Tuesday, January 30, 2007

Disaster

This is what ACS looks like on the ground...

Disaster, the main instrument on the Hubble Space Telescope died on Saturday. The camera, the Advanced Camera for Surveys (ACS) is the most in demand instrument on the telescope. The last call for proposals which only closed on Friday had 747 proposals to use HST, 498 (one of which was mine dammit) of which were to use ACS, thats 67% to you stat lovers. It looks like its not going to be possible to repair the instrument, at least not before the next servicing mission sometime next year, and even then there probably isn't enough time to do much while they are there. This is going to prove to be a huge loss to the astronomical community as no other instrument is capable of the fine resolution over a relatively large field of view that ACS provided. The servicing mission will install a new camera WFPC3, but this just won't be as sensitive as ACS at certain wavelengths (like the ones I'm interested in).

... and this is what it could do when in space.

It looks like we can kiss goodbye to our HST proposal, unless we can come up with a clever way to use one of the other instruments. Hmm, back to work.

Through The Looking Glass


Contact has been made, I'm now a fully signed up member of the Autodynamics Yahoo group. Fear not I haven't been assimilated, or turned to the dark side but it does provide an opportunity to ask some interesting questions. You can see my posts starting here, as you can see I haven't been very original with my screen name. As they already knew who I was, from this very blog, there didn't seem much point in trying to hide my identity. Should I turn up murdered, by a hail of electro-muons (WTF are they supposed to be anyway?), you'll know two things, that they were right after all and that what you don't believe in can still hurt you.

I have only had a few posts so far but have managed to discern certain features already. So far most of the people posting seem very keen to help, in sort of the creepy way you get with religious fanatics, you know what I mean, they offer you loads of free tea and biscuits, you sit there quietly nibbling on a rich tea but all the while you know they're eyeing up your soul, figuring out what it must be worth in the afterlife. Some of the responses are simply mistaken, some confused and some to put it mildly simply bat-shit mad, as in naked man running down the street claiming he can't get the spiders off mad, for example this one.

I have already learned several interesting "facts" about AD, like the fact that in AD E=mc^2 is believed to be true but c can change. So it applies differently to different objects, for electrons/protons c is the speed of light, but if they need to postulate (that's a fancy word for make up) a new particle that can travel faster than light, say the pico-graviton then c can actually be anything, like 27, 100 or the average IQ of and ADherent (50) divided by the number of times electro-muons detected in actual experiments (0) = infinity times the speed of light (Apologies just couldn't resist). Yes I know that's mental, but there you have it. To date I have had ignored the points where AD just doesn't work with what we know about the Universe, things like the existence of neutrinos, in favour of looking for inconsistencies in the theory itself, but I have learned that it isn't so much a theory as a bunch of ad hoc bolt ons, so if you disprove one they just stick another one on, like the non constancy of c as a speed limit. In future I think I may well bring in the selective way they apply their theory, any experiments they can match are good, any they cannot must be wrong etc.

So far its been fun, its forcing me to understand real Physics better, which is good (and useful in my line of work), but I think its also quite interesting to see the dynamics (no pun intended) of the group and how they respond to queries, so far mostly through constant exhortations to buy the book. Which of course I have no intention of doing.

Sunday, January 28, 2007

A Short History Of The Dark Side - Part 3

The Hubble Ultra Deep Field, a view of the distant Universe, at a time before the influence of Dark Energy began to be felt, we think.

I think its time to finally round off the long running "Dark Side" trilogy, and like all final chapters it has to be bigger better and more exciting. So sorry but this one is pretty long.

When we left off we had been investigating the properties of the mysterious Dark Matter that permeates the Universe, despite being strange (only interacting through the force of gravity) DM is nevertheless a physical entity, in most theories some form of elementary particle. The next constituent of the Dark Universe is much weirder, being some strange form of energy which exerts a negative pressure on the Universe causing it to expand. Now I think many Astronomers are happy to admit that they are not happy about Dark Energy, everyone seems reasonably happy to admit the existence of Dark Matter, it simply turns up too often on too many scales, but the properties of Dark Energy at present are known from only one or two methods and even then not too accurately, making naturally cautious Astronomers worry about conclusions being drawn from them. Nevertheless the history and implications of a Dark Energy dominated Universe are interesting, so lets have a look at them.

