Land of Gregs

Mobile studio apartment, would suit seven Astronauts

July 24, 2013

My body and I have been having a rather more violent argument with each other than usual, so it has been a while since my last entry. I am going to try and ease myself back into writing these little asides on science news with some information about Boeing and Bigelow Aerospace‘s new capsule for taking crews up to the ISS and Bigelow’s planned expandable space station/bouncy castle.

It’s called the CST-100 (Crew Space Transportation) capsule, and it’s going up against the current method of getting to the ISS, the Russian Soyuz (Union) and the manned version of SpaceX’s Dragon capsule. Like the Dragon, it can seat up to seven, which is four more than the Soyuz and co-incidentally the same number as the shuttle.

CST-100 interior (Image Credit: NASA/Robert Markowitz) Click to enlarge.

From the pictures it does look fairly roomy for a transport capsule, and if you look closely in the window, you can see a little man in a spacesuit. This is only a mockup, so I’m quite sure they’ll find things to fill the space with, and they’ll probably get rid of the little man.

CST-100 with airbags. (Image credit: PDTillman/via Wikipedia). Click for original image/license.

From an engineering point of view, the fact that it performs a dry landing like the Soyuz and the Chinese Shenzhou(Divine Craft) as opposed to the wet landing of the US’s previous capsules is interesting. It uses a parachute to slow it down, then it inflates airbags on its base to cushion the landing. It could work out to a (relatively) soft landing – this capsule is one to watch!

Posted in Space | Tagged been gone so long the internet's sending out search parties, Bigelow Aerospace, Boeing, CST-100, Shenzhou, Soyuz, Space, SpaceX Dragon | Leave a Comment »

Faster to Mars?

April 6, 2013

Another day, another chance at nuclear fusion. A group at the Plasma Dynamics lab at the University of Washington have come up with a variation on the z-pinch version of plasma confinement fusion. In other words, they take some fusible material (usually a light atom like hydrogen/tritium/deuterium and or helium), and then squish it (in this case, using aluminium or lithium ringlets of plasma) until the nuclei of the material fuses together, releasing energy.
The way they’re selling this method is to reduce the amount of time it takes to get to Mars. Using current methods, it takes about 8-9 months each way. The way in which this method achieves fusion also propels plasma out of the fusion chamber, providing thrust. They estimate that by triggering a fusion event once a minute, that thrust would be enough to shorten the trip to Mars to between 1-3 months, which would be much easier on any human crew that might decide to go along.
This summer, they intend to put all the parts of their fusion implementation (which appear to work fine on their own) together, and hopefully it’ll help move humanity forward if it works.

Posted in Space | Tagged fusion, Mars | Leave a Comment »

An intermission

February 23, 2013

As I am in my beginning-of-year sick period, I have not been able to update my blog. To keep you going, here is Chris Hadfield‘s Space Kitchen!

You can follow him and his amazing Canadian moustache on twitter, where he posts wonderful pictures of earth from the ISS.

Posted in Space | Tagged Canadian moustaches, ISS, space food | Leave a Comment »

Do we get to visit the Tyrant of Sogo?

December 20, 2012

More exoplanet news! A quite a bit nearer than the planet from my previous post, Tau Ceti has been found to have five planets. One of those planets is in the habitable zone, which has excited quite a few people. They shouldn’t be breaking out the champagne quite yet though, as I shall explain.
Tau Ceti has a low metallicity. This means that it is mainly made up of hydrogen and helium, which in turn implies that any planets surrounding it are also made up of the lighter elements, in other words they are likely to be gas giants.

