You don't need to delve into urban legend. Back in 1998, a dozen wireless heart monitors went offline at a major Dallas-area hospital when WFAA-TV turned on its HDTV transmitter for the first time.
According to this report Baylor was using DTV9 on a secondary basis for the heart monitors! It cost them $200,000 to get new equipment. Now that's a fascinating screwup!
I hope this dampening field isn't messing with medical devices like pacemakers, etc. I would like to think that this stuff is tested for all scenarios but,...
This is one of the reasons medical devices have to go through some rigorous testing and use approved frequencies. Even so, mistakes do occur.
When a pacemaker fails, it tends to get noticed. Early pacemakers had trouble with improperly shielded microwave ovens - mostly because the pacemaker itself was improperly shielded. Pacemakers that used a magnetic sensor for the on/off function ran into trouble if a strong magnet was waved over the patient's chest. Some of the early AV sequential pacemakers with the ability to change heart rate based on activity sensors would, if incorrectly programmed, suddenly throw the patient into an artificial 2nd degree heart block when the patient's heart rate exceeded a specific amount.
Urban legends contribute to percieved problems. Notice all the hospitals with "No Cell Phone" signs. Then notice all the cell phones in use by the doctors and the EMS personnel walking around with Handi-Talkies. Oops....
I wonder if anyone else has lost hardware to a duck?
Parrot poop will screw up a keyboard as well. Even when dry, it conducts electricity. When we tried to clean it, we gave it to the same bird (a lovebird) that is an expert at removing keys.
After many "magic" words were said, I finally gave up and bought a new keyboard.
(In case anyone's wondering - no, the lovebird did not learn the "magic" words.)
This is like taking your home address with you, when you move.
1. How long before the lawsuit demanding that you keep your physical home address?
2. Am I just cynical, or will this lawsuit succeed?
2. When a famous physicist said "Remember, no matter where you go, there you are" I don't think this is what he had in mind.
Fate of Payload Inversely Proportional to Cost
on
Build Your Own KiteCam
·
· Score: 2, Funny
"Paul Mutton successfully managed to kill an expensive digital camera taking aerial photos using a kite, parcel tape and some bubble wrap."
High Power Rocketry folks have known for years that the probability of a successful flight is inversely proportional to the cost of the payload divided by the average cost of payloads being flown. For many years, expensive video cameras ensured failure.
It's only been through the addition of multiple onboard altimeters, accelerometers, computers, amateur radio transmitters, GPS units, rocket locators, and other horrendously expensive gizmos that lone video cameras are now fairly easy to fly.
BTW: There's a fun traditions if you are launching an on-board computer running Windows. If the flight fails, you call Microsoft Support and report that your computer crashed.
Of course, if you were running Linux, maybe it wouldn't have crashed....
I want to put this stuff on my car. No more radar speed traps!
You'd have to design the paint for the frequency range used in radar guns - and then it would be totally useless against laser timing or places where they use the stripes on the road.
If you're going to wallpaper your car, be sure to use a good epoxy.
If you can allways tweak the theory to conform then it's a crap theory cause it's not falsifiable.
Not false, but not true.
Honestly, I was being a little humorous in my original message. But I wasn't completely accurate.
There are places where the "Standard Model" should break down that we might be seeing pretty soon. There's even some evidence we're seeing cracks in the Standard Model, but pretty much everyone wants to see something a bit more significant.
The problem is, we know the Standard Model cannot be correct. General Relativity and Quantum Mechanics simply do not get along as both are currently formulated. The so-called "string" and "brane" theories have features that seem to make the relativity problems go away. But there are so many different possible theories, there's no current way to tell which is correct.
So why play with them?
Brian Greene points out in The Elegant Universe that a lot of the current theories appear to complement one another - they may in fact be subsets of the "ultimate" theory. There are some questions that one theory can answer better than another theory, and some calculations that simply can't be done in a third theory that a fourth theory handles almost trivially.
So the physicists play with these theories in the hopes that either a) they'll find something we can test (like "large" hidden dimensions.
