With the finite circle, don't all my comments just apply to the diameter? Middle = small diameter? I had trouble understanding your comments, but in case it's not clear, the circular elastic in this analogy is all of space; there is no "inside the circle", and the circle is not the "edge" of anything.
And with this analogy, we're talking about a sphere where the leading edge is the edge of the sphere are we not? No. If you want to think of the universe as a sphere instead of a 1D circle, then the universe is the 2D spherical surface, not the 3D ball with a 2D "edge".
Picture not a finite length of elastic, but either an infinite length, or a finite circle of elastic. In either case, there is no "middle" and no "edge".
I've read almost every Niven story, and I think all of his Known Space stories, and I can't think of any story like that. I have, however, read more than one story by other authors about creating "baby universes", some of which have life; it's not a rare theme anymore.
I'm having trouble figuring out if there is enough information here. The difference in wavelength of the light we see would certainly tell us the relative speed, but I don't see how that gives us a distance. It seems to me that we asssume the uniform expansion of the universe, thus the further away something is the greater the red shift and thus greater distance. I wonder how uniform the expansion is and how we measure that... You're right. You can't infer distance just from redshift alone; you need some calibration information to determine how the universe has been expanding. Once you know that, then you can translate redshifts into distances.
That calibration information is obtained by looking at objects of known brightness, called "standard candles". By measuring how bright they look to us, we can infer how far away they are, by how much they appear to have been dimmed with distance. Then you also measure their redshift. That gives a calibration between distance and redshift which can be used to infer the expansion rate. Using the expansion rate, you can turn around and infer distance from redshift directly, even for objects at redshifts you haven't seen before.
Black holes' gravity is so strong that it even captures bypassing photons, hence the name 'black hole'. How can it emit energy, since energy is photons? (Note: "energy" is not photons. Photons have energy, as do other particles.)
When people talk about black holes emitting tons of energy, as in quasars, the black holes themselves aren't actually emitting the energy. The radiation actually comes from matter very close to, but outside, the black hole: either from frictional heating of the disk of matter surrounding a black hole, or from charged particles being accelerated in the black hole's magnetic field.
Interestingly, however, it is possible for black holes to directly emit energy, called Hawking radiation. This occurs due to polarization of virtual particles in the quantum vacuum (see here for an explanation). This radiation is undetectably weak for astrophysical black holes and is not what people talk about when they say we can see light from black holes.
Q: How is it that our planet, it's telescopes and astronomers, beat the electromagnetic energy which was suposedly ALL projected from a single object, (the Big Bang Singularity, as I believe members of the new Creationism that is Modern Cosmology call it) to where we are now, to intercept it? You are mistakenly thinking of the Big Bang as the explosion of some object located at some particular point in space, and imagine the bits and pieces from the explosion outracing the light emitted during the explosion.
That has nothing to do with the actual theory of the Big Bang.
Big Bang cosmology holds that instead of matter exploding into empty space, space was once uniformly filled everywhere with matter, and that space subsequently expanded. No matter how far back towards the Big Bang you go, there is always some set of points in space from which their light is reaching us just now; the light from closer points has already reached us, and the light from farther points has not yet had time to reach us.
At the risk of flamebateing, I want to point this out: a true scientist cleaves NOT to any hypothesis that does not jibe with the observations.
I'm not asserting I know what happened, I am just asserting that the "Big Bang" could not have, and all the "evidence" of it is a case of "scientists" trying to fit the data to the hypothesis, and as far as I'm concerned, it's just as much a 'belief system' as any other. May I suggest that instead of the entire scientific community for the last 90 years being total idiots, or conspiring together to suppress or ignore the obvious truth, it could instead be possible that you don't understand Big Bang cosmology?
The error margin is undefined and potentially very high. The error margin is probably less than 20%, based on what I recall of similar studies.
The whole model is based on observations that have led to guesses that have been backed up by more observations, but what if this whole doppler business, at least as it applies to light over interstellar distances, is really a bunch of zany space aliens playing with cosmic cellophane for example? You could say the same thing about measuring distances to stars, planets in the Solar System, or New Jersey. But it's not reasonable to claim that we don't know anything about the measurement errors.
And how can anyone seriously claim to be "able to recreate in laboratories the conditions in the universe to within 10e-33 seconds of the Big Bang"? What they mean is that they can create particles with the same average energy as particles had naturally 10^-33 seconds after the Big Bang.
It's not wholly correct to say that our solar system originated at the center of the universe. Rather, there is no center, and the Big Bang took place everywhere. See this comment for more information.
