# Naked Science Forum

## Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Ron Hughes on 29/08/2010 01:00:53

Title: HOW DOES AN UP QUARK TURN INTO A DOWN QUARK?
Post by: Ron Hughes on 29/08/2010 01:00:53
The caterpillar has a genetic code sensitive to certain environmental conditions that tell it to build a cocoon and then tells the cells to rearrange into a butterfly.
An imaginary picture of the hydrogen atom, the proton is composed of two red up quarks and one blue down quark with the electron being a yellow point. What do you suppose the code is that mixes the electron with one of the red quarks turning into a blue quark and thus a neutron?
Title: HOW DOES AN UP QUARK TURN INTO A DOWN QUARK?
Post by: JP on 29/08/2010 04:46:28
When particles interact, its the forces of that interaction and conservation laws that dictate what the possible outcomes of the interaction are.  The forces involved describe what properties of the particles could change in the interaction.  Conservation laws are along the lines of conservation of energy or conservation of momentum, and say that some total properties of the system won't change even if the particles chance type.

I think there's a slight mistake in the example you mention, which describes the reverse of beta decay.  It's the up/down-ness of the quarks that change (thus changing the proton to a neutron) instead of color.  The force involved is the weak nuclear force, which allows quarks to flip from up to down (thus changing their charge).  Up quarks have +2/3 electric charge, while down quarks have -1/3 charge, so that going (Up Up Down)->(Up Down Down) goes from +1 charge to 0 charge (proton to neutron).  From conservation of charge, you would have to absorb a negative charge to do this, which is why the electron gets absorbed in the process.
Title: HOW DOES AN UP QUARK TURN INTO A DOWN QUARK?
Post by: lightarrow on 29/08/2010 13:21:36
HOW DOES AN UP QUARK TURN INTO A DOWN QUARK?
Turn it upside down  [;)]
Title: HOW DOES AN UP QUARK TURN INTO A DOWN QUARK?
Post by: kenhikage on 14/09/2010 16:19:53
JP, if this forum allowed it, I would +rep that.  [O8)]
Title: HOW DOES AN UP QUARK TURN INTO A DOWN QUARK?
Post by: Ron Hughes on 14/09/2010 23:47:41
I think it's same old smoke and mirrors answer.
Title: HOW DOES AN UP QUARK TURN INTO A DOWN QUARK?
Post by: JP on 15/09/2010 04:01:32
I think it's same old smoke and mirrors answer.

I'm not sure what that means.  It's a model that gives accurate results for predicting scientific experiments, which is what a scientific model is supposed to do!