power full gravity field, then the EM wave that is traveling from the neutron star should undergo a strong gravitational red shift yes ? At least that makes sense. How do we know what the redshift is and what the wavelength originally was ? Because this would give clues to calculate the strength of the gravitational field yes ?
Is this not already done ( I assume of course it already is) ?

 

[Sunny129]

Since the EM waves of a pulsar originated on the surface of the neutronstar, and since the neutron star has an immense power full gravity field, then the EM wave that is traveling from the neutron star should undergo a strong gravitational red shift yes ?

this is correct.

How do we know what the redshift is and what the wavelength originally was ? Because this would give clues to calculate the strength of the gravitational field yes ?
Is this not already done ( I assume of course it already is) ?

unfortunately i'm not familiar enough with any of the scientific techniques used to make these kinds of calculations, but they do exist, and the gravitational red shift can be calculated for any gravitating body. i would imagine that gravitational red shift is simply a function of a body's gravitational attraction, which can be calculated easily enough if you have the data required to calculate it. needless to say, i would have to imagine that scientists have known how to calculate gravitational red shifts since the advent of General Relativity, or perhaps shortly after.

 

[William Gaatjes]

I had been looking around for a short moment, but i found just numbers of the gravitational strength field that looked to much alike and to vague and to much media marketing.

Here is what i am wondering about : :hmm:
Because i was thinking that if for example a hydrogen atom would fall onto the surface, it would have been taken apart already by the magnetic field i assume before the electron and proton (i do not really think we can speak of such sub particles at such an event). That there would be no hydrogen spectral line.
There would be cyclotron radiation i assume because of the greatly accelerated electrons and accelerated protons in magnetic fields. I wonder how would you know the strength of the magnetic field ? The speed of the electrons and protons if still existing ? Are there not a lot of unknowns here ? There has to be a lot of assuming i presume.

The magnetic field is not known. The gravitational field is an estimate.
The acceleration of the charged particles ?

We do know the charge and the mass of the particles. But we do not know the acceleration. From surrounding objects an estimation can be made of the gravitational field. But i have come to understand there is a baryonic mass and a gravitational mass, which both differ. But i assume the gravitational mass is calculated from the gravitational field. We know the EM radiation, but we do not know the exact gravitational redshift to determine the original wavelength ? It does look like a lot of formulas can be substituted with each other.