Artists impression of our sun on the left, Tau Ceti on the right. (Picture by R.J. Hall from wikipedia. Licence: Creative Commons Attribution-Share Alike 3.0 Unported)

The way we can tell that Tau Ceti has such low metallicity is by measuring the light come off it using a technique called emission spectroscopy. In chemistry lessons at school, you held different elements in a Bunsen burner flame and noted the colour of their flames was different for each element. Emission spectroscopy is a continuation of that, in which the light from a star is separated into its constituent electromagnetic frequencies (think a prism separating a white light into its spectrum), and the elements are classified from those frequencies. The easiest ones to measure using visible light are hydrogen and iron, so a star’s metallicity is usually described as the (logarithmic) ratio of iron to hydrogen, or Fe/H.
This doesn’t mean that there can’t be rocky planets around Tau Ceti, but it does make it a lot less likely. Also Tau Ceti is surrounded by a debris disk – a disk of dust and general bits of not-quite-planets – which would mean any planets would be constantly barraged by impacts.
The important thing, however, is the existence of planets in our local neighbourhood, which means that the universe is a lot more familiar that it appeared at our first glances of it.
The paper is here.

Posted in Space | Tagged debris disk, emission spectroscopy, exoplanet, metalllicty, sneaky Barbarella reference, Tau Ceti | 1 Comment »

Videos!

December 17, 2012

A couple of videos to keep you going while I recuperate.

Here is a 25 minute long tour of the ISS by its outgoing Commander, Sunita Williams.

And, waiting for the the end of the fad, students at NASA have released a Gangnam Style parody, which does show us around the Johnson Space Center.

Posted in Space | Tagged ISS, Johnson Space Center, Sunita Williams | Leave a Comment »

Now they’re hiding the Markov Chains!

December 13, 2012

This is just a quick entry to explain why I haven’t been blogging recently. The simplest explanation is that I had a chest cold. I have a number of conditions that make this rather more serious than for healthy people, but that’s no excuse for not blogging! The real reason is that I use speech recognition when I can’t use my hands. As you can imagine, given the current state of speech recognition, a chest cold is not a good thing for getting a computer to understand you. In fact:
“It can imagine giving them a better holding more than they are getting your computer to the new room and”
was the output of my computer’s speech recognition to the previous sentence with my cold.
Speech recognition typically uses a form of a mathematical model that I have discussed before – the Markov model. In fact it uses a more complicated version of it called a Hidden Markov Model or HMM. This uses a set of Markov nodes(states that have a probability of linked to other states) that are not connected to the input or output (and so are called hidden) to allow the model to have a form of “memory” that simple Markov chains don’t. Thus, they can be used to recognize what is likely to come next while the input is streaming in, and so recognize speech. The trouble is, if the input is really different to what it’s used to, it messes up the probabilities, and you get a sentence a bit like the one above.
Hopefully normal service will resume shortly when either my voice or my hands are more usable. Without voice recognition, even this short entry took a few sessions to complete

Posted in Mathematics | Tagged blogging, cold, Hidden Markov Model, speech recognition, talking rot as usual | Leave a Comment »

TED talks in his sleep

December 7, 2012

You may have heard of TED talks. They are a really good platform for scientists and other specialists to put over their research, especially if it’s groundbreaking. It proved so popular that TED branched out to regional talks, put on around the world and hosted by local institutions, who were given the ability to book the best and brightest in their fields from their local area, under the banner of TEDx. This is where things started falling apart.
Once the vetting was out of the primary organizer’s hands, pseudoscience started creeping in, and it became so bad that people started complaining. I would love to give examples, but unfortunately, I live in the UK and our libel laws tend to beggar people, even if they’re proved right. The majority of the talks were still massively informative, such as Sir Roger Penrose’s cosmology talk (and this talk by my old boss) at TEDxWarwick, but the situation became so bad, that the people at TED have had to produce some new guidelines.
“Excellent!” I hear you cry, and I agreed until I got to this line, about things to watch out for: “The neuroscience of [fill in the blank]”, at which point I became filled with righteous indignation, being a neuroscience bod myself(albeit a mathematical one). Then I typed “The neuroscience of” into Google. By a few pages in, I found myself in complete agreement with the new guidelines. Neuroscience explains a lot of things about physiological responses, but the level of extrapolation required for some of those results, along with a truckload of cognitive dissonance, did wonders for worsening my migraine.
Hopefully this will bring a new era for TEDx talks that echoes the joy of discovery that came with the original launch of TED.

