# Suggestion Archive

(Difference between revisions)

## Revision as of 18:33, 1 January 2012

The following are the suggestions that have been added or that will not be worked in.

Suggestions worked into edition 25.x:

• vol 1: Add mechanism of finger noises.
• vol 1: Add escape velocity table.
• vol 1: Add more on blood circulation.
• vol 1: Add more on calorimetry.
• vol 1: Add story about the Lake Nyos CO2 disaster in Cameroon.
• Vol. 1, p. 47: Challenge 44 / "Just try" - please give a hint on how to "think in 4D", especially in that case

• vol 2, p 25, figure 10: the lines of the two observers should be parallel. If not, calculation of t1 is wrong (CS: I do not see any mistake. The lines cannot be parallel, as the two observers have a relative nonzero speed.)
• vol 2 : Add film of star orbits around the black hole at the centre of our galaxy.

• Vol. 3, p. 47: Challenge 33 d / "Now imagine an observer who flies along the wire. The entrance and exit events do not occur simultaneously anymore; the wire is charged for a moving observer." ...this citation from your book explains the answer to the Challenge 33 d (because of entrance and exit events, there is different density of current-carrying charges then fixed "holes" for a moving observer with ANY nonzero speed, even for the speed equal to electron speed or signal speed), but the answer in the book is saying something else..
• vol 3: Add the Goos-Hänchen effect.
• vol 3: Add more on the enteric nervous system.
• vol 3: Add one of the fake terahertz images and the challenge to show why; add backscatter X ray imaging.
• vol 3: Explain fluorescence spectroscopy and fluorescence microscopy.
• vol 3: Explain confocal laser scan microscopy.
• vol 3: Explain circular dichroism.

• vol 4: Add the free will theorem.
• vol 4 Add: lauschen ist rauschen.

Suggestions worked into edition 24.22:

• I read the section on "Entropy" twice and still don't get it. Your sentence "Entropy measures the degree to which energy is mixed up" sounds to me as if entropy is a measure of chaos. So far so good but I don't understand the following two examples ( lamb -> mince meat ???, two bottles put together ). How am I (the reader ) to know anything about the distribution of energy in lamb or minced meat ? And the second example : I imagine water particles with some speed or energy distribution and does it matter how many particles there are ? (CS: Indeed, entropy measures disorder. Yes, more material has more entropy, all other things being equal: entropy is an extensive quantity.)
• Teach calculations, including fractions, including mental calculations. (CS: book on how to do that is mentioned.)
• Try to give easy challenges from time to time. Almost all of the challenges are very hard to solve and remind me of the incredibly stupid exercises in the "Gerthsen" (CS: Which volume do you have in mind? Which challenge is stupid and should be changed?)

Suggestions worked into edition 24.20:

• Clarify the nature of the experiment in book 3, chapter 1, about the measure of the speed of electricity and the command 'ping'. What is actually carrying information? A flow of electrons or an electromagnetic wave?. (CS: How would you like to have it explained?) . I am not completely sure that we can measure the speed of electricity by using the command 'ping'. The information is contained in an electromagnetic wave. It is sent first through a cable to a switch (if done in a local network) and then it goes toward the destination node, again through a cable. I do think there are electrons in the PC, but the transmission of information is carried out by EM waves. Is it right?. Thanks for your feedback. (CS: I will add a sentence with a reference at the beginning; there is a section later in the text called "How fast do charges move" which explains the difference.)
• Enlarge the size of text, thus removing a proportion of the white space on the page for better readability; the textbook has been greatly formatted, but for print form, not digital form for viewing on computer screens. Even on a 1080p resolution monitor, I cannot fit a page on screen without zooming out to <100% and scrolling. (CS: There are so many screen formats... I do not know what to do in this case.)
• Add language to citations in the latex code.
• Make a Kindle version available - I have been a fan for 5 years and have been looking forward to being able to read on the move, but the pdf is too small to read comfortably on the Kindle screen. (CS: I do not own one, so I cannot develop it; one day maybe ...) (CS: Update: Amazon offers a free service to transform pdf documents into Kindle-friendly format; did you try it?)

