Monday, 1 July 2013

Udemy - Learn HTML5 from scratch

I've heard about HTML5 - but didn't really know what it was. So this sounded like a good course to find out.

Its fairly gentle as courses go, and all parts are explained well with all code written from scratch in front of you. It shows you how to do regular HTML first, before moving onto some of the advanced features.

So it starts with basic HTML together with inline styles, tables and input actions.

Then it moves onto CSS files and tailoring the result to look like what is required. It's quite fun to see the website evolving in front of you as you tweak padding, colors and so on.

Then it's on to HMTL5 new things. New tags, new form elements and so on. This is followed by graphics, video, geolocation, SVG graphics, mobile apps, caching and storage extensions. 

Its a very good overview, but you obviously need to know quite a lot of javascript (which isn't explicitly covered) to make good use of some of the new features.

Saturday, 1 June 2013

Udemy - Introduction to Java Programming

So I was doing a bit of Android programming - writing apps and stuff.
I'd played around a bit with java when it first came out, but never written much in it. It's moved on a bit since then, so I thought I might catch up with it using this course.

I'd recommend the course for anyone who wants to learn Java. It's done at a nice slow pace, with lots of examples and takes you through each challenge showing how they would write the answer. This is always good - because normally people skip over the boring bits and head for the answer, missing out a couple of steps that you just can't seem to repeat at home.

Anyway - a great course, a little slow for me - it is meant for beginners though, so I skipped over some of the material and it was all very enjoyable,.

Friday, 31 May 2013

Udemy - Astronomy - state of the art.

Astronomy - State of the art

I spotted this course just moments before it actually started - well a day or two. I hadn't heard of Udemy before - so this was new.

It looked really good - it promised to cover a lot of areas - and I'm often concious that I only get to see stuff on galactic scales, and mostly theoretical - so this looked like it would be good for balance.

I have to say it was fantastic. You can take the course at your own speed. There was some initial attempts to have quizes as part of them - they had issues getting the system to work so they were shelved.

It really did cover pretty much the whole of astronomy, from telescopes, to planets, to stars, black holes, and galaxies to cosmology - and all stops in between in 77 chunks. It breaks down in the following topics.

      • Course Overview,
      •  Description,
      •  Introduction
      • State of the Art Observing, 
      • Telescopes, 
      • Observing Limitations, 
      • Observing Solutions, 
      • Adaptive Optics, 
      • Space Astronomy, 
      • Big Glass, 
      • Gravity Waves
      • Overview - Planetary Exploration
      • Mars
      • Mars and Water
      • Mars Up Close
      • Jovian Planets
      • Solar System Satellites
      • Titan
      • Water Worlds
      • Overview - Extra Solar Planets
      • Exoplanets
      • Detection and Imaging
      • Characterizing Exoplanets
      • Kepler
      • Habitable Zones
      • Overview - Stars
      • Stars and Life
      • Supernovas
      • Pulsars
      • Black Holes
      • Testing Gravity
      • Overview - Structure & Evolution of Galaxies
      • Milky Way
      • Dark Matter
      • Galactic Center
      • Active Galaxies
      • Structure Formation
      • Dark Energy
      • Overview - Cosmology
      • Cosmology
      • Microwave Background
      • Big Bang
      • Early Universe
      • The Multiverse
      • Overview - Life and Astrobiology
      • The Unity of Life
      • Extremophiles
      • Exobiology
      • Weird Life
      • Drake Equation
      • Communication
    As well as videos, there were PDF's to read and slides available. Also supplemental audio recordings of the tutor, Professor Chris Imprey, interviewing other astronomers.

    Towards the end of the course he also conducted some live sessions where we could send in questions either live or by email/twitter and he'd answer them live on video conference. They ranged from "Is there life on Mars?" to "What happens in a black hole?" and many others. Nothing seemed to phase him, and each question got a good 5 or 10 minute answer.

    The course is still going - and anyone can watch the videos, read the material and take part in the interactive sessions. It's well worth it if you are at all interested.

    Even better - after the quantum mechanics course I'd just taken, it was a complete relief to feel on top of a subject!

    Monday, 13 May 2013

    Coursera - Quantum Mechanics

    A course on quantum mechanics! What am I thinking?

    So I signed up for a course on quantum mechanics. I mean, how hard can it be?
    Answer - *!?**!!* hard!

    I brushed off my knowledge of imaginary numbers, I went through the introductory maths materials - they didn't seem too hard. OK - I struggled to remember complex conjugates, and one or two other things.

    I thought there might be a reasonable introduction, and an explanation about things - which there was. However the learning curve was incredibly steep, and was sort of emphasised by the first homework.