And who knows? Some folks suspect that eventually they'll find that only one theory, with only one set of constants, produces a totally consistent theory and that the current universe is the only one possible. Others postulate that we'll find there's an infinite set of possible universes with the same or similar theories, but variables that are random and that our "universe" is merely one of many in the "multiverse."
In the meantime, it's great fun and keeps physicists employed.
I'm wondering if the theoretical predictions presented in the article tip the scales toward or away from any of the various theories of quantum structure.
For any quantum theory [QT] there exist a range of possible values for the arbitrary constants in the theory that will account for all observed data.
Should there fail to be a range of possible values that are consistent with reality, then there is almost certainly some form of "renormalization" which will accomodate the observations.
Should there fail to be constants and renormalizations which give the proper results, then the problem lies with perturbation methods used to calculate the answer and a different method of calculation will need to be used, probably invoking the "small diameter dimensions, multiple string windings/large diameter, single string windings" trick.
While we're mentioning "rolled-up dimensions," claiming that one of the additional dimensions is near-macroscopic (i.e. a hundredth of a millimeter or so) is at the very least a wonderful stalling tactic.
Should all of the above fail, how the hell did you get tenure in the first place?
Most quantum theories cannot be distinguished by anything less than smashing two galactic-center sized black holes together at approximately 99.857% of the speed of light. Even then, about half of the theories can be tweaked to surive the data - more than the experimenters would likely achieve.
I can't swear to it, not being in such a business myself, but I remember it being widely reported that in the 3rd Matrix Movie (Revolutions?), the method they use to hack into the Electricity company is a legit method/exploit.
I have absolutely no memory of this. At least I remember most of the third Matrix movie, which is more than I can say for the second Star Wars prequel. All I remember is Jar Jar yammering away in the counsel chambers or something....
I was in "parrot" mode and left out some important information.
Koko the gorilla distinguishes between balls based on the writing on one ball. I believe that she has learned to associate a few written words with their sounds.
Human reading is a very complex process. Humans use language to a depth and richness that no other being on the planet appears to be able to accomplish. What Alex, Koko, Rico, and others do is demonstrate that they can perform many of the operations that go into creating language. They can express concepts using language, reason based on what they hear, and even manipulate their environment (or at least their owners) with language.
They do not communicate in the way humans do. It does not diminish their accomplishments, nor do their abilities diminish us as humans.
does anyone know if it'd be possible to train an animal to read
You're referring to Alex the Parrot. Dr. Pepperberg has been very careful to document in experiments what she claims for Alex, and to make sure that she can prove those claims experimentally. According to Dr. Pepperberg, Alex has not learned to read, despite what the article says. Instead, she says he has learned to associate sounds and shapes and to assemble them into words. No, I have no idea what the difference is between that and reading.
As far as whether parrots have souls, we have two African Grey parrots like Alex, and a Moluccan cockatoo who is incredibly mechanically inclined. I cannot define "soul" scientifically, although I do believe in them. What I associate with a human having a "soul," I also see in these parrots. They are intelligent, mischevious, sometimes selfish, loving, emotional, inquisitive, and tool-using. They like TV (would you believe "Animal Planet" is a favorite?), and sometimes pause to consider consequences of their actions. They do have impulse control problems, so they don't consider the consequences as often as one might hope. One of our parrots had great fun feeding those canned french fry things to a dog. They will lie to you, although it's easy to tell when they're lying. They would not be good at poker.
Having said that, I will also say that sometimes they are incredibly alien. They do not perceive the world quite the way we do (including vision that extends into the UV). They do not always think the way we do.
The last I heard, Dr. Pepperberg was working at MIT to create a mini-internet for parrots with a simplified interface. Boredom is a problem for these birds in captivity.
"The Commission believes that commercialization of space should become the primary focus of the vision, and that the creation of a space-based industry will be one of the principal benefits of this journey...."
This one point seems so obvious. It has been said many, many times. Yet it's so hard for "The Powers That Be" to implement.
When the history of the airplane is considered, one has to be thankful that the Wrights did not work for the National Aeronautic Administration in 1904.
