Now, the question is how to make it thin without reaching that temperature...

[SAZAR]

Unusual physics question :)

How to make a hair which is still properly rooted to skin (any hair, not just on head) become very thin at the end?
(gradual thinning toward the tip)

:D

How would you approach this physical problem - by applying mechanical force (stretching it, or abrading it, or cutting it at some small angle?? is that possible at all...), by treating it thermally, chemically or maybe some other (possibly ingenious) way?

The only rule is that it must stay rooted to skin (generally no damage to the skin). :D

 

[dacruick]

go to a hair salon.

 

[SAZAR]

:D ha ha...

No, seriously - tensile strength of human hair is 380 MPa (acording to: http://en.wikipedia.org/wiki/Tensile_strength ).
My bet (for now, until proven otherwise) is stretching it.

 

[dacruick]

im being serious. if you are looking for a chemical solution to your answer, the best bet for you is to go and ask them. stretching hair does not work very well. and i know this because when i try to stretch my hair, it breaks

 

[Andy Resnick]

Figure out a way to strip off the cuticle: does anything dissolve keratin?

http://www.pgbeautygroomingscience.com/index.php?id=685

 

[SAZAR]

im being serious. if you are looking for a chemical solution to your answer, the best bet for you is to go and ask them. stretching hair does not work very well. and i know this because when i try to stretch my hair, it breaks

It breaks, but first it gets thin - right?

As I said: "The only rule is that it must stay rooted to skin (generally no damage to the skin)."
I think chemicals would affect the skin as well (the only way to avoid that is to apply chemical to the hair ONLY).

Tricky.

Figure out a way to strip off the cuticle: does anything dissolve keratin?

http://www.pgbeautygroomingscience.com/index.php?id=685

Yea'. I typed "dissolve keratin" and it said: http://www.skintreatmentcream.com/enzymatic/

What about heat?
I googled this:
("heat melt keratin" resulted in "keratin melting pot" - I guess glue made from animal ...stuff)
http://toccohair.en.ec21.com/Keratine_Melting_Pots--1820747_1820767.html
(someone already posed this question)
http://wiki.answers.com/Q/What_is_the_melting_point_of_keratin

It would be cool if hair acts similar to plastic (sort of like when you stretch melted cheese). :B

 

[ideasrule]

Figure out a way to strip off the cuticle: does anything dissolve keratin?

http://www.pgbeautygroomingscience.com/index.php?id=685

Proteinase K?

 

[SAZAR]

What is the...

...ah - there it is:

http://www.webanswers.com/science/at-what-temperature-does-hair-melt-269dba

("At what temperature does hair melt?

Depends on the moisture content of the hair. Dry human hair will melt at around 205 degrees C (401 F), and with a moisture content of 20%, around 155 C (311 F).")

So it is possible!