md65536

The difference is that if you say the words "time dilation" you are reifying time, by making "something" of "it". What is "it" that dilates?, one might reasonably ask. When you use the words "event duration of physical processes dilation", you are simply describing that durations become longer in certain circumstances. It's easy to see that durations can "become stretched out" without having to "be something" that can be stretched out. But with the word "time"... uh... Well see, they're just different, because they're different words. I know it doesn't make any sense when I say it, but owl will explain this all much better than I can.

Well, it made sense when it was on wikipedia. Nah, it still doesn't make sense to me but your previous post makes me see where my error is.

If clocks appear to slow down, doesn't that mean that the "Event Duration of Physical Processes" has lengthened? (That is, the processes involved in say one revolution of a clock hand, take longer duration to complete.)

Observable universe: "In Big Bang cosmology, the observable universe consists of the galaxies and other matter that we can in principle observe from Earth in the present day, because light (or other signals) from those objects has had time to reach us since the beginning of the cosmological expansion. [...] the current comoving distance to the edge of the observable universe is calculated to be 14.3 billion parsecs (about 46.6 billion light years) [...] The age of the universe is about 13.75 billion years, but due to the expansion of space we are observing objects that were originally much closer but are now considerably farther away (as defined in terms of cosmological proper distance, which is equal to the comoving distance at the present time) than a static 13.75 billion light-years distance." [http://en.wikipedia.org/wiki/Observable_universe] I started replying to your post, but then I found everything I was writing in the "Misconceptions" section of the above link. My previous posts have contained misconceptions too! "Distances obtained as the speed of light multiplied by a cosmological time interval have no direct physical significance." -- Sounds like light cones are not the right tool. The wikipedia article should provide some answers. I need to shut up and do some learnin! This is where I was confused, thanks.

A specific light cone is relative to an observational frame of reference (the spacetime point that is the apex of the cone being maybe the most important thing, as least in simple examples???). Events that lie on any specific cone are fixed spacetime points that don't move. Objects move but events don't... only the events remain on the surface of the light cone (whose apex is also a fixed spacetime point, because we're talking about the lightcone of an observer in a single instant), but... the object, extended in time, and described by its world line... is uh... It's not that "an object is fixed to a light cone", it's that its world line always intersects that light cone (for stuff in our spacetime vicinity at least, on the order of billions of years and light years), so there is always an instant where the object (or a past state of the object, one might say) can be observed "on any given light cone". We can gather information about stuff that's not on the surface of a light cone, because of "physical laws". We can use the current observed state of a system and understand previous states that must have preceded it, and we can predict future states to varying degrees of certainty, because the progression of states follows certain laws. One might say that the observable state of a system contains "memory" of previous events. Things are the way they are due to causal relationships that precede observable events. So if we see a nebula, its current state encodes much information of say the star that created it. We observe systems that have memories, and the observer systems can have memories too, where information can oscillate for long periods of time and intersect with many many many different light cones through time. I think you might be talking about extending light cones through time, such as describing "Everything that I see in a day". That's not a light cone. A light cone is a 3D surface in a 4D space. If extended through time I think it becomes a 4D volume that is a subspace of the 4d space. Or, there is the 4D volume that is contained by the past light cone of a single observational instant, which includes everything I see now and everything I could have ever seen and everything that causally affected everything I see or could ever have seen. This is also a 4D subspace.

Quote from the link: "- Distance is defined as the spatial separation at a common time. It makes no sense to talk about the difference in spatial positions of a distant galaxy seen 9.1 billion years ago and the Milky Way now when galaxies are moving. - The Universe is homogeneous and isotropic, so it has no edge. Thus there cannot be a maximum distance. Distances greater than speed of light times the age of the Universe are commonplace. But a uniform grid in the Universe shown at left below is very non-uniform when plotted using the light travel time distance" This doesn't make sense to me. What's the point of talking about the distance between the Milky Way and a galaxy that you can only see as it was 9.1 billion years ago? Sure, you can predict its "true distance right now", but that won't have any effect on us whatsoever for over 9 billion years. There is no causal connection between "us, now" and "that galaxy, now". We see it 9.1 billion LY away, as it was when we are seeing it. What's the point of taking something that we observe, and saying "Well it's not actually there, it's moved. And, it's not actually *that*, it's evolved for 9 billion years so it'll probably be quite different (most of its stars will probably die by then anyway)." I don't see how you could consider what you're talking about as being the same thing as what you observe. -- That can be a philosophical issue but I'm just wondering what the practical point of considering the "current" predicted distance to an observed object is. If you were planning on sending a signal to it, then maybe its distance now is relevant.

