One of the most mind-opening talks I've ever been to was Tamara Munzner's talk at SIGGRAPH '95. In hyperbolic space, as you get closer to an object, it gets larger. Not just appears larger, gets larger. This is incredibly useful for visualizing very large networks.
Tamara kind of dropped off my radar for a few years, but if you look at her software page, there is cool, related stuff there, including an SGI tool for managing web content.
Question for Bill and Suz: does anybody in network management use this stuff, or related ideas?
Question for Wook: can we use this somehow to visualize the state of a quantum computer? This would be highly non-representational, I think, but so is the Bloch sphere (see this text description from Mathworld and this GUI and animation).
Monday, February 21, 2005
Sunday, February 20, 2005
Qubit News, Qulink and the Quantum Pontiff
That last bit, on the Deloitte report, I cribbed from Qubit News, an excellent source of info on upcoming conferences and whatnot.
For what's up in the Kanto area (around Tokyo), see Kae Nemoto's Qulink.
A chattier resource is Dave Bacon's Quantum Pontiff.
For what's up in the Kanto area (around Tokyo), see Kae Nemoto's Qulink.
A chattier resource is Dave Bacon's Quantum Pontiff.
Deloitte on quantum computing
Deloitte has published a report titled, "TMT Trends: Technology Predictions 2005", and it includes quantum computing. PDF is here; they kind of buried the link.)
It's a tad breathless in its assessment, but they conclude in part, "Companies must start giving serious thought to the implications of quantum computing technology...Even during the development phase, the by-products of quantum computing research will have a significant impact on every aspect of computer technology...And when someone, somewhere produces the first commercially viable quantum computer - which is only a matter of time - it will change everything."
It's a tad breathless in its assessment, but they conclude in part, "Companies must start giving serious thought to the implications of quantum computing technology...Even during the development phase, the by-products of quantum computing research will have a significant impact on every aspect of computer technology...And when someone, somewhere produces the first commercially viable quantum computer - which is only a matter of time - it will change everything."
new single-photon source?
A Caltech press release from the Harry Atwater group touts a nanocrystal-based approach to creating photons in silicon structures, published in Nature Materials. A nanobead's size regulates the frequency of photon created, and the small size also makes it possible to inject single electrons and single holes to make photons one at a time - VERY useful for quantum computing.
The press release doesn't discuss the critical technical details of how accurately we can control the timing of the recombination of the electron and hole to create a photon - we want this in attoseconds, if possible, femtoseconds for sure. The other big question is how the direction of emission can be controlled.
I haven't read the actual paper yet, am looking forward to it...
The press release doesn't discuss the critical technical details of how accurately we can control the timing of the recombination of the electron and hole to create a photon - we want this in attoseconds, if possible, femtoseconds for sure. The other big question is how the direction of emission can be controlled.
I haven't read the actual paper yet, am looking forward to it...
Wednesday, January 05, 2005
1.0.4: A new analogy
It seems we're still having some trouble with the fundamental idea that a quantum register, the data storage part of a quantum computer, doesn't normally hold programs, and can only be looked at under tightly constrained conditions before the computation is complete. Let me try a new analogy:
Quantum computing is like CAM - computer aided manufacturing. Better yet, it's like the computed holograms of Mark Holzbach and company at Zebra Imaging. You have a program that runs on your (classical) computer that controls some physical devices such as lasers that illuminate parts of your output (the hologram, or our quantum register) and create interference patterns on the film or the quantum superposition. When you're done, you "develop" it (measure it, in quantum computing), and then you can look at the result.
The analogy isn't perfect; in a quantum computer, you can look at part of the register and get some information out. This is called taking a partial trace, and is critical for the implementation of quantum error correction. You can also use one or more qubits as control lines for gates, so there is a way to get some conditional behavior. However, at the level we are currently working, this is a very far cry from anything like a stored-program computer.
Link of the day: a table of quantum computer simulators from Julia Wallace. Some date as far back as 1994.
Quantum computing is like CAM - computer aided manufacturing. Better yet, it's like the computed holograms of Mark Holzbach and company at Zebra Imaging. You have a program that runs on your (classical) computer that controls some physical devices such as lasers that illuminate parts of your output (the hologram, or our quantum register) and create interference patterns on the film or the quantum superposition. When you're done, you "develop" it (measure it, in quantum computing), and then you can look at the result.
