I and about 6 billion of my closest friends have acquired quite an attachment to this particular (though, yes, arbitrary) frame of reference!
Well as long as it's acknowledged that we're talking about something contingent that we have an emotional attachment to, rather than something of physical significance, and that no physical law whatsoever hinges on whether or not event A is in the past of event B then we're in agreement. I tend to use a Newtonian (Galilean? Aristotelian?) model of time in conversation about everyday things, but I'm very uncomfortable about such language when talking physics about events 7,000 light years away.
Parallax? Dude! Are you crazy? I think there should be a rule on/. Anyone who's going to talk about figures should at least do an order of magnitude calculation on their calculator first. In fact, forget order of magnitude, just order of magnitude of the order of magnitude should be enough to tell you that using parallax to measure the distance of something 10^9 light years away is completely insane. You don't even need a calculator. google will tell you the parallax angle we might get from viewing this cluster from opposite sides of the Earth's orbit.
As a one time mathematical physicist who has studied General Relativity (but my area was ultimately the mathematics of conformal field theory), I can assure you most definitely that the claim that the condition for event #1 (t_1, x_1) to lie in the past of event #2 (t_2, x_2) is merely t_2 > t_1, is complete bullshit unless by 'past' you mean a concept that's more or less useless. Ie. you're defining 'past' simply by picking some arbitrary inertial frame and defining A to be in the past of B if in this frame, the t-coordinate of A is less than the t-coordinate of B. This is a horribly parochial definition that's more or less useless for talking about physical events. It's not a Lorentz covariant notion so it has no physical significance whatsoever. When someone says "X is happened already" they are making a pronouncement about an even that they claim has physical significance. Really, you need to get this stuff sorted out if you're doing research in QFT.
Really, when will people learn not to use the past tense for events outside of our past light cone!
The pillars have already been destroyed by the shockwave
The guy's modeled the pillars and claims that they were destroyed 6000 years ago, 7000 light years away. But if this is the case, then their destruction is outside of our past light cone. So someone else here and now, moving past as at high velocity, using English in the same way, could claim that this event is actually in their future. It doesn't mean that they could visit the destruction because they're outside of any possible future lightcone of any observer starting from here now. Events outside of our light cones are neither past nor future, and you certainly can't go bandying around the word 'already' when you talk about them.
For example there are 20 fluid ounces in an Imperial pint...
Ah yes, that explains why the Birds' Custard Powder that the family brought over from England didn't come out right when mixed with water. I keep forgetting about that.
Dictionaries are hopeless for providing definitions in even a slightly technical domain. Almost every definition of "evidence" in a dictionary is hung up on the notion of proof, probably because of the common legal use of the word. For this reason dictionary definitions tend to define 'evidence' in terms of 'proof'. But read just about any scientific literature - you will find many uses of the word 'evidence' but very few uses of the word 'proof'. In fact, 'proof' is something of a taboo word in scientific circles outside of mathematics. The notion of 'evidence' in scientific discussion is quite separate from the notion of 'proof', and its meaning is close to what I originally said: that which tends to increase the assessment of the likelihood of something. Carl Sagan's quotation is fine for legal discourse, but it's way off the mark for scientific discourse, the domain for which it was intended. Even in informal technical discussion the word 'evidence' ceases to carry the sense of being the thing that clinches the proof.
In science, proof is a very rare thing. All we have are hypotheses that are more or less likely, and evidence that makes them so.
You are confused about the meaning of the word 'evidence'. When you obtain evidence of X you shift your estimate of the probability of X upwards. That's what 'evidence' means. You need to get this distinction.
You say "you are attempting a negative proof or proof of impossibility" which demonstrates you didn't actually read or understand the parent post which stated, quite clearly, "Absence of evidence is prima facie evidence of absence.", not "Absence of evidence is prima facie proof of absence". Until you sort out the difference between proof and evidence the rest of what you say is moot.
For a slightly more formal treatment see here. Sagan was talking out of his ass when he said that and there's nothing more annoying than people who keep quoting it.
Other countries will respond in kind and will provide that information to the US. After all, MI5 do the dirty work for the US that the CIA aren't allowed to do.
I had a touchpad fail on my new Acer a few years back. On their phone technical support they gave me the name of a local company who could repair it. At that point Acer told me I had voided the warranty by having a 3rd party look at it and I had to pay for the repair. This is the dirtiest trick I've ever had played on me by a company. Fortunately I lost less than $100 and was able to get my money back through the store that had sold me it. But it's one of the few times I've felt like firebombing a company.
That's a 'pixellate' rather than a blur. What I describe corresponds to many types of 'blur' that appear in image manipulation packages. The original story has a stupid name, but as a general principle, many image processing operations are theoretically invertible.
...contains almost the same information as the original. Consider a 1D example with a sequence of pixels:
1-10-20-5-8-10
Now perform a simple blur by averaging each pixel withh its neighbors (padding with zero at edges):
3.7-10.3-11.7-11-7.7-6
Suppose we lose the original. Note that we have still have 6 values and we know the equation that generated each one. So we have 6 equations in 6 unknowns, and we can solve. (In real life blurs are more complex, but in practice they are still linear, including blur from camera defocus.) The catch is numerical error, especially if there's quantization. But it's not beyond the realm of possibility to solve these equations and there are countless published 'deconvolution' algorithms out there.
researchers at Oak Ridge have shown that the spin of a pulsar is determined by the shock wave
and
According to three-dimensional simulations...the spin of a pulsar is determined...by the shock wave created when the star's massive iron core collapses.
?