I am grateful for all that NASA has given us. But if we are to truly make the next step, the financial incentives for space must be given a chance to exercise their power.
It's hard to allow a child to move out on it's own, but for the good of both the child and the parent, it must be done. Yes, there will be mistakes and risk and danger. But the alternative is a stunted, deformed life that is nothing but tragedy.
And how do you know what realistic splatters look like?
I don't know about the other guy, but I used to be a paramedic.
This causes problems when I go to movies or watch TV. The blood and gore almost always looks fake and I start this bizarre giggling.
Needless to say, I did not go to see "The Passion of the Christ."
What I was trying to find out is if a picard topology could be the reason why 6(or 7) diminsions was so small.
I wasn't clear. When they're talking about the Picard geometry (which hasn't been proven, either - last year they thought it was a soccer ball), they're talking about an area of space where all dimensions would be small except one - length (assuming length is the legnth of the "horne of plenty."
So, as far as we know, the Picard shape does not determine the size of the (to us) microscopic dimensions. It could be that there is some deep connection, (similar to my gut feeling that 4 dimensions "blew up," leaving the other 6 or so dimensions relatively untouched).
But that's just a guess.
Have fun with Greene's books. I think you'll find them a better read than Hawking and a lot easier than Kip Thorne's Black Holes and Time Travel (still worth reading, though).
What I was thinking was that if a Picard geometry would cause some dimensions to be shrunk to tight circles near it's narrow end, could us being near the narrow end explain why the dimensions predicted by string theory(s) are so tiny.
One of the important points about the Picard geometry discussed in the "horn of plenty" theory is that the universe would look different depending on where you are.
As we look around, the universe appears to be pretty much the same in any direction we look. The fine structure constant and other important physical numbers appear to be same here on earth and in the farthest galaxy we see. There is some question if these constants might have changed over time, but the change is thought to be far, far less than the change one would expect being in the strange part of a Picard universe.
The diameters of the "rolled-up" dimensions are thought to affect the properties of the forces and sub-atomic particles we observe. Why those properties are what they are is one of the great mysteries of Quantum Mechanics and Cosmology. An argument can be made that, if the numbers were different, we wouldn't be here to observe that difference. Some have argued that the numbers are deliberate - that God (or some researcher) caused those numbers to be what they are so that either a) life would exist or b) the universe would be "interesting" (like choosing which rules to use for the game of Life.
Would the diameter of the the rolled-up dimensions be affected in an extreme section of a Picard universe? That's a good question. I'd be tempted to say "no." There are places near a black hole where light orbits - in other words, if you look forward, you can see the back of your head! This is similar to the way the Picard universe behaves at an extreme point. Atoms being torn apart in the accretion disk of a black hole seem to have the same physical constants as atoms on Earth. So that would indicate that no, it doesn't change the smaller dimensions. But who knows? Perhaps a Picard extreme region behaves differently from a black hole region in our section of the universe. Our understanding of why the universe "is the way it is" is primative. My understanding, of course, is far more primative than Hawking, Greene, or Thorne.
I have a crude vision in my mind of a universe where, depending on where you are, you see different dimensions rolled up. Properties would change as you moved from one region of the universe to another - each region being far in excess of 156 billion light years in diameter. My topological intuition begins to fail me, though, and I'm getting a major migrane as a result! I should check to see if my brains are being squeezed out my ears.
I really would suggest that you read Greene's books. In the first one, you might find yourself skipping some of the math. I read through it and humored myself by thinking that I understood the math. I do find that Greene has a wonderful way of tying what you already know into what he's trying to explain.
string theory predics several extra dimensions we can't percieve because they're to small. Any possible relation here?
First off, IANAQP. Most of my modern cosmology and quantum physics comes from SciAm, Brian Greene books, and conversations with Tripoli Rocketry Association member #004. The last time I did tensor calculus was when I looked up Frank Tipler's paper "Rotating Cylinders and the Possibility of Global Causality Violation" twenty years ago. Yes, that is the paper Larry Niven used as the name for a story.