According to the Big Bang theory, everything in the Universe is moving out from one central point No. The Big Bang was the expansion of space, not an explosion of matter into empty space. There was no center point. (Think of the surface of an inflating balloon, not a Cosmic Space Kablooie.) Right now we are receiving light emitted ~14 billion years ago from distant points in space, which have been expanding away from us as the light traveled. In a non-accelerating expansion, we would in the future receive light emitted at the same time, but further away. (The expansion is thought to be accelerating, however.)
When talking about the universe expanding, people seem to only refer to the distances between galaxies increasing. But surely if the universe is expanding, it should be expanding on every level (ie macro and micro). No, that's not true. Systems that are bound (gravitationally, electrostatically, etc.) resist cosmological expansion. See this FAQ.
If one point in space is expanding fast enough ("edge" of space) in relationship to another point (us), and then if the first object was accellerated to close to light speed velocities, away from the second point, wouldn't it appear as if the first object was moving away from the second object faster than the speed of light? Not exactly; this is an issue of relativistic addition of velocities.
The thing is, we know the speed of light within space is constant, and under normal circumstances (all that we know, anyway) can't be breached. But that isn't accounting for the displacement due to "expanding space". Is it, then, possible to observe two extremely distant objects as moving away from each other faster than the speed of light? It's possible for us to see two objects moving away from each other faster than the speed of light, even in a non-expanding universe. We just can't see them moving away from us faster than light.
"That's not true. For instance, if the universe is infinite, we will never be able to see most regions of it at any time, because light won't have reached us." Not true if the universe is infinite which by the balloon analogy it's not. Everything I said applies equally to both infinite and finite universes. I think you are missing something, but I'm not sure what.
Seems to me that one of the following is true: 1) If the universe is expanding slower than the speed of light, we should be able to see all regions of the universe at some earlier point, but doubtfully so close to the beginning of the universe. That's not true. For instance, if the universe is infinite, we will never be able to see most regions of it at any time, because light won't have reached us.
2) The expansion of the universe is slowing (from a speed at or above the speed of light) and the objects on the other side of the "balloon" are now becoming visible. If the expansion slows, then more and more of the universe will become visible. But now it's believed that the expansion is accelerating. Either way, however, we can look as far back in time as we want (or rather, as far as we can — to the creation of the cosmic background radiation).
How large was the universe at the big bang? If the universe is finite, then classically speaking it was of zero size at the Big Bang. If it's infinite, then it was infinite at the Big Bang too, but the observable universe was of zero size. If you apply quantum gravity, then it may have had a minimum size, on the order of the Planck length (about 10^-34 meters).
We know that according to Einstein that matter is not supposed travel faster than the speed of light however if that is true then it would mean that the universe was probably greater than 14 billion light years across if we are able to see light that is about 14 billion years old and we suspect that the universe is 14.7 Billion years old currently. Matter can't travel through space at faster than the speed of light; the universe itself can expand at any rate. The observable universe today is about 100 billion lightyears across, and 13.7 billion years old.
Matter can't move faster than light. Energy can't move faster than light. So how the hell can space, which is defined by putting matter in it (even if it's only one hydrogen atom per cubic light year) be expanding faster than the speed of light? The first two refer to how fast things can move through space. The expansion of space doesn't obey the same laws as the ones governing motion of matter/energy through space.
Think of it as the difference between how fast an ant can crawl across the surface of an expanding balloon, vs. how fast the balloon itself is being inflated. The two speeds are not related to each other, and there can be a limit on the former when there is not on the latter.
Is this truely the light from the very first objects in the universe reaching us, or is this observable stuff just reaching us that took place long after the first things appeared, obliterated, and cycled a few times after? Well, it's light from the first objects that formed after the Big Bang. What happened before that, if that concept even makes sense, is unknown.
How do we know the observable stuff from the true first objects hasn't already reached Earth and passed us by long before we had the ability to detect it? Because beyond these first objects, we can see the cosmic background radiation from an even earlier era: the moment at which the hot primordial plasma coalesced into neutral atoms. But even if that weren't the case, we can always look earlier by looking farther — given any time, there is some sufficiently distant location from which the light from the earliest objects is reaching us. (Assuming we can detect it. We can't see further back than the CBR, though, since the universe was opaque to light before then.)
