The Birth of Quantum Biology 108
Roland Piquepaille writes "Just when you finally have grasped the concept of quantum mechanics, it's time to wake up and to see the arrival of a nascent field named quantum biology. This is the scientific study of biological processes in terms of quantum mechanics and it uses today's high-performance computers to precisely model these processes. And this is what researchers at Rensselaer Polytechnic Institute (RPI) are doing, using powerful computer models to reveal biological mechanisms. Right now, they're working on a "nanoswitch" that might be used for a variety of applications, such as targeted drug delivery to sensors."
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Same-sex appeal? I didn't know quantum physicists were mostly gay...
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Mod parent up (Score:1, Offtopic)
Re:Did someone say Quantum Biology? (Score:5, Funny)
Oh, they are just not sure - nobody's opened the closet yet to find out. =)
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MODS (Score:2)
Schrodengers Closet? (Score:4, Funny)
No, it will not change the outcome. While the biologist is still in the closet unobserved they are both straight and gay at the same time. Note: this is different than bi, this is poly-phasic probabilistic sexuality. Only when the biologist is dragged out of the closet and observed will the quantum wave function collapse into a determined outcome.
This also begs for a joke about "entanglement" that I am going to pass on.
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I also wonder how this is at all new... she models inter-molecular protein reactions using high speed computers and the field has been doing so for quite awhile. The code is in Fortran77, as that seems to be the popular language for such research. It's not that it's not an interesting field, it's just not really a "nas
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Quantam bleep (Score:2)
Animal, vegetable, mineral -- we are all made of matter.
How is this any different? (Score:5, Interesting)
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HOW IS THIS A TROLL?? (Score:2)
Re:HOW IS THIS A TROLL?? (Score:5, Informative)
But when I realised how hard quantum simulations could be it started seeming reasonable again. Quantum simulations aren't just an order of magnitude more difficult. The order of magnitude of difficulty can itself be an order of magnitude bigger!
Re:How is this any different? (Score:5, Interesting)
This isn't anything new per se, just that the complexity of the modelled systems is getting larger, and due to the numercal estimation processes needed to get anything remotely usable these realms haven't been accessible until lately with the increase of computing power. So where does one draw the line between physics, chemistry, biochemistry, and biology? In these cases, what's being modelled are primarily systems consisting of electrons, neutrons, and protons, interacting with Coulomb force (like-charges repel), spin-orbit interactions, spin-spin interactions, Pauli-exclusion principle, etc. Add more atoms, system gets more complicated, and needs bigger computers.
So it's an age-old problem, using almost age-old numerical techniques, running on new shiny computing clusters
So... How much processing power do you want? (Score:2)
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Re:How is this any different? (Score:4, Informative)
The "spherical cow" case is similar. A uniform-density sphere is great for ballistics problems because you can characterize it with only 2 parameters: its radius and its mass. If it's a realistic cow, it becomes a lot more complicated... its mass is distributed non-uniformly, and it's got a complicated shape (and it can move!!).
The real art in physics is figuring out when you can use approximations! If a cow is orbiting the moon, it's probably an excellent approximation to treat it as a sphere in order to determine its orbit. But if a cow is dropped off a cliff, it's not such a good approximation... since its air resistance will depend a lot on its shape.
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Re:How is this any different? (Score:5, Informative)
So in some sense you know the basic 'laws' of the universe, and right now we have pretty reasonable understanding of most things, neglecting large scales (dark matter, dark energy) and large energies (Higgs boson, gravitons, etc). But for stuff within our local spheres of observation, we have basic laws that account for most things we can see, so we should theoretically be able to model anything in this frame. The problem is that it becomes super complex very quickly.
Okay, so why there are so few solvable problems is mathematical. Eg, in the hydrogen atom, we can easily solve the differential equation that comes from the Schrodinger equation. Ie, you write the kinetic energy as T=p^2/2m, you write the potential energy as U=-e^2/r, giving a total energy of E=p^2/2m - e^2/r. You should recognize this as the standard kinetic energy written using momentum instead of velocity, and the Coulomb potential energy between the electron and proton. The system is an electron orbiting a proton, and in the center-of-mass units r is the distance between the two, and m is the reduced mass, which is fairly close to the electron. This is all well and good, and when put into the realm of quantum mechanics, r and p go from being canonical coordinates to being canonical operators. When put into the position basis, the p operator acts as a derivative of the r coordinate, and this yields a differential equation that must be solved to give the eigenstates of the solution. The system is spherically-symmetric which makes things much easier, and after solving the three-dimensional 2nd-order differential equations you get the solutions of atomic orbitals that you probably studied about in high-school chemistry class.
