Iggy

the answer to this... would seem to be that BCD can accurately represent decimal fractions (without rounding) while binary and hex cannot. Do you understand what that means?

yeah... that hex and any base not a multiple of 10

I would guess, although I don't specifically know, the question is looking for this: http://speleotrove.com/decimal/decifaq1.html#inexact It can accurately represent decimal fractions where binary and hex cannot.

I think the perihelion precession was first noticed in the mid 1800s. The light-bending observation happened in the other order... i think. EDIT... imatfaal, the conclusions section (page 75) repeats what you were saying, I know you guys came to an understanding, but I thought you might find interesting, http://www-itp.particle.uni-karlsruhe.de/~schreck/general_relativity_seminar/The_confrontation_between_general_relativity_and_experiment.pdf

It's really not that difficult to apply your idea to the big bang. An argument similar to yours is here: http://www.astrosociety.org/pubs/mercury/31_02/nothing.html Hawking did some work in the area... summing the different types of energy in the universe to zero. The ultimate free lunch they say.

Eh? You quoted it here: Highlighted part: agreed. Non-highlighted part: A timelike tachyon does, not a spacelike tachyon which was the point I was raising earlier. Some models go back as far as the 60's which try to circumvent the problem of a faster than light particle which would oscillate throughout time and the causality problems which closely asist it. The non-highlighted part is what I repeated. Oh, my! I still don't get why you disagreed with post #35 nor what you meant by "timelike tachyons". The material you referenced reinforced the thing I said and the footnote it gave specifically equates "spacelike 4-momentum" with "faster than light" (i.e. tachyons). I don't believe that the argument you cited anywhere claims that tachyons can be taken as timelike or understood in any way to travel slower than light. It seems like you disagreed with my post for reasons that don't disagree with my post. Maybe it's a little off topic though and we should just leave it... ?

Yes... I've heard that argument. It seems not only consistent with what I said, it says the exact same as I said... there always exists a sub-light speed reference frame shift that alters the temporal direction of the tachyon's world-line Now I really don't understand why you disagreed with this:

I don't see how that makes sense, but I'm not too familiar with tachyons. When you say "time-like" do you mean a tachyon that follows a time-like geodesic, because that sounds like a contradiction in terms. Nothing that follows a time-like path would be a tachyon.

The speed of light is special because it's invariant. That is what makes c special, and the existence of speeds faster than c would make c no less special in that regard. If something travels FTL in one frame then it travels back in time in another frame -- not because light is the fastest speed of communication, but because it is invariant (the same in every frame).

The link I gave explains http://en.wikipedia.org/wiki/Not_even_wrong You don't know me. You have no idea what my view of alternative cosmology is. You are confusing my rejection of your idea (which doesn't even seem like a coherent idea) with my rejection of alternative cosmology. Matter is made of particles. Antimatter is made of antiparticles. If you were saying that cosmic voids have antimatter in them then I would know what that means. I don't know what it means for a void to have anti-gravity I don't know what it means to have anti-gravity sprinkled throughout the cosmos. Imagine if I said that I could explain the dry parts of earth's surface because those places have anti-wet. That's it. That's the end of my explanation. If someone asked what I meant I might say that God's voice sprinkled anti-wet across the earth in waves. It isn't an explanation. It's not even wrong.

I don't understand your idea. You're talking about waves of god's voice and antigravity sprinkled throughout the cosmos. None of that means anything to me so I can't intelligently talk about it. If you don't have something quantitative to compare to reality or to compare to the standard model then it's a dead end. The idea is not even wrong.

We've effectively hit a dead end there. Yes. Sure. Space can be measured with a ruler and time can be measured with a clock. Further in space means larger as measured by a ruler. Further in time means larger as measured by a clock. Yes. Presently, the whole universe is expanding faster than the whole universe was expanding a billion years ago. Accelerated expansion means that as time ticks on the rate of expansion increases.

I'm not sure you took what I said how I meant it to be taken. The speed of the tachyon relative to the observer depends on the speed of the sender relative to the observer. I'm not the best with space-time diagrams but I can give it a go... eh.. :-/ Sender-B travels .6c relative to sender-A The tachyons are the dotted lines. They are sent from the senders and received by the observer. Sender-B figures that tachyon-B goes 2c. Sender-A figures that tachyon-A goes 2c. The observer (who is at rest relative to sender-A) figures that tachyon-A goes 2c and tachyon-B goes back in time (she receives tachyon B before it was sent in her coordinate system). Meanwhile, in Universe-A, Hermes-A heads towards the Sun... A... I'm not sure what that means. A cannonball that goes 2 m/s relative to one person might go 1 m/s relative to another person. This doesn't mean we've dropped the relativity of motion. The speed of light is the only invariant speed. Tachyons don't travel at c, so their speed won't be invariant. They would go different speeds relative to different people. Is that what you're referring to? I'm not sure.