I've seen conflicting information. This video: claims that it can't be molten aluminum but shows an experiment where aluminum at the supposed temperatures of the fire is seen glowing as it's poured! At this point I would have to do further research before continuing to claim that there is anything I know to be scientifically impossible in the NIST report. I hope others will continue to bring scientific arguments to this discussion. What's sad is that evidence provided for both sides tells just enough to support a claim, and nothing further, with no room for uncertainty. Anything more is either left out, not worth investigating, etc. The best evidence I've seen so far involves one side trying to prove a point while the evidence they're presenting shows something else, because that something else is just pure evidence, not pre-interpreted evidence presented only to support the interpretation. Another Feynman quote: "The only way to have real success in science, the field I’m familiar with, is to describe the evidence very carefully without regard to the way you feel it should be. If you have a theory, you must try to explain what’s good and what’s bad about it equally. In science, you learn a kind of standard integrity and honesty."

The first part sounds good but is beyond me. It's the reason for the expected "heat death" end of the universe. The second part must be correct. If we can receive a signal from the "intermediate" which has received a signal from the "disconnected", then there must have been time enough to receive a signal from the "disconnected" which means it's not actually causally disconnected. Disclaimer: I'm trying to figure this out as I go and I have no idea about the credibility of the link I quote below. I suppose we can get mixed up on the meaning of "visible universe". I googled to find out the distance to CMB and found this answer: "[...] the today distance to the matter which emitted the light we are now getting as CMB. It says 45.65 billion LY, but you can round that off to 45 or 46. OK strictly speaking that is not the 'distance to the CMB'. The distance to the CMB is zero, it is all around us. It is radiation and some of it is in this room. 46 billion LY is the distance to the MATTER that emitted the CMB radiation that we are currently receiving. Technically, 46 billion LY is called the distance to the 'surface of last scattering'." [marcus, http://www.physicsfo...p/t-280981.html] But now I've confused myself. If the age of the universe is about 14B years, then we cannot see (now) anything beyond 14B LY because it would require more than 14B years for that light to reach us. Therefore I think the causally connected observable universe must be at most 14B LY. HOWEVER, 14B LY is the spatial distance to the event of the "last scattering" of some material, and that material would have kept traveling away from us. Some of that material may now be say 16B LY away???? and may become visible in a few billion years. Other material may be say 30B LY away and moving away faster than the speed of light so it will never be visible to us. Also, since apparently the rate of expansion is increasing, the 23-34B LY boundary should get closer in the future! I think that this means that the currently observable universe is within 14B LY. The causally connected universe extending to 23-24B LY is not currently visible, but events within that range can become visible in the future (but, for events around that range, not until the universe is at least 23B years old). Also... as the age of the universe grows, while the distance to the "causal boundary" or whatever decreases, at some point these two values should be equal. At that point, I think what happens is that the material that gave off the CMB radiation we're then seeing, will quickly be moving away faster than the speed of light???, and the CMB radiation will be the last we'll see of that material! After that point, we should not be able to detect CMB radiation any more.

Sounds alright. I think others would be able to improve that description (better than what I could do). I would say: Everything we observe -- every observation -- can be considered an "event", such as "Neil on Earth", "Neil in space at t=5000", "Neil in space at t=5001" etc. Some of those events can be outside our (Houston's) light cone, such as "Neil on the moon right now", but those same events will be on the past light cone of ours in the near future (about a second in the future in this case). So I would disagree with "he navigates the past light cone of Houston". However, yes, his world line will always intersect with any of our past light cones, so he is always observable. He navigates the spatial realm of Houston's past light cone, but just outside of it in the temporal dimension, as does pretty much everything (according to SR). When you say "he", if you mean him as an object extended through the time dimension, then his spacetime location(s) can be described with his world line, which always intersects with Houston's light cone. If by "he" you mean him existing in different specific single instants (which could be called events), then there will be instants that are on the light cones of Houston's specific instants, and others that are not. The event of him touching down on the surface of the moon is an instant that is only observable in an instant at Houston. But, for any light cone of Houston's, there will be an event corresponding to "Neil intersecting the surface of that light cone". Either way, some "he" is always theoretically observable to Houston. There is probably a simpler way to say this than what I wrote.

