Monday, January 21, 2013

Lasers: Star Trek's tractor beam tugs particles in the real world

Discovery News and others (especially Czech media) didn't overlook an interesting experiment in the Czech Republic – the Institute of Scientific Instruments of the Czech Academy of Sciences in Brno, the country's second largest city (team led by Dr Pavel Zemánek) – that has made some Star Trek dreams come true. It works like this:

You just pick a laser, press a button, and you may transfer your armchair (or a spaceship such as the International Space Station) from one corner of your room to another. It's handy, especially for armchair physicists.

Well, so far, they can do such things with microorganisms and similar objects, not with spaceships and armchairs.

It's interesting that the beam isn't "pushing" the objects by the photons' momentum: it is "tugging" them which was pointed out to be theoretically possible in some recent papers. The new experimental results were reported in Nature Photonics yesterday:
Experimental demonstration of optical transport, sorting and self-arrangement using a ‘tractor beam’
Read the abstract, it's pretty neat.

They claim that the cells may be moved by micrometers and under the beam, they spontaneously sort and rearrange themselves into interesting geometric patterns. Moreover, these patterns move in the opposite direction than the building blocks they are composed of. This behavior of the tractor beam is likely to be used to organize cells in biology very soon because the experimental infrastructure seems to be very cheap and undemanding.

Incidentally, Intel plans to upgrade Stephen Hawking to a state-of-the-art bioelectronic device capable of speaking 10 words a minute and other virtues.


  1. Hmm, it's called Brownian motion (just joking).

  2. Offtopic.

    Have You noticed how low voter activity areas of the recent presidential election match Sudetenland? What's a reason for that, in Your opinion?

  3. Yes, I found it myself. Well, You're Czech and ought to know better than me. My first guess would be that the people there feel themselves not as natives but to the some extent alien and therefore become detached from societal activities.

  4. Right, you're just describing the same data in nearly equivalent words.

    But why don't they feel as natives? They're mostly ancestors of regular Czechs who have either lived there even before the war; or who moved there in the late 1940s or 1950s from the interior of Czechia. Why would any thing of this kind – at most, moving from one place of Czechia to another – affect whether they feel as natives?

    Note that these areas are also typically higher-unemployment rate areas, although the correlation is arguably weaker than yours. They're remaining higher-unemployment areas because many job creators were expelled after the war and much of business had to be built from scratch and/or overtaken by commies who had much more remote relationship to the businesses.

    One may say many things that are true but I don't understand why those things would manifest themselves in the lack of desire to vote.