    Q1 For what was Albert Einstein awarded the Nobel prize?

    • General Relativity
    • The expansion of the universe
    • The photo-electric effect
    • Electron diffraction
    OK - I actually knew that one - although it was in the course materials too.

    Q2 Recall how the Schrödinger equation was motivated by the non-relativistic dispersion relation 
    E=p22m. If we follow the same procedure for the case of a relativistic dispersion relation (E2=p2c2+m2c4), what equation do we arrive at? (For simplicity consider the one-dimensional case)

    Ouch! The gloves are off! The lectures also had a grading system. No stars was for everyone, 1 star had some maths in it, two stars extensive maths, and three stars - mega maths. Most of the videos were in the 2/3 star range.

    I actually enjoyed doing some of the integration - but realised I was gradually losing the plot as the course went on. I never really got a good handle on the bra-ket notation - I still don't really get it's power - I'm missing something I'm sure, but they didn't spend very long on it, and the books I got didn't help. Then it was onto Dirac deltas, Levi-civita notation and stuff about spin. By now I was really struggling with the weekly homeworks, and guessing as many as I was solving - I was no longer learning and close to drowning. I did think about giving up on the course, but I stayed the distance, and finished all the videos, all the homeworks.

    This course had an exam - 1 chance at answer each question - 6 hour time limit. A couple of questions I could answer, the rest I guessed at, except those that required a numeric answer - which I couldn't do. I got 42% which I consider more than fair.

    This gave me a total course mark of 72% - again more than I deserve.

    So I probably got half way before I couldn't keep up, and for me it was hard to turn all that maths back into what it meant in the real world - even in the abstract. I guess that's not unusual in quantum mechanics!

    Wednesday, 27 March 2013

    G+C: Final

    Well - just to complete this, I managed to complete the course satisfactorarily, in fact I got a distinction.

    I didn't learn a huge amount, but then given I picked it because it was within my comfort level, that's hardly surprising. 

    There are definitely a few down sides with this style of presentation. It's had to go at anything other than the pace the videos are delivered at - well that's not true - you can go slower by pausing them, but it's hard to skip ahead as you don't know what you might be missing. This isn't like skim reading hard copy where you can skip ahead and suddenly see something you think is important. 

    Still - for the price - it is excellent value for money! :)

    Tuesday, 5 February 2013

    G+C: Module 7

    So just one module this week, and quite grateful for the respite too. After the week was done, it was revealed that the instructor had gone down with a case of 'flu, and so was not available to record more videos.

    This week was very interesting.
    It started with some discussion of baryons, and where they are and what they're doing.
    Then onto two videos on dark matter, the history and what it might be.
    Then we worked on gravitational lensing, followed by a another on gravitational microlensing.
    This week concluded with a module on dark energy.

    So about 63 minutes in all. I got 8/10 on the quiz, so slipping from the original 10/10 days!

    Interestingly they revealed some course stats today. The course started with more than 28,000 students registered. This is quite mind boggling. I'm use to a few hundred on the OU courses, maybe a thousand or two for the most popular. Apparently the drop out rate is very high - given you haven't paid for it, or anything like that, there isn't any penalty for dropping out. Coursera work on 5-10% making it through to the end.
    This is a difficult course, with some quite scary maths in it, so if anything the drop out rate may be higher.

    At nearly the half way point, there are more than 3,500 active users still present, so that's quite amazing.
    Anyway - there is no wonder there are no written courseworks to be marked!

    I'm quite staggered how popular this course in a rather niche subject is!

    Wednesday, 30 January 2013

    G+C: Module 5 & 6

    So week 3, and this week there are some more topics introduced.

    First it starts with one on Cosmological tests, how you can check what we work out. Then some tests in detail, such as the Hubble diagram, the Cosmic Microwave background (of course) and then source counts.
    It wraps up nicely by look at the concordance model, where all tests are brought together to constrain various values. 54 minutes of video split across 5 topics.

    The next module starts with the very early universe, talking fractions of a second after the big bang. Then some stuff of big bang nucelosynthesis, and a bit about inflation. Then more about the early universe, including recombination and reionisation.
    Just 4 videos in this bit,  42 minutes, so just over an hour and a half total of videos.

    The quiz was a bit harder, and I only managed 7/10 this time. One I think the question was a bit iffy, and a couple were just answers I couldn't find easily.

    Sunday, 20 January 2013

    G+C: Module 3 & 4

    Modules 3 & 4.

    This weeks work is module 3, which is on cosmological models.