The analogy isn't perfect; in a quantum computer, you can look at part of the register and get some information out. This is called taking a partial trace, and is critical for the implementation of quantum error correction. You can also use one or more qubits as control lines for gates, so there is a way to get some conditional behavior. However, at the level we are currently working, this is a very far cry from anything like a stored-program computer.
Link of the day: a table of quantum computer simulators from Julia Wallace. Some date as far back as 1994.
Saturday, December 18, 2004
Blogalog 1.0.3: qubits v. quantum gates
There are a ton of interesting thoughts in Wook's latest posting. I think we'll leave the bigger issues of quantum architecture for a later posting, though I'm looking forward to that. In the meantime I'll encourage you to Google on "quantum Turing machine" and noodle on which parts of the TM need to be quantum. For some concrete stuff on where we are with this, see the references from my Aqua recommendations page and my arithmetic page.
One bit of terminology we ought to straighten out. There are two types of qubits, "flying qubits" and static ones. Flying qubits are typically something like photons. They pass through devices that cause computation, something like data values pass through gates in a classical circuit. Many quantum computing technologies use static ones, such as quantum dots or the spin of atomic nuclei. In that case, a qubit is like a bit in a register, and the "gates" (often microwave pulses) feel more like instructions to a classical computer architect. The "program" is usually called a quantum circuit in either case.
So, rather than saying that a PDP-8 takes 10k gates for its CPU, the question is, how many bits of storage does it have? A machine that can run a program might want, say, a few kilobytes.
In most quantum computing proposals, an underlying assumption is that all qubits are equal; any qubit storage location can be manipulated in an arbitrary way. It's like they are all bits in a classical register; there is no RAM/register distinction and no "load" instruction. One of the few proposals that separates qubit storage from "action" locations is the scalable ion trap processor from the Wineland group at NIST. See http://qubit.nist.gov/ and the Kielpinski Nature paper. We in the Itoh group have been thinking about how to combine different storage technologies into a larger device, like the difference between cache and RAM. Haven't gotten very far yet.
This has already gotten long, so I'll leave simulation and the qubit flythrough for another posting.
One bit of terminology we ought to straighten out. There are two types of qubits, "flying qubits" and static ones. Flying qubits are typically something like photons. They pass through devices that cause computation, something like data values pass through gates in a classical circuit. Many quantum computing technologies use static ones, such as quantum dots or the spin of atomic nuclei. In that case, a qubit is like a bit in a register, and the "gates" (often microwave pulses) feel more like instructions to a classical computer architect. The "program" is usually called a quantum circuit in either case.
So, rather than saying that a PDP-8 takes 10k gates for its CPU, the question is, how many bits of storage does it have? A machine that can run a program might want, say, a few kilobytes.
In most quantum computing proposals, an underlying assumption is that all qubits are equal; any qubit storage location can be manipulated in an arbitrary way. It's like they are all bits in a classical register; there is no RAM/register distinction and no "load" instruction. One of the few proposals that separates qubit storage from "action" locations is the scalable ion trap processor from the Wineland group at NIST. See http://qubit.nist.gov/ and the Kielpinski Nature paper. We in the Itoh group have been thinking about how to combine different storage technologies into a larger device, like the difference between cache and RAM. Haven't gotten very far yet.
This has already gotten long, so I'll leave simulation and the qubit flythrough for another posting.
Blogalog 1.0.2: Skin
We'll get to the latest questions on quantum computer architecture shortly. Meantime, a CG question:
What's the latest on human skin? I've heard (from you) that it's extremely tough because it's partially translucent; I assume the way it stretches, folds, and wrinkles are tough to get right, too.
What's the scoop? Is anyone making significant progress?
What's the latest on human skin? I've heard (from you) that it's extremely tough because it's partially translucent; I assume the way it stretches, folds, and wrinkles are tough to get right, too.
What's the scoop? Is anyone making significant progress?
Wednesday, December 15, 2004
blogalog on QC (quantum computing) & CG (computer graphics)
Wook and I are going to do a blogalog on quantum computing and computer graphics. He asks stupid questions about the former, I ask stupid questions about the latter, maybe a person or two learns something. Sometimes they'll be low-level questions, but I hope that sometimes they will also be thought-provoking.