There's a big difference between a tentative model suggested by a simulation that is explicitly described as 'plausible' and 'researchers have shown that...is determined'.
From 'the first plausible explanation' to 'researchers at Oak Ridge have shown that the spin of a pulsar is determined by the shock wave created when the star's massive iron core collapses'. Shows how poor journalists give scientists a bad name by making their claims seem much stronger than they are. The press release is very careful in how it makes its statements. The/. story isn't.
But the GUI has barely changed since the early days of Windows meaning that we're talking about something that, on average, needs to be learned only a couple of times in a lifetime, so I think the analogy is apt. If Microsoft changed their interface once a year then I'd agree with you.
It takes *years* to learn to write using a commodity pen and paper. So a few extra hours to learn how to use a word processor is hardly a 'learning curve'.
There's an essay in "The Third Chimpanzee" by Jared Diamond about how certain Mayan kings would show off how macho they were by ingesting large amounts of alcohol or other substances and it struck me that this was similar to patterns of caffeine usage among geeks. Fortunately geeks differ from Mayan kings because they don't take caffeine as an enema. Check out the quotation here (scroll down to where "jared diamond" is mentioned). I wonder if they used chilis in this way...
They didn't go home. They got the hell out of the area the moment they noticed their cloaking device had failed. Judging by this controller's reaction, getting the hell out was exactly the right thing to do.
"Macho" doesn't enter in to it. It's just expression.
Last time I looked, thinkgeek didn't have many rowing related objects for sale. Nor does it have many related to any sport, or food or drink that isn't coffee. Saying "It's just expression" is like saying "War and Peace is just a bunch of words". You wouldn't be wrong if you said it, but you're kinda missing the point.
Slashdot Mirror
Parallax? Dude! Are you crazy? I think there should be a rule on /. Anyone who's going to talk about figures should at least do an order of magnitude calculation on their calculator first. In fact, forget order of magnitude, just order of magnitude of the order of magnitude should be enough to tell you that using parallax to measure the distance of something 10^9 light years away is completely insane. You don't even need a calculator. google will tell you the parallax angle we might get from viewing this cluster from opposite sides of the Earth's orbit.
As a one time mathematical physicist who has studied General Relativity (but my area was ultimately the mathematics of conformal field theory), I can assure you most definitely that the claim that the condition for event #1 (t_1, x_1) to lie in the past of event #2 (t_2, x_2) is merely t_2 > t_1, is complete bullshit unless by 'past' you mean a concept that's more or less useless. Ie. you're defining 'past' simply by picking some arbitrary inertial frame and defining A to be in the past of B if in this frame, the t-coordinate of A is less than the t-coordinate of B. This is a horribly parochial definition that's more or less useless for talking about physical events. It's not a Lorentz covariant notion so it has no physical significance whatsoever. When someone says "X is happened already" they are making a pronouncement about an even that they claim has physical significance. Really, you need to get this stuff sorted out if you're doing research in QFT.
In science, proof is a very rare thing. All we have are hypotheses that are more or less likely, and evidence that makes them so.
You say "you are attempting a negative proof or proof of impossibility" which demonstrates you didn't actually read or understand the parent post which stated, quite clearly, "Absence of evidence is prima facie evidence of absence.", not "Absence of evidence is prima facie proof of absence". Until you sort out the difference between proof and evidence the rest of what you say is moot.
For a slightly more formal treatment see here. Sagan was talking out of his ass when he said that and there's nothing more annoying than people who keep quoting it.
Other countries will respond in kind and will provide that information to the US. After all, MI5 do the dirty work for the US that the CIA aren't allowed to do.
I had a touchpad fail on my new Acer a few years back. On their phone technical support they gave me the name of a local company who could repair it. At that point Acer told me I had voided the warranty by having a 3rd party look at it and I had to pay for the repair. This is the dirtiest trick I've ever had played on me by a company. Fortunately I lost less than $100 and was able to get my money back through the store that had sold me it. But it's one of the few times I've felt like firebombing a company.
Did the real 21st century just arrive?
That's a 'pixellate' rather than a blur. What I describe corresponds to many types of 'blur' that appear in image manipulation packages. The original story has a stupid name, but as a general principle, many image processing operations are theoretically invertible.
...but it is the funniest one ever.
There's a big difference between a tentative model suggested by a simulation that is explicitly described as 'plausible' and 'researchers have shown that...is determined'.
Maybe you'd like to try again.
From 'the first plausible explanation' to 'researchers at Oak Ridge have shown that the spin of a pulsar is determined by the shock wave created when the star's massive iron core collapses'. Shows how poor journalists give scientists a bad name by making their claims seem much stronger than they are. The press release is very careful in how it makes its statements. The /. story isn't.
But the GUI has barely changed since the early days of Windows meaning that we're talking about something that, on average, needs to be learned only a couple of times in a lifetime, so I think the analogy is apt. If Microsoft changed their interface once a year then I'd agree with you.
Scroll down to 'science' here for some hilarious quotations from clueless TV personalities.
There's an essay in "The Third Chimpanzee" by Jared Diamond about how certain Mayan kings would show off how macho they were by ingesting large amounts of alcohol or other substances and it struck me that this was similar to patterns of caffeine usage among geeks. Fortunately geeks differ from Mayan kings because they don't take caffeine as an enema. Check out the quotation here (scroll down to where "jared diamond" is mentioned). I wonder if they used chilis in this way...
They didn't go home. They got the hell out of the area the moment they noticed their cloaking device had failed. Judging by this controller's reaction, getting the hell out was exactly the right thing to do.