What the *****?

This thing isn’t an everyday sight for most people, but it is for Quantum Diarist Shohei Nishida. Can you guess what the ***** it is? (Hint: It has something to do with physics.)

Write your hunches, notions, suspicions, and speculations about the thing in this photo in the comments section below. Use your real e-mail address (feel free to substitute "at" for "@" or use any other obvious method to obscure), because the person who guesses correctly or—in the absence of a correct guess—guesses most creatively will win a fabulous World Year of Physics T-shirt. The deadline for submitting your guess is Friday, July 29.

As this week progresses, Shohei will drop hints about the photo to point you in the right direction, so check back often and guess as many times as you’d like. On Friday, he will reveal what the ***** this really is.

Everyone is invited to participate, but if you are a physicist and know what this is because of your work, please give others a chance and hold back your guess. We know you’re smart.

Good luck!

Comments

[Mark Martin]

I'm guessing that the object in the photograph is a block of scintillating material, for use in a high energy collision detector: a calorimeter.

[Dennis Sustare]

It's an aerogel! ("solid smoke")

[Selva]

Any hints?

[Greta Wu]

It is Aerogel.

[Gp]

Its an Aerogel. or it could be a supersolid jelly, yum yum. Im hungry!

[Mark Martin]

It is a block containing an aerogel, for use as a Cherenkov counter in the KEK Belle detector.

[Gordon Stangler]

I think it is a block of dye impregnated Lucite to be used for cosmic ray detectors.

[Till]

That's easy. It's a slab of "that" new meta-material, in which light travels so slowly that what we actually see in the picture is the state of the lab as it was a few days ago, when it was presumably much more in order than it presently is (2nd law of thermodynamics). It's a very useful thing to have as well, for example, you can use a slightly thinner version to take your own portrait, as you will have just enough time to walk around the table and capture the image when it arrives.

[Jim Canterbury]

Its transparent aluminum

[Matthew Tammen]

Hello There
The gomment posted by Till on july is correct. It is transparent aluminum.

[Shoei Nishida]

Hello everybody,

Thanks for many replies. I'll let you know the correct answer,　because some of you got it. The answer of the photo is
- "Aerogel".
Aerogel is the lightest solid material, probably. It's almost　transparent as you can see, but it's fragile.

This aerogel is used in the Belle experiment at KEKB, as one of you　pointed out. The next question is then
- How (or for what purpose) is this used?
You may answer the usage in the Belle　experiment (this might be easy for high energy physicist) or other usages in general.

Shohei

[Mark Martin]

The aerogel is is chosen for its low refractive index, meaning that it yields Cerenkov radiation only above a certain critical velocity for passing particles. This allows for the discrimination between pions and other species of particles which may have velocites close to that typical of pions.

[Greta Wu]

Aerogel can be used as insulators or light-weight structures.

[Yinpeng zhong]

大概是类似隐身衣的东西吧，这个东西吸收一边的光线，然后在另一边放出完全一样的光线，看上去就是透明的了

[Rohan Mittal, Rg]

It's Aerogel: A silicon-based substance and the world's lowest-density solid composed of 99.8% air and is a stiff foam with a typical density of 3 mg per cm3 nicknamed frozen smoke or blue smoke.

It appears bluish because the silicon dioxide scatters longer wavelengths of light much like air in the daytime sky. Despite its diaphanous appearance, it feels like hard plastic foam.

Aerogel has many interesting properties:
* a highly dendritic structure
* extremely low thermal conductivity (approx. 0.017 W/mK), which gives it remarkable insulative properties
* a melting point of 1,200 °C

Aerogel holds 15 entries in the Guinness Book of Records for material properties, including best insulator and lowest-density solid. Aerogel can support 2000 times its own weight without collapsing.

Aerogel was first created by Steven Kistler in 1931.

Aerogel can be made of many different materials; Kistler's work involved aerogels based on silica, alumina, chromia, tin and carbon.

There are a variety of tasks for which aerogel is used. Commercially, aerogel has been used in granular form to add insulation to skylights. Its high surface area leads to many applications, such as a chemical absorber for cleaning up spills. This feature also gives it great potential as a catalyst or a catalyst carrier.

