Re:"The magnetic field lines are clearly visible.
on
Sunspots Return
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· Score: 1
Exactly. The don't move, the simply align with the field. The direction the face is based on the direction of the field at the position of the filing itself. Think of each filing as a compass needle that points in the direction of the field at any point.
Unfortunately, iron filings themselves make for a difficult example other than showing the field. You are right, they become magnetized themselves via induction. The actual physics of the situation changes due to the small changes to the field. However, a sufficiently strong magnet will override any field cause by the filings themselves. Also, remember that the filings are each a "bar magnet" if you will and have a north and south pole which of course point toward each other (via attraction) which tends to cancel out many of the first order effects of the filings.
Your assumption of the filings moving and forming into lines however is incorrect. If you look closely, the filings don't all lie on a line, but simply close together. You're assumption of the effects that the filings have on each other is good though and this tends to cause the "gaps" you often see in pictures of magnets and filings (such as here.
You are also very correct in what you see is actually the OPPOSITE of what the "lines" themselves are doing. As the strength of the field increases, the "lines" get closer together while far from the magnet the lines are further apart. This is evident in the picture in the link above.
Also, you could set up an experiment where you had say some number of filings spread out nearly uniformly (as much as possible). When the magnet was applied, the filings would "spin" and align with the field (magnetic and the induced field). If you took a picture and did the experiment again, you would see a completely different "view" of the filings.
Good call... I'd give you an 'A':)
Re:"The magnetic field lines are clearly visible.
on
Sunspots Return
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· Score: 1
Oops - I should have said that a field is a continuous function in 2 or 3 dimensions but a line is not... a line is continuous in 1 dimension (essentially a line is a 1-D field).
Re:"The magnetic field lines are clearly visible.
on
Sunspots Return
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· Score: 2, Informative
That is one way to think about it but that isn't entirely correct. A line is a discrete mathematical construct. A field is a continuous function but a "line" is not. Think about it this way: let's say you have a piece of paper and some "string". You place several piece of string on the paper. There is "space" in between the pieces of string. You then proceed to add pieces of string in between the others. You can continue to do this ad infinitum (assuming smaller and smaller pieces of string) but they will never match the piece of paper, i.e. the continuous field. They can approximate it but it will never be the same.
In this way, the magnetic field "line" is a mathematical construct used to determine topology. Electric field lines and gravity field lines are much the same thing. There is nothing wrong with saying "magnetic field line" save that iron filings or plasma or whatever is not on a line but in a field. They can be used to visualize the field, so to speak.
Re:It's actually not much of a sunspot group.
on
Sunspots Return
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· Score: 4, Interesting
As a space physicist, I agree. Certainly we have seen an increase in the number of sunspots in the last month but most die out rapidly. However, other solar activity, such as corona holes (of which there are two) are becoming more common. The current set of holes should cause activity at the Earth on or about the 12th of July.
Re:"The magnetic field lines are clearly visible.
on
Sunspots Return
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· Score: 1
Magnetic field LINES are a mathematical construct. The magnetic field is real. Iron filings and plasma etc simply flow in the field. If there were lines, what would be between the lines? There could not be more lines. Therefore it is a continuous field. Iron filings simply represent that field.
Plasma on the other hand is an entirely different case because it is made up of charged particles. Plasma is therefore affected by the electric field as well as magnetic field. In fact, plasma flows with the rules of magnetohydrodynamics.
Re:"The magnetic field lines are clearly visible.
on
Sunspots Return
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· Score: 1
Magnetic field LINES are a mathematical construct. The magnetic field is real. Iron filings are just a way to visualize it. If there were "lines" then what would be in the space between them - couldn't be magnetic field lines... The magnetic field is continuous, therefore no lines.
Fortran is very important in the world of modelling and high speed computation. When I was an undergrad Fortran was taught for the physical sciences but the computer science dept refused to teach it so it was being taught by some geophysical modellers. I'm not sure that the university even offers Fortran anymore.
However, frustrated by that, the dept of physics and astronomy now has two courses in computational physics (both in Fortran) taught by modellers from the department. They deal with real world issues (well, real world modelling issues when applied to a spherical cow right?). Only one course is mandatory but both courses are very popular.
For myself, I use several modelling programs that are purely Fortran that I've had problems dealing with. I'm glad I did take a bit of Fortran though I am much more fluent in other languages these days. In fact my wife, in the private sector, has proprietary software that they use for modelling digital elevations and gravity fluctuation that is written purely in Fortran as well - simply for speed. Until someone invents a real quantum computer, I don't think Fortran in the physical sciences is going anywhere.
