The most incomprehensible thing about the world is that it is comprehensible.

- Albert Einstein
7
May
New make of lasers may help us find earth’ish planets (no word on ET)

frequency comb nist exo planetScientists from the University of Konstanz and the National Institute of Standards (NIST) have succeeded in producing a very powerful laser that also produces short pulses at very high speeds (press release here). While this may sound like something that doesn’t really concern us a whole lot (aren’t lasers for DVD players?) it turns out that this could actually have a big impact on finding earth-like planets in orbit of other stars.

To start with let me wow you with some numbers, the laser can produce 40 billion pulses per second and each one of those lasts only 40 femtoseconds, with the average power being 650milliWatts. Those may all be very impressive numbers (and trust me, they are), but let me tell you why this is something to be excited about aside from being the equivalent of porn for engineers. Well it turns out that lasers with these properties, can be used as so-called frequency comb’s, which is more or-less a measuring stick of sorts for light. You can think of this one as having a lot more notches on it and can therefore differentiate between much finer frequencies than it’s predecessors. For a great article on frequency combs, check out an article on NIST’s website, although long, it is not riddled with math and tries to explain it in a way so everyone can follow.

Now i said before that this could help with finding planets, and if you are a regular reader of ReducedMass.com, this may not surprise you. One of the most successful methods of finding exo-planets (planets orbiting other suns) is to detect a slight wobble in the light of a sun that is caused by the gravitational pull of an orbiting planet (Henrik wrote a great article about it a few weeks ago). Obviously, a bigger planet has a stronger pull, causing more severe wobbles that are easier to detect, but small planets, like ours, would make very small pulls on the sun, and therefore require a very precise measurement of light in order to detect it. Current technology does not allow for this, but they claim that this laser just might do the trick.

One thing that made me pause a bit though is the claim that it will improve the accuracy of detection 100-fold, which certainly seems like a tall order. I’m not really basing that on anything scientific (and the fact that the press-release comes from NIST probably means that my concerns are unfounded), but an improvement by two orders of magnitude is not something seen every-day.

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