Suggestions worked into edition 23.14:

Suggestions worked into edition 23.12:

• Add comment on motionmountain logo/picture: There are optimal trajectories climbing a mountain. They depend on human metabolism. They found following formula for the metabolism in kJoule/m where a is the tangens of the angle of gradient: M(a) = 2.635 + 17.37a + 42.37 a*a - 21.43 a*a*a +14.93 a*a*a*a. If angle is bigger than 16 degree, the better way is to zigzag the mountain. (see Marcos Llobera, Tim Sluckin: Zigzagging: theoretical insights on climbing strategies, Journal of Theoretical Biology, 249, (2), 206-217 (CS: thank you, this is pretty! I did not know this work; I just read it, and I will mention this somewhere.)
• Correct the vignettes in volumes 1 to 5.
• What shines/glows at night in a forest? (In a desert? On a mountain?) Why?
• Latex acronyms: how do they work in titles, in index, in captions, and in bookmarks?
• Page 328, Section "People Names". "In Russia, the family name is never used, but the first name of the father." -- This is not exactly true, or at least needs qualification. The family name is very rarely used when addressing a person in conversation. One of the exceptions was the formal addressing between the members of the Communist Party. Stalin was practically always addressed as "Comrade Stalin". However, the family name is commonly used when mentioning a third person, both orally and in writing. "For example, Lev Landau was called Lev Davidovich (‘son of David’) in Russia." -- The form 'first name + patronymic' is used in formal addressing and formal referencing. For his friends, Landau was simply 'Lev'. "For example, one finds the spelling Tarski, Tarskii and Tarsky for the same person." -- The context of the sentence somehow implies that Tarski was Russian; in fact, he was a Polish Jew. 'Tarski' even wasn't his real last name: he was born Alfred Tajtelbaum. (CS: Aargh, that of Tarski is a bad mistake. Of course he was Polish! But I do not get your point about the Russian patronymic: what should be changed in the text? The statement about Russian names is not really wrong. And Stalin was not a family name anyway.)

My further comment:

Starting from the end :-) : (1) 'Stalin' was not the dictator's family name, but it was ALWAYS used as his family name. I wouldn't envy a person who dared to call him Dzhugashvili. 'Stalin' is no less a last name than 'Tarski'. (2) What should be changed in the text? - Again: "In Russia, the family name is never used, but the first name of the father" is an inaccurate statement ("never" is an overstatement; and the first name of the father is used in some situations, but not always -- see above). A more accurate statement would be something like: 'In Russia, when addressing a person in conversation, the family name is rarely used, but in the formal setting, the first name of the father is added to the person's first name.' I am sure you can make it sound better :-) . (By the way, in Russian, if you address a person in conversation by the last name preceded by 'Mr.' ('Gospodin' in Russian), it is considered very formal -- much more formal than 'first name + patronymic'. Should you omit the 'Mr.' prefix, the addressing would sound very rude. Pretty funny, but I am sure that Russian is by far not the most peculiar language in this respect.)

• Add more topics on mechanisms and robots.
• Mathematics is the language and backbone of sciences, and especially so for the fundamental science known as physics. It would be cool to also include some sections to introduce the concepts of mathematics, especially on space and vectors, and the different coordinate systems, DIFFERENTIAL and integral equations that is so vital to describe anything is physics in a precise manner. (CS: spaces and vectors are explained in the text already in detail; different coordinate systems will probably not be included; more on differential equations brings the book too far from its aim, namely to get a feeling for motion.)

Suggestions worked into edition 23.8:

