How much more can we reasonably hope to learn from practical physics?
January 5, 2010 3:35 PM Subscribe
How much more can we reasonably hope to learn from practical physics?
To be clear, I'm not asking "Is it worth the cost?" or "What gadgets will we get out of it?"
Perhaps it will help to use a specific example. I'd like to know the ultimate fate of the Universe - not a matter of any great practical import. Could the $9 billion Large Hadron Collider tell us? (At least to the degree of certainty with which we have established the Big Bang.) Or would it take a $900 billion Super Enormous Hadron Collider? Or is it even determinable by any physical experiments we can presently conceive?
If TUFOTU is out of reach for budgetary or scientific reasons, then the question becomes: What can we hope to learn from any physical experiments within the realm of feasibility?
And how large an expansion of our current knowledge would those hoped-for discoveries represent? Would it only be sharpening the focus of a picture we've already more-or-less drawn? Or would it be filling in the "Here be monsters" part of the map for the first time?
Is practical physics already a poor relative to theoretical physics? Might the era of practical physics come to an end within the careers of today's graduate students?
To be clear, I'm not asking "Is it worth the cost?" or "What gadgets will we get out of it?"
Perhaps it will help to use a specific example. I'd like to know the ultimate fate of the Universe - not a matter of any great practical import. Could the $9 billion Large Hadron Collider tell us? (At least to the degree of certainty with which we have established the Big Bang.) Or would it take a $900 billion Super Enormous Hadron Collider? Or is it even determinable by any physical experiments we can presently conceive?
If TUFOTU is out of reach for budgetary or scientific reasons, then the question becomes: What can we hope to learn from any physical experiments within the realm of feasibility?
And how large an expansion of our current knowledge would those hoped-for discoveries represent? Would it only be sharpening the focus of a picture we've already more-or-less drawn? Or would it be filling in the "Here be monsters" part of the map for the first time?
Is practical physics already a poor relative to theoretical physics? Might the era of practical physics come to an end within the careers of today's graduate students?
Response by poster: GuyZero: "Do you consider materials science to be part of "practical physics"?"
[returning from having looked up what "materials science" is...]
I was thinking more of TUFOTU than new casing materials for iPods. But if the latter gives the physicists new work to do, that counts.
posted by Joe Beese at 3:53 PM on January 5, 2010
[returning from having looked up what "materials science" is...]
I was thinking more of TUFOTU than new casing materials for iPods. But if the latter gives the physicists new work to do, that counts.
posted by Joe Beese at 3:53 PM on January 5, 2010
Experimental physics can't be done without testable theories. Progress in theoretical physics can't be made without verification by experiments. I doubt there will be an end to either endeavor any time soon, unless civilization collapses or something like that.
posted by Blazecock Pileon at 3:56 PM on January 5, 2010
posted by Blazecock Pileon at 3:56 PM on January 5, 2010
What do you mean by "practical"? For example, superconductors used to be confined to the research lab and cryogenic temperatures. They now work at liquid nitrogen temperature, and are being pushed higher (along with truly practical parameters, like critical currents and materials-science techniques to strengthen the form) hopefully to room temperature.
There are other fields that have only begun to be explored. Quantum computing/information research only started in the 90's, and there are so many ideas and experiments being tossed around that I can easily imagine it going strong 100 years from now. Fusion research is hardly being done right now, too.
So is it crazy that a brand new line of research pops up within the next 100 years, which has another 100 for it? I think it's totally possible, especially if you count multidisciplinary things like biology+physics.
posted by gensubuser at 4:04 PM on January 5, 2010 [1 favorite]
There are other fields that have only begun to be explored. Quantum computing/information research only started in the 90's, and there are so many ideas and experiments being tossed around that I can easily imagine it going strong 100 years from now. Fusion research is hardly being done right now, too.
So is it crazy that a brand new line of research pops up within the next 100 years, which has another 100 for it? I think it's totally possible, especially if you count multidisciplinary things like biology+physics.
posted by gensubuser at 4:04 PM on January 5, 2010 [1 favorite]
TUFotU won't come from any one experiment. I'm sure the particle physicists might like to tell you it will from the LHC. As a cosmologist, I would love to tell you it will come from astronomical surveys and space science, not a tunnel under Switzerland. The truth is more likely that it will take both, and other experiments besides, just to get a good guess.