... an old VAX machine from the mid-80's. We have several large spool tape drives around too, but I'm not sure they still work. Personally my wife made me throw out most of my old stuff, though I have several old floppies from my Apple II from the early 80's.
Having written both my theses in LaTeX I could not imagine trying to do half the things I did in LaTeX in Word. Most importantly, I have a style that allows me to switch from my full thesis style required by my university, to a nice book style, and also a small paperback style all with the stoke of a key (just need to comment the proper lines).
Since all my computers except my laptop run linux, I never had the choice of Word. However, even using my laptop I find myself writing in LaTeX before using word for anything remotely technical. If I need to spin off a quick document such as a meeting agenda, then I use word (or open office) but otherwise it is LaTeX for me.
As far as journals, they "prefer" LaTeX files. In fact many conferences I go to require plain text or LaTeX files for the submitted abstracts. Go figure who will win this war - in the science world anyway.
It may seem defeatist to you, A.C., but it is important to understand the marketplace when starting a new business. While I applaud his efforts and back him 100% in trying to provide something useful to the locals, you have to understand how your business is going to function in its environment. Good ideas, while the basis of entrepreneurship, aren't all that's required. Many businesses have been sunk over the years by bigger or monetarily stronger companies who do they same job (more or less) but in a shoddy way or charge the customers prices that are outrageous because no one is doing it better. When someone tries to do it better, they bring in the high-priced suits to slow down or stop the competition and the little guy generally gets squeezed out. It's unfortunate but that's business.
Seems the big ISPs don't really want your kind in the broadband business. Watch what happens when good ideas meet greed - i.e. Greenlight providing competition to the greedy last mile ISPs.
What is preventing anyone from rescanning the books or getting a similar agree? Personally, I often scan important journal articles that aren't already electronic and often chapters of books that are popular amongst researchers yet hard to find.
You do realize that if your suggestions were taken into account, it is likely that important bills would not get passed because it would take FAR too long to do so. For example, bills to amend the criminal code or a bill for protecting the Arctic waters from pollution.
I certainly agree with your third point however. The bill should only deal with 1 subject matter and amendments to the bill should only be related to that subject matter.
I'm sure my parents wouldn't use 5GB a month... my mom uses it to print her pictures and my dad uses it for work (i.e. writing word documents and sending the odd email) in the evening if he needs to get something done.
After reading that paper and a couple of others, it appears that there are some significant difference between CME-SEP (Solar Energetic Particle) events and Impulsive Flare - SEP events like the one described in the paper you mention (this paper talks about the difference).
My understanding is the CME-SEP events follow the standard view of IMF frozen-in conditions with the solar wind, though the solar wind can be as high as ~2000 km/s (or perhaps as high as 5000 km/s estimated for the Carrington event). The Flare-SEP is different as the ions/electrons have a different acceleration mechanism from the type of formation of the solar flare. These events cause "beams" of only high-energy particles (and associated X-ray and Gamma-ray bursts) such as you noted, but no IMF fields that would accompany them which would be what causes the strong currents in the power grids.
The magnetosphere should protect the majority of the Earth from bombardment of this particles (except the areas that are connected to the solar fields via open field lines) though it would certainly cause the magnetosphere to become highly disturbed.
You are right, however, as the amount of radiation (gamma and x-ray) that is output from such flares would be highly dangerous to the people on the ISS, surface of the Moon or travelling to Mars. There are projects that are attempting to examine how to protect people from such effects for extended missions.
I'm interested to see the affects of this on the magnetosphere so I'm going to investigate further.
I guess there are different criteria. Personally, while you are correct in saying the observation of a reversed-polarity sunspot likely constitutes the "start" of the cycle, I'm more of the opinion that a cycle "starts" with an increase in solar activity.
Recent (very recent - like in the last week) solar activity in the form of high speed solar wind flows may signal a start of stronger solar activity beginning. This maybe what I would consider the "start" of the next solar cycle.
Indeed, there are some here in my research group that are spelling the doom-n-gloom, as you put it, of a new Little Ice Age. I personally doubt that this is the case but it is not unheard of in the sunspot record to have a very low sunspot count in between to larger cycles. It is far to premature to say anything about a new Maunder Minimum to be sure.
Actually, the optics from the solar flare would reach the satellite or Earth well before the effects would. The average speed for the solar wind is about 400 km/s and up to 1000 km/s during severe conditions (think hurricane). Therefore the effects of the flare, CME, or other detected solar event would not reach the Earth for quite some time after.