• '...thousands of years ago chariot races in stadia went anticlockwise. As a result, all races still do so to this day.' (page 42 volume 1) but seventeen races in Formula One in 2009, only four have played in anticlockwise circuits, twelve in clockwise circuits, and one in both (Suzuka) (CS: interesting; can you give me a reference? I will then add it to the text.) Here are links to each circuit http://en.wikipedia.org/wiki/2009_Formula_One_season#2009_calendar (CS: thank you!)
• In volume I, page 90, in the first foot note you say that magnetism is not a central force. In challenge 157 you say that however for an interaction to obey relation (18) it does not necessarily have to be central. It is true. The general condition is that the forces must be equal and opposite. But magnetism does not obey even this general condition. For example consider this (from Goldstein classical mechanics page 8): two charges moving (instantaneously) so as to "cross the T", i.e., one charge moving directly at the other, which in turn is moving at right angle to the first. Then the second charge exerts a non-vanishing magnetic force on the first, without experiencing any magnetic reaction force at that instant. I think, in electrodynamics mass is defined in such a way that the total momentum (including momentum of field) is conserved. I also think all of these will be automatically corrected in special relativity where energy and mass are equated. So mass works for magnetism only in the form defined in special relativity. If it is true I think it's useful to mention it in challenge 157. (CS: I have clarified the wording in the new edition.)
• In Band 2: Lichtgeschwindigkeit, S20 1 höchstgeschwindigkeit, ruhe und licht: 3.Abschnitt: Im täglichen Leben wissen wir auch, daß ein Stein uns schneller erreicht, wenn wir ihm entgegenlaufen ... Dies ist missverständlich, umgangssprachlich: früher<->schneller. Besser: mit höherer Geschwindigkeit. (CS: danke!)
• What is the "Umbrella" on FIGURE 61, vol. 3? (CS: the image shows roughly what one sees when looking at a street light at night through a black umbrella. I'll make it clearer.)
• Allow fuller use of the initial view tab in document properties. This will allow a user to open the file at the last page they were viewing. (CS: if you explain me how to do this in Acrobat Pro 8, I will implement it.)
• Add a brightness table (sunlight, candle, etc.) in the main text.
• Phone Füssmann at the MPI for plasma cloud movie.
• If possible use mirrored left-right margins to printing and binding more effective. The copyright strip should be on the inner and the challenges and page refs on the outer margin. Also the inner margin could be a little wider. I really really like the text and like to curl up with a printed section. (CS: to bind it for yourself, print it on one-sided paper and bind it on the left side. For a bound paper edition, see http://stores.lulu.com/motionmountain.)
• Provide document in ePub or .mobi format that can be read on a Kindle. (Kindle allows pdf but the text is too small) (CS: tell me how to do it, and I will consider it. Note that I only own Macs, and I cannot use PC sowftware. The Mobi creator does not work on a Mac, I found out.) SP: Try http://calibre-ebook.com/ They have an OS-X version and can convert a large number of formats to mobi. I use the program almost daily. Alternatively, Amazon will convert and publish for you, but I don't know much about that. (CS: I tried Calibre on one volume as a converter to Kindle .mobi format; the result is unreadable, much worse than ascii text. In short, I will not be able to make an epub book by myself, I'm afraid. A readable conversion will be quite some work, will require a dedicated Latex typeset, and will need somebody to help out.)

Suggestions worked into the 23rd edition:

