Our changing sun...

So Glad

I've heard a lot of things about the sun becoming brighter, more magnetic and possibly preparing a pole-shift. This is really important, anyone know anything about this?

Thanks,

Dav.

Redshift

The sun does indeed flip it's poles relatively frequently, from what I've read it's expected to do so again around 2012. The earth also flips it's poles though much less frequently, although it's apparantly way over due the next one and some signs are present that it's preparing to do so.
The sun will naturally become hotter and brighter as it ages something on the order of 10% per billion years(could be wrong on this) until in about 5 billion years from now when the sun has exhaused it 's fuel supply of hydrogen it will leave the main sequence and start fusing helium which will cause the sun to swell into a red giant possbily engulfing the earths orbit.

There is tons of info on google about this

So Glad

Yes, but I wonder what effect this'll have on us, radiation and the sort. It's not an easy thing to live through, could this be the source of global warming do you think?

Sev

Is there any actual physics to back any of this up?

As a physics student, the idea of a systematic and regular sudden pole shift that we can predict will happen in 2012 sounds like nonsense. Intuitively, it just doesnt make any sense and breaks conservation laws.

Son Goku

Sev wrote:

Is there any actual physics to back any of this up?

As a physics student, the idea of a systematic and regular sudden pole shift that we can predict will happen in 2012 sounds like nonsense. Intuitively, it just doesnt make any sense and breaks conservation laws.

Which quantity wouldn't be conserved? Is it a quantity related to the electromagnetic field or momentum/energy conservation for the matter in the Sun?

There isn't going to be an unusual pole shift beyond the standard Solar Maximum one, but I thought that would come from the dynamics rather than a conservation. Unless I'm missing something.

Redshift

So Glad wrote:

Yes, but I wonder what effect this'll have on us, radiation and the sort. It's not an easy thing to live through, could this be the source of global warming do you think?

Well it happens every 11 years so chances are you've survived more than one solar pole reversal;)
The earths pole reversal is a matter of more concern, it is far less predictable
with intervals ranging from 5,000 to 50,000,000 years between flips.
The only thing that is certain that it has happened many times before and the evidence for this is literally etched in stone.
How the transition takes place is really an unknown it could degrade slowly to zero gauss and cease to exist for a time before reforming with the opposite polarity and I probably don't need to tell you what this means for life on earth.
or the more popular theory is that the field becomes disordered and chaotic for a time possibly with several north/south poles existing for a time before the field eventually reorganises with a reversed polarity.

slade_x

So Glad wrote:

Yes, but I wonder what effect this'll have on us, radiation and the sort. It's not an easy thing to live through

having no protection wouldn't be possible to live through, if the earths magnetic field strength dropped to zero, every location on earth facing the sun would be bombarded by highly charged ions or as they are commonly refered to as Cosmic Rays. Without this protection all life would be subject to intense radiation. UVB, UVA etc, would be nothing compared to what we would be exposed to if we werent protected.

To the original poster if you're interested in the subject here are a few links about inconstant magnetic fields

http://www.nasa.gov/vision/earth/lookingatearth/29dec_magneticfield.html

Earth's Inconstant Magnetic Field
Our planet's magnetic field is in a constant state of change, say researchers who are beginning to understand how it behaves and why.......

http://science.nasa.gov/headlines/y2001/ast15feb_1.htm

The Sun Does a Flip
NASA scientists who monitor the Sun say that our star's awesome magnetic field is flipping -- a sure sign that solar maximum is here.......

http://earthobservatory.nasa.gov/Newsroom/MediaAlerts/2002/2002101610862.html

KEY TO THE NATURE OF EARTH’S MYSTERIOUS CORE FOUND BENEATH ARCTIC ICE

In the high Canadian Arctic, researchers at the University of Rochester have stripped away some of the mystery surrounding the powerhouse that drives the Earth’s magnetic field. The research strongly suggests that several of the characteristics of the field that were long thought to operate independently of one another, such as the field’s polarity and strength, may be linked. If so, then the strength of the field, which has been waning for several thousand years, may herald a pole reversal-a time where compasses all over the Earth would point south instead of north. The findings are being published in today’s issue of Proceedings of the National Academy of Sciences..........

SonOfPerdition

slade_x wrote:

having no protection wouldn't be possible to live through, if the earths magnetic field strength dropped to zero, every location on earth facing the sun would be bombarded by highly charged ions or as they are commonly refered to as Cosmic Rays. Without this protection all life would be subject to intense radiation.

I've been reading that there is a suggestion the field strength drops to about 10% of its nominal strength during a flip. If that is true what sort of timescale would it take for the radiation to wipe out all life or would that 10% be enough to protect us?

also,this website states the following.... "in the past 15 million years, there have been four reversals every 1 million years"

it seems to be a regular enough event that life has survived many times, but is it possible that life would only survive near the equator where the protection is strongest?