Posts Tagged‘mirror’

NASA Gets Crafty: The Glitter Mirror.

Your garden variety telescope is usually what’s called a refracting telescope, one that uses a series of lenses to enlarge far away objects for your viewing pleasure. For backyard astronomy they work quite well, often providing a great view of our nearby celestial objects, however for scientific observations they’re usually not as desirable. Instead most large scientific telescopes use what’s called a reflecting telescope which utilizes a large mirror which then reflects the image onto a sensor for capture. The larger the mirror the bigger and more detailed picture you can capture, however bigger mirrors come with their own challenges especially when you want to launch them into space. Thus researchers are always looking for novel ways to create a mirror and one potential avenue that NASA is pursuing is, put simply, a little fabulous.

NASA Glitter Mirror

One method that many large telescopes use to get around the problem of creating huge mirrors is to use numerous smaller ones. This does introduce some additional complexity, like needing to make sure all the mirrors align properly to produce a coherent image on the sensor, however that does come with some added benefits like being able to eliminate distortions created by the atmosphere. NASA’s new idea takes this to an extreme, replacing the mirror with a cloud of glitter-like particles held in place with lasers. Each of those particles then acts like a tiny mirror, much like their larger counterparts . Then, on the sensor side, software is being developed to turn the resulting kaleidoscope of colours  back into a coherent image.

Compared to traditional mirrors on telescopes, especially space based ones like the Hubble, this has the potential to both significantly reduce weight whilst at the same time dramatically increasing the size of the mirror we can use. The  bigger the mirror the more light that can be captured and analysed and a mirror designed with this cloud of particles could be many times greater than its current counterparts. The current test apparatus (shown above) uses a traditional lens covered in glitter which was used to validate the concept by using 2 simulated “stars” that shone through it. Whilst the current incarnation used multiple exposures and a lot of image processing to create the final image it does show that the concept could work however it requires much more investigation before it can be used for observations.

A potential mission to verify the technology in space would use a small satellite with a prototype cloud, no bigger than a bottle cap in size. This would be primarily aimed at verifying that the cloud could be deployed and manipulated in space as designed and, if that proved successful then they could move on to capturing images. Whilst there doesn’t appear to be a strict timeline for that yet this concept, called Orbiting Rainbows, is part of the NASA Innovative Advanced Concepts program and so research on the idea will likely continue for some time to come. Whether it will result in an actual telescope however is anyone’s guess but such technology does show incredible promise.

The Curiously Limiting Twist for Google Glass Applications.

There’s little doubt that Google’s Project Glass is going to be a disruptive technology, although whether that comes from revolutionizing the way we interface with technology or more because of the social implications will remain to be seen. Considering that the device has been limited to the technically elite and the few that got in on the #ifhadglass competition (disappointingly restricted to US citizens only) we still don’t have much to go on as to how Glass will function as an everyday technology. Sure we’ve got lots of impressions about it but the device is still very much in the nascent stages of adoption and third party development on the platform is only just starting to occur.

Google Glass Up Close

We do have a much better idea of what is actually behind Google Glass though thanks to the device reaching more people outside the annals of the Googleplex. From what I’ve read it’s comparable to a mid range smartphone in terms of features with 16GB of storage, a 5MP camera capable of taking 720p video and a big enough battery to get you through the day with typical usage. This was pretty much expected given Glass’ size and recent development schedule but what’s really interesting isn’t so much the hardware that’s powering everything, it’s the terms with which Google is letting you interface with it.

Third party applications, which make use of the Mirror API, are forbidden from inserting ads into their applications. Not only that they are also forbidden from sending API data, which can be anything from feature usage to device information like location, to third party advertisers. This does not preclude Google from doing that, indeed the language hinges on the term 3rd party, however it does firmly put the kibosh on any application that attempts to recoup development costs through the use of ads or on-selling user data. Now whether or not you’ll be able to recoup costs by using Google’s AdSense platform remains to be seen but it does seem that Google wants to have total control of the platform and any revenue generated on it from day 1 which may or may not be a bad thing, depending on how you view Google.

