Archive for the 'software' Category

University of Leicester wants to abolish pure math research

Wednesday, April 28th, 2021

To those who are not aware of the fact: The main authors of this randform blog (Tim and Nad) are math Ph.D.’s. Since now quite a while we are very concerned about the fact that (pure) math research is increasingly put under high retrenchment pressure. So for example under the name of “shaping for excellence”, the University of Leicester will decrease its fundamental research capacity. For “pure” math this means: the University VC (=vice chancellor) proposes to cease research in pure mathematics and wants again to fire all researchers. It is claimed that this is necessary because: “…to ensure a future research identity in AI, computational modelling, digitalisation and data science requires ceasing research in Pure Mathematics in order to invest and extend activities in these areas.”
For those who know about the mathematics behind AI, computational modelling and digitalization this sounds not only absurd but rather like to cut one’s nose to spite one’s face. But it seems things are even worse that is this “triage” seems to be a pretense as they give no concrete plan “to invest or extend activities” but just to cut in fundamental mathematics research.
As a matter of fact this plan affects a high amount of female researchers. In fact by comparing with the list of academic staff (I count 39 academic staff members) and/or the list of group members in “applied math” and/or the list of women in mathematics on the equal opportunites web page it seems all women but 3 of Leicester’s math department are going to be fired.

Moreover University of Leicester management apparently refused to share data on finances with unions.

-> Please donate and Help Leicester Pure Maths fund Legal Support
or at least sign the petition.

What is going on at the Sun?

Saturday, February 2nd, 2019

In the randform blog post Information about solar irradiance measurements sought, I had posted a visualisation of irradiance data from the Laboratory for Atmospheric and Space Physics (LASP). In the post it was discussed that there could be a rise in irradiance based on the data from their SORCE mission. I think the rise is also somewhat visible in this interactive plot at the Interactive Solar Irradiance Data Center (LISIRD)…that is it is visible until about July 2015. In this post I also posted a picture of the line 774nm, i.e. “red light” which is slightly out of the visible spectrum. The reason was that it seemed that specific line ranges displayed a stronger rise than others (see circles in the other image in this post). Back then I even made some screenshots from the LISIRD visualization, here you can see the close-by line 798.83nm:

Here it is again in my visualization:

Both visualizations look pretty much the same apart from some visualization effects. But this is how the line in the above time range (here until Dec 18 in 2016) looks as of today in the new LISIRD app:

So things look very differently since about early summer 2015. Is this a correction?
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ShutterSploshShredderPlots

Sunday, October 7th, 2018

Remark: The code as posted at the randform post ShutterSploshScatterPlots needs to include the new Content Security Policy.
That is you have to embed the following lines (at least thats how it worked here for the moment) into your html head:

<meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self'">
<meta http-equiv="X-Content-Security-Policy" content="default-src 'self'; script-src 'self'">
<meta http-equiv="X-WebKit-CSP" content="default-src 'self'; script-src 'self'">

Moreover the javascript has to be pasted into a separate file and referenced accordingly within your html body, like for example as:

 <script src="shutter.js" type="text/javascript"></script>

In case you feel a bit overcharged by all that – as a courtesy for you I quickly filmed the program output with my mobile and turned it into a gifanimation, which you can watch after the ” Read the rest of this entry”.

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august note

Friday, August 31st, 2018

This month no new randform post.
The previous post is hard enough to digest.

On a personal note:
The previous post is actually a main result of a phase between mid/end 2012 – spring 2015. In this phase I was investigating in which way I could apply my math/physics and visualization skills to climate science. In 2015 I more or less ended the investigation, since I found that -amongst others- my programming skills were not good enough for a continuation on a more professional level and started to work in a company in which I have been working since then.

simple greenhouse gas models

Sunday, July 29th, 2018

Rotatable with your mouse after you click on “Read the rest of this entry“.

Most of randform readers might have heard that the socalled greenhouse effect is one of the main causes of global warming.

The effect is not easy to understand. There are two posts which give a nice intro to the greenhouse effect on Azimuth. One is by Tim van Beek and one is by John Baez.
The greenhouse effect can also be understood in a slightly more quantitative way by looking at an idealized greenhouse model.

In the above diagram I now enhanced this idealized greenhouse model (as of Jan 2017) in order to get an idea about the hypothetical size of the effect of an absorption of non-infrared sunlight and it’s reradiation as infrared light, i.e. the possibly effect size of a certain type of fluorescence.

I sort of felt forced to do this, because at the time of writing (February 2017) the current climate models did not take the absorption of UV and near infrared light in methane (here a possible candidate for that above mentioned hypothetical greenhouse gas) into account and I wanted to get an insight into how important such an omission might be. The simple model here is far from any realistic scenario – in particular no specific absorption lines but just the feature of absorption and reradiation is looked at.

The above diagramm shows the earth temperature in Kelvin as a function of two parameters, as given by this enhanced model. The two parameters can be seen as being (somewhat) proportional to densities of a hypothetical greenhouse gas, which would display this type of fluorescence. That is the parameter x is seen as (somewhat) proportional to the density of that hypothetical greenhouse gas within the atmossphere, while y is (somewhat) proportional to the density near the surface of the earth. Why I wrote “somewhat” in brackets is explained below.