The truth is we won't know with certainty after any experiment, but we might know with some degree of confidence. It won't be anything that will impact the human race on any conceivable timescale, whatever those experiments might say.
We don't know if TUFotU or the Theory of Everything or whatever will ever show up at our doorstep, we don't know what discoveries are around the corner, and we don't know what impact they will have on our lives. We don't know what it will take before we run out of questions, big or small.
Experimental physics and theoretical physics are necessarily tied together closely, and neither is a poor relative to the other. Each is impotent without the other. We don't know if we will find an acceptable answer, the limits to testing of which are way beyond conceivable bounds or if we will be able to build a Larger Hadron Collider to find a deeper answer. We don't know if it will turn out to be 'turtles all the way down'.
We only know one thing for certain - it will be very, very interesting.
"Physics is like sex. Sure, it may give some practical results, but that's not why we do it." - Richard Feynman.
posted by edd at 4:10 PM on January 5, 2010 [1 favorite]
The truth is we won't know with certainty after any experiment, but we might know with some degree of confidence. It won't be anything that will impact the human race on any conceivable timescale, whatever those experiments might say.
We don't know if TUFotU or the Theory of Everything or whatever will ever show up at our doorstep, we don't know what discoveries are around the corner, and we don't know what impact they will have on our lives. We don't know what it will take before we run out of questions, big or small.
Experimental physics and theoretical physics are necessarily tied together closely, and neither is a poor relative to the other. Each is impotent without the other. We don't know if we will find an acceptable answer, the limits to testing of which are way beyond conceivable bounds or if we will be able to build a Larger Hadron Collider to find a deeper answer. We don't know if it will turn out to be 'turtles all the way down'.
We only know one thing for certain - it will be very, very interesting.
"Physics is like sex. Sure, it may give some practical results, but that's not why we do it." - Richard Feynman.
posted by edd at 4:10 PM on January 5, 2010 [1 favorite]
I think a fair number of these unsolved problems in physics will probably be settled by experimental evidence someday. I'd say many of these represent "here be monsters" territory.
For example, there is the small matter of of the incompatibility of quantum mechanics and general relativity. We don't yet even know whether gravitons (not to be confused with Gravitrons) exist. Ongoing (LIGO) and upcoming (LISA) experiments hope to find one, but what if they don't? Also, are the fundamental physical constants really constant, or do they change over time?
And don't worry, we'll think up new questions when we answer these.
posted by partylarry at 4:38 PM on January 5, 2010 [1 favorite]
For example, there is the small matter of of the incompatibility of quantum mechanics and general relativity. We don't yet even know whether gravitons (not to be confused with Gravitrons) exist. Ongoing (LIGO) and upcoming (LISA) experiments hope to find one, but what if they don't? Also, are the fundamental physical constants really constant, or do they change over time?
And don't worry, we'll think up new questions when we answer these.
posted by partylarry at 4:38 PM on January 5, 2010 [1 favorite]
One of the biggest remaining questions is this one: How, exactly, is it that mass can become energy, and energy can become mass? If we can find out the answer to that one, it'll be revolutionary.
posted by Chocolate Pickle at 4:45 PM on January 5, 2010
posted by Chocolate Pickle at 4:45 PM on January 5, 2010
Is practical physics already a poor relative to theoretical physics? Might the era of practical physics come to an end within the careers of today's graduate students?
It's the other way around. Experimental or practical physics has money. Theoretical physics doesn't have that much.
When I was doing undergrad physics a theoretical prof talked a bit about his career. He'd done brilliantly but was finding it incredibly hard to get a job. Experimental physicists on the other hand found all sorts of jobs. Optics, solid state physics, geophysics, quantum computing are continuously being worked on by many experimental physicists.