What got me though was the strict limitation of Glass only talking to web applications. Whilst this still allows Glass to be extended in many ways that we’re only really beginning to think of it still drastically limits the potential of the platform. For instance my idea of pairing it with a MYO to create a gesture interface (for us anti-social types who’d rather not speak at it constantly) is essentially impossible thanks to this limitation, even though the hardware is perfectly capable of syncing with BlueTooth devices. Theoretically it’d still be possible to accomplish some of that whilst still using a web app but it’d very cumbersome and not at all what I had envisioned when I first thought of pairing the two together.

Of course that’s just a current limitation set by Google and with exploits already winding their way around the Internet it’s not unreasonable to expect that such functionality could be unlocked should you want it. There’s also the real possibility that this limitation is only temporary and once Glass hits general availability later this year it’ll become a much more open platform. Honestly I hope Google does open up Glass to native applications as whilst Glass has enormous amounts of potential in its current form the limitations put a hard upper barrier on what can be accomplished, something which competitors could rapidly capitalize on.

Google aren’t a company to ignore the demands of developers and consumers at large though so should native apps become the missing “killer app” for the platform I can’t imagine they’d stave off enabling them for long. Still the current limitations are a little worrying and I hope that they’re only an artefact of Glass being in its nascent form. Time will tell if this is the case however and the day of reckoning will come later this year when Glass finally becomes generally available.

I’ll probably still pick one up regardless, however.

You Thought Hubble Was Awesome? Check out the E-ELT!

There’s no denying the fact that space based telescopes are by far the best instruments for us to observe the universe. They don’t suffer from atmospheric interference, observe targets for incredibly long periods of time and aren’t limited to observing a section of the sky. Of course they come with quite a lot of drawbacks as well often being incredibly expensive to build, launch and operate and unless you’re the Hubble you can forget ever being serviced or repaired, you’re more likely to be ditched in the pacific while your replacement is launched. Still it’s not like ground telescopes are useless by comparison and in the not too distant future our most powerful telescope might just be one located here on terra firma.

That, my friends is a rendering of the European Extremely Large Telescope (E-ELT) an upcoming ground telescope that has just received approval from the European Southern Observatory organisation to go ahead. The tiny car at the bottom of the picture gives you some clue into just how large this particular telescope will be, dwarfing nearly all those that have come before it. House inside that giant building is primary mirror array that is some 39.3 meters across, about half the length of a football field. To put this in perspective Hubble’s main mirror is about 8 meters across or almost 5 times smaller than that of the E-ELT.

Ah, I hear you say, but what about the fact that this one isn’t in space but Hubble is? Well traditionally that was quite a problem for telescopes as there wasn’t a good way to compensate for the changes in the atmosphere leading to blurred or low resolution images. There’s a couple ways to combat this and the usual method was to locate the telescope in a place that had favorable conditions for night time observations. This is usually in high up places so the amount of atmosphere is decreased but places like the Atacama desert, known as the driest place on earth, also provide excellent viewing opportunities almost all year round (320 out of 365 days are cloud free). There’s also a much more advanced way of dealing with atmospheric disturbances and that’s called adaptive optics.

Whilst I referred to the E-ELT as having a 39.3m mirror it is in fact more accurate to say it has a mirror array consisting of 800 individual elements that are all about 1m across. Each of these mirrors can be adjusted independently to compensate for any changes in the above atmosphere. They do this by using a laser to illuminate the sky above them providing a kind of artificial star with a controllable brightness that they can use to adjust the mirror array. Additionally the telescope has a secondary focusing mirror that has over 6000 actuators able to make adjustments 1000 times per second. Combining all of this together means that the E-ELT will have imaging capabilities far surpassing that of any telescope previously and will be the first telescope able to directly image rocky planets like our own orbiting other stars.

It’s that simple fact which has got me so excited about this new telescope. We’ve been able to directly image some planets around other stars in the past but we haven’t been able to get much detail out of them past a bright blob on a black background. The E-ELT will be able to resolve objects with astonishing levels of detail and I’m sure that our hunt for planets like our own will receive a massive boost at the hands of its giant mirror array. It’s projects like this, real envelope pushers, that keep me so excited about the wide vastness of space and how much of it we still have to explore.