Alright, I will agree with you that simpler explanations are better. I will also say that a LOT of stuff happened that day, and just like the rest of life there's going to be some very unlikely things happening mixed in with all the likely things. If something seems unlikely (like WTC 7 collapsing due to heat expanding a specific beam and weakening others), that doesn't mean it couldn't have happened that way. If we debunk all of the "scientific" claims against the official explanation, then we should be left with the "likelihood" of the official explanation, and that might give us some high or low degree of confidence in the explanation, but unless it was statistically impossible I can't really say "It couldn't have happened that way." However, an explanation that relies on scientific impossibilities is a complication, not a simplification. Claiming that the molten metal is aluminum is a complication, because molten aluminum does not glow as seen in the videos. An explanation I've come across in some of the videos is that it was molten aluminum well-mixed with burning office materials. This is a complication because office materials don't mix with aluminum. They float on top. A simple explanation for the molten metal is that it is steel melted with thermate. There are complications with this too, including that there was no evidence of thermate found. However this has a simple explanation too! "NIST simply never checked for the presence of thermite or thermate" [http://en.wikipedia....piracy_theories] The simple explanation for why they never checked is: "NIST did not test for explosive compound residue in steel samples, stating the potential for inconclusive results, and noting that similar compounds would have been present during construction of the towers," [same ref as above], or "When asked why NIST did not test for explosive residues, NIST spokesman Michael Newman responded that NIST saw 'no evidence saying to go that way.'" [http://en.wikipedia....ld_Trade_Center] Saying that there was no thermate in the wreckage because none was found and nobody looked for it, is like saying that length-contraction doesn't happen at human scales because no one has done an experiment that can confirm it. If the likelihood of thermate is low (negligible, as NIST implies), then it currently falls under "Unlikely, but not impossible". If the glow of the dripping molten metal can't be explained, then "it is molten aluminum" falls under "not possible." The case for thermate can be considered even less likely, if there's an alternative explanation that is scientifically possible.

I'm not sure what you're saying here. Do you mean the theories are elaborate, or that they tend to be far-reaching (ie. involving a lot of conspirators)? I suppose that if we have a lack of understanding of a situation, and think that we can fill in the details with guesses and assumptions, then it's easy to grow a conspiracy theory. It will probably have holes in it, so if you keep filling the holes with guesses it can get pretty complicated. Any theory built on layers of conjectures is probably pretty bad. That goes both ways though... as soon as you put together a few assumptions like "The government has no reason to lie so they wouldn't; it would take thousands of conspirators to pull off something like this; it would be impossible for anyone to have access to the buildings before 9/11" etc, the theory can become unreliable. Also, what do you mean by "easier"? I don't think it's easy to say that something that is not scientifically possible actually happened.

The Loose Change link reminds me of something else. The Iraq war lie was exposed but I don't remember anyone facing any consequences for the lie. Clinton was impeached for lying about sex. A large percentage (I remember ~35% but the first link on Google says 84%! http://www.prisonplanet.com/articles/October2006/141006poll.htm) of people think that 9/11 was a lie, among them both experts and lay people. That proves nothing about whether or not they're right, but it does show that exposing the lies doesn't necessarily mean that anything will be done about it. This wasn't kept secret for a decade. People know about it. People demand answers, and are ignored. I'd also like to speculate on ways that the conspiracy could have been pulled off without a lot of people "in" on it, but it would require a lot of guesses and would be unlikely to be correct. I'm sure that whatever really happened makes a lot more sense than anything I could imagine, and NIST's version of things as well. If anyone's still interested in discussing the science of it, the biggest mystery for me at the moment is the glowing molten metal that is seen dripping from one of the towers. I think that the official explanation has been debunked.

I'm not caught up in this conversation but... A world line of an object is the path of that object through 4d spacetime. The world line is defined by its object. Different objects would each have their own world lines. You could though describe the world line of a molecule, or describe world lines for each of the molecule's atoms and they'd be very close to "the same" world line at macroscopic scale. Where two world lines intersect, you have two objects collocated in spacetime. A collision event might be described that way, where the collision event is essentially on both world lines... the same point could be said to be on both world lines, even though each world line is still associated with its own object. I suppose that some sets of objects can never occupy the same place and time, so their world lines would never touch.

