Why are icicle long and thin?

Here is a great image of three icicles.

As water drips onto an icicle and freezes, it releases heat. The warm air rises up the sides of the icicle. That warm air layer acts like a blanket that’s an insulator, and so the blanket is very thin near the tip and thick at the top. That allows the top to grow very slowly and the tip to grow rapidly — creating a long, thin icicle.

The height of an icicle is proportional to the radius to the four third!

The apex angle is about 15 degrees

How the ripples form on the icicle issue has not been fully resolved yet. I am not even sure if the problem of optimal distance between the icicles has been resolved either!

Why does cigarette smoke rise smoothly at first, but then form swirls after some distance?

Here is a gorgeous, detailed image of blue and white smoke ascending.

And the reason why the smoke rises smoothly at first and then starts making swirls:

The hot gas that carries the smoke particles initially rises slowly.

However, its net buoyancy, due to its higher temperature than surrounding gas, causes it to accelerate upward.

When the speed reaches a critical value, the flow becomes turbulent and breaks up into eddies. The critical speed is typically obtained after a rise of up to a few centimeters.

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Physicist Timmothy Stowe’s periodic table places elements in discrete levels. It is plotted in three dimensions, with the three axes representing the principal quantam number, n the orbital quantam number, l and the orbital magnetic quantam number, m(sub)l

This is one of my favorite elemental video about the periodic table, mainly because instead of just reciting the names of the elements, it gives an example of where they appear or shows a sample of the element itself.

There is also a higher quality version of this video at YouTube.

The video is by Tom Lehrer, it especially appropriate to post it today because he is celebrating his 80th birthday today! Happy birthday Tom!

If you want to hear his sing about the derivatives and how to calculate it, please click here. The song is called there is delta for every epsilon.

I really admire people who fall in love with a concept, and feel so strongly about it that they are motivated to have it tattooed on their body.

The highest respect one can give to a symbol is to have it permanently scribed on your own self. It is the most personal commitment one can make.

Having a tattoo of a physics or math equation is surely better than having a tattoo of your latest love-interest’s name; he/she may come and go, but you know for sure that the Euler Identity will always remain true!

If you really want to be certain that the equation you are about to get tattooed on your behind remains correct during your life time, go with a math tattoo; physicists are notorious for mucking around with their equations.

Here are a couple of interesting math tattoos:

The story behind the tattoo:

I got the tattoo because I like the idea of math not being well behaved. That sound’s lame and I really don’t mean that in some kind of A is for Anarchy type way. I just think that its kind of nice that something as perfectly functional as math can kink up around the edges.

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Here is another one: e to the x

Photographer’s comment:

My good friends, Nina (L) and Margot (neck/R) are both in the the fields of economics and math. It has some beautiful amazing explanation that I can’t regurgitate well enough to explain. I’ll have them give me a one liner and then I”ll post it here.

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“Licorne” test in French Polynesia 1970, (France) (click on the image for a stunning large version)

Click on the image for a better view. Licorne test July 3rd 1970

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It is beautiful in its destructiveness

The event, which will take place at institutions around Manhattan at the end of May, features a variety of scientific and cultural events intended to help connect the public to science. What’s in store? Two of the Festival’s prime movers, physicist Brian Greene and actor Alan Alda, some fascinating talks, the heads of many of New York’s educational institutions, and a performance by Bunsen Honeydew of Muppet Labs.

The Festival is all about reminding people that “we live in a world that runs on science,” Alan Alda said, “we can become excited by science if we hear about it from people who really love it

Beyond Einstein
1:00 PM - 2:30 PM , NYU - Kimmel Center for University Life

In Search of the Ultimate Explanation — Join leading physicists Leonard Susskind and Jim Gates, historian of science Peter Galison, and Nobel Laureate Paul Nurse for a spirited discussion of the progress and implications of Einstein’s dream of a unified theory of physics

Next time a person tells me that I don’t need a digital camera with more than 6-10 mega pixel resolution, I am going to hit him/her on the head with the sharp corner of my camera (my potential targets here, here and all over).

People who say that you don’t need more than 6 Mega pixel resolution in your camera are the same people who proclaimed “64K computer memory should be enough for anybody”.

These myopic folks miss the basic point of why one takes pictures. One does not take pictures to print out 3×4 prints from the local drug store; one takes pictures to preserve the memory, capture the moment for ever.

When people are running away from their burning house, what do they grab first? their old pictures! It is one of the most precious possession in people’s lives. Why would you want the most precious thing in your life to be of a mediocre quality?

When I click the shutter on my camera, I want to capture at least what my eyes can see. Apparently, if you converted the resolution of what an eye can perceive in to mega pixel, it turns out that an eye can see at 576 Mega pixel. So, I want my camera to be at least 576MP camera; is that too much to ask?

When I look out, I see in stereo; with full depth - is it too much to expect that my camera does the same?