Hubble's observation that essentially all galaxies are receding from us with a velocity that is proportional to the distance between the Milky Way and them was a vital discovery that provided the first evidence that the Universe was expanding. Naturally the idea of a finite age for the Universe (revolutionary at the time) intrigued people, what had happened in the past and what would happen in the future? For a long period of time the belief in the astronomical community was that the Universe started in a Big Bang and that over time the force of gravity would begin to counteract the expansion and slow it.


Hubble's original plot showing that distance to a galaxy and recessional velocity (or redshift) are related.


The mathematical formalism that determines the behaviour of the Universal Expansion shows that in this picture there are 3 possibilities for the fate of the Universe:

1. The Universe is not dense enough to halt the expansion and the Universe expands forever.
2. The Universe is exactly dense enough to overcome the expansion when the Universe reaches infinite size. It has the so called "critical density".
3. The Universe is more than dense enough to counteract the expansion and the Universe re-collapses.

Astronomers were therefore keen to determine which of these fates awaited the Universe. To do that they could make use of one of the best standard candles: Type 1a supernovae. In Type 1a supernovae a dense white dwarf that has been accreting matter from a companion suddenly passes over a limiting mass: the Chandrasekhar mass. At this mass the star becomes unstable, undergoes rapid runaway fusion and blows itself apart. Because the Chandrasekhar limit is so precisely defined it means that all Type 1a supernovae have almost exactly the same intrinsic brightness, they also have unique signatures in there spectra that mean they can be separated from other non-uniform SN, hence they can be used as standard candles. Put simply, one supernovae that is observed to be a quarter as bright as another must be twice as far away. To make this technique even more useful these things are bright, as in bright enough to be seen across billions of light years.

In the mid 1990's two groups were using these Type 1a supernovae as standard candles, in attempt to measure how much the expansion of the Universe had slowed since the Big Bang. To do this they combined the physical distance information from the supernovae with the redshift of the galaxy in which the supernovae occurred, this redshift through Hubble's law is also a distance but one that depends on the expansion of the Universe. Hence by plotting one against the other you get a plot of how the expansion of the Universe has changed over time, in essence you are looking for how Hubble's linear relation changes or curves over larger times/distances. When both groups plotted their results they both found the same puzzling result: instead of the rate of the expansion slowing over time it has actually been increasing. Damn it, I'm sure both teams thought as they contemplated all the extra work involved. But very rapidly it probably occurred to them that there's a Nobel prize in it for someone, hence a healthy dose of rivalry between the two teams.

You can see this in the top half of the figure above, which shows the results from the two surveys, what you see is the magnitude of the supernovae (a distance indicator) plotted against its redshift (a measure of the expansion of the Universe). The three lines show three predictions for the constituents of the Universe. Two dashes are for a Universe where the entire critical energy density is made up by mass (matter and dark matter), the three dashes are for a Universe where only 30% of the critical density exists in mass, and the solid line (which is best fit by the data) is for one where the Universe has the critical density, 30% being due to mass and 70% due to dark energy. New data on more and more supernovae at larger and larger distances has all agreed very well with the original results, meaning the Dark Energy has slowly become accepted as just another constituent of the Universe.

So what could be this strange Dark Energy? To date there are two main contenders, A cosmological constant and quintessence.

The cosmological constant can be thought of as a pressure of a vacuum, particle physics in fact predicts that empty space should have vacuum fluctuations that provide exactly the type of negative pressure required, unfortunately the predictions from particle physics for the level of this pressure are out by up to 120 orders of magnitude, often called the most incorrect prediction in history, oops. The problem is how to cancel out most of this pressure but not all of it, to date no one is sure how to do this. The implications of a cosmological constant are that the expansion will necessarily increase without end, as space is what is causing the expansion the more space there is the more expansion there is. Eventually all structures not gravitationally bound will be separated by so much space light will never be able to pass between them, turning the Universe Dark. In other words in a Milky Way in the distant future, all of the galaxies beyond out local group will slip beyond this distance and disappear forever. Not a very cheerful thought, but hey, who said existence had to be cheerful?

Quintessence is thought to be some sort of particle-like excitation with a possibly dynamical nature. In other words it need not be a constant value per area of space as the cosmological constant, it could vary in strength over time and possibly have different strengths in different areas of the Universe. This is similar to the behaviour of the field that is thought to have caused the intense period of expansion in the early Universe known as inflation. Quintessence could even reverse and cause a contraction of the Universe at some point.