• Add more on the sea and on sunsets!
• Structure the sections into a minimal and an extended program (by SV).
• Write to France for the falling cat images (Musee Marey).
• Check neighborhood definition in appendix; I took that non-standard definition from a math text and cannot remember which one it was!
• Why is SFBX font used for displayed quotations? First occurrence: top of p.10
• Maybe add something to the section on Black Holes about Eddington-Finkelstein and Kruskal coordinates and the topology of the extended spacetime manifold? (CS: no, out of scope)
• Explain in more detail the working of a gravity wave detector (by CH). (CS: done in part)
• Add film of group and phase velocity. (CS:done)
• Add film of bouncing water droplet, maybe in a material science section on surfaces. (CS: done)
• What is shown in Fig. 169? It isn't clear from the figure caption. What are the white fishtails? (CS: the small spot between the "fishtails" is the floating atom; I will add an arrow. The fishtails are stray light from the apparatus)
• This wonderful book about motion cannot be complete without at least one video clip of Michael Moschen, juggler, artist, dancer, physicist. I'm believe he would be delighted to contribute to this effort. (CS: I did not know him. Being an amateur juggler, I watched the videos on his homepage; but somehow I have difficulties relating any of his performances to the book. If you have a suggestion, let me know.)
• Section "Simple motion of extended bodies - oscillations and waves" - should define more properly group velocity and phase velocity (and maybe include signal velocity and anomalies with group velocity and transport of energy and information). Avoid terms like velocity of individual waves (e.g. page 230, 8th line from the bottom). Maybe show why is group velocity dw/dk and for phase velocity w/k. (CS: I want to include a film in the text, but have not yet found a beautiful one that I am allowed to use)
• I think it would be impressive to explain in details how scientists and physicists proved the following two cases independently:
a) Light is absolute (i.e.: Maxwell's equations shouldn't be not an evidence because the constants themselves might by a function of the speed in which he might not have taken into account). (CS: light is not "absolute"; I do not even know what you mean by this. Maybe you mean that "light speed is invariant." That is measured to be so in many experiments. See the first chapter of my volume II, on relativity.)
b) Time is relativistic (i.e.: Was the train experiment for true or just an assumption? Was it true that atomic clocks were testified at high velocities to cause time dilation?) (CS: this is explained in the same, first chapter of volume II.)
• Why would we expect light to reflect from mirrors at same speeds independently of relative motion as was done by Michelson–Morley experiment and calculations? (CS: this is measured to be so. Mawell's equations also predict this.)
• What makes scientists believe the Gravitational constant wouldn't be also a function of speed? (i.e.: Why don't we think it another way that there might be other laws and constants in general which we can't simply realize in our Galaxy unless we live in another high velocity system?) (CS: G is measured to be independent of speed; scientists only use what is measured.)
Indeed I used to ask these questions myself and I am still not convinced with the Relativity at all.--Email4mobile 21:53, 10 October 2009 (CEST) (CS: it is a pity that you do not read books on relativity; these issues are all answered there, including in my own.)
Thank you very much for your quick response. Forgive me for not selecting appropriate terms because I didn't study about Relativity in details and I'm not an English speaker. I tried to understand it reading some relevant books and may times I couldn't be satisfied. Perhaps, it was my problem, or the questions I was looking after were not included. For instance a book might say that "Maxwell did extensive mathematical calculations on electromagnetic equations and deduced that their speed was ...etc. Scientists were surprised how Maxwell's Eqs. could be independent of motion...." but I couldn't understand how the points (a) and (b) in question were proved experimentally and individually. I will have to read more, thanks at all.--Email4mobile 09:16, 11 October 2009 (CEST)
• I forgot to ask you about the title of your book, Motion Mountain; does it have a meaning (e.g.: Mountain of motion). This is because I wrote an Arabic article about the book on Arabic Wikipedia (here), but didn't know whether to translate the book title into Arabic or just leave it with the same original title.--Email4mobile 09:26, 11 October 2009 (CEST) (CS: keeping the English title is ok; the title is explained in the first chapter of the first volume.)
• Presently, the user experience on several e-reading platforms (e.g. Sony Reader, Smartphones etc.) is quite poor due to reduced page size and lack of reflowing capabilities. Suggestion is to publish the document in ePub format, hence enabling portable device users to reflow the pdf source, dramatically improving usability on these media.If that should not work for the complete version, it should be at least feasible for the read aloud version (e.g. no pictures = smoother reflow). Alternatively: upload the book on www.feedbooks.com, they provide this service for all the books uploaded on their site. (CS: converting by myself is not possible in my lifetime, due to time limitations; using www.feedbooks.com is not possible because of their unfair copyright agreement)
• How about recompiling it with a different size, so it is easier readable on 6" e-ink devices? At least for sony reader, the following settings "lmargin=3mm, tmargin=2mm, rmargin=6mm, bmargin=3mm, paperwidth=88mm, paperheight=115mm" together with 11pt or 12pt font work for me. (CS: not in my lifetime)
• Work with Bookdepository [1] or similar publisher to create a low-cost hardcopy version of the book. Reading the online version is useful for latest material, but a physical copy would be much easier. I could print it out, bind it etc. but easier just to purchase a good quality version. It can be "non profit", or maybe a low profit to support your foundation or physics promotion etc. It would also be available to more people who may not have internet access in less developed countries. (CS: I did not find a way to use book depository to create a hard copy version. I am trying with lulu.com, but I am appalled by the high costs that lulu.com charges for a colour book. I am afraid that a colour book will never be low-cost.)
• The future of physics? A cosmological model with no dark matter, no dark energy, no space expansion is presented at http://arxiv.org/abs/astro-ph/0208365 "A relativistic time variation of matter/space fits both local and cosmic data" by Alfredo Gouveia Oliveira, and other. I ask a comment please (I know that it is not mainstream, but mainstream will be past, always, and in the paper I saw no contradiction with any established fundamental law). (CS: I already answered per email that the paper is not worth any comment.)

Suggestions worked into the 22nd edition:

