Test Question :)

Rocketman · 07-09-2011, 11:39 PM

Was asked about properties of Propylene Glycol today and you guys know how much I love test questions

So here it is. One of the liquids in the photo is water. A correct guess gets you 1 point. A correct 'WHY' gets you an extra credit point. Blond gets you another extra credit point

To help with the calculations: liquid temperature was 23.8 degrees C

DevonMoonshire · 07-09-2011, 11:54 PM

Here is my Guess based on purity and viscosity.

The Vial on the left is water
The Vial on the right is the PG

I come to this conclusion based on what I believe to be true that Water is less thick than propylene glycol, therefore it stands to reason that there would be less light refractive properties to the Water which would reduce distortion which is evident in the bottle on the right.

Or I could have that completely bass ackwards LOL

tek · 07-10-2011, 06:41 AM

My hazzard to a guess is a lil different, the one on the right, is probally pg, the surface tenstion is flat, aka surface is level, the one on the left is water, cause it has a convex surface tention, also i have knoticed my ejuice to magnify light so the one on the right. Also i am not blond but my child is, does that count?[IMG]

[/IMG]

RY4 · 07-10-2011, 11:12 AM

Dang Rocky how am I suppose to know.

Sure hope I don’t need to use the Index of Refraction or Snell's Law cause I would have to go digging for some old textbooks. I believe PG is the consistency along the lines of syrup but not sure.

So, I believe it is water on the left and PG on the right. When light enters water, it slows down. If the surface of the water is curved, the light is also bent into a new path. The rounded shape bends the light outwards. As the light spreads out, the image that you see gets larger. The same principle holds using flashlight against the wall and making a shadow larger or smaller. The further the flashlight from the wall-- spreading the light out, the larger the shadow and distortion. Some substances bend and spread light more than others, which impacts how much they magnify things. Karo syrup will bend the light more than water and thus magnify more. Therefore, if PG is similar to the consistency of syrup, then it will magnify an object more than water will.

Do I get a point for being blonde then another for being a true blonde

berger · 07-10-2011, 11:19 AM

water on the left..just cause...LOL

added later:
OK OK... viscosity affects refraction (not reflection)...water has less refraction then PG which has higher viscosity as observed by lesser spreading of the mm markings in the water...either that or he used trick cylinders

DevonMoonshire · 07-10-2011, 11:40 AM

Quote:

Originally Posted by tek

My hazzard to a guess is a lil different, the one on the right, is probally pg, the surface tenstion is flat, aka surface is level, the one on the left is water, cause it has a convex surface tention, also i have knoticed my ejuice to magnify light so the one on the right. Also i am not blond but my child is, does that count?[IMG]

[/IMG]

WHOA!!! Tek your Child looks just like my God Daughter Joy!! That is Crazy!! I mean almost a mirror image!!

RY4 · 07-10-2011, 12:08 PM

Quote:

Originally Posted by berger

water on the left..just cause...LOL

LOL! What? No going to even try for an extra point

Sometimes you can make something up that sounds real good and get a half a point.

Brutus · 07-10-2011, 12:18 PM

I think that the water is on the left due the the presence of a meniscus in the photo (have not used that term since chem122 at Ohio state) This is just a guess and I did not read the other posts yet, so excuse this newb and my potential ignorance. Water has a polar structure and is attracted to the surface of the container.

Hopefully my first post turns out well!

I also want to say that i have learned so much lurking on here; at first I thought my head would explode but only three weeks in I'm vaping like a champ.

40bikes · 07-10-2011, 02:04 PM

Welcome Brutus.
Heads around here implode not explode due to drawing extreme vacuums while vaping from old gummed up cartos.

Brutus · 07-10-2011, 04:26 PM

Thanks for the welcome. I should have said that my brain hurt due to the overwhelming amount of (mis)information and sheer variety of models, flavors, vendors, as well as opinions.

Sorry to derail the exam here rocket but did we pass?

I guess I should head over to the intro page and say hello to the rest of the gang.

RY4 · 07-10-2011, 04:29 PM

Quote:

Originally Posted by Brutus

Thanks for the welcome. I should have said that my brain hurt due to the overwhelming amount of (mis)information and sheer variety of models, flavors, vendors, as well as opinions.

Sorry to derail the exam here rocket but did we pass?

I guess I should head over to the intro page and say hello to the rest of the gang.

Welcome Brutus and yes, all the information can make your head hurt. Don't worry about derailing the thread, some of us hijack threads all the time... keeps it interesting

Rocketman · 07-10-2011, 06:29 PM

Quote:

Originally Posted by Brutus

Thanks for the welcome. I should have said that my brain hurt due to the overwhelming amount of (mis)information and sheer variety of models, flavors, vendors, as well as opinions.

Sorry to derail the exam here rocket but did we pass?

I guess I should head over to the intro page and say hello to the rest of the gang.

Welcome and derailing is the norm here

Besides, I wouldn't put it past that Rocket guy to put two cylinders of water (one bottled, one tap) . He's like that you know.

40bikes · 07-10-2011, 06:52 PM

Sorry, posted in the wrong thread. And Brutus it wasn't even intentional.

mrwizard · 07-10-2011, 10:32 PM

Quote:

Originally Posted by Rocketman

Welcome and derailing is the norm here

Hi Brutus, welcome to the group therapy known as Vapeatron.
As for derailing... I'm pretty sure the big white A in the Vapeatron logo stands for ADD.

Quote:

Originally Posted by Rocketman

Besides, I wouldn't put it past that Rocket guy to put two cylinders of water (one bottled, one tap) . He's like that you know.

