The size of the change seems to vary in space, but they're talking about a time variation in alpha as a function of time.
We're in agreement.
(What's even more concerning about this result is that if I read it right, stuff ~12 billion years ago had notably different alphas in the two directions. But at that time, the universe would have been much smaller, so those parts of the universe would have been closer together. That doesn't make it seem any more palatable.)
Wow. Check out Figure 5. It's hard to believe there's any systematic signal in their data, they have blue and red points mixed up all over the sky. They claim there's an excess of one color in one hemisphere and the other color in the other hemisphere, but it's not very strong signal at all. This isn't my field (I work on Saturn's rings), but my first reaction is amazement that this is serious enough to be talking to the press about.
(I'm also more than a little put off by the fact that this hasn't been accepted, evidently, merely submitted to a journal. And not even an astrophysical journal like AJ or ApJ which seem like a far better fit for this subject matter and the audience.)
Right, but other groups haven't found any variation in time or in space. It's possible that they looked in exactly the wrong directions, I suppose, but that's kind of unlikely.
I'm not saying that this result is wrong. I'm just saying it squares badly with other measurements and it's more likely at this point that something is else confusing the result, either experimental error or some other effect.
Sure it needs verification, but I am also not surprised other institutes downplay what wasn't their finding.
That's the problem, there are other tests out there and they don't show the effect. This isn't some new measurement, it's an old measurement (perhaps done better, perhaps not) that is showing a previously unseen behavior.
Also, yes, it's true that other groups are liable to downplay the finding (although that happens less than you might think, speaking as an astronomer myself), but the team themselves do the opposite. Why believe one is biased and the other isn't?
If it varied at all, the result would be significant just on principle. It would mean that the laws of physics have varied in time, which is not something that most current models allow for. (At least, not that I've heard. I work on something a little closer to home, so I might have missed something.)
This isn't the first time that some team has claimed this. Around 2000, someone made the same claim. I recall it not standing up when other teams checked it.
Measurements like this have been done before and usually show a constant, er, constant to within experimental uncertainty.
Note, for example, this paragraph buried at the end of the article:
Nonetheless, the study “is as speculative as the previous claims,” asserts Patrick Petitjean of the Institute of Astrophysics in Paris, whose team has looked for variations in the fine-structure constant with the Very Large Telescope as far back as about 11.5 billion years ago and found none (SN: 4/8/04, p. 301).
In other words, I wouldn't get excited at all yet.
nobody understands that an on-ramp is an ACCELERATION LANE.
Not really. A lot of on-ramps (particularly inside cities) are not designed for acceleration due to twists, lights, or being uphill. And even if you do have a good ramp for it, they often kill your merging lane so fast you want to enter cautiously because you may not be able to get into traffic before your lane goes away. Going faster gives you less time and a smaller segment of traffic to sample from.
Basically, whoever designs on and off ramps seems to be doing a lousy job. (Or, more likely, the guys giving them their instructions. I suspect a lot of it has to do with rules like, "Don't take up more than X amount of space.")
One of the reasons that String Theory is so popular is _because_ gravity comes up straight away, without assuming it. That is why it is so popular.
No, it doesn't. No one has yet managed to merge gravity into the quantum paradigm successfully. Unless I missed a major, major breakthrough in the past few years since graduate school.
"Cling to it" meaning what? If another idea came along and did better than String Theory, people would switch to it.
You're clinging to this idea that ST has provided any value so far. It hasn't. It's an intriguing idea that may pan out and pay great dividends if it does. But it has yet to give us any new power of prediction. So there's really nothing to be "better" than. It hasn't yet shown itself to be better than QM yet, so I don't know why you think it's the theory to beat.
Quantum Mechanics can (and has) been tested. Repeatedly. What makes String Theory different is that while it includes QM, it doesn't generally offer any new predictions. A theory that offers nothing new (neither predictions nor a paradigm that is either easier to work with or provides more insight) is useless. If all ST can do is reproduce QM exactly, it's at best a more complicated what to do the same math.
(That said, I seem to recall ST making a new, testable prediction in the cosmological constant. I also seem to recall it being way, way, way off. But I may be misremembering that.)
We've demonstrated several times that bacteria -- and I believe lichens -- can at least survive extended exposure in low earth orbit, so at that point it's not difficult to believe they could get here from somewhere else.
Yes and no. It's possible, provided they can survive for longer periods of time, to get living creatures from, say, Mars to Earth. The dynamics are tricky (it tends to take quite a while to get from one to the other, particularly if you don't want a high relative velocity when yous smack into the Earth) and lofting the material (and then landing it) in such a way as to not sterilize the rock is tricky. Couple that with the lack of conclusive evidence that life has existed on Mars in the past and I lean toward "less probable" for that route. Again, it doesn't rule it out, but it does take a backseat to local origin in my mind.
