Bacteria being naughty

 

This is nothing more than a pre-weekend, "isn't that interesting", eye-candy, filler post. It is a video I saw about a month ago that shows flashing bacteria.

Basically it shows bacteria that spontaneously flash (hence why they're being naughty... oh nevermind). Here is an article that explains what they're doing in more depth.  When on their own, this flashing is mostly random. In fact, even when they are in small bunches they appear to flash randomly. However, when in large packs they all flash in unison.

I suppose it is somewhat aesthetically pleasing just on its own, but the thing that drew my attention was how fascinating it was that the individual bacteria behaved differently when a part of a large collection as opposed to when on their own. It appears groupthink exists even at the microscopic level of life.

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What does the sound of the Big Bang look like?

Six weeks ago I wrote a post where I tried to explain how we know that the Big Bang definitely happened. There are of course other reasons why we know the Big Bang happened, but I decided to focus on one, relatively easily explained piece of evidence, which is the existence and frequency spectrum of the Cosmic Microwave Background (CMB).

Quickly summarising: The CMB is very cold radiation that permeates the entire universe. It was created when the expanding and cooling universe cooled to a point where it was cold enough for hydrogen atoms to form. Before this point, the electrons and protons in hydrogen had enough energy to be free from each other to form an opaque plasma. Once neutral hydrogen formed the universe became transparent and the CMB was formed and travelled (almost) freely forever after. We have detected and measured this CMB and its intensity as a function of its frequency (effectively, the brightness of each colour) is exactly what the Big Bang predicted. If there was no Big Bang there would be no reason to expect a CMB to exist, let alone for it to have this particular property. For more details please read my previous post and the links within.

When writing that post I had intended to say quite a bit more about the CMB and the Big Bang than I ended up having space for. It is not quite true that the mere existence (and spectrum) of the CMB is enough to conclusively determine that the Big Bang must have happened. However the existence of the CMB did build the metaphorical equivalent of a thousand big, bold and bright neon signs that all pointed aggressively towards the Big Bang being true.

When I began writing that earlier post and claimed that the CMB does conclusively prove that the Big Bang happened I had in my mind what I actually discuss in this post. This is the fact that we can see in the CMB the effects of sound waves that existed in the primordial hydrogen plasma. It is these sound waves and our measurements of them that puts the final nail in the coffin of all things not the Big Bang. They also represent what I claimed in that earlier post to be “jaw-droppingly stunning pieces of detective work”.

The glorious Planck satellite, measurer of all things CMB

Poetrees

This is something I saw on the internet that was kind of nice. It seems that the Scottish Poetry Library in Edinburgh is haunted by a mysterious artist. The artist takes books (not library books, thankfully!), turns them into sculptures and then surreptitiously places them in the library. A more thorough story on the sculptor is here (though not the identity).

Chris Scott/flickr

The library itself named the first work, a poetree... so don't blame me for the title of the post. The image above is a movie theatre with the characters leaping out of the screen and challenging the audience (a different angle below).

Chris Scott/flickr

There are lots of other equally nice sculptures, such as the original poetree, as well as a pleasant detective mystery to go with the missing identity of the surreptitious sculpture. All can be seen at the news article, so why not go read it?

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Leonardo: A Painter at the Court of Milan, for the Twenty-First Century

Study of Arms and Hands, c. 1474

Study of a Woman, c. 1490

Earlier this month, one of those once-in-a-lifetime exhibitions opened in London: Leonardo da Vinci: Painter at the Court of Milan. It runs at the National Gallery until early February.

This isn't a review, since I haven't seen the show. But it amazes me that an exhibition like this exists, so consider this another 'live stream' post—a placeholder for reflections and mullings on and around Leonardo's unbelievable images, with some suggestions about why we are seeing more of this work; and subject to being updated with new links, reviews and so on.

To state the obvious, it isn't easy to put together an exhibition like this. In fact there has never been, and will never be, a 'complete' Leonardo retrospective in the manner of a Picasso, a Judd, or a Richter survey—those big, bulky exhibitions that cover the full range of a capacious individual's oeuvre, and of which one can say, with a certain admiration, "I am large, I contain multitudes." These kinds of shows are necessarily overwhelming because they cover a multifaceted life. But in this case the reasons are practical: some of these fifteenth- and sixteenth-century frescoes are site-specific (painted directly on a wall), and they are universally under bureaucratic lock and key: all Leonardo's work, from the most magnificent painting to the quickest, most fleeting of drawings are owed by institutions and individuals (and the Royal Family). So the problems of red tape for any curator contemplating this kind of mountainous show is unimaginable.