I'm having trouble understanding how the WMAP diagram and a 2D diagram of what's observable fit together. Is the WMAP image a representation of the entire universe (of which we don't know the size, right?), or just the observable universe? What I think is that it is not meant to be either, but rather just a diagram of history, or the history of distance, where the bell-shaped curve is the distance between two completely arbitrary astronomical spatial coordinates??? Yes, the diagram is pretty empty, because it's a 2D image of a 4D representation of the universe. The galaxies and junk in the image are shown at one moment in time... but these don't exist only for a moment of time! Every object in the diagram could be "extruded" along the time dimension to show its history. Every bright object would have a "birth" along the time axis where presumably it formed from less luminous materials, and each would eventually have a "death" where it exploded or evolved into other things. So, everything that's in this diagram can be traced back through time to an earlier part of the diagram. None of the objects that you show outside the light cone should have come from an earlier part of the universe that was outside the light cone. That is, something that's 15 billion LY away and unobservable to us right now, was something else in the past, say 13 billion years ago when it was 13 billion LY away from us and thus visible to us at the moment.* Your "empty diagram" suggests that visible things are blinking in and out of existence, instead of existing for long periods of time and only being observed in single instants. Presumably, the objects on the diagram are placed "illustratively" roughly in the era that they existed as shown. I assume they'd want to be shown in formative parts of their lifetimes, rather than arbitrary times in their lifetime. But all the material that's shown in the diagram exists for the entire length of time in the diagram, in different forms as stars form and explode and reform into new stars etc. Smear the diagram horizontally from CMB to WMAP and vice versa, and even though it still only shows a handful of the hundreds of billions of observable galaxies, the diagram will become pretty full. * Note: I have a feeling this statement is wrong, due to my feeble understanding of inflation. A correction from someone who knows GR would be appreciated. Inflation must involve updates to simultaneity?? -- Due to inflation, an event may have been say only 12 B LY away, 13 B years ago local time, and be visible now 13 B LY away, right???

You keep using those words. I do not think they mean what you think they mean. Before you get too entrenched in scientific debate in the Speculations forum, you might want to brush up on a thread like http://www.scienceforums.net/topic/58293-frame-of-reference-as-subject-in-subjective-idealism/, where you will see that owl has already soundly defeated the "theory" of relativity, and his claims remain untouched by even the most seemingly convincing of logical arguments. I know 26 pages is a lot to read through, but as owl really dislikes repeating the same thing over and over and over, it would be courteous to get up to speed on the whole "What is IT that is time?" field of study so that we can skip any questions that have already been answered and go full speed into the ontological discussion of the quantum eraser experiment.

I see now. On the first video I posted they've cut that part out, making it seem like the 6.6-second collapse of the outer part is the entirety of the collapse. That certainly damages the credibility of the claims made in the video.

I don't know. Failing to keep one secret does not prove that no secrets can be kept. The answer is related to the answer to "How did the truth come out about the Iraq war?" As OP said, Many people are speaking up but they're still being ignored. Perhaps a key difference is that much of the 9/11 evidence (for either side) is scientific and highly technical; perhaps the evidence related to Iraq was easier for average people to understand, or harder to hide behind intricate explanations. Another aspect is that 9/11 is history, while the Iraq was ongoing, and perhaps there was the ultimately false sense that exposing the lie could prevent the continuation of the war. Many people seem to just not care, perhaps believing that nothing like 9/11 will ever happen again, as per the old saying in Tennessee, "Fool me — You can't get fooled again." Personally I prefer, "Those who cannot remember the past are condemned to repeat it," as authorities certainly learn from what they do and don't get away with. But like I said, if NIST's science made more sense to me I'd be more confident in their version.