(Also, note that Mars, or any other planet in our system, doesn't solve a timescale problem. In fact, the transit time makes it worse.)
The other option is to get it here from outside our system. That does solve the timescale problem, potentially, but that adds a vast amount of time on to the transit. Any organism would have to be able to survive in space for millions, if not billions, of years. And the impact probability of a piece of interstellar junk and our system (let alone Earth) is awfully low. Plus, impact speed with an extrasolar bit of rock is a lot higher than from something already in our system. Barring a long series of orbital manuvers to alter the trajectory before meeting Earth (lower probability still), minimum relative speed at infinity is around 11 km/sec, assuming exactly optimal alignment. (More likely is in excess of 40 km/sec, and that's generously assuming that the speed relative to the Sun is very small.) Your minimum impact speed is therefore around 16 km/sec, which I can't imagine increases the odds of successfully seeding life here.
Again, this doesn't rule it out, but this is just why I feel that panspermia creates more "problems" (where I mean "low probability requirements") than it solves.
You don't need a mathematical singularity to create the problem. You just need a highly compact, near-singularity. Both the Big Bang and the interiors of black holes qualify, unless QM or GR is wrong.
So wait, we have two theories that describe different realms and no data for the intersection of the two realms, but people are trying to come up with a theory for the intersection?
Um, the cross-over objects exist. Grandparent poster is wrong, you don't need small black holes; any singularity has the problem of needing quantum mechanics and general relativity to describe it. This is true of the inner workings of any black hole, for example. (No, we can't get data from one, as far as we know.) Or, just fer instance, the Big Bang. There is a surprising amount of interest in modeling that one.
So, we need a new theory that gives the same predictions at QM and GR in the realms that we can measure them. This is where string theory etc comes in.
Not really. Last I checked, String Theory hasn't made any useful predictions about systems like this. No one has managed to fold gravity into a Theory of Everything yet, unless I missed an important update. (Feel free to correct me if I have.)
TL;DR - People complain at string without proposing anything better.
A theory that offers no new powers of explanation and prediction is itself no better than the pre-existing paradigms. Until String Theory can show itself to have some value (leaving aside the issue of whether it's the best such model), there's no reason to cling to it. "Better" implies that ST was somehow useful to begin with.
. This one does have the advantage of offloading the origin-of-life-on-earth, in which case you can at least claim that maybe biogenesis only happened once somewhere else and is being blown all over the Universe, rather than having only one planet and only a billion years in which to fit your explanation.
How does that help, exactly? You still have the problem of abiogenesis somewhere. At least here on Earth you know you have the right ingredients in abundance and you don't need to invoke a low-probability transfer mechanism to explain how it got here.
I'm not saying that this rules out panspermia, but it does make it seem like rather the more complicated option, all else being equal.
A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.
That's a protection.
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.
That's a protection, worded as a limit on Congress, but two centuries of interpretation says that it's a protection for individuals.
The list goes on. You might be technically correct in that the constitution is about the government (not just federal, by the way), but when it forbids the government from abridging a freedom, that's a protection to individuals. (And it's interpreted as applying to all lower levels of government, by the way.)
I didn't say you couldn't write a rule that says "one subject per bill." I said I didn't see how you could write it to be really complete. And yes, while all laws require interpretation, this is different. It seems like it'd require constant interpretation. "I know it when I see it," is a horrible basis for the law.
I never understood why in the hell this is possible in the first place.
How would you prevent it?
Seriously, how do you come up with an absolute metric (one that can be made law or, harder, an amendment) that determines whether a given part of a bill is related to the main point of the bill sufficiently? Sure, there's a common-sense, sniff test, but there is so much gray area and that's so hard to define clearly that I can't see it ever standing up in a real situation (ie, court).
Many governments control the press and the means of speech to the point where they can actually keep things from being printed or said, yes.
But apart from that, the cases in which consequences result are generally civil suits, which has nothing to do with Congress. The SCOTUS standard for criminal restrictions tend use words like "clear and present danger", but those seem to be rarer.
So yes, free speech is still free even if there are consequences. No one says you can't get fired for calling your boss an asshole, that you can't get sued for saying that Glenn Beck had sex with and then killed a panda, or that you can't be charged for publishing the identities of covert US intelligence assets. The idea that there wouldn't be repercussions seems absurd.
I don't think that you're arguing against anything I said. In fact, I think you're making an argument that the "new media" shouldn't be afforded the same protections we're considering giving the "old media".
What input would the second amendment possibly have?
Slashdot Mirror
Commute is a bitch, though.
Yes, that's what I said:
The size of the change seems to vary in space, but they're talking about a time variation in alpha as a function of time.
We're in agreement.
(What's even more concerning about this result is that if I read it right, stuff ~12 billion years ago had notably different alphas in the two directions. But at that time, the universe would have been much smaller, so those parts of the universe would have been closer together. That doesn't make it seem any more palatable.)
