Cold science

[Rob_K]

Completion of the IceCube array in Antarctica.

http://www.icecube.wisc.edu/news/2010/1219.php


Cheers -

[CraigS]

Hmm .. a milestone .. one has to wonder what sort of results they might produce .. 'twill be an interesting to watch.

The following quote is also interesting ..

One highlight of the camera deployment was seeing an expected volcanic ash layer at about 300 metres deep in the ice with the camera system.

Pretty deep finding for undisturbed volcanic 'ash' .. fairly old eruption, eh?

Cheers
PS: Maybe not that old .. this one dated at just over 2,200 years ago (the biggest in 10,000 years) .. Ancient Antarctic Eruption noted .. says "We believe this was the biggest eruption in Antarctica during the last 10,000 years. It blew a substantial hole in the ice sheet, and generated a plume of ash and gas that rose about 12km into the air."

[Rob_K]

Originally Posted by CraigS

Pretty deep finding for undisturbed volcanic 'ash' .. fairly old eruption, eh?

LOL, very recent Craig, considering volcanoes have been with us for billions of years, since the Earth's crust first formed!

I love the use of the whole Earth as the instrument's filter - now that's big thinking!

Cheers -

[CraigS]

Originally Posted by Rob_K

LOL, very recent Craig, considering volcanoes have been with us for billions of years, since the Earth's crust first formed!

Cheers

Yeah … lucky I sneeked in with my "PS" at the end of my post !! Just in the nick of time !! Haven't recovered from Christmas celebrations, yet !

Mind you, I did say 'undisturbed' .. still a fairly unique sample … for that reason alone.

Cheers

[sjastro]

Very impressive technology.
We have gone from using buckets of water to blocks of ice.

Rather than neutrinos being detected it is the eerie blue glow of Cherenkov radiation.

Regards

Steven

[CraigS]

Originally Posted by sjastro

Very impressive technology.
We have gone from using buckets of water to blocks of ice.

Rather than neutrinos being detected it is the eerie blue glow of Cherenkov radiation.

Regards

Steven

Hmmm;
Cherenkov radiation happens when a charged particle (eg: electron) passes through a dielectric at a speed greater than the phase velocity of light in that medium.
So, I guess this would have a very characteristic spectrum (?)

Detecting neutrinos … hmmm .. not sure about this one ..

Are you saying that they're more likely to detect Cherenkov radiation, rather than neutrinos ?

Cheers

[renormalised (Carl)]

That's how they detect the neutrinos in the first place, via Cherenkov radiation. The neutrinos hit an electron in the atoms in the ice/water and they give off the characteristic blue "ping" when they relax and go back to their original state.

They don't actually detect the neutrinos physically, per se.

[sjastro]

Originally Posted by CraigS

Hmmm;
Cherenkov radiation happens when a charged particle (eg: electron) passes through a dielectric at a speed greater than the phase velocity of light in that medium.
So, I guess this would have a very characteristic spectrum (?)

Detecting neutrinos … hmmm .. not sure about this one ..

Are you saying that they're more likely to detect Cherenkov radiation, rather than neutrinos ?

Cheers

Cherenkov radiation has a characteristic spectrum defined by it's blue colour.

When a neutrino collides into water molecule it is converted into a muon. A muon is a heavy mass version of the electron and carries the same charge. The muon continues to travel through the medium.

Water molecules are orientated in the ice due to hydrogen bonding.
When a charged muon passes by orientation of the water molecules changes (polarization is induced). The molecules are now in an excited state.
When the molecules return to the ground state Cherenkov radiation is emitted.

Hence Cherenkov radiation is an indirect detection of neutrinos.

Regards

Steven

[CraigS]

Originally Posted by renormalised

That's how they detect the neutrinos in the first place, via Cherenkov radiation. The neutrinos hit an electron in the atoms in the ice/water and they give off the characteristic blue "ping" when they relax and go back to their original state.

They don't actually detect the neutrinos physically, per se.

CARL !!!

You're back !!!

Great to hear from ya !!

WELCOME BACK !!
...Great to see your words again !!

That's terrific !! Made my day !!

I know ziltch about this project .. just reading up on it now.

Cheers & Rgds
Cheers

[sjastro]

Originally Posted by renormalised

That's how they detect the neutrinos in the first place, via Cherenkov radiation. The neutrinos hit an electron in the atoms in the ice/water and they give off the characteristic blue "ping" when they relax and go back to their original state.

They don't actually detect the neutrinos physically, per se.

Who is this stranger?

[renormalised (Carl)]

Thought I'd drop by and grace these pages with my presence

[renormalised (Carl)]

It's a lot of effort just to find one tiny particle.

[CraigS]

Originally Posted by sjastro

Who is this stranger?

More importantly ….

… What are his views ???

I think a short test is in order !! (Just to check his allegiances).

But what should be the first question ?? Something innocuous … non-controversial ..

Errr … my mind has gone blank ..

Cheers

[sjastro]

Originally Posted by CraigS

More importantly ….

But what should be the first question ?? Something innocuous … non-controversial ..

How about if he has had a cup of coffee with Alex.

[renormalised (Carl)]

Originally Posted by sjastro

How about if he has had a cup of coffee with Alex.

Don't drink coffee