• Vector E (el. field): bold upright or bold italic? Done.
• Buy O Reilly ‘‘Unix power tools’’? No.
• Use more readable fonts for screen reading, for example sans serif fonts instead of serif fonts, especially Verdana. (CS: I'll consider making a separate screen version. Considered it - have no time.)
• Although html is not as nice as pdf, it is really much easier for conversion to ebook readers or machines with small screens. When I tried to convert the pdf to my reader, either the text was too small, or I lost the links and/or the pictures. A simple (not optimized) html version would be quite nice. (CS: true, but the amount of work is more than what I can realize in this life. And html is too ugly anyway.)
• For readability's sake, increase the space between the lines. (CS: probably not, use the magnifier of your program)
• A study guide to accompany each chapter/section for those that want to learn a topic. E.G. Guided excercises for each topic, possibly a separate appendix? (CS: I'll slowly change the structure, starting with edition 22, to make this possible.)
• Clouds. (6th Jan 2008) I enjoyed your section on clouds p1244, but all the clouds you referenced were clouds of fixed objects. How does the theory stand up to clouds which exist as a consequence of a transient phase or energy level change. The cloud 'parked' on top of a mountain is a typical example. Warm air is driven up one side of the mountain until it passes above a critical point, when its water vapour is unable to stay in gas phase and undergoes a phase change to liquid which we see as the cloud. The air continues over the top of the mountain in liquid phase mode and then descends the other side of the mountain. When the air passes back down through the critical point when the liquid water is converted back into gas and the cloud stops. The cloud is static to the mountain but the air and water that constitute the 'static' cloud continually flow through the cloud itself -- the constituent particles of the cloud are transient and dynamic. What keeps a cloud together in this situation when the cloud only exists as a condition of a fluid undergoing a phase change as it passes through a standing wave? Another and even more amazing example is shown by the Nasa picture that follows. In this example the air is essentially static, and the cloud is attached to the plane travelling at mach 1. The cloud 'stays together' within the confines of the energy wave. How does this fit in with your three modes of clouds staying together? http://antwrp.gsfc.nasa.gov/apod/image/0708/sonicboomplane_navy.jpg (CS: such clouds are not static objects: the particles flow through them. They are kept together by the geometry of the flow.)
• Perhaps adding a section to the expansion of the universe explaining how with bigger and better telescopes we are able to look back at light/energy from near the time of the big bang. Yet this light would have passed us billions of years ago and be far beyond the reach of any telescope. (CS: no!) It would be like shining a flashlight into the sky and trying to use a telescope to see the beam heading away from us. (CS: no!)
• I imagine that translations are driven by the availability of willing translators more than anything else but, if one were to target languages by the number of speakers, one would maximize the percentage of the world's population that had access to the book. There seems to be some debate about the precise ordering of languages by number of speakers but those with more than 100 million look to be Mandarin, Spanish, English, Arabic, Hindi, Portuguese, Bengali, Russian, and Japanese. (CS: thank you.)
• In sections discussing mathematics, use blackboard bold to represent number sets (i.e. use \mathbb{Z} for integers on page 793, might need the amsmath package) (CS: done in version 22)
• Problem with copy-pasting from PDF version to other sources whereby ligatures (combined letters created automatically by your layout program) do not appear when pasting. Also, copy difficulties when reader highlights margin text as well as paragraph text (esp. in Preview on Mac OSX) (CS: this will be corrected in edition 22.)
• Use Küster’s Minion math (CS: done in edition 22)
• Page 14: In the appetizer section the list of limits should also be explained in words either before or after the symbolic statements. In this section of the text you are highlighting its accessibility however the list of limits without explanation (a least a little) made me skip over that section. (CS: done)
• Page 234, 2nd footnote: I was struck by the revelation about the "true" story of the Galileo trial. Since I had never heard of this theory before, I tried to learn more and I have found a (very interesting) paper in JSTOR [2] that thoroughly dissects and rebuts Redondi's 1983 book. I think you should investigate if Redondi's thesis has ever gained any consensus among scholars. Even if I am sympathetic to "revolutionary" ideas, the counter arguments that I read in the paper look very, very compelling. (CS: I have read the paper and Redondi's answer to it - which appeared only in Italian, I think. I have also corresponded with all authors involved. Furthermore, I have read the new research results, which have been published in 2000. The ideas of Redondi have been vindicated by new findings in the archives. The new version of the text will contain a better explanation, because my summary in version 21 also contains several errors. The rebuttal you quote is unprofessional and not to be taken seriously.)
• Page 249, Challenge 494: Mention Magnus effect (lift when ball is rotating), which is altered by dimples and hairiness of the balls. (CS: have tendency not to, as the question is about drag.)