So where does that leave us? What is the eventual fate of the Universe? The truth is that we really don't know for sure, our theoretical knowledge of what is causing the accelerating expansion is not good enough to allow us to determine with certainty what the Universe in the very distant future will be like. The best we can do at present is to try to determine if either of the two cases above can be ruled out. The trick to determining which of these two cases is correct (if either is) is to extend the observations of Type 1a SN to higher redshift and track how the speed of expansion changes. There are many studies ongoing to try to do this to higher and higher precision, expect more interesting results in the coming years.


More Gravity Fun - Update

So it looks like the good people over at the Autodynamics discussion group have decided to answer my queries (specifically this one) in the most emphatic way possible; by totally ignoring it. They have posted a response to a previous question without allowing my message to be published. Now maybe this is because they are trying to come up with a solution, but that really shouldn't matter, they should be open about the issues raised and see if any of the other 165 members of the board can come up with a solution.

I'm going to repost the message tomorrow, if it is blocked again I'm going to have to put this down to yet more hypocrisy on their part, after all they are always claiming mainstream science ignores or suppresses alternative views.

Saturday, January 27, 2007

Britain On The Web

Whilst searching for pictures for my previous post I came across this little gem: geograph. The aim of the site is simple, to collect at least one photograph of the main geographical features of every 1km x 1km grid square in the UK ordinance survey maps. So far they have over 300,000 images covering almost 150,000 square km of the UK (or about 62% of the surface area of the UK). Whats cool about the site is that you can search by postcode/placename, or by clickable map and find any photograph taken within that area.

As you would expect most photographs in a given area tend to focus on the same areas, so the grid square for Durham City is of course dominated by pictures of the castle and cathedral. However there is also an attempt to show the real use of areas as well, so the Durham grid square has pictures of the annual miner parade, London has views of gridlocked cars etc.

The question now is whether or not Google already offers this, and if not how long until it does.

New Links.


I'm planning on periodically adding to the links section on the sidebar to the right, I'm not sure how often this will be, it all depends on how much work I have on. Anyway, here is the first set of new links, all to do with pictures of Science:

The Hubble Heritage site has a very good selection of some of the HST's greatest hits, many will be familiar but there are one or two new ones, and others that have changed slightly since they were first released. See them in all their glory here.

In a similar vein, but looking the other way, here is a link to the US Geological Survey's image gallery, check out the galleries called Earth As Art.

The Earth Science Picture of the Day, is set up along much the same lines as the Astro-Picture of the Day, in particular check out the archives for many spectacular pictures of the Earth and natural phenomena.

The National Geographic also has a picture of the day, the archive found here is again worth a look (its where the picture at the top comes from).

Friday, January 26, 2007

More Gravity Fun

In an attempt to get an explanation of the apparent inconsistency in Autodynamics explained in a previous post I have sent the following message to their discussion board:

Hi All
As you are probably aware I have been looking at your
Autodynamics work, I freely admit that I just don't get
your velocity sum equation, but for now I think a more
obvious problem with Autodynamics is its treatement of
E=mc^2. I wonder if you could clear up my confusion?

In Autodynamics it is stated throughout the website
that E=mc^2 is assumed to be true, it is then used in
the derivation of the Autodynamics kinetic energy
equation, which is used to calculate the Autodynamics
solutions for problems like the Compton effect etc. This
is fine as far as I can tell, E=mc^2 is pretty securely
demonstrated.

The problem is in Autodynamics treatment of gravity,
the pico-graviton is calculated, apparently using
perihelion advance of Mercury, to be a massive particle
travelling at superluminal velocities. This itself is not
a surprise, all theories of push gravity tend to have very
superluminal particles. The problem lies in the fact that
even in Autodynamics, it is impossible for any massive
object to travel faster than the speed of light if E=mc^2
is correct.

So how can you reconcile the fact that to explain gravity
Autodynamics requires E=mc^2 to be false, but to explain
particle phenomena it requires it to be true? You claim
both predictions as significant successes of your theory
but they are mutually exclusive.

I hope you can see that this is an interesting an important
point and try to explain it without too much bluster.
It apparently has to be moderated by the group, so we'll just have to see how open they are about criticism. I'm quite happy to be proven wrong, we shall see.

Thursday, January 25, 2007

Banned Books


Thanks to the wonder that is stumbleupon I've just come across this little gem: Forbidden Library (and through it to this one) a list of books previously banned or objected to. I'm pleased to say I have actually read quite a few of them, probably making me a godless pinko subversive in the eyes of many of the type of people that seem to have done most of the objecting.

Along with the obvious choices, 1984, Fahrenheit 451 etc there are some pretty unusual choices, who I wonder would really object to Charlie and The Chocolate Factory because it espouses "a poor philosophy of life", alright both film versions were creepy, but I always remember the book being alright.

