...But perchance someone may say, "What is this? You, who have promised to give directions in regard to the education of free-born children, are now evidently disregarding the eduction of the poor children of the common people, and you acknowledge that you are offering your suggestions for the rich only." To these it is not difficult to make reply. My dearest wish would be that my scheme of education should be generally useful; but if some being needy in their private circumstances, shall be unable to avail themselves of my directions, let them lay the blame therefor upon fortune and not upon him who gives this counsel. Even the poor must endeavour, as well as they can, to provide the best education for their children, but, if that be impossible, then they must avail themselves of that which is within their means.
From The education of children which is attributed but almost certainly was not written by Plutarch.
Quite random notes
quite, n. Pronunciation: Brit. /ˈkiːteɪ/ , U.S. /ˈkiˌteɪ/ A series of passes made with the cape in order to distract the bull from a vulnerable picador, horse, etc.
Monday, November 25, 2013
Wednesday, October 30, 2013
Different kind of history
“It is in this respect that the present study will be found to differ most strongly from ‘history of ideas’ approaches, which often tend to avoid going in any depth into technical details. However, as this book will show, it is precisely through the technical details, which become most absorbing when seen in the light of their full significance, that the true electric current of discovery runs. If we do not follow the current closely, we shall not really understand what happens and why. To use another image: the technical details are like the hinges of a door opened on a new vista. The change in view they make possible seems out of all proportion comes from the fact that, like hinges, they are mounted on a secure support: successful mathematical description of observed phenomena. And we cannot understand why the door swings unless we see how the hinges work.”
Julian B. Barbour, The discovery of dynamics, vol. 1 (1989) p. 17.
Julian B. Barbour, The discovery of dynamics, vol. 1 (1989) p. 17.
Saturday, April 27, 2013
Remote kernel for Mathematica via home router
Let's
say you are sitting at home, surfing internet via your wireless router,
and suddenly feel the unexplained urge to run some Mathematica
computations. You can not do that using your laptop: the urge is
too powerful, it requires 16 parallel kernels. But you can do that
using your workstation which is sitting at your office 10 miles away
(it's raining outside). “Remote kernel is a solutions”, you think.
So you open “Kernel Configuration Options” in your local copy of Mathematica and add a remote kernel with just basic options:
Machine Name: my.office.work.edu
Remote Login: killbull
Kernel Program: math
You type “2+2” in the Front End, enter ssh password and get, instead of “4”, the frustrating error message:
The
kernel New Kernel failed to connect to the front end. (Error =
MLECONNECT). You should try running the kernel connection outside the
front end.
Being a smart person you immediately realize the following:
- Remote kernel can’t talk to your local Front End since you have firewall running. You add exception for the remote workstation’s IP address right away.
- Since you use the router your IP is 192.168.1.10 and is not visible from the ourside world. You have to make a VPN connection to your office network to allow the remote kernel to talk to your local Front End. It’s done in no time.
$ math -mathlink -linkcreate -linkprotocol TCPIP
Link created on: 33234@129-3-222-111.vpn.uh.edu,23253@129-3-222-111.vpn.work.edu
So remote Mathematica’s kernel will happily communicate with 129-3-222-111.vpn.work.edu. Obviously, you can google "what is my IP" and it instead.
Now
you return to Mathematica’s “Kernel Configuration Options” and edit
your remote kernel's properties. You click “Advanced Options” and instead
of Mathematica’s default
`java`
-jar `mathssh` killbull@my.office.work.edu math -mathlink -LinkMode
Connect -LinkProtocol TCPIP -LinkName "`linkname`" -LinkHost `ipaddress`
you enter
ssh
killbull@my.office.work.edu /home/killbull/install/bin/MathKernel
-mathlink -LinkMode Connect -LinkProtocol TCPIP -LinkName "`linkname`"
-LinkHost `129-3-222-111.vpn.work.edu`
Here
-
“ssh” is instead of “`java` -jar `mathssh`“ so that Mathematica will
use regular OpenSSH to communicate. This will allow you to make use of
your huge .ssh/config file.
-
“/home/killbull/install/bin/MathKernel” instead of just “math” since
your Mathematica binaries on the remove machine are not in the PATH.
- “129-3-222-111.vpn.work.edu” instead of “ipaddress” so that remote Kernel will know where to find you local Front End.
Now everything work’s, and you can start to satisfy your urge immediately.
Monday, October 24, 2011
Wiener on scientific cooperation
“[Cybernetics is a] boundary regions of science which
offer the richest opportunities to the qualified investigator. They are at the same time the most refractory to the accepted techniques of mass attack
and the division of labor [...] a proper exploration of
these blank spaces on the map of science could only
be made by a team of scientists, each a specialist
in his own field but each possessing a thoroughly
sound and trained acquaintance with the fields of
his neighbors; all in the habit of working together,
of knowing one another’s intellectual customs, and
of recognizing the significance of a colleague’s new
suggestion before it has taken on a full formal expression. The mathematician need not have the
skill to conduct a physiological experiment, but he must have the skill to understand one, to criticize
one, and to suggest one. The physiologist need not
be able to prove a certain mathematical theorem,
but he must be able to grasp its physiological significance and to tell the mathematician for what
he should look.”
Norbert Wiener. Cybernetics: or Control and Communication in the Animal and the Machine. The Massachusetts Institute of Technology, second edition, 1948. p.2
Cited from arXiv:1107.2984v1
Thursday, July 21, 2011
On the link between epistemology and tolerance
“It was this doctrine of an essential human fallibility which Nicolas of Cusa and Erasmus of Rotterdam (who refers to Socrates) revived; and it was the ‘humanist’ doctrine (in contradistinction to the optimistic doctrine of which Milton relied, the doctrine that truth will prevail) which Nicolas and Erasmus, Montaigne and Locke and Voltaire, followed by John Stuart Mill and Bertrand Russell, made the basis of the doctrine of tolerance. ‘What is tolerance?’ asks Voltaire in his Philosophical Dictionary; and he answers: ‘It is a necessary consequence of our humanity. We are all fallible, and prone to error; let us then pardon each other's follies. This is the first principle of natural right.’”
Quoted from: K. Popper, Conjectures and Refutations, Routledge (2008) p. 22
Friday, July 15, 2011
K. Popper on theories that are not (yet?) scientific
“I thus felt that if a theory is found to be non-scientific, or ‘metaphysical’ (as we might say), it is not thereby found to be unimportant, or insignificant, or ‘meaningless’, or ‘nonsensical’. But it cannot claim to be backed by empirical evidence in the scientific sense—although it may easily be, in some genetic sense, ‘the result of observation’.”
Quoted from: K. Popper, Conjectures and Refutations, Routledge (2008) p.50-51
Quoted from: K. Popper, Conjectures and Refutations, Routledge (2008) p.50-51
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