Ask a Scientist: Is Pudding a Solid or Liquid?

For the first installment of "Ask a Scientist," I will diving into the world of pudding.  But first...

Pudding takes the shape of it's container so it must be a
liquid, right?

I went back and read my original "Ask a Scientist" post and I wanted to clear something up first.  I never intended for the post to sound arrogant or snobby.  My only intention was to try to find some new interesting subjects to look into and write an informative post on them.  I am not saying that I know all the answers or that I am a genius.  I just enjoy researching all kinds of science and I also love to share fun science (such as quantum locking)!  So without further delay, let's get back to pudding.  Which is an awesome topic to discuss!

So is pudding a solid or liquid?  Short answer, it is a liquid.  Long answer, it is hydrocolloidial gel.  I'll explain...

Milk is another example of a colloid,
because the solid fat molecules are
dispersed in the water of milk.

Short answer; if we look at pudding like we were in grade school again and try and determine it's state of matter we would classify it as a liquid.  It has no definitive shape (it takes the shape of the container it is in) but it will not diffuse out of an open container.  So by all accounts it is a liquid.

Long answer; when making pudding there are essentially two phases that make up the pudding.  The first is the powder mix (or raw ingredients if you happen to be a grandma or Paula Dean) that consists of a starch, sugar, flavorings, colorings, and probably some preservatives.  This comes in the form a of solid powder.  Then we have the liquid phase, usually water or milk (which is essentially water for our purposes here).  Now when these two phases are combined and are not completely miscible they form a colloid.  Miscibility is the ability for two things to coexist as one medium (like when you dissolve sugar in warm tea to make sweet tea).  Colloids are when one phase is dispersed within another phase.

Pudding is the same state of matter as hair gel!
A liquid dispersed within a solid.

Here, the main two ingredients that determine the overall state of matter for pudding is starch and water.  Because starches have variable molecular weights and consist of chains of sugars, they tend to form amorphous solids, solids without a definite crystal structure and have a little liquid like properties.  Once the water is dispersed within the amorphous solid of the starch, this increases the liquid like properties overall.  This type of colliod is called a hydrocolloid because it specifically uses water.  Lastly, this is considered a gel because the water is dispersed within the solid.  So thus the hydrocolloidial gel!  Which is actually more like a solid.

So to answer the question is pudding a solid or liquid, it is both!  I hope that helps and you can impress your friends at your Christmas parties!  Thanks melpels for the question!

PS - Tapioca pudding is the easiest example of this hydrocolloidial gel that is both a solid and liquid, because there are literal chunks in that pudding, ugh.

Friday Fragments (11/4/11)

Alright, no screwing around! Here are some fragments to get you through the afternoon...

-A study out of Yale University has mathematically shown that there is such a thing as a "hot hand" in basketball (or as NBA JAM won't put it, "He's on FIRE!!!").  They don't have any proposed mechanisms per say but they have uncovered some statistically significant results from years of NBA data.  Although anyone who has played basketball, or any sport for that matter, can tell you there are times when you are just in the zone. I tend to get that way for table tennis but that's another story.  Here's a summary of the study, rather than the actual research paper.

-1996...I was 9 years old and the internet was still very young too. I remember going to the computer lab to work on bulky PCs and even a few MACs, using programs like Creative Writer and Oregon Trail 2.  I happened to stumble upon this pro/con list of the internet circa 1996.  Sadly, much hasn't changed!

-I really like this footage from the moon taken in 1971 that proves Galileo was right about gravity.  Watch the video below to see a hammer and a feather fall at the same rate.

 

-Crystal skulls are always fascinating....period.

-Here is a list of 10 common food myths.  I particularly like the one about tryptophan and I cannot wait to challenge this answer in Trivial Pursuit (I'm looking at you, Mom).

-And lastly, stem cell research took a small step forward recently.  Scientists were able to produce stem cells from an unfertilized egg using someone else's DNA.  However (there's always a catch) they had to leave the native DNA in the egg as well which produce essentially worthless stem cells, as the donor would reject the stem cells for having some native properties.  But it is a step in the right direction, and for those who are sensitive about the whole embryonic stem cell debate, this is a good step in the right direction.

Killing Time

After the long weekend I found myself motivated this morning to get "stuff" done.  So after reading a couple papers on LLPS (that's liquid-liquid phase separation for those of you keeping track of all the abbreviations), getting some homework finished, and preparing to teach lab this afternoon I have found myself with a little time to kill.  Unfortunately I am no longer as motivated to start a new project and I figured I would write quick blog post.

If you haven't noticed, the frequency of my posts has decreased since school started back up a couple of weeks ago.  Things are settling down a little school-wise and I hope to get back to some regularity.  Enough with formalities...

This last weekend marked the beginning of the college football season and our Boilermakers somehow squeaked out a win against the Blue Raiders of Middle Tennessee State, 27-24.  Yep, there are no typos in that sentence and it was actually a really good football game as far as excitement value.  I believe Carson Wiggs is my favorite player this year because if the ball is in the stadium, he can put it through the uprights.  If you happen to make it to West Lafayette for a game this fall, look me up because my friend and I are planning on tailgating (front row) for as many games as we can! October 1st is the night game for Notre Dame (hint hint)!

Also last week I went to dinner with the guys from 105B.  They are the guys from the Taylor Lab group and we are starting to do some male bonding as the rest of the lab group in the basement are girls.  Anyway, it was my first major experience with authentic (or as authentic as you can get in the US) Indian food.  Not too bad!  I recommend going to an Indian buffet with someone familiar with the cuisine and customs.  There is a post-doc from India who was able to show us around the food and it made the whole experience enjoyable.  I do like learning and trying new things, especially from other parts of the world.  This week I believe we are going disc golfing and possibly playing some table tennis, and if you know me you know how I feel about table tennis.  But as a whole we have a really nice, diverse group of guys and it has already made working in the lab more comfortable.

Classic Design Fender Acoustic

Lastly, I am looking into getting an electric guitar this month as a birthday present to myself.  I have an acoustic (Classic Fender) but I think I want to give electric a try.  If you have any suggestions for guitars or amps for both quality and price that would be greatly appreciated!