I'm thinking of using the list as a sort of "must read" compilation, though I'm not that fussed about reading "The Celluloid Closet", or "Where's Waldo" for that matter.

Monday, January 22, 2007

Fun with Gravity

What is gravity? One of the fundamental questions of physics, a force which affects our every move. Any successful theory seeking to explain the Universe must be able to explain gravity. To date there have been two successful theories of gravity (or gravitation).

The first, Newtons theory of gravity postulates that mass gives off a force that attracts other mass, this force decreases in strength as the inverse of the square of the distance between the two masses, such that

F = G*m1*m2 / r^2

This theory was incredibly successful in predicting the motions of planets, moons and other heavenly bodies, but it lacks a cause, no particle has been found that carries the gravitational force, a problem that Newton himself worried about, never quite being able to reconcile himself to this "action at a distance".

The second theory Einsteins General Relativityhas superseded Newton's theory for an important reason, it better reproduces the observations, especially in those regimes where gravity is strong. Einstein explained gravity as being due to mass curving space and time, so gravity is not a force pulling on a mass, it is a result of mass curving space/time such that what appears to be a straight path is actually curved, the moon follows a straight path but to an observer because of the curvature of space/time it appears to orbit the Earth. Of course this merely shifts the question, its now no longer a question of how gravity transmits force from one mass to another, but how does mass itself influence space/time? It is an active field of physics at present to try to answer this question.

The ADherents to Autodynamics believe that they have come up with a theory that explains the inverse square law of gravity naturally and whats more provides a physical explanation for it. This explanation is actually just a re-tread of a theory that was popular until the turn of the 19th century, the Le Sage theory of gravitation. I'll let the Autodynamics people to explain the theory (in which they use the term pico-graviton instead of Le Sage ultramundane corpuscle):
The Pico-Graviton (PG) is very similar to the concept called the "graviton". The concept of gravitons is that gravity is created by the "shadowing" affect. In affect, celestial bodies partially block the the flux of pico gravitons causing a low pressure area between the bodies. This pushes the bodies together.

The main difference between the pico-graviton and gravitons, is that pico-gravitons are somehow absorbed by mass. Most pico-gravitons push on the mass, but a very very tiny fraction are absorbed.
Now, there are many problems with this theory, as listed on this wikipedia page, go ahead its an interesting read. For now I think what would be more interesting that picking the overall theory apart (as the wiki article effectively does) would be to examine the logical inconsistencies in Autodynamics through this theory of gravitation. On this page the Autodynamics people explain their investigations of their version of the le Sage theory:
Using calculations for perihelion advance, he came up with the following numbers: the pico graviton has the mass of around 1x10-81 kilograms, and travels at around 27 times the speed of light. Another person in the SAA has claimed to find approximately the same values for the properties of the pico-graviton through completely different methods but the calculations have not be confirmed.
So the pico-graviton to explain the observations, must be both massive (as in it has some non-zero mass) and travel at superluminal velocities. Now this is a problem, even for Autodynamics, never mind the real world, on this page when talking about faster than light travel they state:
Autodynamics says that if E=mc^2 is correct, than no mass can accelerate beyond the speed of light. Why? Because in Autodynamics, mass moves by expending energy to push itself forward. According to current equations, all mass, no matter what the size could only result in a single photon going at the speed of light.
So far so good, they correctly point out that if E=mc^2 is true, then faster than light travel is impossible for massive objects even in Autodynamics. So for the pico-graviton to be real, and for it to match the observations, E=mc^2 must be false. Now lets just ignore for the moment the mountains of experimental data that show E=mc^2 to be true, lets just look deeper at the Autodynamics for a second. Specifically here. At the bottom of the page you will notice that the very same E=mc^2 has been used to derive the Autodynamics kinetic energy equations. Those very same kinetic energy equations that are supposed to explain amongst other things: muon decay, Compton effect, and nucleus-nucleus interactions.