Theoretically we know how to create fusion power. Practically however....
posted by sien at 5:01 PM on January 5, 2010 [1 favorite]
The way an experimentalist changes the pretty walled garden worlds of the theorists is by finding a result that the theoreticians can't explain. The finding is more significant the less amenable to explanation it is.
To use your example, people are getting excited about the LHC because it's one of the current best chances to spit out a particle that the quantum mechanics can't explain. Now, the quantum mechanicians have had a good run; it's been 110 years since Plank first proposed quantization. Aside from gravity, there isn't anything in the universe current quantum mechanics doesn't explain very well. This makes a lot of physicists have itchy feet---we know QM isn't perfect; it doesn't explain gravity or the "arrow of time" at all---but it doesn't have (m)any identifiable holes.
This is where the LHC comes in. If it produces the predicted results, like a Higgs particle, this will be exciting because we know that QM explains even more of the universe. Fêtes and prizes will be had. However, if it produces a particle or an event that QM can't explain, then a new theory will be needed. You can bet that a whole host of physicists have this hope in their secret hearts.
New theories could, would, mean change that is unimaginable to us now. QM isn't the first "theory of everything" to dominate physical understanding. In the late 1800s, people thought that electro-magnetic theory had it all figured out and that nothing much would change in the future. Without QM, almost none of the artifacts of the 20th century would exist. Electronics and computers are obvious, but modern metalurgy, pharmacology and even space travel would not be possible without QM theory.
How would a new TOE change our world? That's an unanswerable question. In the same way that Jules Verne and Wells fell short of our 2000, I doubt that we would be able to understand (now) what future a change as fundamental as the dethroning of QM would be.
posted by bonehead at 5:22 PM on January 5, 2010 [1 favorite]
To use your example, people are getting excited about the LHC because it's one of the current best chances to spit out a particle that the quantum mechanics can't explain. Now, the quantum mechanicians have had a good run; it's been 110 years since Plank first proposed quantization. Aside from gravity, there isn't anything in the universe current quantum mechanics doesn't explain very well. This makes a lot of physicists have itchy feet---we know QM isn't perfect; it doesn't explain gravity or the "arrow of time" at all---but it doesn't have (m)any identifiable holes.
This is where the LHC comes in. If it produces the predicted results, like a Higgs particle, this will be exciting because we know that QM explains even more of the universe. Fêtes and prizes will be had. However, if it produces a particle or an event that QM can't explain, then a new theory will be needed. You can bet that a whole host of physicists have this hope in their secret hearts.
New theories could, would, mean change that is unimaginable to us now. QM isn't the first "theory of everything" to dominate physical understanding. In the late 1800s, people thought that electro-magnetic theory had it all figured out and that nothing much would change in the future. Without QM, almost none of the artifacts of the 20th century would exist. Electronics and computers are obvious, but modern metalurgy, pharmacology and even space travel would not be possible without QM theory.
How would a new TOE change our world? That's an unanswerable question. In the same way that Jules Verne and Wells fell short of our 2000, I doubt that we would be able to understand (now) what future a change as fundamental as the dethroning of QM would be.
posted by bonehead at 5:22 PM on January 5, 2010 [1 favorite]
One of the things often overlooked in these discussions is the fact that lots of interesting (both practical and impractical) stuff comes from looking in a place no one else has yet to look. What we find may not be the reason we're looking, but a good scientist and a healthy scientific ecosystem will notice the important stuff. It's also important to note there are a lot of places which we haven't yet been able to look, and it's not always about money some things take lots of time and development to really know what we're looking at.
The whole mesoscopic world (length scales too big for quantum but too small for classical physics) has an enormous amount of unexplored (and unexplained) territory. This gives rise to new theories, new modeling and simulation techniques, and lots of new practical applications (MEMS devices, new materials, etc.). In the end, new ways of looking at the world which we can then apply elsewhere...
posted by NoDef at 5:28 PM on January 5, 2010 [1 favorite]
The whole mesoscopic world (length scales too big for quantum but too small for classical physics) has an enormous amount of unexplored (and unexplained) territory. This gives rise to new theories, new modeling and simulation techniques, and lots of new practical applications (MEMS devices, new materials, etc.). In the end, new ways of looking at the world which we can then apply elsewhere...
posted by NoDef at 5:28 PM on January 5, 2010 [1 favorite]
How much more can we reasonably hope to learn from practical physics?