• Page 270, 2nd footnote: Your division by 2 arises from consideration of quadratic systems, whose energy is proportional to some randomly-distributed coordinate squared. Keith Stowe's text illustrates this nicely. Thus it's useful in many, but by no means all, cases. In that context non-quadratic spin, laser, and other systems capable of inverted population states would also let you extend your temperature table on Page 260 past positive infinity into the negative absolute temperature range. more (CS: negative temperatures are a funny curiosity but never to be taken seriously. I will add a a few statements on them. But the k vs. k/2 issue is not easy; I'd like to have more details on it; are you saying that other system can go lower than k/2? I have never seen such a system.)
• Page 396: Twins paradox. Maybe mention that "true reason" is due to acceleration / deceleration (higher energy states) needed for travailing twin in order to return, since during the constant speed travel, traveling twin would see twin on Earth aging slower, since Earth is moving away. This is general relativity topic of course. (CS: of course not, as explained in every book)
• Page 396: Sentence on 1st paragraph: "The price of the retained youth is, however, that everything around one changes very much more quickly than if one is at rest with the environment." indicated that there is a special frame of reference namely "environment". It should be change to point out that there is no fixed "environment", just different frame of reference. That is from a point of few of falling muons the people are terribly slow creatures. (CS: hm)
• Page 696 Figure 349: WHAT? Sugar water BENDS light? Only after reading the text I learn that the concentration changes with depth. Apart from the fact that there is no such thing as a "light beam" in reality*, you should make this clear in the picture. -- *) That's why your book makes no improvement over any other physics book. The reader is confronted by the same unreal concepts and has to take it or be assumed stupid. What is needed in physics is a book that explains the origin of these concepts, not the same boring repetition of the already "known". (CS: There are observations and there are concepts. If you do the experiment by pouring concentrated sugar water in a tank, light is bent. Even if you do not like the idea. Also, most people have observed light beams. At least in this reality; in other realities this might be different. There are no assumptions here, just observation. And if you find a concept in the text that is not explained, let me know; I will add the explanation.)
• It is said that butterfly effect does not exist due to friction and dissipation. True, but requires substantial rewriting and explanations. (CS: done)
• A preliminary translation into Italian of the beginning of the book, from the Preface to the Acknowledgements, was prepared; in wait for prof. Schiller's answer to publish it. (CS: I need to have it in latex format ...)
• The statements about Redondi's book and the newest research results on the trial have to be corrected and updated. Several are incorrect. (CS: done in new version)
• Concepts are invented - particles in classical physics only approximately correspond to particles in quantum mechanics. (CS: can you say a bit more about what you mean?)
• The maximal power/force concept is poorly explained. It is unclear why two black holes can't evaporate simultaneously to produce a twice larger power. (CS: the power addition paradox is addressed in the text; essentially, the two pulses cannot overlap, but must come after each other, so that the power does not add up) What is the power of all stars in the universe? Is it larger than this c^5/4G limit? (CS: no, it is lower; but probably it just saturates it.) The explanation of the maximal force also has a drawback. Namely, the statement "to produce a force exceeding the limit value, we need to store large (elastic) energy in the rope" is false. If the rope is unstretchable, by pulling on both sides one performs no work and therefore stores no elastic energy in the rope. Only because absolutely rigid bodies don't exist, the rope will store some elastic energy, but the amount of this energy depends on elasticity of the rope (how much it extends when pulled with some force). Therefore this piece of argument as presently stated is wrong. (CS: Argument rephrased.)
• A comment on your remark above that the power of all stars in the universe probably saturates the power limit. If this is true, then there should be strange cause-and-effect relationships happening. Indeed, if some extra power source like a supernova happens in our galaxy, this means somewhere else an equal amount of power should vanish in order not to exceed the limit. This means every new power source (even a small one) should wait for some power 'vacancy' in the universe. What is the mechanism of a power source "knowing" if there is a vacancy or not? From this argument I would suppose that the universe is far from the power limit. (CS: this apparent counter-argument is wrong - it is a good puzzle to find out. Added in edition 22.)
• Show film of quartz oscillator. (CS: in edition 22)
• You specify permissive distribution terms on your webpage. It might be even better to explicitly specify a Creative Commons license for your work. In particular your terms seem to match the CC-BY-NC-ND license (no commercial usage, no derivative works). Using a CC license (and linking it on your page) will automatically index the work in Creative Commons databases, and clearly signals to readers that they are allowed to redistribute copies to others. (CS: will be done.)
• Study guide based RSS/Email feed, daily, weekly, monthly etc. To gently introduce people to the idea, as the whole book is very intimidating. (CS: one day maybe ...)
• Add an FTP and/or a BitTorrent download in addition to the current one. (CS: would you explain me how to organize a bittorrent? I know nothing about it ...)
• Add your book to the Open Library catalog of every book ever published. this could make more people find it and read it. the site address is: http://openlibrary.org/ (CS: done)