So the question is, is E=mc^2 correct and hence the pico-graviton non-existent, or is E=mc^2 false and all of the AD "solutions" to atomic processes incorrect? A perfect example of why in Physics its usually impossible to change one "small" thing, everything is connected tweak one parameter to better fit some observations and you may well make the fit to other observations much worse. There are many other objections to the whole pico-graviton idea (especially the superluminal part), which I may get round to posting if I can sort out the maths.
I appear to have been challenged to point out where Autodynamics is wrong, well that sounds like it could be some fun, so below is a list of problems I have identified on the Autodynamics website. I have endeavoured here to avoid anything too mathematically complicated, so it should be fun and instructive for the average reader, its simply too difficult to explain issues like how they "prove" special relativity doesn't conserve energy so for now I'll stick to the easy to understand stuff. You will note that most examples are not definite refutations of AD, in the next post I aim to point out one fairly obvious problem that seems to have been ignored, for now lets just look at how they mis-interpret mainstream science and contort the facts in an attempt to justify their beliefs. I apologise for the poor English and spelling throughout for once this isn't entirely my fault I'm just repeating their information.

On this page. The startling claim is made that in the mainstream picture Black Holes contain infinite mass. This of course is utterly bogus, BHs contain as much mass as went into them (less some mass that would be radiated away as energy before the matter crosses the event horizon), but they are always finite in mass. They are infinite in density, because there is a finite amount of mass confined in an infinitely small space, but the mass always remains finite. I can see why they have problems with GR if they believe stuff like this.
Einstein's equations approach infinitely as objects approach the speed of light. One of the consequences of this is the so-called "singularity" at the center of black holes. At that point, mass is infinite and light and time do not exist - the exact same state of the universe at the beginning of the supposed "big bang".
On the same page some claims are made regarding entropy:
Another important difference that is related to the other concepts in Autodynamics concerning the cosmos, is "entropy". Entropy is the concept that things in the universe are getting more complex. Autodynamics, shows us a universe that is getting more complex and less complex in local areas but overalls remains constant.
This of course is incorrect, entropy is generally thought to lead to a decrease in complexity, simply put at the microscopic level things tend to get more disordered. This fact which is central to the second law of thermodynamics has even been abused by creationists to claim that evolution is impossible because more complex forms evolve from simpler ones. They also have missed the point of the second law, it is possible for areas of the Universe to become more complex, say stars, planets, us etc, its just that on the whole the Universe is constantly increasing in entropy, things become more disordered.

This page lists many claims for Autodynamics. One of which is the following:

There is a conspicuous absence of support for Einstein's Special theory of Relativity. Groups such as the Natural Philosophy Alliance and the SAA are systematically refuting "proof" for Special Relativity and many aspects of General Relativity.
Well the first statement is so untrue that it is actually funny. What about observations of the decay of Muons formed by Cosmic Rays hitting the upper atmosphere? Without the time dilation effects of SR, these Muons would not last long enough to be detected on the ground. What about all the other experiments that show time dilation of exactly the amount required by SR?, more details here. The second statement is interesting too, it says there is no support for SR, yet that the SAA and the NPA are refuting "proof" of GR, so which is it? No proof, or proof that is being refuted? The NPA it refers to is also interesting, if you look at their website the membership is a who's who, of anti-mainstreamers and cranks, oddly lacking de Hister or Carenzani, they also helpfully on the front page give us this insight into their motives for attacking relativity:

Several NPA members believe that the main benefit of criticizing and replacing special relativity may be--beyond even the likely development of new energy sources this will facilitate--the undermining of the relativism and subjectivism that have increasingly infused many areas of thought over the past century, since the iconoclastic amorality of Nietzsche. It will then become more difficult to support ethical relativism, and to argue that truth and values are not objective, absolute, eternal, and/or rationally based.
In other words that they think by attacking a physical theory (special relativity) they will be able to do away with the modern worlds moral relativism, undoubtedly to bring us closer to one god or another. Forgive me if I doubt the intentions of people attempting to overthrow accepted scientific opinion to remake morality in line with their own wishes. I mean honestly, does the fact that you can't go faster than the speed of light make you a worse person in the long run?

On the same page there is this screed:

The infamous atomic clock experiment has been refuted and the data is bogus. In a swarm meeting of the AAAS in Flagstaff Arizona in 1996, Dr. Domina Spencer, physics mathematician from the University of Connecticut, presented a talk "Analysis of the Hafele-Keating Experiment". She received the raw data from one of the authors of the original experiment and concluded that the data published was "completely and utterly fabricated". See http://www.ebicom.net/~rsf1/npa/flag96.htm.
I have to admit until I looked it up I didn't know what infamous clock experiment they were talking about. It was actually an experiment where two atomic clocks were flown around the world in different directions twice and then their times were compared. The measured times were exactly in line with what SR+GR would predict (they would lose or gain time due to their motions relative to a stationary clock). The claim is made in the AD statement that the work was discredited, I can find no reference to this anywhere, the link is dead and nothing seems ever to have been published, the talk is referenced on the NPA site, but appears to have been given at an NPA seminar not the actual AAAS meeting (not a good sign). It may be true, at present I can't verify it either way. Either way, the experiment has been repeated many times since the original and has always matched the expectations of SR + GR extremely well, see here for a good description of a repetition done 25 years after the original. So, were all the repetitions the result of fraud?