I want to take pictures for the unknown technology that will be available to me in 20 years, not for the 3×4 print that can be printed now! Even today, there are methods that can take a regular print and create a 3D scene out of it. God know where this technology will be in 20 years. And when that technology is available, do I want a digital picture taken at resolution of 5MP or 500MP?

Even the displays are getting bolder and sharper. In 20 years, there may be life like displays, and on that display, would you like to use a picture taken with 5MP or 500MP resolution? When you recreate that precious moment in holographic 3D, which image do you think will show the details?

The main mistake these so called “experts” make, is that they believe that the only thing that can and will be done with a digital image, is to print it! A digital image is nothing but a piece of digital data; you can do a lot with it and when you are manipulating data, it is better to have as much original data as possible! It is not about being able to crop the image, it is about preserving most available data for future technology and processing advances.

If I can’t afford to buy 576MP camera or I can’t handle a multi lens camera, that is a different story; just don’t patronize me and tell me that I don’t need anything beyond 6MP camera.

Here is an example of a gigpixel image; see how much you can capture.

You can also visit the gogapxl image gallery.

<Rant complete> We now return you to our regularly scheduled program.

The plane’s near-supersonic speed changes the temperature and pressure of the air around it, causing ambient moisture to condense. Clouds naturally follow.

As an attorney and as a physicist, people have asked me about my views on the recent law suit to stop the Large Hadron Collider. In the law suit, a few concerned individuals have argued that LHC might create blackholes and endanger our planet, and hence any further work on LHC should be stopped.

I support the plaintiffs in this case and also plan to provide free legal services to them. I think this is the least I can do to help the humanity.

I am against LHC, not because I am afraid of micro-blackholes, or that some worm-hole will be created (I know these objects: I co-edited a book called Blackhole, wormholes and superstrings eons ago), I am against LHC because I do not want Higgs particle to be found, period. Life will be so boring if Higgs particle was indeed in the range that it is expected. I want physicists to keep struggling to find something beyond the God particle.

I would take the $8-10 Billion dollars that it is going to cost and get 100,000 more high energy theorists to start working on all the unsolved problems - I think the humanity will learn much more from 100,000 theorists then it will from LHC operations.

Physicists make it soooo easy to pursue these kinds of law suits because physicists are incapable of saying that something is “impossible”. As the law suit says :”No absolute refutation of the adverse scenarios that have been described has yet been articulated”

I’ll give you a simple example, ask any person “what are the chances that you will win$10 Billion in a lottery by next month?” Answer would be “impossible, because no state/country offers $10B in lottery prizes and then on top of it, for me to win that prize is just not going to happen”. Ask the same question to a physicist and chances are he/she will start calculating the chances of accumulating the powerball prize, buying all possible lottery tickets, chances that dollar will devalue so much that 1 Euro will be worth $1M and then come up with a probability that you will win $10 Billion next month. As I said, physicists are incapable of saying that something is impossible.

<Posting on April 1st - filed under Physics Humor>

All physics & Math PhD students should be required to get a tattoo of the most important equation from their work.

Notes about the above physics tattoo:

“I’m currently a Ph.D. student studying maths in Australia (submitting next week). The the tattoo on the top, I got about three years ago in Berkeley, CA. The other tattoo I got about a year later in Sydney, Australia. Both these tattoos are closely related to the research I’ve done for my Ph.D., which is in the area of elliptic partial differential equations. The top equation is called the Monge-Ampere equation and is the archetype of the equations I currently study. The bottom equation is called the ‘Infinity Laplacian’ and was chosen because it is correlated to variational theories which I find to be beautiful. Loosely speaking these equations are correlated to how surfaces (in arbitrary dimension) bend and curve. I figured since I did half my Ph.D. in the US and half in Australia, I would get at least one tattoo in each of those countries. The tattoos are meant to represent a memory of the time I spent in my studies.”

Tattoo from Greg, via Carl Zimmer

This full-scale Schlieren image shows the discharge of a .44 Magnum revolver.

The basic optical Schlieren system uses light from a single collimated source shining on a target object. Variations in refractive index caused by density gradients in the fluid distort the collimated light beam. This distortion creates a spatial variation in the intensity of the light, which can be visualized directly with a system designed to capture shadows.

Two spherical shock waves are seen, one centered about the gun’s muzzle (the muzzle blast) and a second centered on the cylinder.

The supersonic bullet is visible at the far left.

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Here are some of the most common physics errors in SF movies:

• There’s no sound in space - next time I hear an explosion when a spaceship breaks apart, I am calling the physics police. Also, sound and light don’t travel at the same speed and can’t arrive at the same time!
• There are no fires in space - even if you provided oxygen, the vacuum of the space will dissipate it all so fast! No flaming things in the space please.
• You can’t see a laser beam in space. You see the laser beam on earth because of the reflections from the dust particles.
• And there’s no reason why someone would move in slow-motion in zero gravity; in fact, they should be moving around much faster. Stop showing those goofy slo-mo movies.

The bad movie physics - report card.

Help, I am a multidimensional being trapped in a linear time-space continuum!

-273 degrees celcius is the coolest.

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Click for a better view.

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