Depends how well we teach it. If we succeed in destroying basic physics competence at school, in fifty years we won't be doing enough practical physics to learn anything much.
posted by flabdablet at 5:33 PM on January 5, 2010 [1 favorite]
Depends how well we teach it. If we succeed in destroying basic physics competence at school, in fifty years we won't be doing enough practical physics to learn anything much.
posted by flabdablet at 5:33 PM on January 5, 2010 [1 favorite]
Hell, we've hardly even gotten started. If human civilization survives the next century or so, we'll see some kickass technology. Here's a list of some crazy stuff that I think is still to come:
Practical quantum computers - they exist, but they can currently only compute with a handful of bits - probably around 80 years for something useful
--- Revolution in cryptography
--- Acceleration of scientific and technological advance through computer simulation
--- Computational solution of outstanding mathematical problems
Room-temperature superconductors - watch the news - higher-temperature ones are being discovered all the time.
--- we still don't understand the physics of "high-T" SC alloys. Here there be monsters.
--- Massive reduction in transmission losses for electricity (currently ~7% of energy production is lost in transmission)
Fusion reactors - probably around 50 years. We understand much of the physics, but there be many monsters in the details and the engineering.
--- The last word on infinite energy sources. Once we figure this out, we'll have a useful energy source for as long as the stars are shining. No more messing around with pressurized plant fossils for energy.
Advanced nanomaterials - materials with structure engineered on the nanometer scale.
--- Anyone's guess what these could do. Look for magical optical properties, incredible electromagnetic properties.
--- Eventually silicon computer processor will be made obsolete by something from this field. You'll be able to play some freaking awesome 3-D first person shooters.
Genetic engineering - as we speak - we're on the cusp of this revolution.
--- Just last year a 100% artificial human-constructed bacterial genome has been built for scratch (Craig Venter decided it was too risky to bring it to life)
--- Bacteria are the nanomachines SF writers have been dreaming about. Want something done on a molecular level? Bioengineers will be able to make bacteria to do that.
--- Life itself can be our playground (we just have to get over our fear of it)
High-thrust ion rockets - next 20-30 years.
--- Speedy interplanetary personnel transport
--- Cheap space colonization
Suspended animation - not for a while
--- generational space travel for colonizing nearby star systems
Medical imaging - as we speak
--- Magnetic resonance technology is always improving, and it has a long way to go.
--- Resolution improvements could lead to much earlier detection of anomalies.
Medical advances
--- Watch for a cures for cancers in the next 10-20 years, vaccine for AIDs, etc.
Energy storage - as we speak
--- Within 20 years we'll probably have batteries (or fuel cell systems) that store more energy than your gas tank.
Solar cells - as we speak
--- The best solar cells commercially available convert 20-30% of incident energy into electrical energy. That figure is constantly rising.
Those are some of the things that I'm most excited about seeing from science in my lifetime. It's a very small sampling of what we're likely to get.
There are many undiscovered countries remaining in physics, and the wonderful thing is that it's nearly impossible to predict what the practical applications of them might be. For example, the marriage of general relativity and quantum mechanics will massively expand our understanding of how the universe works. The ideas people have come up to fill in these blanks are as varied and colorful (and some as ridiculous) as the monsters seafarers drew on the margins of their maps.
I hope I don't sound patronizing or annoyed - I'm not - it's an interesting question. Cheers!
posted by Salvor Hardin at 6:46 PM on January 5, 2010 [2 favorites]
Practical quantum computers - they exist, but they can currently only compute with a handful of bits - probably around 80 years for something useful
--- Revolution in cryptography
--- Acceleration of scientific and technological advance through computer simulation
--- Computational solution of outstanding mathematical problems
Room-temperature superconductors - watch the news - higher-temperature ones are being discovered all the time.
--- we still don't understand the physics of "high-T" SC alloys. Here there be monsters.