I guess I'll repeat what I said before to no effect. The cosmological constant is a component of gravity that works in empty space to do as you say "driving space apart, space carrying the galaxies with the expansion". How is your idea different from dark energy?

I don't know about "science is not science without the math". But, I know that claiming to have a scientific theory capable of modeling aspects of cosmic voids without math is absurd.

I agree, "confirm" is used somewhat differently than "verify". There is actually a reason for this that has to do with circumstance and not logic. This discussion of verifiability in science was first had in German. Some of the German terms were translated awkwardly like Popper explains: Carnap translated my term 'degree of corroboration' ('Grad der Bewährung'), which I had first introduced into the discussions of the Vienna Circle, as 'degree of confirmation'... and so the term 'degree of confirmation' soon became widely accepted. I did not like this term, because of some of the associations ('make firm'; 'establish firmly'; 'put beyond doubt'; 'prove'; 'verify'; 'to confirm' corresponds more closely to 'erhärten' or 'bestätigen' than to 'bewahren'). I therefore proposed in a letter to Carnap (written, I think, about 1939) to use the term 'corroboration'. (This term had been suggested to me by Professor H.N. Parton.) But as Carnap declined my proposal, I fell in with his usage, thinking that words do not matter. This is why I myself used the term 'confirmation' for a time in a number of my publications. Yet it turned out that I was mistaken: the associations of the word 'confirmation' did matter... I have therefore now abandoned it in favor of 'degree of corroboration'. Logic of Scientific Discovery -- 79 Like Popper, I would rather say that a theory can be corroborated (or supported). I would have an issue saying that it can be "confirmed" or that there is a "degree of confirmation" for the same reasons Popper gave. It would make more sense to me (and maybe you meant) that theories are not inductive and therefore can't be considered true or verified. Theories are deductive in that they propose conclusions based on the deductive reasoning applied to axioms or postulates. The method has been called the Hypothetico-deductive method which wiki characterizes: The hypothetico-deductive model or method, first so-named by William Whewell,[1][2] is a proposed description of scientific method. According to it, scientific inquiry proceeds by formulating a hypothesis in a form that could conceivably be falsified by a test on observable data. A test that could and does run contrary to predictions of the hypothesis is taken as a falsification of the hypothesis. A test that could but does not run contrary to the hypothesis corroborates the theory. A more authoritative source would again be The Logic of Scientific Discovery -- page 317 of this link: Scientific theories can never be 'justified', or verified. But in spite of this, a hypothesis A can under certain circumstances achieve more than a hypothesis B—perhaps because B is contradicted by certain results of observations, and therefore 'falsified' by them, whereas A is not falsified; or perhaps because a greater number of predictions can be derived with the help of A then with the help of B. The best we can say of a hypothesis is that up to now it has been able to show its worth, and that it has been more successful than other hypotheses although, in principle, it can never be justified, verified, or even shown to be probable. This appraisal of the hypothesis relies solely upon deductive consequences (predictions) which may be drawn from the hypothesis. There is no need even to mention induction. [his bold] They are the same. "Dark energy" is shorthand for the vacuum energy density of space. Lambda (called the cosmological constant) is the variable saying how much vacuum energy density space has. In 1931 Eddington translated Lemaitre's 1927 article modeling an expanding universe. He actually worked on the model from 1925 through 1927. In 1931 (and more so with another publication in 1933) the model became widely known. 1931 is also the year he traced the expanding cosmos back to the singularity and coined the term 'primeval atom'. Friedmann published the same in 1922. The important thing is that an expanding cosmos is a direct result of relativity and not as you characterize "Big Bang was ONLY thought of because when the discovery was made that most galaxies seem to be flying away from each other the quick answer was the primitive one, explosion, which we are familiar with since age two seeing firecrackers blow up." That is an unfair characterization. In my last post the two references I made are accompanied by links to their source. The links are underlined in all modern browsers. "anti-gravity" sounds an awful lot like negative pressure of the vacuum which is what dark energy is. You would need to give an equation modeling the expansion of the void. If it is, [math]\frac{\ddot a}{a} = - \frac{4\pi G}{3}\left(\rho + \frac{3p}{c^{2}}\right) + \frac{\Lambda c^{2}}{3}[/math] then it is the same as we already have. If it is different then it may not agree with reality. Is it the same?