Studies of Water passing Obstacles and falling, c. 1508-9

Real time World War II

[Edit: the url to follow this twitter account is this one, https://twitter.com/#!/RealTimeWWII. You don't need your own twitter account to read the page. Also, I somehow convinced myself that yesterday (when I wrote this post) was the 29th, when it was actually the 28th. The Winter War starts on the 30th.]

There is a twitter account that tweets as if it is a news agency reporting World War II live (@RealTimeWW2). I find this account fascinating and have been following it now for more than a month.

The depth and the breadth of what this account adds to one's understanding of the war is actually quite large, so I can only touch the surface in this post. The first thing I noticed was how this method of telling the story of WWII really gives you a much more accurate sense of the timescales involved than you get from reading a history book. Six years is a long time. I discovered the account a few days into the initial German invasion of Poland; Britain and France soon declared war and yet no military action has taken place between any of these nations, apart from a few skirmishes at sea.

It would be foolish to interpret this as somehow making the war boring. Though, in fact, contemporary Britain did make this mistake. There are regular tweets describing British behaviour that makes it obvious why the name they gave this part of the war was the “Phoney War”.

“German pilot who fought off 3 planes to let his crew escape is guest of honour tonight at an RAF dinner in France. Off to POW camp tomorrow”

However, it can be assured that from the perspective of the Poles, the Czechs and the Jews in occupied Germany, this war has been far from phoney so far.

“New German decree: 'Aryans' married to Jews have been given 1 year to divorce their Jewish husband/wife or 'face the consequences'.”

"Occupied Poland: New decree orders all Jews in Krakow to wear an armband with a blue Star of David, as seen being sold: http://pic.twitter.com/GUOdpg8o"

I have toyed with writing a post about this account for a while and decided sometime ago that today would be the day I write the post. Today is the eve of the second major event of The War. That is, the Winter War between Finland and The Soviet Union. Tweets that have gone out in the last 48 hours are ominous and frightening:

“The USSR has renounced its non-aggression treaty with Finland due to "hostile actions"; Moscow radio reports 3 more incidents on border”

The “incidents” were of course incidents that were faked by Soviets on their own outposts to justify military action. By doing such acts their aggression is made more morally ambiguous and their own populace can be made much more supportive of any action.

"Nature, red in tooth and claw." and blue, and green, and yellow, and...

The picture above is a 'brainbow' created by a lab in Harvard - it is a fluorescent microscopy image of the hippocampus of a mouse genetically engineered to express three fluorescent proteins. Depending on how the genes of the individual neurones are randomly recombined, each cell will express a different combination of the three proteins, giving each a unique colour! I love the beauty of the resultant image, and it is a great example of the meeting of scientific and aesthetic research that is becoming more and more widespread. Another example is given below - natural fireworks revealed by labelling actin microtubules in dividing cells. These pictures and plenty of others are available in an online exhibition run by the journal Cell at the Cell Picture Show. The images are incredible and there are explanations of what's being shown for those without a biology background - well worth a visit!

Image rights belong to Cell and the original creators.

Adaptive by name, adaptive by nature - your immune system the tactical genius!

The previous post in this series can be found here.

In my last post I described how the adaptive branch of the immune system is the real player when it comes to fighting infection. In this post I hope to give you some idea of just how sophisticated a tactical machine this system is.

The battle plan

As any good general knows, not all enemies can be fought in the same way. History is littered with examples of mighty empires who were stopped in their tracks by relatively small opponents who simply fought in a way that they were not used to and couldn’t adapt to. The wars that are being fought inside you right now are no different, and require your battle strategies to be adaptive if they are to keep you alive.

Pathogens come in all shapes and sizes. They can be viruses that highjack your cells’ own replicating machinery to make more of themselves; intracellular bacteria that smuggle themselves into your cells and devour them from the inside; extracellular bacteria that float around in the blood or other fluids and generally make a nuisance of themselves; or they can even be multicellular parasites that can be big enough to see, such as tapeworms or the Plamodia that cause malaria. The fact that they all have different molecular components is not a problem since, as discussed in my last post, your B and T cells all have different antigen recognition receptors, and so you’ve most likely got one somewhere that can recognise whatever’s invading you. However, deploying those B and T cells in the most effective way possible is the tough task that awaits your immune system when a pathogen first invades you. A strategy must be devised and honed to the specific weakness of the enemy – but how is this achieved?