physicists-from-the-united-kingdom

"It is 33 years since I got my PhD."

"8 or 9 hours now, but I used to do 10 to 12 when I did more research."

"I am currently Head of the Astronomy Division and I was Acting Director for about 18 months following the death of the Director."

"Less bureaucracy would help in almost every single way."

"What is clear in South Africa is that many things were strongly biased against women prior to our first democratic election in 1994."

"All in senior engineering or IT posts. Of the 25 astronomers on the SAAO staff, 5 are women only one of them born in South Africa."

"The legislation that was put in place to try and remove racial discrimination."

"I have a husband, John Menzies, who is also an astronomer and who has always been very supportive."

"If you are going to get married and or have children then you must find a partner who is a true partner."

"As far as my career is concerned I am sure I have got where I am going."

"At SAAO there are a few women in scientific posts."

"That bias has been more or less eliminated since."

"I have also been President of the South African Institute of Physics."

"Is also dealing with other types of discrimination but it will take time."

"The only woman and only astronomer to hold that position."

"That is not to say that women occupy 50% of top posts, but there are at least some women in top posts and the profile of the workforce is gradually changing."

"The racial imbalance in the workforce remains the major problem."

"Of the 5 astronomers on the Executive Committee, I am the only woman."

"I do not have children, and am immensely impressed by women who do and also manage to be successful astronomers."

"It is well worth it, but astronomy has to be your life, not just your job, or you are unlikely to do well or be happy."

"Astronomy has to be your life, not just your job, or you are unlikely to do well or be happy. If you are going to get married…then you must find a partner who is a true partner, because it is impossible to do everything yourself."

"It is impossible to do everything yourself."

"In my house I have four , I sometimes adjust them so that at least two, but rarely more than three, strike the hour within a few seconds of each other. Fortunately, the pleasure I get from my clocks does not depend on them all telling the same time. When I switch on the in my car, however, things are different. It very quickly latches on to at least four atomic clocks high in the sky, all of which tell the same time to about a hundred millionth of a second. If they did not, my GPS would guide me to somewhere other than my desired destination."

"On 19 March 1791 five of the great luminaries of French science, Laplace, Lagrange, Condorcet, and , met at the in Paris and drew up a document that laid down the definition of the new basic unit of length, the , for the proposed new system of measurement that would become the ."

", the science of measurement, is part of the essential but largely hidden infrastructure of the modern world. We need it for high-technology manufacturing, human health and safety, the protection of the environment, global climate studies and the basic science that underpins all these. Highly accurate measurements are not exclusively the preserve of the and engineering; many areas of chemistry, and medicine are now dependent on accurate quantitative measurements. in all manufactured and agricultural products is strictly controlled by regulations that need accurate metrology for their implementation."

"... of may allow us to say that "this object is hotter or colder than that one." But even this apparently simple statement is fraught with pitfalls for the unwary. For example, take hold in turn of a block of , a piece of expanded and a rod of , all near room temperature but differing slightly slightly in temperature from one another. It is not easy to make any useful statements about which is hotter or colder. This means, of course, that the is a poor thermometer, but the reasons for this being so are by no means straight-forward: they are related to the way in which sensations of hotness and coldness are generated in the human body ..."

"It has long been recognized that the basic units in science – such as the and the – should be defined in terms of fundamental physical phenomena. Indeed in 1870 James Clerk Maxwell recognized that the units of , and would only remain unchanged and reproducible if they were defined by the , period of vibration and absolute mass of molecules rather than by the physical properties of the Earth. However, it took over a century for the metre and the second to be defined in terms of the quantum properties of atoms. And it was only in 1990 that reproducible standards of and were linked to quantum phenomena."

"[[wikt:stability#Noun|[S]tability]] of solids, the fossils and rocks... exist... essentially unchanged. ...[T]he configuration carries intrinsic semantic information... different intelligent beings can in principle deduce the law or process.. Support for this is is the independent discovery of evolution by natural selection by Wallis and Darwin."

"There is one metalaw of science: it cannot exist without structured things. d variety is the ground of being. That is what gives content to both science and life."

"Consider the example of a time capsule... geologists... establish[ed] detailed correlations between the structure of fossils and rocks... They concluded... an immense , vastly longer than the bible-deduced... 6000 years. They explained... a long process... in accordance with... laws of nature. They discovered ... and... present evidence for it extends today... to all branches of science, especially cosmology and genetics."