Now this is the 'simple' system. When you start adding relativistic corrections to that kinetic energy and when you add the interaction of the electron's magnetic moment interacting with the magnetic field creating as it orbits the proton, this yields the fine structure. You can also add in the spin-spin interaction between the magnetic moment of the electron and the proton, which gives the hyperfine interaction. Each of these things makes the differential equations MUCH harder to solve, and at some point we just don't mathematically know how to solve these complex systems of equations. Helium atom gets much harder because there are now two position coordinates of each atom, and an extra Coulomb interaction term. This is a quantum three-body problem, and even in classical mechanics the three-body problem cannot be solved in general. Ie, there is no KNOWN exact solution for any three bodies.
Anyway, you can see where this is going. But while we cannot know exact solutions, we can approximate them numerically to arbitrarily-small precision (at least with classical mechanics where there is no uncertainty principle). This is where the shiny computers come in. We can model easily how 10 bodies orbit around the sun AND interact with each other, but to get a general algebraic solution of them for any point in time, we cannot do.
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So in essence we can get "good enough" approximations. Is there evidence that you can get significantly more explanatory power by trying to take into account all the additonal factors? Is it a problem of observation (data acq) or of processing power?
When I ask this I'm thinking of a note in Brian Goodwin's book How the Leopard Changed Its Spots, in which the author (very gently IMO) takes proponents of the Modern Evol
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Using todays supercomputers, we can deal with about ten thousand atoms. So by Moores law, it takes eight years to double the number of atoms.
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It sounds like plain biochemistry given a new window dressing.
Not exactly ... there's actually something new here (2-3 years old in fact).
There are 3 "levels" of Computational chemistry :
- ab-initio method : a resolution of the Schrödinger equation for the studied system with only a few approximations mandatory to solve problem more complex than the hydrogen atom. This method is fairly demanding on number crunching power and is applied on models of hundreds of atoms.
- semi-empirical method
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Uncertainty principle and medicine (Score:5, Funny)
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So Schrodinger's Cat... (Score:1)
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DISCLAIMER: No, I am not a creationist.
No - the Cat's Schrodinger... (Score:2)
Curious (Score:1)
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Doesn't work (Score:5, Funny)
Teh awesome (Score:1)
Re:Doesn't work (Score:5, Funny)
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But the cat fries it generates are deeelicious! My dog especially loves 'em.
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Very funny... (Score:3, Funny)
If that's the case, I invented this 26 years ago!
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1966 (Score:3, Informative)
Required training for Schrodinger's vet (Score:1)
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What a brilliant idea - "Schrodinger's vet (bill)" - finally - a way to combine Schrodinger's cat [wikipedia.org] and Bistromathematics [wikipedia.org]:
to whit:
"What will Schrodinger's vetrinarian charge you, depending on whether the cat is dead or alive".
Modeling PROTON tunneling? (Score:2)
Overhyped (Score:3, Interesting)
Precisely modeling these processes? Biggest overstatement EVER. Total hype.
When looking at large systems you are screwed and you can generally screw yourself in 1 of 2 ways:
1) Preciesly model few configurations, in which case, your results are not comparable to reality, which is an ensamble average over billions of configurations
2) Model things in an emprirical/semi-empirical, yet surprisingly CRUDE way: allowing one to sufficiently sample phase space, but not in an analytically useful way.
Quantum mechanics in biological systems are typically done with QM/MM, where the "QM" is semi-EMPIRICAL, i.e., it takes parameters. These methods and parameters were NOT designed with biological systems in mind. They were chosen to reproduce small molecule heats of formation. People have found that they work poorly for biological studies unless they are reparametrized (quite frankly, you need to know "the answer" in order to get "the answer" "right") or unless other post-priori, ad hoc corrections are applied. Only a small portion of people who use QM/MM actually reparatrize the semiempirical method and those who do find the new parameters are not very transferable for use between different types of biological systems. For crying out loud, most semiempirical hamiltonians don't even provide the functional forms needed for some of the most basic molecular interactions, e.g., London dispersion, proper polarization to external fields, hydrogen bonding, orthogonalization errors in torsional barriers, etc..
This stuff isn't really new and it's extremely overhyped.
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This stuff isn't really new and it's extremely overhyped.