So, based on my rather crude understanding of the whole mess, the answer to your question is "yes." We don't see the extra dimensions in our universe because they are curled up and small. If you look out your window at a telephone wire, the wire appears to be 1 dimensional - it only has length. A closer look shows that the second dimension is "wrapped" around and meets itself.
These dimensions are thought to be exceedingly small, although some string theories allow for the possibility that they could be as big as a millimeter in diameter. The last experiment I remember reading about indicated that, while a millimeter might be too big, they couldn't rule out dimensions on the order of.1 mm. If one of the dimensions is that large, we should soon be able to measure the failure of the inverse square law at very small distances, where gravity leaking into the other dimensions can be seen.
If the four macroscopic dimensions (3 spatial, one time) form closed loops, we might indeed have a strange geometry in space, such as a "horn of plenty."
It's comforting to think that the 4 large dimensions curl up like the small ones. The universe can be "infinite but bounded." There's no messy questions about what happens when you reach the edge of the universe or the universe being infinite in size, although I'd still wonder what's "outside" our universe. There's a symmetry - the big dimensions are simply blown up versions of the small ones and (in some ways) the big dimensions might actually be the same size as the small ones! Measuring the diameter of a dimension can be tricky, since in string theory large and small dimensions are indistinguishable mathematically.
Alas, there's no guarantee that the 4 macroscopic dimensions have their "ends" meet. String theory can handle infinite dimensions and non-loop strings with end points as well. If you could travel far, far faster than light, you might simply keep going in one direction, never returning to your point of origin.
We may never know the answer. If the universe is far bigger than the 156 billion lyrs minimum, then we'll never see edge effects on the cosmic microwave background. The macroscopic universe might go on forever or loop back around or come to a dead stop at a giant brick wall - and we'll never know.
There are two major problems with current quantum cosmologies. One is that they're exceedingly and increasingly difficult to calculate. What good is an equation that is the "answer to everything" if there's no possible way to solve it or even come up with a decent approximation to an answer? The other problem is that there are probably an infinite number of possible theories, and even if they can be solved, the vast majority predict the same answer at any level we could ever hope to explore in any conceivable experiment.
Think of it as job security for physicists.
I wish I could find a link to George Carlin's riff on the Catholic Church's answer "It's a mystery!" It would be oddly appropriate.
Slashdot Mirror
According to this report Baylor was using DTV9 on a secondary basis for the heart monitors! It cost them $200,000 to get new equipment. Now that's a fascinating screwup!
This is one of the reasons medical devices have to go through some rigorous testing and use approved frequencies. Even so, mistakes do occur.
When a pacemaker fails, it tends to get noticed. Early pacemakers had trouble with improperly shielded microwave ovens - mostly because the pacemaker itself was improperly shielded. Pacemakers that used a magnetic sensor for the on/off function ran into trouble if a strong magnet was waved over the patient's chest. Some of the early AV sequential pacemakers with the ability to change heart rate based on activity sensors would, if incorrectly programmed, suddenly throw the patient into an artificial 2nd degree heart block when the patient's heart rate exceeded a specific amount.
Urban legends contribute to percieved problems. Notice all the hospitals with "No Cell Phone" signs. Then notice all the cell phones in use by the doctors and the EMS personnel walking around with Handi-Talkies. Oops....
You mean like McKees Rocks - which is within easy driving distance of where I live?
(I'm cheating. Someone in NC told me about Chatmag.)
I was just about to post the same comment, only to find that a relative had already done so. Go figure.
Parrot poop will screw up a keyboard as well. Even when dry, it conducts electricity. When we tried to clean it, we gave it to the same bird (a lovebird) that is an expert at removing keys.
After many "magic" words were said, I finally gave up and bought a new keyboard.
(In case anyone's wondering - no, the lovebird did not learn the "magic" words.)
1. How long before the lawsuit demanding that you keep your physical home address?
2. Am I just cynical, or will this lawsuit succeed?
2. When a famous physicist said "Remember, no matter where you go, there you are" I don't think this is what he had in mind.