"[W]e must distinguish three kinds of information: [1] Shannon’s information, the uncertainty as to which message will be selected from a source; [2] factual information, the content of such a message; and [3] intrinsic semantic information, which distinguishes a random message, or configuration, from one that carries meaning and to some extent explains its... genesis. All... have... underpinning in things."

"Shannon information... [which] he also called entropy or ... involves things (...Shannon ...messages) and probabilities for those things."

"Greek astronomers observed intricate motions of the sun, moon, and planets on the two-dimensional sky. They explained them—saved the appearances—by positing simple regular motions... in three dimensions. The success... [was] brought to a triumphant conclusion by Kepler..."

"[[Symbols|[S]ymbols]] have no meaning if divorced from the entities that they represent."

"I find no reason to reverse the standard assumption of physics... what we experience can be explained by the assumption of an external world governed by law."

"I argue... this weakens but not necessarily destroys the argument that nature is fundamentally digital and continuity an illusion."

"The concepts of message and probability enable one, for a definite source of N messages, to define Shannon’s information. If p_i,\quad i = 1, 2, ..., N, is the relative probability of message i and \log p_i is its base-2 logarithm, then the information I of the given source is(1) \quad I = - \sum_{k=1}^N p_i \log p_i.The minus sign makes I positive because all probabilities, which are necessarily greater than or equal zero, are less than unity (their sum being\textstyle \sum_{i}^N p_i = 1, so that their logarithms are all negative."

"and variety are central to my critique of 'it from bit'. For we can only talk meaningfully about a thing, including a , if it has distinguishing attributes. The way that they are knit together, as in the taste, shape and colour of an apple, defines the structure of the thing."

"Shannon-type message sources could not exist if the universe were not subject to laws of nature and far from ."

"Richard Feynman... said, "Time is what happens when nothing else does." ...[T]hat's ...not the right way to think about time."

"[A NOW] has no duration. ...[I]t's absolutely instantaneous. There is no thickness to it. Nothing changes. ...So these s, in one sense, are truly eternal, because they never change, and on the other hand, because nothing changes, they are experienced as a flash. ...[It]'s a nice contradiction... [T]he eternal is experienced as a flash, because nothing changes."

"There is nothing in between... [NOWs]. Each are separate snapshots. ...These [real photographs] ...are not changed by ...reversing the order ...It may be convenient for ...for the way we think about the world and for ordering our experiences, to suppose that these come in a certain order; but ...the picture is not changed... the snapshot is... self-contained."

"[I]n 1898... Henri Poincaré wrote... "On the Measure of Time" and he said... there are two fundamental problems to do with time. One... with the definition of duration... What does it mean to say that a second today is the same... [H]e said there's another issue... [not] so widely recognized. ...[H]ow do you define simultaneity at spatially separated points?"

"He... explain[ed] how the astronomers... had to grapple with the problem of defining definition, because for 2 1/2 millennia there had been just one standard of time... the rotation of the earth. ...[T]hat had provided an incredibly accurate clock. It's... lost only a few hours in 2 1/2 thousand years. ...Very easy to use. Astronomers only... had to glance at the night sky, at the... Big Dipper... to tell the time within a minute or two... But in the 1890s a crisis developed when they found that using the earth... and... Newton's laws of motion and gravity... the Moon was speeding up. ...[T]hey thought ...the earth was slowing down because of the tidal effects of the moon... and... this would mean that the earth was not a good timekeeper at the accuracy that they wanted."

"How do you define duration? What does it mean to say that a second today is the same as a second tomorrow? Newton in his... Principia... 1687, gave a... definition of absolute time, which he says flows uniformly without relation to anything external... [H]e says... if nothing... were to happen in the universe... if everything froze... time would still pass uniformly. ...[S]o ...time exists before anything else..."

"[W]hat we call yesterday is self-contained and has its experience of being yesterday, and today has memories of yesterday; and therefor I say that it's later... but each is completely self-contained, and there's no reason why you should put one... here, and another one there..."

"[T]he work that I did with... has shown... time that is measured by clocks is... an average of all the changes in the universe."

"It is a mistake to believe that the digits 0 and 1, being abstract, represent the immaterial. Quite... the contrary... they stand for something quintessentially concrete."

"Ontological primacy should not be given to information but to things, as has always been the standpoint of realists."

"If you could freeze the camera now and... show me as I am, and all the atoms... and... the whole universe... like a snapshot, the would be... a NOW."