If it took 14 billion years for the light to reach us, and the universe is 14 billion years old, does that mean that we are on the very edge of the expanding universe? No. There is no edge to the universe. Think of the universe as the surface of an expanding balloon, which has no boundary. The light travels between two points on that expanding surface (which are growing farther apart as the light travels). Light from 14 billion years ago doesn't imply anything about where the original point was (in particular, it's not at "the edge of the universe", or halfway around the balloon, or whatever); it just originated from the farthest points that we can currently see. (There is more space beyond which we can't see, because light from it hasn't reached us yet.)
Poor analogy. Baseball bats are not intended to be used in the home. For a device that is intended by the manufacturer to be used in the home, more safety precautions are necessary. Morever, Nintendo explicitly specified in the instruction manual that use of the wrist strap is necessary to prevent accidental damage to nearby objects. If they felt compelled to state that, then they knew there was a real risk of that kind of accident happening, and thus it is their legal responsibility to build a safe device. The manufacturers of other devices which have safety straps, locks, etc. are held responsible for the quality of those measures; why should Nintendo be any different? The wrist strap is a safety device, one that Nintendo themselves stated should be used, but it does not work as intended.
And it won't leave your hand if used as directed. How was it directed to be used, and how does that compare to how it was advertised as being used?
Not once has it left my hand unless I was setting it down or handing it to another person. Well, that's nice, but that's irrelevant to the question of Nintendo's legal liability, which doesn't have anything to do with how you, personally, happen to use it.
The strap should be viewed merely as a convenience to help guard against accidental drops... As I said to Ahnteis, that may be how you think it ought to be viewed, but from a legal standpoint, what matters is what the operations manual says the strap is for, and how that relates to both its recommended and advertised use.
Unless Nintendo specifically said "wave it as HARD AS HUMANLY POSSIBLE..." in the manual then it's hard to infer that that was the intended use. I don't think it requires "waving as hard as humanly possible" in order for it to slip from your grasp. It just requires sweaty hands. And you can't deny that all of Nintendo's advertising depicts extremely vigorous usage; in light of that, it's not totally unreasonable for a consumer to expect the thing to stay on their wrists when emulating the kind of gameplay that Nintendo's own marketing condones.
The physicist Richard Feynman described in his autobiography his own personal "human bloodhound" experiments. He found that, with little training, he could identify by smell which of a collection of objects had been recently handled. However, upon getting down on the floor and sniffing around, he determined that, unlike his dog, he couldn't follow people's tracks by their scent.
You might say that's what it's for, but what did Nintendo say it was for? They currently say, "Wearing the wrist strap will help prevent the Wii Remote from flying across the room if you accidentally let go of it during game play." Of course, that's after all of the complaints of broken wrist straps. From the standpoint of legal liability, what's just as important is what they said in the operations manual that came with the Wii. Does anyone know? If the manual originally stated that the strap is there to prevent the remote from going flying across the room, then they're responsible for making a strap that really will prevent it from doing so.
Furthermore, from a legal standpoint, companies are held liable for what happens when their products are used in ways that the consumer (not just the company!) will commonly find reasonable, unless they specifically warned against such usage. Did the manual say, "Warning: wrist strap will not restrain remote under vigorous usage", or such?
The fact is, the Wii remote was intended to be manipulated in a more vigorous manner than is a camera, and it's possible Nintendo may be found legally liable.
No where in the instructions does it say that you should ever let go of the remote. Honestly, if you can't hold onto the thing, maybe you should practice a little more self-restraint and control. True, but the fact that Nintendo saw fit to include a wrist strap in the first place could be legally construed as a tacit acknowledgment on Nintendo's part that the remote can slip from one's grasp during reasonable use. If their lawyers try the "Duh, if you can't hold onto it you shouldn't be using it" defense, the prosecution will respond with "So what's the wrist strap for, then?"
Slashdot Mirror
Picture not a finite length of elastic, but either an infinite length, or a finite circle of elastic. In either case, there is no "middle" and no "edge".
I've read almost every Niven story, and I think all of his Known Space stories, and I can't think of any story like that. I have, however, read more than one story by other authors about creating "baby universes", some of which have life; it's not a rare theme anymore.
That calibration information is obtained by looking at objects of known brightness, called "standard candles". By measuring how bright they look to us, we can infer how far away they are, by how much they appear to have been dimmed with distance. Then you also measure their redshift. That gives a calibration between distance and redshift which can be used to infer the expansion rate. Using the expansion rate, you can turn around and infer distance from redshift directly, even for objects at redshifts you haven't seen before.