Wow. Check out Figure 5. It's hard to believe there's any systematic signal in their data, they have blue and red points mixed up all over the sky. They claim there's an excess of one color in one hemisphere and the other color in the other hemisphere, but it's not very strong signal at all. This isn't my field (I work on Saturn's rings), but my first reaction is amazement that this is serious enough to be talking to the press about.
(I'm also more than a little put off by the fact that this hasn't been accepted, evidently, merely submitted to a journal. And not even an astrophysical journal like AJ or ApJ which seem like a far better fit for this subject matter and the audience.)
Farther away = farther back in time due to the finite speed of light.
The size of the change seems to vary in space, but they're talking about a time variation in alpha as a function of time.
Right, but other groups haven't found any variation in time or in space. It's possible that they looked in exactly the wrong directions, I suppose, but that's kind of unlikely.
I'm not saying that this result is wrong. I'm just saying it squares badly with other measurements and it's more likely at this point that something is else confusing the result, either experimental error or some other effect.
Units wouldn't work then, though. I don't think you can change that exponent without doing something to at least one other term.
Sure it needs verification, but I am also not surprised other institutes downplay what wasn't their finding.
That's the problem, there are other tests out there and they don't show the effect. This isn't some new measurement, it's an old measurement (perhaps done better, perhaps not) that is showing a previously unseen behavior.
Also, yes, it's true that other groups are liable to downplay the finding (although that happens less than you might think, speaking as an astronomer myself), but the team themselves do the opposite. Why believe one is biased and the other isn't?
If it varied at all, the result would be significant just on principle. It would mean that the laws of physics have varied in time, which is not something that most current models allow for. (At least, not that I've heard. I work on something a little closer to home, so I might have missed something.)
This isn't the first time that some team has claimed this. Around 2000, someone made the same claim. I recall it not standing up when other teams checked it.
Measurements like this have been done before and usually show a constant, er, constant to within experimental uncertainty.
Note, for example, this paragraph buried at the end of the article:
Nonetheless, the study “is as speculative as the previous claims,” asserts Patrick Petitjean of the Institute of Astrophysics in Paris, whose team has looked for variations in the fine-structure constant with the Very Large Telescope as far back as about 11.5 billion years ago and found none (SN: 4/8/04, p. 301).
In other words, I wouldn't get excited at all yet.
nobody understands that an on-ramp is an ACCELERATION LANE.
Not really. A lot of on-ramps (particularly inside cities) are not designed for acceleration due to twists, lights, or being uphill. And even if you do have a good ramp for it, they often kill your merging lane so fast you want to enter cautiously because you may not be able to get into traffic before your lane goes away. Going faster gives you less time and a smaller segment of traffic to sample from.
Basically, whoever designs on and off ramps seems to be doing a lousy job. (Or, more likely, the guys giving them their instructions. I suspect a lot of it has to do with rules like, "Don't take up more than X amount of space.")
And I'm here to tell you that it's way, way too slow. Even photons bitch about how long it takes to get through Nebraska.
One of the reasons that String Theory is so popular is _because_ gravity comes up straight away, without assuming it. That is why it is so popular.
No, it doesn't. No one has yet managed to merge gravity into the quantum paradigm successfully. Unless I missed a major, major breakthrough in the past few years since graduate school.
"Cling to it" meaning what? If another idea came along and did better than String Theory, people would switch to it.
You're clinging to this idea that ST has provided any value so far. It hasn't. It's an intriguing idea that may pan out and pay great dividends if it does. But it has yet to give us any new power of prediction. So there's really nothing to be "better" than. It hasn't yet shown itself to be better than QM yet, so I don't know why you think it's the theory to beat.
Quantum Mechanics can (and has) been tested. Repeatedly. What makes String Theory different is that while it includes QM, it doesn't generally offer any new predictions. A theory that offers nothing new (neither predictions nor a paradigm that is either easier to work with or provides more insight) is useless. If all ST can do is reproduce QM exactly, it's at best a more complicated what to do the same math.
(That said, I seem to recall ST making a new, testable prediction in the cosmological constant. I also seem to recall it being way, way, way off. But I may be misremembering that.)
We've demonstrated several times that bacteria -- and I believe lichens -- can at least survive extended exposure in low earth orbit, so at that point it's not difficult to believe they could get here from somewhere else.
Yes and no. It's possible, provided they can survive for longer periods of time, to get living creatures from, say, Mars to Earth. The dynamics are tricky (it tends to take quite a while to get from one to the other, particularly if you don't want a high relative velocity when yous smack into the Earth) and lofting the material (and then landing it) in such a way as to not sterilize the rock is tricky. Couple that with the lack of conclusive evidence that life has existed on Mars in the past and I lean toward "less probable" for that route. Again, it doesn't rule it out, but it does take a backseat to local origin in my mind.