The middle of the “plate” is at x=0, y=0 (please hover over the diagram) which is the “realistic” case of the idealized greenhouse model, i.e. the case where infrared absoptivity is 0.78 and the reflectivity of the earth is 0.3. The main point of this visualization is that linearily increasing x and y in the same way leads to an increase of the temperature. Or in other words, although raising x by a certain amount leads to cooling this effect is easily trumped by raising y by the same amount.

As far as I learned from discussions with climate scientists the omission of non-infrared radiation in the climate models was mostly motivated by the fact that an abpsorption of non-infrared is mostly happening in the upper atmossphere (because methane is quickly rising (but there are also circulations)) and thus leading rather to a global cooling effect than a global warming effect and so it in particular doesn’t contribute to global warming. The enhanced simple model here thus confirms that if absorption is taking place in the upper athmossphere then this leads to cooling. The enhanced model however also displays that the contribution of methane that has not risen, i.e. methane that is close to the earth surface, is to warm upon absorption of non-infrared light and that the effect of warming is much stronger than the cooling effect in the upper athmosphere. Unfortunately I can’t say how much stronger for a given amount of methane, since for assessing this one would need to know more about the actual densities (see also discussion below and the comment about circulations). Nonetheless this is a quite disquieting observation.

I had actually exchanged a couple of emails with Gunnar Myrhe, the lead author of this corresponding chapter in the IPCC report, who confirmed that non-infrared light absorption in methane hasn’t sofar been taken into account, but that some people intended to work on the near-infrared absorption. He didn’t know about the UV absorption that I had found e.g. here (unfortunately my email to Keller-Rudek and Moortgat from 2015 whether there is more data for methane especially in the range 170nm-750nm stayed unanswered) and thanked for pointing it out to him. He appeared to be very busy and as drowning in (a lot of administrative) work, so that I fear that those absorption lines still might not have been looked at. That is also why I decided to publish this now. I sent a copy of this post to Gunnar Myrhe, Zong-Liang Yang and John Baez in June 2017, where I pointed out that:

I have strong concerns that the estimations of the global warming potential of methane need to be better assessed and that the new value might eventually be very different then the current one.

– but I got no answer.

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energy prospects

Sunday, February 25th, 2018

Sende-Pentode RS289 from radio technology museum Königs-Wusterhausen

There was again a discussion with randform reader Oekologisch Interessierter about the development of nuclear energy production. The original post was in Oct. 2010 i.e. briefly before the Fukushima disaster in Mar. 2011 and the outlook cited there looked quite differently from what actually happened.

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We will tailor what you want

Thursday, December 28th, 2017


“We will taylor what you want ” Hannah Perner-Wilson explaining the shop concept of her and Mika Satomi’s new shop, the: “KOBA Maßschneiderei”
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galaxy flush reloaded

Wednesday, November 29th, 2017




pan and zoom as usual

In 2006 Tim played around with swarm simulations in processing and ended up with funny flush like settings. We tweaked the parameters in such a way that it ended up looking like and sounding like a galaxy being flushed down the drain and made it into the art work “dipper galaxy flush” where dipper refers to the wellknown patterns in the constellation Ursa Major. Our comment wasn’t though referring to a particular galaxy there but to galaxies in general – which could include our own.

If you look at the processing code you see that Tim’s simulation doesn’t use e.g. Newtonian gravity, although Tim used a force which is similarily “centralizing” as dark matter.

Inspired by discussions about dark matter and dark energy and general relativity at John Baez’ social media I wanted to get a feeling of how important the feature of dark matter is in order to allow for galaxy formation.
The above is a realtime javascript simulation using purely newtonian gravity with no dark matter but two giant masses (indicated by blue circles, which size is not proportional to the smaller circles) and something that could be called an “inelastic binding”. That is if the distance between masses is smaller than some number then those “close-by” masses behave as if they stuck together as in an inelastic collision, or in other words: the velocity of a mass is set to be the weighted average velocity of the close-by masses (details in the code, how much inelastic collision you want is set by the parameter “mix”).

It was acutally not so easy to find a configuration which somewhat mimicks galaxies, but the above looks a bit as if, I find. If I find the time I may add a 3D viewer. Try yourself – the source code is open.
Here how a scientifically advanced galaxy simulation, which includes dark matter looks on a super computer: World’s first realistic simulation of the formation of the Milky Way and here an interview with the author Lucio Mayer. Just like us many other users think it looks like a filmed flush – if you read the comments.
Here another simulation by Fabio Governato on his youtube channel: The Formation of a Milky Way like Galaxy. He has a whole variety of galaxy formation videos.

remark: the simulation is a modification of Mike Bostocks canvas swarm simulation at https://bl.ocks.org/mbostock/2647922

update 1.12.2017: There was a mistake in the addition of the z-speed, which is now corrected in the above version. Luckily the correction did affect the overall appearance only slightly.

ShutterSploshScatterPlots

Friday, September 29th, 2017

Mohammad Ali (mohdali) had made a nice illustration of the socalled rolling shutter effect. He wrote a programm in javascript which uses the library d3 called Rolling shutter.

This program was used by artist Scriptique to program a kind of “paint-by-number recreational occupation for your browser” (as the artist called it). It should display something like “a paint drop dropping”.

The program has a MIT licence and you can see how well your browser paints by numbers by pasting the program into a file and then opening the file in your browser (tested with firefox).

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Sunday Drone

Wednesday, June 7th, 2017

Tim has to cope with an increasing workload, moreover heavy commuting also takes its toll, so he currently doesn’t get too much recreational time – even not on weekends. But over pentecost he now managed to create a nice drone with matching visuals.