When people talk about black holes emitting tons of energy, as in quasars, the black holes themselves aren't actually emitting the energy. The radiation actually comes from matter very close to, but outside, the black hole: either from frictional heating of the disk of matter surrounding a black hole, or from charged particles being accelerated in the black hole's magnetic field.
Interestingly, however, it is possible for black holes to directly emit energy, called Hawking radiation. This occurs due to polarization of virtual particles in the quantum vacuum (see here for an explanation). This radiation is undetectably weak for astrophysical black holes and is not what people talk about when they say we can see light from black holes.
That has nothing to do with the actual theory of the Big Bang.
Big Bang cosmology holds that instead of matter exploding into empty space, space was once uniformly filled everywhere with matter, and that space subsequently expanded. No matter how far back towards the Big Bang you go, there is always some set of points in space from which their light is reaching us just now; the light from closer points has already reached us, and the light from farther points has not yet had time to reach us. At the risk of flamebateing, I want to point this out: a true scientist cleaves NOT to any hypothesis that does not jibe with the observations.
I'm not asserting I know what happened, I am just asserting that the "Big Bang" could not have, and all the "evidence" of it is a case of "scientists" trying to fit the data to the hypothesis, and as far as I'm concerned, it's just as much a 'belief system' as any other. May I suggest that instead of the entire scientific community for the last 90 years being total idiots, or conspiring together to suppress or ignore the obvious truth, it could instead be possible that you don't understand Big Bang cosmology?
It's not wholly correct to say that our solar system originated at the center of the universe. Rather, there is no center, and the Big Bang took place everywhere. See this comment for more information.
1) If the universe is expanding slower than the speed of light, we should be able to see all regions of the universe at some earlier point, but doubtfully so close to the beginning of the universe. That's not true. For instance, if the universe is infinite, we will never be able to see most regions of it at any time, because light won't have reached us. 2) The expansion of the universe is slowing (from a speed at or above the speed of light) and the objects on the other side of the "balloon" are now becoming visible. If the expansion slows, then more and more of the universe will become visible. But now it's believed that the expansion is accelerating. Either way, however, we can look as far back in time as we want (or rather, as far as we can — to the creation of the cosmic background radiation).
Think of it as the difference between how fast an ant can crawl across the surface of an expanding balloon, vs. how fast the balloon itself is being inflated. The two speeds are not related to each other, and there can be a limit on the former when there is not on the latter.
The journal articles that go along with the story:
New Measurements of Cosmic Infrared Background Fluctuations from Early Epochs
On the Nature of the Sources of the Cosmic Infrared Background
(These were posted in the article, but only under a tiny "More info" link at the bottom that is easy to overlook.)
Poor analogy. Baseball bats are not intended to be used in the home. For a device that is intended by the manufacturer to be used in the home, more safety precautions are necessary. Morever, Nintendo explicitly specified in the instruction manual that use of the wrist strap is necessary to prevent accidental damage to nearby objects. If they felt compelled to state that, then they knew there was a real risk of that kind of accident happening, and thus it is their legal responsibility to build a safe device. The manufacturers of other devices which have safety straps, locks, etc. are held responsible for the quality of those measures; why should Nintendo be any different? The wrist strap is a safety device, one that Nintendo themselves stated should be used, but it does not work as intended.
The physicist Richard Feynman described in his autobiography his own personal "human bloodhound" experiments. He found that, with little training, he could identify by smell which of a collection of objects had been recently handled. However, upon getting down on the floor and sniffing around, he determined that, unlike his dog, he couldn't follow people's tracks by their scent.
By the way, nobody was "throwing" the Wii remote (as far as I know); it slipped from their grasps.
You might say that's what it's for, but what did Nintendo say it was for? They currently say, "Wearing the wrist strap will help prevent the Wii Remote from flying across the room if you accidentally let go of it during game play." Of course, that's after all of the complaints of broken wrist straps. From the standpoint of legal liability, what's just as important is what they said in the operations manual that came with the Wii. Does anyone know? If the manual originally stated that the strap is there to prevent the remote from going flying across the room, then they're responsible for making a strap that really will prevent it from doing so.
Furthermore, from a legal standpoint, companies are held liable for what happens when their products are used in ways that the consumer (not just the company!) will commonly find reasonable, unless they specifically warned against such usage. Did the manual say, "Warning: wrist strap will not restrain remote under vigorous usage", or such?
The fact is, the Wii remote was intended to be manipulated in a more vigorous manner than is a camera, and it's possible Nintendo may be found legally liable.