• Page 927, 1st para. "Since action is a measure of change, a minimum observable action means that two successive observations of the same system always differ by at least ħ. ... all the atoms and electrons are continually buzzing around." The reader may wonder whether the minimum observable action is a property of the observed system or merely arises from the process of observation. A traditional argument (de Broglie's?), at the level of particles "buzzing around", is that the observer interacts with the observed system by observing it, at a minimum sending a photon whose wavelength L corresponds to the position uncertainty of the observation and whose momentum is h/L, thereby disturbing the observed system by order h. 'Quantum theory' says that, even so, the action uncertainty is inherent in nature. The electrons (etc) are just around, not buzzing like flies. This doesn't come out until p932 with the use of the term "indeterminacy". As this has been understood for decades (and was also mentioned in footnote p270), why not enlighten the reader at the start, for instance by introducing electron diffraction? (CS: because that paragraph is on the effects of hbar on *rest*; diffraction comes a few pages later.)
• Page 360, Challenge 492: Maybe to add that constant flow yields shrinking of stream as it falls (observable with any tap), since the speed gets larger. For longer funnel the speed throughout hole pipe is constant and equal to exit (constant flow yield constant velocity of fluid), thus there must be a drop in pressure inside the pipe (p/ρ+gh+v^2/2=const). We can also think of this smaller pressure (compared to atmospheric one) to be responsible for faster suction of water in the container. (CS: good point, I'll add the suction topic.)
• Page 360 (253), Challenge 508. The explanation is confusing for me (first two sentences and its relation to the problem). (CS: I'll improve it.)
• Page 1115, "Microscopic evolution can be pretty slow": the champion of long-lived metastable nuclear isomers is of course tantalum-180m, with a half-life above 10^15 years. (CS: Is already in 2 tables; I'll add it there as well; but Bi 209 is even slower: 10^19 years!)
• Have you thought about a pared down version of the book targeted to children (in homeschooling families, for instance)? (CS: yes, but I have abandoned the idea - I like more to write for the present target group)
It is self evident that a major event is triggered by some preceding smaller event, and that smaller event by some even smaller event, all amplified by the positive feedback from a system primed with potential energy - everything from a war to an earthquake, from an avalanche to a tornado. (CS: no, that is not correct)
Systems that have acquired an imbalance of energy, be it air laden with water vapour or rock under huge shear pressure in a tectonic fault, can relieve their imbalance through two routes, diffusion or catastrophe (or of course any number of intermediary combinations of these two). Provide no more energy is fed into the system, or a catastrophic trigger is not provided, the energy in a weather system will diffuse away into the surroundings and the pressure in the rocks will relax as the rocks flow like glass. But if the energy is in that system and an appropriate trigger occurs, then the catastrophic feedback occurs releasing the energy in either a devastating storm or earthquake.
The flap of the butterfly wing did not cause the tornado all by itself, it did not whip up all the energy of a tornado from nothing, no, it was the tiny trigger in the right place at the right time in an appropriately primed weather system that was magnified by the positive feedback mechanisms of that system into becoming the tornado. Don't forget, just about any spark in a forest full of fuel can trigger a forest fire and likewise, just about any butterfly wing flap or other tiny initial perturbation could trigger the tornado, but there has to be a trigger somewhere, and the point is that it could just as easily be the flap of our hypothetical butterfly! (CS: No, a butterfly flap cannot trigger a tornado, whether you believe it or not.)
If you have not already done so, might I suggest a look through the numerous books by Mark Buchanan on Tipping Points and The Power of Networks. (CS: these books are not about physics - using their ideas to describe motion would be a gross violation of reason and the scientific method.)
• Tried Aquamacs (Emacs for mac)?
• Learn to use convert from imagemagick to convert from animated gif to mpeg; do it with ‘‘atom in box’’.
• Cmap for dvips needed (acrobat does not find ‘‘flower’’)! (See MinionPro.sty's documentation on what to do) CS: the manual says to use \input glyphtounicode and \pdfgentounicode=1, but if I read the manual correctly, this is not possible in the pdflatex -> dvips -> ghostview route which this text uses? Or is it possible now?
• Learn how to allow comments in pdf file: with Acrobat Professional. Need to buy it.
• Decide between pdftex (better quality, no eps but jpg figures, no pstricks, no raw postscript, no psfrag but pdffrack and unpsfrag) and dvips (no cmap, by Vladimir Volovich)
• Consider hardcopy readers (it's tough to read from a screen for hours on end). Printing would be considerably speeded (and use less paper) if there weren't so much whitespace on each page. Maybe a double column layout with narrow margins? (CS: not for the moment)
• Consider producing an e-reader version, Sony Reader, Irex's Iliad. (CS: I did, but the demand is too small yet.)
• Could you perhaps produce a PDF of a single chapter with size 88.184mm x 13.854mm or 13.854mm x 88.184mm for testing on a sony reader? (CS: this is very low on my priorities, sorry.)
• In the quote from Macbeth at the start of chapter 42--"Throw physic to the dogs; I’ll none of it."--"physic" refers to medicine. (Perhaps this is intentional but it may appear to some as though it were a mistake.) (CS: yes, it is intentional.)
• Just a quick question. What do you think about Garret Lisi's work using E8 as start point. Seems he is definitely shaking up physics in a very cool way. Your book is terrific BTW. I posted a short article about in in www.byondrealtime.com. Have learn a lot reading it. R. Moran (CS: first impression: Gisi's work does not seem to answer any of the open questions of physics that are listed in the chapter "Quantum physics in a nutshell")