The next post I think will be more interesting for those interested in science, it will revolve around gravity and discuss the differences between the Newtonian and the General Relativistic interpretations for gravity. Oh and I may mention AD a bit.

Sunday, January 21, 2007

More Autodynamics

So I have received another comment from what I assume is an adherent to AD (see previous post), they point out that calling them ADiots is rude, which is true, and exactly the reason I do it. They and their related websites are allowed to call physicists everything under the sun, from fantasists to fraudsters and post titles like "Relativity's Incestual Child Must be Euthanized", but I have to be polite to them? Bullshit.

They seem to be confusing science with religion, in the sphere of religion all ideas are equal (there's no evidence for any one being more true than another), in science this is not the case. All theories are not equal, some of them have observations that back them up, AD does not, it therefore deserves even less deference than the average theory. All theories are there to be disproven, they are quite happy to jump on perceived problems in mainstream physics yet have very thin skins when it comes to their own pet theories. Another example of the hypocrisy common to those that support "alternative" theories, anything mainstream is fair game, but not their own ideas.

The comment also makes a lot about me not understanding the difference between a kinematics and a dynamics equation, well that's true, I'm happy to admit I don't have a clue what the hell the AD velocity equation means (it definitely must be being used in some non standard way), If there is an ADiot out there that can explain it to me I'd love to here it. As far as I can tell though, no one seems capable of explaining how AD refers to the real world, their own discussion board seems to be pretty good at making this clear.

To explain the final point the comment makes that I have quickly moved onto other problems with AD is simple and obvious, no-one seems capable of explaining my first, I could spend the next six months fussing over velocity addition but the fact is that would get bring pretty fast, and why bother when there are more amusing things to look at?

Saturday, January 20, 2007

Flights of Fantasy: And Watching The Watchers

One of the main problems I have with Autodynamics is the way its adherents (The ADiots) can be extremely hypocritical in the way they choose to attack mainstream science (and Physics in particular).

The case that best sums this up is their behaviour regarding the humble neutrino, this is an elementary particle that is given off in many particle reactions, including those that fuse hydrogen to helium in the sun, in fact trillions of neutrinos from the Sun are passing through you right now. Now neutrinos are almost mass less and don't interact strongly with other particles (so they're not doing you any harm), but this makes it very difficult to detect them. Nevertheless many groups around the world do this on a regular basis, learning important facts about the Sun and particle physics reactions in the process, check out the wiki link at the top for a crash course.

Now the ADiots hate the neutrino for some reason I can't fathom, constantly saying it doesn't exist and that it was invented to plug gaps in special relativity (see here).

led to the invention of a second(1) powerful fantasy of the twenty century: The Neutrino.
All of their sites are littered with such pronouncements. It wouldn't really bother me except that Autodynamics has invented several new particles of its own, none of which have a single shred of evidence to back them up. This selective behaviour, in which the neutrino is attacked for being invented to plug holes in special relativity, whilst at the same time inventing new particles to plug holes in your own is pure hypocrisy. For a good example of a particle if not invented by Autodynamics then at least co-opted by it we have to look at the pico-graviton.

The pico-graviton is what ADiots use to explain gravity, seeing as they don't believe General Relativity to be correct. The pico-graviton required by AD is apparently 1x10-81 kilograms and travels at 27 times the speed of light, pretty impressive, but anythings possible if you don't have to obey physical laws. Now in the AD pages they actually don't give a lot of details about what the pico-graviton actually is, I haven't come across anywhere where they actually set out important parameters, like if it has standard properties of particle physics, like spin, charge, colour charge etc. They also didn't invent the idea, its basically just a renamed version of the Le Sage theory of gravity, the web pages do not make this too obvious though, to the casual reader it seems like Carenzani though the whole thing up himself.

The problem with the pico-graviton/Le Sage gravity idea apart from the obvious is that there are loads of problems with the Le Sage theory. See the wiki article for plenty of gory details, like the Earth being heated up by 10^26 degrees per second, oops. You can also read about the theory and its "push"-like nature there, its interesting as a history lesson about how people thought about gravity before relativity and while all they had at their disposal was classical mechanics.