It may be possible that you are assuming that the EM field from the Sun would travel at the speed of light. Well, the interplanetary magnetic field (IMF) which would be part of the event's effect, is "frozen-in" to the solar wind plasma and travels at the same rate of speed as the solar wind. (See Baumjohann and Treumann,"Basic Space Plasma Physics", Imperial College Press, 1997 pg. 76 as an example)
Yes - also a good site is Space Weather Prediction Center. It monitors several instruments including pictures of the Sun, GOES X-ray, ACE, ground and satellite information in near real-time and current and past solar conditions.
Interesting idea but not feasible with the power system as currently built. This would especially be a large electromagnetic field enveloping a very large portion of the power grid. New technology would have to be developed to even understand HOW to capture this power.
Y2K is nothing compared to what this could do. Y2K affected only computers - and only specific computers running specific software. This could take out the entire electrical grid for a very long time in some countries or very large regional areas.
Not irrelevant at all. Like watching your satellite TV or using your GPS when you get lost? Better hope that we begin to understand space weather so that precious satellites can be "switched off" or set into a protected mode to protect any of its electronics.
This is a link to an article from Jan 2008. In reality, the new solar cycle has not started. Although in the last month there has been some activity which may indicate that the cycle is starting. Given that this cycle is nearly 2 years late starting (not unusally for it to not be exactly 11 years but 2 years off is pretty large).
As a space physicist, I eagerly await the next solar cycle though it appears it maybe muted and the smallest of the last few.
While that's true, as a space physicist ACE is the primary satellite used in studying the solar wind and IMF which are the primary driver for space weather. Also, I'm not sure where this 15 minute number came from but in general, the solar wind takes about 60 minutes at a velocity of about 400 km/s to reach Earth. Real time ACE measurements would take much less than this. It would be the dissemination of the information that would take the longest.
Other warning systems are beginning to be developed based on solar observations but they are not as well defined at this point and not nearly as quantitatively accurate. If we can actually develop good predictors based on optical observations, it would take 8 minutes for the light to arrive at Earth but much more time for the actual solar effects.
Many power companies have learned there lessons from events such as the Quebec blackout and heeding warns given by space physicists in developing safety systems. These safety systems will protect against most solar events but it would be unlikely to survive a massive event such as the Carrington event.
Very true. But, if others don't step up this could be an issue. The gov't mandate for the NIH funded research publications goes a long way towards pushing the publishers in the right direction. If further pressure by a big body like the NSF would do something similar, I think that publishers would have little choice.
Of course, to compensate for the control of the copyright, they would likely charge more for actually publishing in the journals. That is something that I think they could get away with doing if the granting agencies were mandating the publishing of funded research.
P.S. Thanks for reminding that it is the journal's impact score (I could not for the life of me remember what they were called this morning)
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Exactly. The don't move, the simply align with the field. The direction the face is based on the direction of the field at the position of the filing itself. Think of each filing as a compass needle that points in the direction of the field at any point.
Unfortunately, iron filings themselves make for a difficult example other than showing the field. You are right, they become magnetized themselves via induction. The actual physics of the situation changes due to the small changes to the field. However, a sufficiently strong magnet will override any field cause by the filings themselves. Also, remember that the filings are each a "bar magnet" if you will and have a north and south pole which of course point toward each other (via attraction) which tends to cancel out many of the first order effects of the filings.
Your assumption of the filings moving and forming into lines however is incorrect. If you look closely, the filings don't all lie on a line, but simply close together. You're assumption of the effects that the filings have on each other is good though and this tends to cause the "gaps" you often see in pictures of magnets and filings (such as here.
You are also very correct in what you see is actually the OPPOSITE of what the "lines" themselves are doing. As the strength of the field increases, the "lines" get closer together while far from the magnet the lines are further apart. This is evident in the picture in the link above.
Also, you could set up an experiment where you had say some number of filings spread out nearly uniformly (as much as possible). When the magnet was applied, the filings would "spin" and align with the field (magnetic and the induced field). If you took a picture and did the experiment again, you would see a completely different "view" of the filings.
Good call... I'd give you an 'A' :)
Oops - I should have said that a field is a continuous function in 2 or 3 dimensions but a line is not... a line is continuous in 1 dimension (essentially a line is a 1-D field).
That is one way to think about it but that isn't entirely correct. A line is a discrete mathematical construct. A field is a continuous function but a "line" is not. Think about it this way: let's say you have a piece of paper and some "string". You place several piece of string on the paper. There is "space" in between the pieces of string. You then proceed to add pieces of string in between the others. You can continue to do this ad infinitum (assuming smaller and smaller pieces of string) but they will never match the piece of paper, i.e. the continuous field. They can approximate it but it will never be the same.