(Also, note that Mars, or any other planet in our system, doesn't solve a timescale problem. In fact, the transit time makes it worse.)
The other option is to get it here from outside our system. That does solve the timescale problem, potentially, but that adds a vast amount of time on to the transit. Any organism would have to be able to survive in space for millions, if not billions, of years. And the impact probability of a piece of interstellar junk and our system (let alone Earth) is awfully low. Plus, impact speed with an extrasolar bit of rock is a lot higher than from something already in our system. Barring a long series of orbital manuvers to alter the trajectory before meeting Earth (lower probability still), minimum relative speed at infinity is around 11 km/sec, assuming exactly optimal alignment. (More likely is in excess of 40 km/sec, and that's generously assuming that the speed relative to the Sun is very small.) Your minimum impact speed is therefore around 16 km/sec, which I can't imagine increases the odds of successfully seeding life here.
Again, this doesn't rule it out, but this is just why I feel that panspermia creates more "problems" (where I mean "low probability requirements") than it solves.
You don't need a mathematical singularity to create the problem. You just need a highly compact, near-singularity. Both the Big Bang and the interiors of black holes qualify, unless QM or GR is wrong.
So wait, we have two theories that describe different realms and no data for the intersection of the two realms, but people are trying to come up with a theory for the intersection?
Um, the cross-over objects exist. Grandparent poster is wrong, you don't need small black holes; any singularity has the problem of needing quantum mechanics and general relativity to describe it. This is true of the inner workings of any black hole, for example. (No, we can't get data from one, as far as we know.) Or, just fer instance, the Big Bang. There is a surprising amount of interest in modeling that one.
Does that make more sense?
So, we need a new theory that gives the same predictions at QM and GR in the realms that we can measure them. This is where string theory etc comes in.
Not really. Last I checked, String Theory hasn't made any useful predictions about systems like this. No one has managed to fold gravity into a Theory of Everything yet, unless I missed an important update. (Feel free to correct me if I have.)
TL;DR - People complain at string without proposing anything better.
A theory that offers no new powers of explanation and prediction is itself no better than the pre-existing paradigms. Until String Theory can show itself to have some value (leaving aside the issue of whether it's the best such model), there's no reason to cling to it. "Better" implies that ST was somehow useful to begin with.
. This one does have the advantage of offloading the origin-of-life-on-earth, in which case you can at least claim that maybe biogenesis only happened once somewhere else and is being blown all over the Universe, rather than having only one planet and only a billion years in which to fit your explanation.
How does that help, exactly? You still have the problem of abiogenesis somewhere. At least here on Earth you know you have the right ingredients in abundance and you don't need to invoke a low-probability transfer mechanism to explain how it got here.
I'm not saying that this rules out panspermia, but it does make it seem like rather the more complicated option, all else being equal.
I was looking for "forfuckssake". We need that one.
A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.
That's a protection.
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.
That's a protection, worded as a limit on Congress, but two centuries of interpretation says that it's a protection for individuals.
The list goes on. You might be technically correct in that the constitution is about the government (not just federal, by the way), but when it forbids the government from abridging a freedom, that's a protection to individuals. (And it's interpreted as applying to all lower levels of government, by the way.)
I didn't say you couldn't write a rule that says "one subject per bill." I said I didn't see how you could write it to be really complete. And yes, while all laws require interpretation, this is different. It seems like it'd require constant interpretation. "I know it when I see it," is a horrible basis for the law.
I never understood why in the hell this is possible in the first place.
How would you prevent it?
Seriously, how do you come up with an absolute metric (one that can be made law or, harder, an amendment) that determines whether a given part of a bill is related to the main point of the bill sufficiently? Sure, there's a common-sense, sniff test, but there is so much gray area and that's so hard to define clearly that I can't see it ever standing up in a real situation (ie, court).
The Constitution specifically prohibits this, but that provision has been ignored for so long (like many other provisions) that it is meaningless.
I'm afraid that I'm not familiar with this clause. Can you please be specific?
Many governments control the press and the means of speech to the point where they can actually keep things from being printed or said, yes.
But apart from that, the cases in which consequences result are generally civil suits, which has nothing to do with Congress. The SCOTUS standard for criminal restrictions tend use words like "clear and present danger", but those seem to be rarer.
So yes, free speech is still free even if there are consequences. No one says you can't get fired for calling your boss an asshole, that you can't get sued for saying that Glenn Beck had sex with and then killed a panda, or that you can't be charged for publishing the identities of covert US intelligence assets. The idea that there wouldn't be repercussions seems absurd.
I don't think that you're arguing against anything I said. In fact, I think you're making an argument that the "new media" shouldn't be afforded the same protections we're considering giving the "old media".
What input would the second amendment possibly have?