I think it would be interesting to hear a few more details about the pico-graviton from the AD side, it would be nice to have actual numbers, something that can be examined and compared to experiment. Something like cross sections in reactions, spin, charge etc.

P.S I think some of the posts I have been making may have riled them a little. Their latest PhysicsPolice (TM) post is even less lucid than usual even for that bunch of crackpots. I urge everyone to check it out here, its even complete with a non too liberal dose of neutrino bashing.

Erratum

It has been pointed out to me (In a mildly rude comment, which you can see in the comments section to the previous post) that my calculation in the previous post is incorrect. The final velocity predicted by Autodynamics should in fact be 14.3km/h.

I'm allways willing to point out where I have gone wrong, I won't be correcting the original post or removing the comment as I don't think that would be ethical.

So does this change anything? Well no, no at all, autodynamics still cannot reproduce one of the most basic observations in science. I ask again what good a theory is if it cannot reproduce the behaviour of phenomena in the actual Universe, after all thats the whole point of having a theory.

As I don't believe that I will get a more useful response to the question of why Autodynamics can't handle simple dynamics, I'll move onto some of the other amusing contradictions of Autodynamics in my next post.

Thursday, January 18, 2007

Velocity Dumb

So the ADiots have noticed my earlier post about them. They seem to be peeved in particular that I have such trouble understanding the wierd autodynamics velocity sum equation. Its not just me thats having problems though, a guy called Will is pointing out that the way they do things is wrong, but to no avail so far, its actually interesting reading how they deal with his well reasoned points, mostly by ignoring them, its like a bunch of five year olds sticking their fingers in their ears and going "I'm not listening to you" check out the first post here. They even accused him of being me, he isn't, I don't use sock puppets, If I wanted to talk to them directly I would.

To those just joining the fun the velocity sum equation is what those of us in the reality based world use to work out how different systems appear from different viewpoints. To illuminate this I'm going to use the example they themselves have provided on their own website (here), I've changed the numbers slightly but the result is unaffected.

Imagine you are a travelling in a slow car along a long straight road, you are moving at 10km/h according to your speedometer. You are overtaken by another car, which from your viewpoint appears to be travelling at 10km/h. The question is how fast does the other driver think they are travelling at? What does their speedometer read?

In classical mechanics the answer is simple you simply sum the velocities of the two cars to work out that the second car is travelling at 20km/h. In special relativity the equations are not so simple but at low velocities (those a bit less than the speed of light) special relativity gives an answer identical to classical mechanics, within any reasonable measurement.

The autodynamics equation for velocity sums is somewhat non standard and in this case gives a velocity of... wait for it... 28.28 km/h (Correction: 14.14km/h, see next post)for the car overtaking you. If the driver looks at his speedometer it reads 28.28 km/h.

Now the point Will, and in fact several others have tried to make to the ADiots is that this is plainly nonsense. We can measure this easily, just get yourselves two cars and a speedcamera in one of them and you can prove this is not the case. It happens every day when police are chasing speeding cars, if the ADiots were right, the police would always be measuring significantly higher velocities for the other car than they were, now some out there may claim that is the case, but I've never heard of a sharp lawyer trying to use this one to get out of a speeding ticket.

So what do the ADiots themselves have to say about this? Well their response are generally along the lines of, "your thinking like a relativist", or that AD conserves energy when relativity doesn't (it does btw), essentially anything to distract from the central point. What good is a theory of motion if it doesn't work in the real world? I'm waiting for the ADiots to explain this one. Feel free to do it here in a comment, I'll post it for all to see.

Hobbit Galaxies

According to this story from space.com the SDSS has found 8 more dwarf galaxies in the local group. Seven of which appear to be satellites of the Milky Way, these seven galaxies, all of which are very faint and diffuse appear to be essentially old. The one new galaxy which is not thought to be bound to the MW appears to still be forming stars and to have a significant reservoir of neutral hydrogen with which to form more stars.

This is all very interesting because it has implications for one of the big problems of modern cosmology, the so called "missing satellite" problem. This is the observation that cosmological simulations of structure formation in a dark-energy, dark matter dominated Universe seem to predict many more small satellite galaxies around larger galaxies like the MW than we see. If however these galaxies do exist and they are simply very faint and hard to see as the SDSS results imply, then there isn't any problem at all. Seeing as the SDSS only covers about an eighth of the sky, and doesn't see very faint things, it does imply that there should be many more of these galaxies left out there to be found. I think a cottage industry of trying to find these things is probably about to spring up.