In this way, the magnetic field "line" is a mathematical construct used to determine topology. Electric field lines and gravity field lines are much the same thing. There is nothing wrong with saying "magnetic field line" save that iron filings or plasma or whatever is not on a line but in a field. They can be used to visualize the field, so to speak.
As a space physicist, I agree. Certainly we have seen an increase in the number of sunspots in the last month but most die out rapidly. However, other solar activity, such as corona holes (of which there are two) are becoming more common. The current set of holes should cause activity at the Earth on or about the 12th of July.
Magnetic field LINES are a mathematical construct. The magnetic field is real. Iron filings and plasma etc simply flow in the field. If there were lines, what would be between the lines? There could not be more lines. Therefore it is a continuous field. Iron filings simply represent that field.
Plasma on the other hand is an entirely different case because it is made up of charged particles. Plasma is therefore affected by the electric field as well as magnetic field. In fact, plasma flows with the rules of magnetohydrodynamics.
Magnetic field LINES are a mathematical construct. The magnetic field is real. Iron filings are just a way to visualize it. If there were "lines" then what would be in the space between them - couldn't be magnetic field lines... The magnetic field is continuous, therefore no lines.
Fortran is very important in the world of modelling and high speed computation. When I was an undergrad Fortran was taught for the physical sciences but the computer science dept refused to teach it so it was being taught by some geophysical modellers. I'm not sure that the university even offers Fortran anymore.
However, frustrated by that, the dept of physics and astronomy now has two courses in computational physics (both in Fortran) taught by modellers from the department. They deal with real world issues (well, real world modelling issues when applied to a spherical cow right?). Only one course is mandatory but both courses are very popular.
For myself, I use several modelling programs that are purely Fortran that I've had problems dealing with. I'm glad I did take a bit of Fortran though I am much more fluent in other languages these days. In fact my wife, in the private sector, has proprietary software that they use for modelling digital elevations and gravity fluctuation that is written purely in Fortran as well - simply for speed. Until someone invents a real quantum computer, I don't think Fortran in the physical sciences is going anywhere.
... an old VAX machine from the mid-80's. We have several large spool tape drives around too, but I'm not sure they still work. Personally my wife made me throw out most of my old stuff, though I have several old floppies from my Apple II from the early 80's.
Having written both my theses in LaTeX I could not imagine trying to do half the things I did in LaTeX in Word. Most importantly, I have a style that allows me to switch from my full thesis style required by my university, to a nice book style, and also a small paperback style all with the stoke of a key (just need to comment the proper lines).
Since all my computers except my laptop run linux, I never had the choice of Word. However, even using my laptop I find myself writing in LaTeX before using word for anything remotely technical. If I need to spin off a quick document such as a meeting agenda, then I use word (or open office) but otherwise it is LaTeX for me.
As far as journals, they "prefer" LaTeX files. In fact many conferences I go to require plain text or LaTeX files for the submitted abstracts. Go figure who will win this war - in the science world anyway.
It may seem defeatist to you, A.C., but it is important to understand the marketplace when starting a new business. While I applaud his efforts and back him 100% in trying to provide something useful to the locals, you have to understand how your business is going to function in its environment. Good ideas, while the basis of entrepreneurship, aren't all that's required. Many businesses have been sunk over the years by bigger or monetarily stronger companies who do they same job (more or less) but in a shoddy way or charge the customers prices that are outrageous because no one is doing it better. When someone tries to do it better, they bring in the high-priced suits to slow down or stop the competition and the little guy generally gets squeezed out. It's unfortunate but that's business.
Seems the big ISPs don't really want your kind in the broadband business. Watch what happens when good ideas meet greed - i.e. Greenlight providing competition to the greedy last mile ISPs.
All I have to say is - good luck!
What is preventing anyone from rescanning the books or getting a similar agree? Personally, I often scan important journal articles that aren't already electronic and often chapters of books that are popular amongst researchers yet hard to find.
You do realize that if your suggestions were taken into account, it is likely that important bills would not get passed because it would take FAR too long to do so. For example, bills to amend the criminal code or a bill for protecting the Arctic waters from pollution.
I certainly agree with your third point however. The bill should only deal with 1 subject matter and amendments to the bill should only be related to that subject matter.
I'm sure my parents wouldn't use 5GB a month... my mom uses it to print her pictures and my dad uses it for work (i.e. writing word documents and sending the odd email) in the evening if he needs to get something done.
I think my "basic" plan has a cap around 60GB/month for $35 CDN. There are still several residential plans above mine where the caps are over 100GB.
I looked at the a bunch of data and some of it is quite interesting. If you'd like a run down, send me an email.