To understand why a theory is different from a fact and why theories are not verifiable I suggest chapter 3 ("Theories") of the Logic of Scientific Discovery. Page 48 and 49 in particular: google book. It's odd that I'm needing to support this after you already said, "I think true science keeps an open mind, a mind that says despite heavy evidence of confirmation, this theory may still be wrong". You were spot on about that. The variable in general relativity and in the big bang model responsible for dark energy is Lambda. It has been a part of general relativity since around 1915. Einstein explains how to set the value: The postulate of general relativity requires the introduction of Lambda into the field equations. It will be our factual knowledge of the composition of the starry heavens, of the apparent motions of the stars, and of the state of spectral lines as a function of conditions far from us that will allow us empirically to answer the question whether Lambda equals zero or not. Conviction is a good mainspring, but a bad judge! -Einstein, April 1917 Since about 1998 we have been in a position to do just that. Cosmologists have been able to put reasonable constraints on the value of Lambda (ie the amount of dark energy). This is an entirely appropriate thing to do... and an exciting development. It's good science. I don't know why you characterize this by saying "When 2 + 2 in Big Bangism add up to 3.1 someone adds .9, for instance, Inflation, Dark Energy, Dark Matter.", but it is an unfair characterization. Phi for All has generously done the legwork on that... with my thanks. The thing that surprised them was not that further galaxies recede faster. We've known that there is a distance/velocity relationship since 1929. The surprise was that the recession speed at a certain distance (let's say 1 billion light-years) used to be less. You could say that 5 billion years ago, a galaxy that was 1 billion light-years away had a smaller recession speed than a galaxy that is 1 billion light-years away today. In other words, the surprise was not that the speed of expansion increases with distance -- but rather that it increases with time. Also, it may be misleading to call this a surprise without a couple caveats. Most cosmologists before 1998 intuitively suspected that Lambda would be zero, but everyone understood that it had to be measured to be known for sure. You see Einstein saying that in the quote I gave and you can look at papers predicting the consequences of a positive value Lambda... I think Carroll 1992 for example... so it was somewhat unexpected, but not unforeseen. Dark energy certainly was NOT created recently to explain the acceleration of expansion. Like Einstein said in 1917 "The postulate of general relativity requires the introduction of Lambda (i.e. dark energy) into the field equations". We just didn't have a good indication of its value until recently. Crying foul as a guide to good friendship

If the two tachyons are sent from A's location -- one from A's gun and another from a gun at rest relative to B -- only one of the tachyons goes back in time in B's frame. The one from A's gun reaches B when B's clock is at 4 seconds. The one from the other gun reaches B when B's clock is at 16 seconds. It isn't clear to me why you think this is a problem, but it might be that you're assuming that the speed of the tachyon should not depend on the speed of the source. It does depend on that. Agreed. Agreed. No, they both received the signals when they were at the same location -- the reason is that the two return signals go different speeds. Looking at the diagram I'd estimate that the return tachyon coming from the ship at rest relative to A goes about 20% faster than light (1.2c) in B's frame. The other return signal travels much faster. I agree that they don't follow defined paths... tachyons aren't like light which is always 45 degrees on the diagram. But, it shouldn't depend on the speed of the receiver. It depends on the speed of the sender. Observers at different speeds in the same location would both detect a tachyon signal at that location. Different tachyons take different paths through spacetime (they travel at different angles on a spacetime diagram) depending on the speed of their source. C is the only invariant speed. Anything going faster than c or slower than c will travel different speeds in different frames.

Should we just keep repeating that it is impossible to confirm a theory? What variable in general relativity and in the big bang model is responsible for dark energy? How should scientists go about setting that variable? Friedmann and Lemaitre both 'created' the big bang model before the 1929 discovery of the redshift-distance correlation of galaxies. Hubble's law without dark energy says that further things recede faster. In other words, dark energy is not the reason why "the further out galaxies are the faster they are flying". Again, there is nothing mean spirited about telling someone that their impression of science is warped. I said nothing about what should be. I didn't say that NASA should launch WMAP, Hubble, Spitzer, and other telescopes in order to test the big bang model. I said that they did do that, already. I did not say that every theoretical physicist should have the goal of creating new physics. Let me put it this way... Why do you think billions of dollars are being spent on the LHC? Scientists have pushed the standard model of particle physics as far as they can push it with current technology. But, they want to break it and they are spending gobs of money in that effort. They do this because finding out where the standard model diverges with reality will be the best indicator for the direction of new physics. Does that sound like people who are just so happy with the current model that they consider it dogma? No. What you are claiming makes no sense at all. The Soviet government? I don't understand. I also don't know what "proposed black holes" means. Black holes were proposed before the existence of the Soviet Union. The US government? What physics did the model use? I mean, if you calculate a prediction what laws of physics guide the calculation?

