Well, I don't know about liquid nitro, but when I was in high school, I saw this kid douse his hand in Piccardi (sp?) 151 and light it on fire for about 5 seconds before putting the flames out. Didn't even singe the hair on his knuckles...
This would be definitevely a good idear. Sometimes i think to do to my self some esthetic surgery : what about a lipoaspiration of my abdominal wall ... </strong><hr></blockquote>Could you perhaps e-mail me a diagram? I hate doing only hernias
Okay fellas, one more try. . . . understanding that it's liquid nitrogen.
Remembering high school chemistry class, heat transfer is part of an equation based on a temperature difference, a ratio of masses, specific heats, and a time interval dT.
If the time interval dT is very short, then not much heat can be transferred away from the hand. If you rapidly dive your hand into a bucket of icy water, there's barely a sensation. In the case of Liquid Nitrogen, I imagine that the effect is not much different.
<strong>Okay fellas, one more try. . . . understanding that it's liquid nitrogen.
Remembering high school chemistry class, heat transfer is part of an equation based on a temperature difference, a ratio of masses, specific heats, and a time interval dT.
If the time interval dT is very short, then not much heat can be transferred away from the hand. If you rapidly dive your hand into a bucket of icy water, there's barely a sensation. In the case of Liquid Nitrogen, I imagine that the effect is not much different.
At normal temperature nitrogen is gazeous, when you drop your hand in it , at the contact of the warm of the skin, the liquid nitrogen turn into gaz, gaz is a bad thermic conductor, much more worse than liquid. This small thick of gaz protect you. If you continue to drop your hand in the liquid nitrogen, the skin of your hand is becoming cooler and the gazeous interface disapear. Liquid nitrogen came in contact directly with the skin, and your hand will froze.
<strong>Well, I don't know about liquid nitro, but when I was in high school, I saw this kid douse his hand in Piccardi (sp?) 151 and light it on fire for about 5 seconds before putting the flames out. Didn't even singe the hair on his knuckles...</strong><hr></blockquote>Bacardi.
Yes, that's an old trick. I've scared a few people doing that before. Once I set a tissue on fire (pre-soaked in alcohol), held it up for a while, and then put out in a bowl of water -- I lifted it up and to everyone's amazement, it wasn't even singed.
<strong>My personal website is under construction. In one month or two it will be ready. </strong><hr></blockquote>Cool. I will attempt one on the crane. A "World's First"
They are able to get it during very short time with the help of a LASER, in this state all the moleculars elements are organised in a very straight way.</strong><hr></blockquote>
No...
Unfortunately we are unable to reach absolute zero itself. It is forbidden by the third law of thermodynamics. In practice, though, it is often the heat input from the outside world (or "heat leak") into an experiment which prevents further cooling. In the low temperature limit, all heat capacities C go to zero so that for a heat energy input Q the temperature rise dT = Q/C becomes increasingly large. Even absorbed cosmic rays can produce a significant heat leak.
Unfortunately we are unable to reach absolute zero itself. It is forbidden by the third law of thermodynamics. In practice, though, it is often the heat input from the outside world (or "heat leak") into an experiment which prevents further cooling. In the low temperature limit, all heat capacities C go to zero so that for a heat energy input Q the temperature rise dT = Q/C becomes increasingly large. Even absorbed cosmic rays can produce a significant heat leak.
Comments
<strong>
This would be definitevely a good idear. Sometimes i think to do to my self some esthetic surgery : what about a lipoaspiration of my abdominal wall ...
- T.I.
Remembering high school chemistry class, heat transfer is part of an equation based on a temperature difference, a ratio of masses, specific heats, and a time interval dT.
If the time interval dT is very short, then not much heat can be transferred away from the hand. If you rapidly dive your hand into a bucket of icy water, there's barely a sensation. In the case of Liquid Nitrogen, I imagine that the effect is not much different.
[ 06-06-2002: Message edited by: Splinemodel ]</p>
<strong>Okay fellas, one more try. . . . understanding that it's liquid nitrogen.
Remembering high school chemistry class, heat transfer is part of an equation based on a temperature difference, a ratio of masses, specific heats, and a time interval dT.
If the time interval dT is very short, then not much heat can be transferred away from the hand. If you rapidly dive your hand into a bucket of icy water, there's barely a sensation. In the case of Liquid Nitrogen, I imagine that the effect is not much different.
[ 06-06-2002: Message edited by: Splinemodel ]</strong><hr></blockquote>
At normal temperature nitrogen is gazeous, when you drop your hand in it , at the contact of the warm of the skin, the liquid nitrogen turn into gaz, gaz is a bad thermic conductor, much more worse than liquid. This small thick of gaz protect you. If you continue to drop your hand in the liquid nitrogen, the skin of your hand is becoming cooler and the gazeous interface disapear. Liquid nitrogen came in contact directly with the skin, and your hand will froze.
<strong>Could you perhaps e-mail me a diagram? I hate doing only hernias
- T.I.</strong><hr></blockquote>
My personal website is under construction. In one month or two he will be ready.
<strong>Well, I don't know about liquid nitro, but when I was in high school, I saw this kid douse his hand in Piccardi (sp?) 151 and light it on fire for about 5 seconds before putting the flames out. Didn't even singe the hair on his knuckles...</strong><hr></blockquote>Bacardi.
Yes, that's an old trick. I've scared a few people doing that before. Once I set a tissue on fire (pre-soaked in alcohol), held it up for a while, and then put out in a bowl of water -- I lifted it up and to everyone's amazement, it wasn't even singed.
Thanks, Mr. Wizard's World!
<strong>My personal website is under construction. In one month or two it will be ready.
- T.I.