High Power Rocketry folks have known for years that the probability of a successful flight is inversely proportional to the cost of the payload divided by the average cost of payloads being flown. For many years, expensive video cameras ensured failure.
It's only been through the addition of multiple onboard altimeters, accelerometers, computers, amateur radio transmitters, GPS units, rocket locators, and other horrendously expensive gizmos that lone video cameras are now fairly easy to fly.
BTW: There's a fun traditions if you are launching an on-board computer running Windows. If the flight fails, you call Microsoft Support and report that your computer crashed.
Of course, if you were running Linux, maybe it wouldn't have crashed....
This could get interesting.
People have gotten cancer, had the cancer removed, and then had someone find a use for the cancerous tissue in the lab.
If I remember right, the courts have ruled that the patient did not have any rights to the tissue removed.
I wonder how putting yourself under a LGPL would affect this.
As always, I may be a lot of things, but a lawyer ain't one of them.
You'd have to design the paint for the frequency range used in radar guns - and then it would be totally useless against laser timing or places where they use the stripes on the road.
If you're going to wallpaper your car, be sure to use a good epoxy.
Not false, but not true.
Honestly, I was being a little humorous in my original message. But I wasn't completely accurate.
There are places where the "Standard Model" should break down that we might be seeing pretty soon. There's even some evidence we're seeing cracks in the Standard Model, but pretty much everyone wants to see something a bit more significant.
The problem is, we know the Standard Model cannot be correct. General Relativity and Quantum Mechanics simply do not get along as both are currently formulated. The so-called "string" and "brane" theories have features that seem to make the relativity problems go away. But there are so many different possible theories, there's no current way to tell which is correct.
So why play with them?
Brian Greene points out in The Elegant Universe that a lot of the current theories appear to complement one another - they may in fact be subsets of the "ultimate" theory. There are some questions that one theory can answer better than another theory, and some calculations that simply can't be done in a third theory that a fourth theory handles almost trivially.
So the physicists play with these theories in the hopes that either a) they'll find something we can test (like "large" hidden dimensions.
And who knows? Some folks suspect that eventually they'll find that only one theory, with only one set of constants, produces a totally consistent theory and that the current universe is the only one possible. Others postulate that we'll find there's an infinite set of possible universes with the same or similar theories, but variables that are random and that our "universe" is merely one of many in the "multiverse."
In the meantime, it's great fun and keeps physicists employed.
Only 99%?
For any quantum theory [QT] there exist a range of possible values for the arbitrary constants in the theory that will account for all observed data.
Should there fail to be a range of possible values that are consistent with reality, then there is almost certainly some form of "renormalization" which will accomodate the observations.
Should there fail to be constants and renormalizations which give the proper results, then the problem lies with perturbation methods used to calculate the answer and a different method of calculation will need to be used, probably invoking the "small diameter dimensions, multiple string windings/large diameter, single string windings" trick.
While we're mentioning "rolled-up dimensions," claiming that one of the additional dimensions is near-macroscopic (i.e. a hundredth of a millimeter or so) is at the very least a wonderful stalling tactic.
Should all of the above fail, how the hell did you get tenure in the first place?
Most quantum theories cannot be distinguished by anything less than smashing two galactic-center sized black holes together at approximately 99.857% of the speed of light. Even then, about half of the theories can be tweaked to surive the data - more than the experimenters would likely achieve.
Someone's in a dismal mood today....
I have absolutely no memory of this. At least I remember most of the third Matrix movie, which is more than I can say for the second Star Wars prequel. All I remember is Jar Jar yammering away in the counsel chambers or something....
I was in "parrot" mode and left out some important information.
Koko the gorilla distinguishes between balls based on the writing on one ball. I believe that she has learned to associate a few written words with their sounds.
Human reading is a very complex process. Humans use language to a depth and richness that no other being on the planet appears to be able to accomplish. What Alex, Koko, Rico, and others do is demonstrate that they can perform many of the operations that go into creating language. They can express concepts using language, reason based on what they hear, and even manipulate their environment (or at least their owners) with language.