My answer to this is also, "no". The NIST explanation is that a beam was knocked off its seat. If you watch the video of the collapse, and consider that an east section of the building is unsupported and begins to fall, pulling the westward sections off their support, allowing them to fall, does this seem reasonable? The east section begins to fall only slightly before the west. Look at the very short distance that the east section falls before completely removing the support of the west sections. Another possibility is that the westward supports were already removed before the east side began to collapse. For example, if an eastward beam was knocked off its seat and collapsed, pulling and breaking westward supports, and then the unsupported top/outer structure began to fall. This would mean that the support structure was completely compromised by fire without using any of the kinetic energy of the collapsing building to help demolish the supports. Does this seem reasonable? There may be other reasonable possibilities. The NIST explanation does not seem plausible to me, but I can't prove at this point that none of these possibilities are at all possible. Wouldn't that make you want it to be investigated more, before you accepted the explanation that you doubted? Conspiracy theories often arise when the accepted explanation doesn't make sense to people, and they're forced to consider alternatives that do. The problem is that a lot of things that have good scientific explanations, don't make sense to a lot of people. Then others group all doubters of "the official explanation" as conspiracy nuts ("if you think the NIST findings are dubious then obviously you think the moon landing was faked too" etc). The question of this thread involves whether an explanation of the 3 towers' collapse is scientifically valid without involving controlled demolition.

Sure, I'll answer it if you answer mine. Mine can also be answered yes or no, though an explanation of any answer would be acceptable because I know it's not really simple.

How do you answer a question like "What is IT?"? Say you're considering at the moment just two options A or B. To be able to answer that IT is one but not the other, there must be some difference between A and B, that you could ascertain. Then if you can show that IT is like A but not B, you can say that IT may be A but is not B. Science is concerned with these questions. Science is also concerned with the question "Is there even a detectable difference between A and B?" Science is not concerned with a question like "If there's no way to tell if IT is A or B, then which is IT really???" Philosophy may be concerned with such questions, but some of those questions can be proven with science to be unanswerable. I would say that philosophy is relevant to science because at the very least there's a lot of overlap between the two, but that the answers to unanswerable questions are not relevant to science. That's why experimental evidence is so important. If there's no practical difference whether IT is A or B, how can you ever answer the question? How can you know the answer? What would the point of an answer be, if it really made no possible difference?

Really, this comment is rated up? I thought it was kind of off-topic. Fine, I'll answer it. Yes, I believe that men landed on the moon. I've seen evidence in favor of and opposed to the claim. All the evidence that I've seen against it can be simply and plausibly explained in ways that are consistent with humans having actually landed on the moon. It was certainly a situation outside normal human existence, so like 9/11 it evokes many conspiracy theories. But unlike 9/11, the official story regarding the details of space travel do not contradict basic high school-level physics etc. Here's a direct question for you, in return: Do you think that the US government has never lied to the country to justify either entering into armed conflicts or acquiring additional authoritative power?

Not relevant to WTC 7.

Yes, I don't believe in a lot of things. Is it not also that way for you? Are there only a few things you don't believe? I say the video proves that it's possible to cut girders with thermite (or thermate). I call it "science". Edit: Sorry, I misread that... I thought they were both "not believe". My evidence #5 didn't involve "experts" but people directly involved in conversations about plans to demolish the buildings. No, my confidence in their testimony is not 100%. I've already agreed that point #5 can be ignored. Quote: The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn't know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty damn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty — some most unsure, some nearly sure, but none absolutely certain. Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure, that it is possible to live and not know. But I don't know whether everyone realizes this is true. Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question — to doubt — to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained. -- Richard Feynman When you provide evidence that the official explanation is plausible, it increases my confidence in that. When you show that a simpler possibility is comparably likely, it decreases my confidence that a conspiracy theory is the correct conclusion. I should hope that the converse is true for all of us, but it appears not to be so. If someone's claim (no matter how much of an expert/s they are) goes against my understanding of the world and against common sense, then the science has to be pretty damn convincing before I'll accept it. NIST's science is suspect.

I believe it's viewed from midtown. This video shows multiple angles: Not a lot more to see, but the upper left video shows that the northwest and southwest corners of the building fell in unison. I still have no confidence in the official report, but I can't prove (beyond the evidence I've already posted) that the very rapid domino-effect collapse described on wikipedia, is impossible. If you think that the official explanation is reasonable, after considering the counter arguments, enough that you have no doubt in the validity of that explanation, then I don't think I can change your mind.

I was going by information in the thread. If the official story is that debris didn't contribute to the collapse, then it must be that fire alone (using only the building and its contents as fuel) caused a near simultaneous structural failure of all of the building's interior supports. If the official story is that debris was significant in the destruction of the inner columns, it (and the fire) was still insufficient to completely compromise the structural integrity of the outer support (at least timely enough that the outer building could fall on its own -- it was pulled down by the inner supports as we've agreed).