That would be evil.
I knew there was a reason I like you.

However, this time that doesn't appear to be the case.
If they were both freshwater (tap, bottled, distilled, RO/DI, etc.) then the refractive index would still be they same.
Since one is creating noticably greater magnification the refractive indexes must be different.
Higher refractive index = shorter wavelength = more bending = greater magnification.

Seeing that both liquids are contained in identical 100ml graduated cylinders with a diameter of ~27mm we could do the math and get an approximate refractive index for each liquid... or we could just use Google.

Water has a refractive index of 1.33 and Propylene Glycol has a refractive index of 1.43, so the vial on the right must be the PG.

As Brutus noted, there's also a concave meniscus present on the left and not one on the right indicating a difference in adhesion/cohesion properties between the two liquids and the glass... either that or Rocky didn't wash one of them very woll.

Crap. I made another typo and I'm all out of Wite-Out. I hate when that happens.
(Pathetic attempt to get the Blonde point.)

RY4 · 07-10-2011, 10:49 PM

Now, I asked if we had to use the Refraction Index.... but I didn't know that info. off the top of my head and all, ya know cause it is blonde and all ...

Do I get my extra points?

Rocketman · 07-10-2011, 10:54 PM

OK enough is enough. Everybody is correct. The meniscus and higher refractive index were the indicative visual parameters. The distortion (the 7 on the scale that was severely distorted) is due to either the focal length of the PG double convex cylindrical lens being shorter than the water lens and that spot being close to the focal point, or the boundary of the Pyrex and PG causing TIR around the curved path. Who cares

The primary purpose was not to "show off" or to make anyone feel silly about replying but to stir up a little interest in learning about the stuff we vape. We shopped for cigarettes partly because the pack looked pretty. Got some killed, some almost. Learn all you can about vaping. The day of the 'sheep' is over.

Some comments:
Viscosity really doesn't play into this. Some thin liquids have a high RI. PG and cooking oil are about the same viscosity. VG and Karo about the same. Diameter isn't really needed to figure out the RI since the containers are round, the scale is tangent to both and the scale divisions are visible for the air path, the water path and the PG path. Just remember to use the formula for a cylinder lens (two plano convex with r=t).
As far as points, grade your own

RY gets the blond point (and no you don't get TWO blond points, not without proof

), tek gets half a blond point.

Oh, and thanks guys for playing along.

mrwizard · 07-10-2011, 11:01 PM

Quote:

Originally Posted by Rocketman

RY gets the blond point (and no you don't get TWO blond points, not without proof

)

Dammit Rocky, you should've held out for photographic proof before giving out the first point... now we'll never know.

RY4 · 07-10-2011, 11:03 PM

Quote:

Originally Posted by Rocketman

OK enough is enough. Everybody is correct. The meniscus and higher refractive index were the indicative visual parameters. The distortion (the 7 on the scale that was severely distorted) is due to either the focal length of the PG double convex cylindrical lens being shorter than the water lens and that spot being close to the focal point, or the boundary of the Pyrex and PG causing TIR around the curved path. Who cares

The primary purpose was not to "show off" or to make anyone feel silly about replying but to stir up a little interest in learning about the stuff we vape. We shopped for cigarettes partly because the pack looked pretty. Got some killed, some almost. Learn all you can about vaping. The day of the 'sheep' is over.

Some comments:
Viscosity really doesn't play into this. Some thin liquids have a high RI. PG and cooking oil are about the same viscosity. VG and Karo about the same. Diameter isn't really needed to figure out the RI since the containers are round, the scale is tangent to both and the scale divisions are visible for the air path, the water path and the PG path. Just remember to use the formula for a cylinder lens (two plano convex with r=t).
As far as points, grade your own

RY gets the blond point (and no you don't get TWO blond points, not without proof

), tek gets half a blond point.

PROOF! Well, I can send ya a picture of me as a kid

Rocketman · 07-10-2011, 11:04 PM

Quote:

Originally Posted by RY4

PROOF! Well, I can send ya a picture of me as a kid

Yeah right. That's ALL I NEED, kiddie porn on my computer.

(of course it is a touch screen

)

mrwizard · 07-10-2011, 11:11 PM

Quote:

Originally Posted by Rocketman

Diameter isn't really needed to figure out the RI since the containers are round, the scale is tangent to both and the scale divisions are visible for the air path, the water path and the PG path. Just remember to use the formula for a cylinder lens (two plano convex with r=t).

I took a wild guess and bluffed since I'm too lazy to actually look up formulas and do the math beyond Googling the RI... you can take my points back and maybe use em to get another pic from RY4.

RY4 · 07-10-2011, 11:12 PM

Quote:

Originally Posted by Rocketman

Yeah right. That's ALL I NEED, kiddie porn on my computer.

(of course it is a touch screen

)

Oh my goodness!!! LMAO! No, hair on head color as a child. No porn. No, no.

Rocketman · 07-10-2011, 11:14 PM

Quote:

Originally Posted by mrwizard

I took a wild guess and bluffed since I'm too lazy to actually look up formulas and do the math beyond Googling the RI.

me too

So, you want me to forward the kiddie porn to you also?

RY4 · 07-10-2011, 11:14 PM

Quote:

Originally Posted by mrwizard

I took a wild guess and bluffed since I'm too lazy to actually look up formulas and do the math beyond Googling the RI... you can take my points back and maybe use em to get another pic from RY4.

I don't think so but I will take your points if ya don't want 'em.