They do not communicate in the way humans do. It does not diminish their accomplishments, nor do their abilities diminish us as humans.
You're referring to Alex the Parrot. Dr. Pepperberg has been very careful to document in experiments what she claims for Alex, and to make sure that she can prove those claims experimentally. According to Dr. Pepperberg, Alex has not learned to read, despite what the article says. Instead, she says he has learned to associate sounds and shapes and to assemble them into words. No, I have no idea what the difference is between that and reading.
As far as whether parrots have souls, we have two African Grey parrots like Alex, and a Moluccan cockatoo who is incredibly mechanically inclined. I cannot define "soul" scientifically, although I do believe in them. What I associate with a human having a "soul," I also see in these parrots. They are intelligent, mischevious, sometimes selfish, loving, emotional, inquisitive, and tool-using. They like TV (would you believe "Animal Planet" is a favorite?), and sometimes pause to consider consequences of their actions. They do have impulse control problems, so they don't consider the consequences as often as one might hope. One of our parrots had great fun feeding those canned french fry things to a dog. They will lie to you, although it's easy to tell when they're lying. They would not be good at poker.
Having said that, I will also say that sometimes they are incredibly alien. They do not perceive the world quite the way we do (including vision that extends into the UV). They do not always think the way we do.
The last I heard, Dr. Pepperberg was working at MIT to create a mini-internet for parrots with a simplified interface. Boredom is a problem for these birds in captivity.
We must have been typing at the same time.
"The Commission believes that commercialization of space should become the primary focus of the vision, and that the creation of a space-based industry will be one of the principal benefits of this journey...."
This one point seems so obvious. It has been said many, many times. Yet it's so hard for "The Powers That Be" to implement.
When the history of the airplane is considered, one has to be thankful that the Wrights did not work for the National Aeronautic Administration in 1904.
I am grateful for all that NASA has given us. But if we are to truly make the next step, the financial incentives for space must be given a chance to exercise their power.
It's hard to allow a child to move out on it's own, but for the good of both the child and the parent, it must be done. Yes, there will be mistakes and risk and danger. But the alternative is a stunted, deformed life that is nothing but tragedy.
This should get it's own Slashdot article: do they ever get ANYTHING right in the movies? I may have to see if it's ever been done on Slashdot....
No, I'm not serious....
I don't know about the other guy, but I used to be a paramedic. This causes problems when I go to movies or watch TV. The blood and gore almost always looks fake and I start this bizarre giggling.
Needless to say, I did not go to see "The Passion of the Christ."
So then we don't have to worry about England being burned down!
Well, I just hope it goes better for you Brits than that launch at Dartmoor.
I wasn't clear. When they're talking about the Picard geometry (which hasn't been proven, either - last year they thought it was a soccer ball), they're talking about an area of space where all dimensions would be small except one - length (assuming length is the legnth of the "horne of plenty."
So, as far as we know, the Picard shape does not determine the size of the (to us) microscopic dimensions. It could be that there is some deep connection, (similar to my gut feeling that 4 dimensions "blew up," leaving the other 6 or so dimensions relatively untouched).
But that's just a guess.
Have fun with Greene's books. I think you'll find them a better read than Hawking and a lot easier than Kip Thorne's Black Holes and Time Travel (still worth reading, though).
One of the important points about the Picard geometry discussed in the "horn of plenty" theory is that the universe would look different depending on where you are.
As we look around, the universe appears to be pretty much the same in any direction we look. The fine structure constant and other important physical numbers appear to be same here on earth and in the farthest galaxy we see. There is some question if these constants might have changed over time, but the change is thought to be far, far less than the change one would expect being in the strange part of a Picard universe.
The diameters of the "rolled-up" dimensions are thought to affect the properties of the forces and sub-atomic particles we observe. Why those properties are what they are is one of the great mysteries of Quantum Mechanics and Cosmology. An argument can be made that, if the numbers were different, we wouldn't be here to observe that difference. Some have argued that the numbers are deliberate - that God (or some researcher) caused those numbers to be what they are so that either a) life would exist or b) the universe would be "interesting" (like choosing which rules to use for the game of Life.