Below are suggestions that have already worked in earlier editions.

0b. General

• Don't bother zipping a PDF, which is already compressed. The ~7% reduction in size does not offset the complexity of having to manually un-zip it, not to mention peope who don't know how to do that or don't have the proper tool. To maximize readership, don't put obstacles in their way. But it is large, so next to the link you should probably suggest that people download it rather than just click on it to open it in their browser. (CS: Both options are now available.)

1b. Suggestions for new images and films that have already been included in version 21

• Add more pictures of machines (maybe in a separate section; e.g. paper mill, coal digger, tiny machines)
• Film of Foucault's pendulum: there is an animated GIF in wikimedia commons (open source media): Foucault's Pendulum (CS: thank you, added link in version 21)
• Add photo of deformed tennis ball during impact (CS: will be included in version 21)
• Add photo of sun dogs or the like (CS: will be included in version 21)
• Add galaxy image (CS: will be included in version 21)

2b. Suggestions already worked in version 21

• Change square root signs (CS: no)
• Typography: Make brackets have the right size to contain their content. (E.g. using \left( ... \right) or \Bigl( ... \Bigr) etc.) (CS: where exactly?)
• Add more problems; not just the conceptual kind, but more practical world problems (CS: please specify your favorite topics for which you want this!)
• Why is it true? You may like to answer this question in the textbook: Why do people consider the theories in this book true or false? I think this would really help... Thanks. (CS: The reason is: agreement with observation. There is already a section called "What is a lie?" that answers this in more detail, together with the sections before and after it. Enjoy.)
• Chapter 1 needs more material on biology and scaling. (CS: will be added in version 21)
• More topics for engineers! (CS: more will be part of version 21)
• Transform the whole book into a wiki? (CS: no plans: picture rights issues, typography issues, amount of work)
• Amend story about origin of the equal sign (CS: will be corrected in version 21)
• Page 23: The concept of 'soul' is a bit obscure at best and people might get the wrong idea about psychologists. Even though I understand that it is about wetting peoples appetites, perhaps an equally enthusiastic word such as 'mind' would be more appropriate? Moridin 18:03, 13 August 2007 (CEST) (CS: Agreed; will be changed in version 21.)
• Page 143: Mention new classification group: "dwarf planets" and maybe include dwarf planet Eris, which is larger than Pluto (also dwarf planet). (CS: Thank you, will be added in version 21.)
• Page 153: Should include viscous term (linear in velocity) in air resistance. (CS: Thank you, will be added in version 21.)
• Page 820: separability is not clearly defined, and clashes with separability definition in rest of text; by Daniel Huber (CS: will be stated correctly in version 21)
• Page 1043: energy dependence and limit is not well explained. (CS: will be improved in version 21)
• Page 1267, Challenge 298: At full Moon and new Moon, the Sun, Earth and Moon are lined up, producing the higher than normal tides. Thus there is correlation between Moon phases and the gravity effects (although not causal). Maybe the question should be reformulated. (CS: Thanks! The question will be reformulated in version 21 to make clear that it was about effects on humans only. Tides have never been detected on human bodies.)

3b. Suggestions for new topics and tables that are already worked in version 21

• Add more topics on music. (CS: will be included in version 21)
• Make extra pdf for BW printing? (CS: NO - I recheked the figures on my printer)
• Add more on sport, the human body, and the senses. (CS: will be included in version 21)
• Add chapter, why vacuum tube guitar amplifiers sound better than transistor solid state amplifiers to guitar player ears (CS: see also wikipedia tube sound)
• Add tables for light intensities (CS: will appear in version 21)
• Artificial and computer intelligence (CS: some aspects mentioned in the section on the brain; more will not be added; too far from the topic of the text and from the expertise of the author)
• Add Daniel Hawkins's solution to the car parking problem. (CS: will be included in version 21)
• Add ‘‘Nr Page caption’’ in both appendices in subsequent pages. (CS: not needed in version 21)
• Quotes at the beginning of sections could be accompanied by english transations (CS: which one did I forget?)