--- Massive reduction in transmission losses for electricity (currently ~7% of energy production is lost in transmission)
Fusion reactors - probably around 50 years. We understand much of the physics, but there be many monsters in the details and the engineering.
--- The last word on infinite energy sources. Once we figure this out, we'll have a useful energy source for as long as the stars are shining. No more messing around with pressurized plant fossils for energy.
Advanced nanomaterials - materials with structure engineered on the nanometer scale.
--- Anyone's guess what these could do. Look for magical optical properties, incredible electromagnetic properties.
--- Eventually silicon computer processor will be made obsolete by something from this field. You'll be able to play some freaking awesome 3-D first person shooters.
Genetic engineering - as we speak - we're on the cusp of this revolution.
--- Just last year a 100% artificial human-constructed bacterial genome has been built for scratch (Craig Venter decided it was too risky to bring it to life)
--- Bacteria are the nanomachines SF writers have been dreaming about. Want something done on a molecular level? Bioengineers will be able to make bacteria to do that.
--- Life itself can be our playground (we just have to get over our fear of it)
High-thrust ion rockets - next 20-30 years.
--- Speedy interplanetary personnel transport
--- Cheap space colonization
Suspended animation - not for a while
--- generational space travel for colonizing nearby star systems
Medical imaging - as we speak
--- Magnetic resonance technology is always improving, and it has a long way to go.
--- Resolution improvements could lead to much earlier detection of anomalies.
Medical advances
--- Watch for a cures for cancers in the next 10-20 years, vaccine for AIDs, etc.
Energy storage - as we speak
--- Within 20 years we'll probably have batteries (or fuel cell systems) that store more energy than your gas tank.
Solar cells - as we speak
--- The best solar cells commercially available convert 20-30% of incident energy into electrical energy. That figure is constantly rising.
Those are some of the things that I'm most excited about seeing from science in my lifetime. It's a very small sampling of what we're likely to get.
There are many undiscovered countries remaining in physics, and the wonderful thing is that it's nearly impossible to predict what the practical applications of them might be. For example, the marriage of general relativity and quantum mechanics will massively expand our understanding of how the universe works. The ideas people have come up to fill in these blanks are as varied and colorful (and some as ridiculous) as the monsters seafarers drew on the margins of their maps.
I hope I don't sound patronizing or annoyed - I'm not - it's an interesting question. Cheers!
posted by Salvor Hardin at 6:46 PM on January 5, 2010 [2 favorites]
Oops, I just noticed you asked specifically about physics. Sorry for the other stuff that slipped in there.
posted by Salvor Hardin at 6:46 PM on January 5, 2010
posted by Salvor Hardin at 6:46 PM on January 5, 2010
From time to time I've come across the idea expressed that the field of experimental particle physics is tapped out or just in the "sorting out the details" phase but it's never really seemed to jive with the reality of what actual scientists are up to. I mean the LHC hasn't even gotten started and there are still tons of economically feasible projects in the future mix. Look at the kind of stuff they're talking about here for example. And there is always, of course, the stuff you can't predict because you don't know that you don't know about it yet.
I'm definitely not smart enough to come to have any firm convictions about the future of big, cosmological/theoretical questions like TUFOTU or the TOE, though my numbskull layman's (for the most part) instinct is that these goal will continue to shift, pushed continuously outward by the ever-increasing complexity of our discoveries. I don't think the end of the "era of practical physics" is on any foreseeable horizon as long as organized technical society manages to persist.
posted by nanojath at 8:34 PM on January 5, 2010 [1 favorite]
I'm definitely not smart enough to come to have any firm convictions about the future of big, cosmological/theoretical questions like TUFOTU or the TOE, though my numbskull layman's (for the most part) instinct is that these goal will continue to shift, pushed continuously outward by the ever-increasing complexity of our discoveries. I don't think the end of the "era of practical physics" is on any foreseeable horizon as long as organized technical society manages to persist.
posted by nanojath at 8:34 PM on January 5, 2010 [1 favorite]
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posted by GuyZero at 3:42 PM on January 5, 2010