I agree on the overhype. What the article fails to properly elucidate is that this is a common expansion of existing molecular modeling techniques. All modern molecular modeling simulations are based on equations of force and motion experienced by the individual atoms. Even with "simple" interactions such as electrostatics, the equations are often rendered into power series approximations of the more complicated higher order equations. This makes it easier to do computationally intensive calculations
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Quantum mechanics in biological systems are typically done with QM/MM, where the "QM" is semi-EMPIRICAL, i.e., it takes parameters. These methods and parameters were NOT designed with biological systems in mind. They were chosen to reproduce small molecule heats of formation. People have found that they work poorly for biological studies unless they are reparametrized (quite frankly, you need to know "the answer" in order to get "the answer" "right") or unless other post-priori, ad hoc corrections are applied.
By the sounds of it, you are just parameterizing yourself practically back to MM with fudged factors to allow bond-breaking etc. Are you saying QM/MM cannot be used to predict an enzyme mechanism? Is this a limit of current quantum theory or a limit because of calculation times? I'd appreciate any good recent references.
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That's the big variational transistion state theory guy, right? Pay special attention to the details of how those potential energy surfaces are contructed - especially from the groups at that university. All of their QM/MM results match experiment almost perfectly (because after doing a QM/MM simulation they either "correct" the resulting "potential of mean force" curves or "correct" the effective PES o
Wasn't this an Episode... (Score:1)
Cool (Score:2)
just quoting the article (Score:2, Insightful)
Great work but not quite Quantum Biology (Score:2)
Puhleease: Put Roland Piquepaille blog elsewhere (Score:5, Insightful)
I read
Roland Piquepailles submissions has not met this criterium. At least filter away the combination "Piquepailles", "nano" and "quantum".
Take a bottle of nano-beer (yes the water molecules are nano particles), eat some nano-pretzels (the baking soda produced a nano-gas that puffed them up), and run this script.
Here is one of many greasemonkey script to remove piquepaille stories
http://userscripts.org/scripts/show/5735/ [userscripts.org]
You should mod this up if you agree or mod away as flamebait/offtopic/troll if you dont agree, but at least mod it.
Re:Puhleease: Put Roland Piquepaille blog elsewher (Score:2)
"Here is one of many greasemonkey script to remove piquepaille stories." Apparently it doesn't work very well...?
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Re:Puhleease: Put Roland Piquepaille blog elsewher (Score:2)
Re:Puhleease: Put Roland Piquepaille blog elsewher (Score:2)
There's a place for your rant, but this submission is not it.
Re:Puhleease: Put Roland Piquepaille blog elsewher (Score:2)
Misleading article summary (Score:2)
My physics professors always made fun of people who talked like this. Nobody has ever "finally grasped the concept of quantum mechanics".
Your so wrong... he obviously never met... (Score:1)
Anesthesia (Score:1)
Won't need an epidural for that.
HyperNanoQuantumium (Score:2)
I think Hyper- has gone out of fashion recently just like Super- went out of fashion long time ago. Our university still has a department called Hypermedialab - now it just sounds so 90's and cheese...
Incidently I'm looking for a grant for my biology research on Supercalifragilisticexpialidocious-cells...
Sincerely
Dr. Johann Gambolputty de von Ausfernschplendenschlittercrasscrenbonfri
I've always wondered about this (Score:2)
One of the things I've wondered about in the past is that of supposed ps
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But suppose there were some fancy physics that could form the basis for direct brain-to-brain communication. What would have happened during natural selection? If such a mechanism were available, surely it would have been selected for over speech. Speech requires years before users master it
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Maybe the curent world situation is a mess of the telepaths' making, to keep us normals distracted while they hang out in their clubhouse with their cigars and champagne and telepathic passwords.
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Entanglement (this "spooky action at a distance") can, however, be used to increase (double, in fact) the bandwidth of classical communication. See superdense coding [wikipedia.org]. It can be argued that since we can communicate classical information at the speed of light without entanglement, superdense c
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Supposing there were su
Penrose (Score:1)
Another book I read on the subject a long time ago was The Quantum Brain, by Jeffrey Satinover.
Wrong Name (Score:2)
They may be looking at smaller things, but not small enough to consider quantum effects. I wonder if the scientists themse
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Proteome (Score:1)
Who let Roland the Plogger have a blog link? (Score:2)
It's Roland the Plogger, trolling for his blog again. For a while, Slashdot was careful about not letting him get a link to drive traffic to his blog, but somebody slipped up.
Right... (Score:2)
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Whats the difference... (Score:1)