NASA used it to trap space dust particles aboard the Stardust spacecraft. NASA also used aerogel to insulate the Mars Rover.

Due to their extremely high surface, carbon aerogels are used in supercapacitors, ranging up to thousands Farads of capacity.

Finally, aerogels are used in particle physics as radiators in Cherenkov detectors. ACC system of the Belle detector at KEKB is a recent example of such use.

Preparation: Aerogel is made by drying a gel composed of colloidal silica in an extreme environment. Specifically, scientists start with a liquid alcohol like ethanol and mix it with a silicon alcoxide precursor to form a silicon dioxide gel (silica gel). Then, through a process called supercritical drying, the alcohol is removed from the gel. This is typically done by exchanging the ethanol for liquid carbon dioxide and then bringing the carbon dioxide above its critical point. The end result removes all liquid from the gel and replaces it with gas, without allowing the gel structure to collapse or lose volume.

Commercial manufacture of aerogel blankets began around the year 2000. This blanket is a composite of silica aerogel and fiberous reinforcement that turns the brittle aerogel into a durable, flexible material. The mechanical and thermal properties of the product may be varied based upon the choice of reinforcing fibers, the aerogel matrix, and opacification additives included in the composite.

[Tony Tsiligiannis]

is there anyone who can explain to me how the physicist are so sure for the small black holes which created with the big bang and immediatelly disapeared. I meen that these black holes had less than 1000000000000000 gr mass more specificly less than the mass planc and disapeared in less than planc time which is 0.00000000000000000000001 sec if i am not wrong. So as i know physic can't study events which happen so rapidly. I am 16 years old from Greece so i would like to apologise for my English and my short of knowledge in physics. This e-mail adress belong to my father. please reply.

[Shohei Nishida]

Hi Rohan and all,

Great. Probably I don't need to make further explanation....

One thing I can add is that aerogel loses its performance such as transparency when it is exposed to humidity. In Belle, this problem has been solved by developping hydrophobic aerogels. So far, we see no significant degradation of the performance, fortunately.

Shohei

[QD Editor]

We have a winner! Congratulations to Dennis Sustare, who guessed "aerogel" on the first day. He won a World Year of Physics T-shirt. Thanks to all of you who contributed your expertise, creativity, and sense of humor to making this a fun event. Stay tuned for the next mystery photo!

Who is Dennis Sustare, after all? We asked him, and this is how he replied:

"I started out as a physics major at Caltech, way back in 1957. Alas, this was before Feynmann took over the freshman course. It was also a time in which I had more freedom than ever before in my life... and my studies suffered (though I was having lots of fun, including being in the pitcrew of a formula III car). I dropped out of college at the end of '59.

"Two years later, unemployed and not in school, with Vietnam heating up, and 1A in the draft, I decided the Navy was better than the Army. I spent my time as an electronics technician, and got out after four years active duty.

"I returned to college, this time in biology at the University of Texas, and did much better, graduating in '67. I then went to grad school at Wisconsin, involved in all that was going on politically, environmentally, socially, musically, and chemically. Somehow, I managed to get my PhD, with my research in sensory physiology of frogs and toads.

"I spent six years teaching at an engineering school, Clarkson College (up near the Canadian border in New York state), but did not get tenure. Fortunately, I was able to get a job in game design at Coleco, and essentially doubled my academic salary. I had always wanted to get back to Texas, though, and when I got the chance after six years in Connecticut to transfer to Texas with an aerospace job, I jumped at it. I've been working for that company ever since (though it has changed names and ownership several times).

"And no, I'm not working in either physics, biology, or game design now. Mostly analysis and some software and human interface design.

"I've always stayed interested in both physics and space (I was a kid in Cocoa Beach), and discovered the Quantum Diaries on one of my web-snooping days.

"I learned about aerogels from their potential space applications, though. They are so strange, and cool!

"Favorite diarist? Would probably be Maaike Limper, if I could just read Dutch. ;-) So probably either Stephon Alexander or David Waller."

Thanks for participating, Dennis, and congratulations again.