Would the diameter of the the rolled-up dimensions be affected in an extreme section of a Picard universe? That's a good question. I'd be tempted to say "no." There are places near a black hole where light orbits - in other words, if you look forward, you can see the back of your head! This is similar to the way the Picard universe behaves at an extreme point. Atoms being torn apart in the accretion disk of a black hole seem to have the same physical constants as atoms on Earth. So that would indicate that no, it doesn't change the smaller dimensions. But who knows? Perhaps a Picard extreme region behaves differently from a black hole region in our section of the universe. Our understanding of why the universe "is the way it is" is primative. My understanding, of course, is far more primative than Hawking, Greene, or Thorne.
I have a crude vision in my mind of a universe where, depending on where you are, you see different dimensions rolled up. Properties would change as you moved from one region of the universe to another - each region being far in excess of 156 billion light years in diameter. My topological intuition begins to fail me, though, and I'm getting a major migrane as a result! I should check to see if my brains are being squeezed out my ears.
I really would suggest that you read Greene's books. In the first one, you might find yourself skipping some of the math. I read through it and humored myself by thinking that I understood the math. I do find that Greene has a wonderful way of tying what you already know into what he's trying to explain.
First off, IANAQP. Most of my modern cosmology and quantum physics comes from SciAm, Brian Greene books, and conversations with Tripoli Rocketry Association member #004. The last time I did tensor calculus was when I looked up Frank Tipler's paper "Rotating Cylinders and the Possibility of Global Causality Violation" twenty years ago. Yes, that is the paper Larry Niven used as the name for a story.
So, based on my rather crude understanding of the whole mess, the answer to your question is "yes." We don't see the extra dimensions in our universe because they are curled up and small. If you look out your window at a telephone wire, the wire appears to be 1 dimensional - it only has length. A closer look shows that the second dimension is "wrapped" around and meets itself.
These dimensions are thought to be exceedingly small, although some string theories allow for the possibility that they could be as big as a millimeter in diameter. The last experiment I remember reading about indicated that, while a millimeter might be too big, they couldn't rule out dimensions on the order of .1 mm. If one of the dimensions is that large, we should soon be able to measure the failure of the inverse square law at very small distances, where gravity leaking into the other dimensions can be seen.
If the four macroscopic dimensions (3 spatial, one time) form closed loops, we might indeed have a strange geometry in space, such as a "horn of plenty."
It's comforting to think that the 4 large dimensions curl up like the small ones. The universe can be "infinite but bounded." There's no messy questions about what happens when you reach the edge of the universe or the universe being infinite in size, although I'd still wonder what's "outside" our universe. There's a symmetry - the big dimensions are simply blown up versions of the small ones and (in some ways) the big dimensions might actually be the same size as the small ones! Measuring the diameter of a dimension can be tricky, since in string theory large and small dimensions are indistinguishable mathematically.
Alas, there's no guarantee that the 4 macroscopic dimensions have their "ends" meet. String theory can handle infinite dimensions and non-loop strings with end points as well. If you could travel far, far faster than light, you might simply keep going in one direction, never returning to your point of origin.
We may never know the answer. If the universe is far bigger than the 156 billion lyrs minimum, then we'll never see edge effects on the cosmic microwave background. The macroscopic universe might go on forever or loop back around or come to a dead stop at a giant brick wall - and we'll never know.
There are two major problems with current quantum cosmologies. One is that they're exceedingly and increasingly difficult to calculate. What good is an equation that is the "answer to everything" if there's no possible way to solve it or even come up with a decent approximation to an answer? The other problem is that there are probably an infinite number of possible theories, and even if they can be solved, the vast majority predict the same answer at any level we could ever hope to explore in any conceivable experiment.
Think of it as job security for physicists.
I wish I could find a link to George Carlin's riff on the Catholic Church's answer "It's a mystery!" It would be oddly appropriate.