    It starts by introducing the cosmological parameters, then takes us briefly through solving the various Friedman equations for different models. It then looks at the different cosmological models that arise from these, what sort of universe they predict, and what they would look like. Finally a quick introduction to distances in cosmology.

    4 videos comprising 37 minutes

    Module 4  is on distance scale, age of the universe and expansion
    So it starts by looking at the scale of the universe, then starts with the cosmic ladder of distances, from parallax and upwards. This is followed by distance indicator relationships, and then a look at supernova standard candles. Then 3 more videos, on the HST distance project, estimating the age of the universe, and finally tests that can tell us if the universe is expanding, or light is just "tired".

    So 7 videos in this section. 75 minutes in total.

    This together with the module 3 videos I found quite a lot to squeeze into a week. It takes a while to get through all these and there is only so much you can take in in one go.

    The quiz was a bit harder than last weeks, I had to go searching for some of the answers, another 10 questions, but I managed to get through them all eventually. Some I thought slightly imprecise, but anyway - all ok.

    So onwards and upwards - next section is early universe stuff like the big bag, inflation and nucleosynthesis.

    Thursday, 10 January 2013

    G+C: Module 2

    The second module is all about basic cosmological stuff. There are another 4 lectures with embedded questions running to about 25 minutes in total.

    It starts with some basic definitions, then discusses homogeneity and isotropy. Then some time spent on the expanding universe, and finally a quick derivation of the Friedman equations.
    The questions I'm getting more use to and managing to cover OK. A few of them I have to think a little, but so far not needed pencil and paper, but that will probably change with the questions that are up coming.

    So nothing I haven't seen before, but I struggled to follow the mathematical derivation - I have done it before so if necessary I think I could follow it.

    So after thinking about it, I decided to tackle the questions. There were 10 multiple choice questions based on the text, and most of them were reasonably easy to answer. A few were more tricky, and I had to review material, but actually still nothing requiring pen and paper as yet.

    Tuesday, 8 January 2013

    G+C: Module 1

    So - the course starts! First thing is it seems to go at quite a rate. We're expected to go through two chapters a week, and then answer a quiz on the topic. You need 60% to pass for each quiz. You get two deadlines to complete the quiz by, with only half marks available if you slip the first dead line. So the pressure is on!

    The first lecture is a 15 minute video on the history of cosmology and some background material. The video is powerpoint like slides mostly with narration over it, and occasional inset video of the speaker.

    I noticed some yellow marks on the slider at the bottom of the video, and found when it got to that point the video paused and you got asked some questions. You get instant feedback on these so it's quite interactive.
    However some of the questions were suddenly a little heavy for late night consumption!
    Quick, integrate between limits 0 to 1 ex dx. What quantum jump gives the H-alpha line. I admit to having to google that one - I thought it was probably 3-2 but wasn't confident when it came to it.

    A couple of things I did learn from this though, which I presumed I'd learn some new things.

    • Bolometric output is the whole output of something. I sort of knew that, but it's not something that concerns me normally, but something clicked here.
    • He went over Olber's paradox, and said not only did it apply to light, but also to gravity. You can recast the paradox into "why aren't we ripped apart by the total tidal force of the gravitational interactions?"
    So most of it was a general introduction. The spontaneous calculus was a bit of a shock - but apart from that it was ok.

    The next two videos were on more general history leading up to CMB and Dark matter and things like that, taking us up to the present day. These also had quizes in them, but I found them much easier to answer!

    So that's module 1 done - about 45 minutes of video in all, with some questions thrown in. Not bad for the first day :) I need to do module 2 though before attempting the assessed quiz.

    Monday, 7 January 2013

    Change of direction

    So I finished my OU degree, and I've gone into postgraduate studies in astronomy now. I did do one last OU course, SXP288, but really only for the residential component. The way education is funded has also changed, and this means the course fees have quadrupled. I can get some transitional arrangements if I was studying for another degree, but I think I don't really have time for that, and really I would only want to pick and choose which courses I would do.

    So reluctantly, I've probably come to the end of my time with the OU, through pressure of time, finance and the changing face of education.

    I'm learning a lot of new stuff in my postgraduate studies, and did 6 course last year local to the university, which I'll skip over. However chatting to a friend, she mentioned the new set of courses which are free through - and I thought, why not give them a try, So here I am, signed up for something reasonably relevant - a course on Galaxies and Cosmology. Yes - I'm staying somewhat in my comfort zone, and partly worried I won't be able to manage it which would be embarrassing. I'm also just interested in what the format will be (this one comes from CalTech!) and how it will all work.

    So slightly scary, but well worth the price!