After reading that paper and a couple of others, it appears that there are some significant difference between CME-SEP (Solar Energetic Particle) events and Impulsive Flare - SEP events like the one described in the paper you mention (this paper talks about the difference).
My understanding is the CME-SEP events follow the standard view of IMF frozen-in conditions with the solar wind, though the solar wind can be as high as ~2000 km/s (or perhaps as high as 5000 km/s estimated for the Carrington event). The Flare-SEP is different as the ions/electrons have a different acceleration mechanism from the type of formation of the solar flare. These events cause "beams" of only high-energy particles (and associated X-ray and Gamma-ray bursts) such as you noted, but no IMF fields that would accompany them which would be what causes the strong currents in the power grids.
The magnetosphere should protect the majority of the Earth from bombardment of this particles (except the areas that are connected to the solar fields via open field lines) though it would certainly cause the magnetosphere to become highly disturbed.
You are right, however, as the amount of radiation (gamma and x-ray) that is output from such flares would be highly dangerous to the people on the ISS, surface of the Moon or travelling to Mars. There are projects that are attempting to examine how to protect people from such effects for extended missions.
I'm interested to see the affects of this on the magnetosphere so I'm going to investigate further.
I guess there are different criteria. Personally, while you are correct in saying the observation of a reversed-polarity sunspot likely constitutes the "start" of the cycle, I'm more of the opinion that a cycle "starts" with an increase in solar activity.
Recent (very recent - like in the last week) solar activity in the form of high speed solar wind flows may signal a start of stronger solar activity beginning. This maybe what I would consider the "start" of the next solar cycle.
Indeed, there are some here in my research group that are spelling the doom-n-gloom, as you put it, of a new Little Ice Age. I personally doubt that this is the case but it is not unheard of in the sunspot record to have a very low sunspot count in between to larger cycles. It is far to premature to say anything about a new Maunder Minimum to be sure.
Actually, the optics from the solar flare would reach the satellite or Earth well before the effects would. The average speed for the solar wind is about 400 km/s and up to 1000 km/s during severe conditions (think hurricane). Therefore the effects of the flare, CME, or other detected solar event would not reach the Earth for quite some time after.
It may be possible that you are assuming that the EM field from the Sun would travel at the speed of light. Well, the interplanetary magnetic field (IMF) which would be part of the event's effect, is "frozen-in" to the solar wind plasma and travels at the same rate of speed as the solar wind. (See Baumjohann and Treumann,"Basic Space Plasma Physics", Imperial College Press, 1997 pg. 76 as an example)
Yes - also a good site is Space Weather Prediction Center. It monitors several instruments including pictures of the Sun, GOES X-ray, ACE, ground and satellite information in near real-time and current and past solar conditions.
Interesting idea but not feasible with the power system as currently built. This would especially be a large electromagnetic field enveloping a very large portion of the power grid. New technology would have to be developed to even understand HOW to capture this power.
Y2K is nothing compared to what this could do. Y2K affected only computers - and only specific computers running specific software. This could take out the entire electrical grid for a very long time in some countries or very large regional areas.
Not irrelevant at all. Like watching your satellite TV or using your GPS when you get lost? Better hope that we begin to understand space weather so that precious satellites can be "switched off" or set into a protected mode to protect any of its electronics.
This is a link to an article from Jan 2008. In reality, the new solar cycle has not started. Although in the last month there has been some activity which may indicate that the cycle is starting. Given that this cycle is nearly 2 years late starting (not unusally for it to not be exactly 11 years but 2 years off is pretty large).
As a space physicist, I eagerly await the next solar cycle though it appears it maybe muted and the smallest of the last few.
While that's true, as a space physicist ACE is the primary satellite used in studying the solar wind and IMF which are the primary driver for space weather. Also, I'm not sure where this 15 minute number came from but in general, the solar wind takes about 60 minutes at a velocity of about 400 km/s to reach Earth. Real time ACE measurements would take much less than this. It would be the dissemination of the information that would take the longest.
Other warning systems are beginning to be developed based on solar observations but they are not as well defined at this point and not nearly as quantitatively accurate. If we can actually develop good predictors based on optical observations, it would take 8 minutes for the light to arrive at Earth but much more time for the actual solar effects.
Many power companies have learned there lessons from events such as the Quebec blackout and heeding warns given by space physicists in developing safety systems. These safety systems will protect against most solar events but it would be unlikely to survive a massive event such as the Carrington event.
Of course, to compensate for the control of the copyright, they would likely charge more for actually publishing in the journals. That is something that I think they could get away with doing if the granting agencies were mandating the publishing of funded research.
P.S. Thanks for reminding that it is the journal's impact score (I could not for the life of me remember what they were called this morning)