All right, first question:
I'm doing some graphics for my quantum computing stuff, and I need to pick the location of the camera and which direction it is pointing in. I want all of my objects to appear at reasonable sizes, and the frame to be mostly full, and nothing to be cut off. My objects (just spheres and some pipes and some floating text) are of a fixed size, but the number and location vary according to the size of the quantum algorithm I'm animating, and the specific quantum computer topology. Often they are in a line, sometimes they are in a 2D grid, later they will be in more complex arrangements.
How do I pick my camera location and pointing direction?
All right, first question:
I'm doing some graphics for my quantum computing stuff, and I need to pick the location of the camera and which direction it is pointing in. I want all of my objects to appear at reasonable sizes, and the frame to be mostly full, and nothing to be cut off. My objects (just spheres and some pipes and some floating text) are of a fixed size, but the number and location vary according to the size of the quantum algorithm I'm animating, and the specific quantum computer topology. Often they are in a line, sometimes they are in a 2D grid, later they will be in more complex arrangements.
How do I pick my camera location and pointing direction?
Monday, December 13, 2004
Aqua: Advancing Quantum Architecture
Okay, so I'm way behind on posting to the blog. I've been sticking to that 20th
century technology, the mailing list.
century technology, the mailing list.
At any rate, this is a test to see how long it will take Google to pick up the new Aqua (Advancing Quantum Architecture) web page I've created at
http://www.tera.ics.keio.ac.jp/person/rdv/quantum/index.html.
Friday, August 13, 2004
Firefox test
Just a test to see if Firefox works with the Blogger WYSWIG editor...
Have doubts about the Firefox Japanese support, may need to download a different version...
Have doubts about the Firefox Japanese support, may need to download a different version...
Saturday, July 17, 2004
Goodness Gracious
Goodness Gracious
(played uptempo, with a good acoustic guitar hook)
I think this song was written a couple of years prior, during the Bush
I years. Big deficits, AIDS, the first Iraq War, the spook in the
White House.
But, I was struck by how relevant the lyrics seem today.
Kevin Gilbert was part of Toy Matinee, my own personal favorite One
Album Wonder. How many bands write songs for Salvador Dali and Vaclav
Havel? The solo album was recorded in his apartment in Pasadena.
Shortly thereafter, he died; I'm not sure how. Earlier he was part of
a band called Giraffe.
Within minutes of me sending out email, Myles had a link for me, and
there's now a Giraffe CD wending its way to Tokyo...
http://popplusone.com/
(played uptempo, with a good acoustic guitar hook)
Goodness Gracious is there nothing left to say?
When the ones that get to keep looking
are the ones that look away
It's pabulum for the sleepers
in the cult of brighter days
Goodness Gracious at the mercy of the crooks
We're broke and stroking vegetables
and there's way too many cooks
In every pot a pink slip, in every mouth a hook
Goodness Gracious I'm not listening anymore
Cause the spooks are in the White House
and they've justified a war
So wake me when they notify
we're gonna fight some more
Goodness Gracious not many people care
Concern is getting scarcer
true compassion really rare
I can see it in our faces, I can feel it in the air
Goodness Gracious me.
Goodness Gracious my generation's lost
They burned down all our bridges
before we had a chance to cross
Is it the winter of our discontent or just an early frost?
Goodness Gracious of apathy I sing
The baby boomers had it all and wasted everything
Now recess is almost over
and they won't get off the swing
Goodness Gracious we came in at the end
No sex that isn't dangerous, no money left to spend
We're the cleanup crew for parties
we were too young to attend
Goodness Gracious me.
Goodness Gracious my grandma used to say
The world's a scary place,
things were different in her day
What horrors will be commonplace
when my hair starts to gray?
--
Kevin Gilbert
from the album "Thud", 1994
I think this song was written a couple of years prior, during the Bush
I years. Big deficits, AIDS, the first Iraq War, the spook in the
White House.
But, I was struck by how relevant the lyrics seem today.
Kevin Gilbert was part of Toy Matinee, my own personal favorite One
Album Wonder. How many bands write songs for Salvador Dali and Vaclav
Havel? The solo album was recorded in his apartment in Pasadena.
Shortly thereafter, he died; I'm not sure how. Earlier he was part of
a band called Giraffe.
Within minutes of me sending out email, Myles had a link for me, and
there's now a Giraffe CD wending its way to Tokyo...
http://popplusone.com/
welcome
People have been telling me for a while that I should be blogging, rather than just sending out tons of email. So...
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