Thanks to Ben Goldacre’s Twitter feed for this news.

Posted in Neuroscience | Tagged pseudoscience, science, TED, TEDx | Leave a Comment »

Curiouser and curiouser

December 3, 2012

So, we finally had the Curiosity rover talk at the American Geophysical Union Fall Meeting, where they outlined what had been found, as I talked about here, and the update here. There were some interesting insights, not least that Martian soil contains water with a very high percentage of deuterium(“heavy” hydrogen, which with oxygen makes “heavy water”), which is hydrogen with a neutron as well a proton in its nucleus (normal hydrogen just has a proton).

Curiosity Rover having a look at some rocks.(Artist’s impression – Credit: NASA)

Deuterium is quite useful as a neutron moderator in nuclear fission reactors, but if we can get nuclear fusion off the ground, it would become far more useful, as it can be used as fuel for both deuterium-tritium fusion and deuterium-deuterium fusion (you can make tritium from heavy water too).
The other news from that talk was that some carbon-chlorine compounds(the slide at 21 mins 17 secs in the talk linked above) were found, which are, strictly speaking organic molecules. The reason NASA are not confirming whether the organic molecules are from Mars is because they’re not quite sure where the carbon came from – was it native to Martian soil, did it come from meteorites or some other form of contamination? This is why they were being rather cagey about their find.
As I’ve said before, this is just the beginning of Curiosity’s mission, so hopefully we’ll get a clearer picture in the days to come.

Posted in Space | Tagged american geophysical union, Curiosity Rover, deuterium on Mars, Mars, NASA, organics, science | Leave a Comment »

I’d better bring my sunhat

November 30, 2012

A followup to my previous blog post. Apparently, the news from Mars that was going to be “one for the history books” was a big misunderstanding between the NASA scientist and the Slate interviewer. NASA have confirmed that they haven’t found organics. What they have found is volcanic sand, the mineral makeup of which has been compared to the sand on the volcano Mauna Kea in Hawaii. This is interesting in itself, but not as exciting as we hoped. We’re still at the beginning of Curiosity’s mission, so we can hope for more news in the future.

MESSENGER approaching Mercury (Credit: NASA)

On the other hand, this news has been trumped by some news from the MESSENGER probe that is orbiting Mercury. This has found not only organics, but ice as well! On a planet that experiences temperatures more than 400 degrees celcius this is surprising, but it appears that the craters offer enough shade. The other interesting thing to note is that the organics are covering the ice, which means they were probably deposited by comets. Their proximity could imply that life may exist under the ice, but there’s not enough information as of yet. This could prove to be an unexpected one for the history books.

Posted in Space | Tagged Curiosity Rover, ice, life, Mars, Mercury, MESSENGER, one for the history books, organics | 1 Comment »

It’s life, pretty much as we know it

November 28, 2012

The results have come in, and life has been found under Lake Vida in Antarctica. Carbon isotope measurements of the surrounding ice show that the life has been separated from the atmosphere and light for around 2,800 years.
Whilst other extremeophiles have been found in places like geothermal vents, at least their means of sustenance is pretty well understood. Lake Vida is very salty and cold, so it’s not clear how they have survived, although they could have gone into a form of suspended animation over the last three millenia. They do look quite chipper for having a snooze, though.
This discovery does, however, expand our understanding of under what conditions life can survive. This comes on the heels of the widening of the Goldilocks Zone – the distance from the sun which would support the kind of life found on Earth. Hopefully, this means that life throughout the universe is more common than once thought, which in turn could bring back a sense of adventure in our exploration of our little bit of space.
The paper is here.

Posted in Space | Tagged Antarctica, geobiology, life, nature, science | Leave a Comment »