Wednesday, January 17, 2007

The Nerdiest Thing In The World


Another tip of the hat to the excellent bad astronomer for bringing this gem to my attention. Possibly the nerdiest picture I have ever seen (click on it for the full version), but one that may well answer many an argument over coffee at the office (If like me you work in an almost all male astronomy department). A scale picture of just about every spaceship you can think of from TV or film and I thought I had too much time.

Who Watches the Watchers?

So the resident loons over at autodynamics (that's the de Hilster clan) have decided to set another website up, physicspolice.org, its introduction is interesting:
Welcome to the physics police website. Our goal is to do what governments, universities, and journalists do not do: read the content of articles published by physicists and cosmologists around the world and look for sweeping statements, contradictions, and the biggest crime - not looking for alternatives to explain something that until now has been ruled by fantasy and dogma.
Sounds reasonable really, until you begin to read their stories further down the page. The best one is this one. They actually take the time to try to pull apart a humorous Christmas story about how Santa uses relativity to get around the world in one night. Its a joke for Christs sake, a bit of fun written for kids. de Hilster goes to the effort of criticizing the quoted scientist for an apparent contradiction about whether relativistic frames are physically real or not (AD holds that relativity is wrong). It was written for a bunch of 5 year olds for Gods sake. If this is the level of journalistic fervor we can look forward to from the physics police we're in for fun.

On a more serious note, he again uses that good old lie of people that refute relativity, that GPS systems don't use relativistic corrections, the quote from wikipedia (and its references) is enlightening here:

For GPS satellites, this discrepancy is 38 microseconds per day. To account for this, the frequency standard on-board the satellites are given a rate offset prior to launch, making it run slightly slower than its desired frequency on Earth, at 10.22999999543 MHz instead of 10.23 MHz, a difference of -4.465 parts in 1010. The atomic clocks on board the GPS satellites are precisely tuned, making this a practical engineering application of the scientific theory of relativity in a real-world system.
Now I believe that this correction may be negligible compared to the accuracy of the system, but the correction is made.

On an even lighter note it has been pointed out to me that the ADiots are now aware of me and this blog (see here), specifically they are annoyed by my demolition of their mad velocity sum equation (see here). I can't wait for the reviews of my real research by the physics police after this.


Tuesday, January 16, 2007

Education, Edukation, Edjuckation


Hi All, its been a long time since I lasted posted, this has mostly been due me being away for Christmas, working on Phase IIs for the telescope time I got (this is where we set up the way we want our observations to be taken), writing a paper, and trying to help my girlfriend through the awful confusion that is teacher training.

Anyway now I'm back and want to jump right into something I noticed while at home. In a town near my home called Blyth there are plans to set up a new Academy, nothing too special there except that this Academy is going to be partly funded by the Christian Fundamentalist "Philanthropist" Peter Vardy. For those of you who don't know who he is, he is a man who made his fortune selling cars, now he spends his time and money trying to brainwash children to try to buy back his soul. His Emmanuel Schools Foundation currently runs 3 schools, with plans for 4 more (apparently 7 is an auspicious number in the Bible).

The schools are built and run under one of the governments worst thought out Private Finance Initiatives, for the investment of £2million (or about 9%) of the cost of building one of these schools, Peter Vardy gets total control of the school, he chooses the Headteacher all but 2 of the board of governors. This despite the schools running costs being entirely met by standard funding from the Education authorities. Does this seem like a terrible deal to anyone else? It gets worse when after 25 years the land the school is built on also becomes legally theirs! Land that was probably owned by the council and worth considerably more than £2 million, it seems Mr Vardy has gone from dodgy cars to dodgy real estate deals now.

The schools have courted a great deal of controversy through their teachings, which have occasionally seemed to contradict the guidelines of the DFES, as well as their hiring practices. I personally know of one teacher at one of the academy's that was told they would not be hired if they "lived in sin", remember their wages are being paid for by you and me (well not me, yet), yet one man who will actually make a huge amount of money out of the deal gets to decide who is suitable to teach our children. I could go on for hours listing all the things that are wrong with these schools, from the fact that they teach creationism, to the fact that they are inherently homophobic intolerant places, but other people have done it better so here are some links.

This one is particularly good.
Wiki as always has the goods.

I sincerely hope Blyth manages to keep these wing nuts away from their schools, and shame on the government for blackmailing them so that the only way they can get the new schools Blyth so obviously needs is by selling their children's minds.

For a final thought, what a crazy world we live in when a left wing government gives control of education to a bunch or right wing zealots.