warped means "twisted out of shape". Your impression of science is twisted out of shape. This is neither an insult nor is it evidence that the world will end next year. You need to understand, when scientists make observations and do experiments their goal is to break current models and theories. When NASA launches Hubble or WMAP they don't know if the observations will fit the current models or not. The observations will either support the current models or break them. If the model were dogma then everyone wouldn't be putting all their effort into pushing the model to the brink and trying to break it now would they? It is the goal of every theoretical physicist to find new physics -- to replace the old. The method of science -- the whole endeavor in doing science -- is entirely structured around that goal. The goal is to find new information that will indicate and support new and better explanations. That is the whole point.

I'm sorry -- I was not very clear. Classical mechanics is the "it". Classical mechanics, and the laws that make it up, could never be proven universally true. Like Phi says, one could never test its whole domain. It could only be supported, and it was in fact very well supported in the 19th century, but no observation or group of observations could ever confirm it in an absolute sense. Observations such as the perihelion precession of mercury and the 1919 solar eclipse observation actually ended up proving classical mechanics wrong. Those same observations supported relativistic mechanics. Classical mechanics is still very useful because it is a good approximation to relativity and quantum mechanics at slow speeds and large size. The slower the speed and the larger the size under consideration the better it works. Classical mechanics was also a stepping stone leading to those theories. So, even though the classical laws of mechanics are not exactly correct, it was by no means a waste of time for Newton to develop them.

It is conceptually impossible to prove true and it has been falsified. I understand if you don't have time to look this stuff up before you say it, but you should at least follow your own advice:

Classical mechanics, as an example, cannot be proven true while no one would hold that Newton was wasting his time developing and supporting it. It got us to the moon. The scientific laws and theories that predict and explain the working of dynamite (such as the laws of entropy and enthalpy) are not proven universally true by their successful application. For example, you might use the laws of chemical thermodynamics to predict how to make dynamite. If that prediction is confirmed by doing the procedure and successfully creating dynamite it does not prove the laws of chemical thermodynamics universally true. There may be yet another prediction of the laws which ends up being false. The successful confirmation of a prediction of a law or theory does not prove the law or theory true, but a failed prediction does, in general, prove it false. The recipe for dynamite itself is not a law, theory, or model of science. To give another example... relativity predicted time dilation before it was observed. When that prediction was confirmed it did not prove relativity true -- it supported the theory. Every test of relativity remains potentially fatal to the theory. I wasn't calling you warped, but rather your impression of science. I chose the word "warped" deliberately in the sense that your understanding of how science works twists your conclusion about scientists out of shape -- saying that they are dogmatic.

I am not My response: Big Bang cannot be proven. Yet it's Consensus Science. you've confused "cannot be proven" with "cannot be proven wrong". The big bang model could conceivably be proven wrong. There are conceivable observations which would falsify it. That is what makes it scientific. If it could not be proven wrong no matter what observation or experiment were made then it would be non-falsifiable and pseudo-scientific. With all due respect, I don't think you are in a position to characterize what "scientists often do", because -- quite frankly -- you clearly don't know. The point is that scientific theories are structured so that an experiment or an observation can conceivably prove them wrong. A theory that could never be proven wrong no matter what future observations or experiments show is worthless. Facts, unlike scientific theories, can easily be proven true. Facts speak for themselves. It may be that you find science dogmatic because it accepts facts. It may be for some other reason. Whatever the case, your impression seems quite warped to me.

Good. No, that is not right. Pseudoscience is pseudoscience if people consider it fact or not. Astrology, for example, is pseudoscience even if nobody considers it fact. Pseudoscience or non-science is something that cannot be proven wrong -- something that is not falsifiable. That is fundamental to science. If the 'other person' is proposing something scientific then they can be proven wrong using the scientific method. No scientifically inclined person (or anyone with even an elementary understanding of the scientific method) would think that observations can prove a theory true. They either prove it false or support it. Science is skeptical. Your impression of science, like your impression of pseudoscience, seems somewhat warped to me.