<strong>Cool. I will attempt one on the crane. A "World's First"
- T.I.</strong><hr></blockquote>
Yes and the webcam of Zermatt will be able to film you. Your identity will discover and all the secret network disassembled : a real nightmare though
[ 06-07-2002: Message edited by: powerdoc ]</p>
<strong>
They are able to get it during very short time with the help of a LASER, in this state all the moleculars elements are organised in a very straight way.</strong><hr></blockquote>
No...
Unfortunately we are unable to reach absolute zero itself. It is forbidden by the third law of thermodynamics. In practice, though, it is often the heat input from the outside world (or "heat leak") into an experiment which prevents further cooling. In the low temperature limit, all heat capacities C go to zero so that for a heat energy input Q the temperature rise dT = Q/C becomes increasingly large. Even absorbed cosmic rays can produce a significant heat leak.
<a href="http://www.sun.rhbnc.ac.uk/~uhap057/LTWeb/Absolute.html"; target="_blank">http://www.sun.rhbnc.ac.uk/~uhap057/LTWeb/Absolute.html</a>;
<strong>
No...
Unfortunately we are unable to reach absolute zero itself. It is forbidden by the third law of thermodynamics. In practice, though, it is often the heat input from the outside world (or "heat leak") into an experiment which prevents further cooling. In the low temperature limit, all heat capacities C go to zero so that for a heat energy input Q the temperature rise dT = Q/C becomes increasingly large. Even absorbed cosmic rays can produce a significant heat leak.
<a href="http://www.sun.rhbnc.ac.uk/~uhap057/LTWeb/Absolute.html"; target="_blank">http://www.sun.rhbnc.ac.uk/~uhap057/LTWeb/Absolute.html</a></strong><hr></blockquote>;
You are right , but with the help of laser cooling : they can obtain ultra low temperature and a new state of gaz the Bose-Einstein condensate :
Absolute zero has never been obtained and may not even be possible.
Absolute zero is defined as the temperature at which all thermally induced
motion stops. As objects (matter) get hotter (acquire more energy) they
move faster. All matter that is not at absolute zero is in motion.
All matter that has a temperature greater than absolute zero also radiates
energy. At ambient or room temperature, the radiation is mostly in the
infrared part of the electromagnetic spectrum. The heat we feel when we
get close to a hot object comes from our bodies absorbing the infrared
energy being radiated by the hotter object. Infrared radiation transfers
energy from hotter to colder objects.
In terms of heat transfer, the inside of a hollow closed sphere is called
a blackbody. Any part of the inside surface of the sphere is radiating
energy to all the other parts of the surface. Any hot part of the surface
will radiate energy to the colder parts of the sphere. The temperature
inside the sphere will quickly become the same and the transfer of energy
from one location to another will stop. In this condition, when the
inside surfaces are at the same temperature, there will be no net gain or
loss of energy inside the sphere. This is called thermal equilibrium.
The same thing happens if you place an object inside of the blackbody. If
the object is hotter than the sphere, it will radiate energy into the
sphere until both the sphere and the object are at the same temperature.
The opposite will occur if the sphere is hotter than the object. Energy
will transfer from the hotter object to the colder object until they are
in thermal equilibrium.
A closed capsule and objects placed inside the capsule will not
spontaneously cool to absolute zero. So how do you cool something to
temperatures approaching absolute zero? A gas cools when it expands into
a larger volume. This is called adiabatic expansion. Adiabatic expansion
is used in most refrigerators and air conditioners to provide cooling.
Using adiabatic expansion to remove energy from the gas and lower its
temperature can liquefy gasses. Liquid helium at ?269.9 degrees K
provides the lowest temperature that can be achieved this way. To get
even lower temperatures it is necessary to remove more energy than is
possible using only adiabatic expansion. It is also necessary to keep the
object being cooled from coming into contact with the container. To
accomplish this, gasses of elements such as sodium or rubidium are
levitated using magnetic fields to form magnetic bottles. Very carefully
tuned laser light then collides with the gas atoms in a way that reduces
the speed of the gas atom. Light can act like a wave or a particle.
Particles of light are called photons. Photons that collide with the
atoms of the gas can carry away tiny amounts of energy. The more
collisions between the gas and the light, the greater the amount of energy
removed from the gas atoms. Less energy equals lower temperature. By
manipulating the laser beams and the magnetic fields the rubidium atoms in
a small chamber at the National Institute of Standards and Technology
(NIST) were cooled to less than 100 nanokelvin. That is 0.00000001
degrees K above absolute zero. Somewhere near this temperature the
rubidium atoms that make up the gas stop bouncing off of each other and
acting independently and start to all move the same way. The gas becomes
something called a Bose-Einstein condensate when all of the atoms begin to
move uniformly. The atoms in a Bose-Einstein condensate drop into the
lowest possible energy state and the motion is reduced even further. The
temperature of the Bose-Einstein condensate drops to 0.5 nanokelvin or
less!!!
This is the lowest temperature ever observed. It is still not absolute
zero, but there are a lot of zeroes after that decimal point!
The information on the work at NIST was extracted from a paper by Dr. Eric
Cornell which was published in the Journal of Research of the National
Institute of Standards and Technology, Volume 101, Number 4, July-August
1996. Dr. Cornell attempted to present the information in a manner that
would be understood by general audiences. I attempted to simplify it even
more. I hope my interpretation is helpful and correct. The text of the
original article can be found at:
<a href="http://physics.nist.gov/Pubs/Bec/j4cornel.pdf."; target="_blank">http://physics.nist.gov/Pubs/Bec/j4cornel.pdf.</a>; You will need Acrobat
Reader to view it.
Bob Novak
Sr. Process Engineer
Carpenter Technology Corporation
Now that *is* exciting!
How fun!
You mentioned above that each zero we can place after the decimal point leads to new science.
Like what?