The Orion capsule at the head of Nasa's Delta IV rocket as it launched today. Image: Screenshot of Nasa live feed
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Orion, Nasa's next-gen Mars rocket, launches on first successful test flight

Major milestone passed as part of ongoing plan to land humans on Mars by 2030.

After being delayed for 24 hours by high wind speeds (and, at one point, a boat sailing beneath its intended flight path), a Delta IV rocket launched from Nasa's Cape Canaveral base in Florida today with an empty Orion capsule aboard. The mission - Exploration Flight Test One (EFT-1) - is the first major test of many more to come, as Nasa continues towards landing a human crew on Mars in 2030.

The Orion capsule represents the next generation of manned space flight from Nasa, which retired its Space Shuttle in 2011. Its design is similar to that of the famous Apollo missions - it sits above a large rocket, which burn through its fuel and falls away in stages until it deposits the capsule itself into orbit. It will spend 4.5 hours in space, loaded with sensors and ballast to mimic the weight of the astronauts and equipment that a future manned mission may carry, but the mission for today is to simply survive two orbits of Earth, one of which will loop up through the Van Allen Belt with a peak altitude of nearly 6,000km, and back again for splashdown in the Pacific Ocean.

Getting through the Van Allen Belt safely is one of the mission's main objectives. It's the band of radiation - from the solar wind and from cosmic rays - trapped by the Earth's magnetic field, like iron filings scattered on a piece of paper lying on top of a bar magnet, and it poses a huge risk to any craft which sails through it, from satellites to rockets and everything in between. The sensors aboard Orion will be hoping to find that the radiation shielding on the capsule works as planned to protect both all of its electronic instruments and any future travellers aboard.

The data from today's mission will go towards the next one, planned for three years from now. By then, Orion will be carried by Nasa's next-generation rocket: the Space Launch System, a rocket even more powerful than the Delta IV (which is itself about ten years old, and insufficient for the kinds of missions Nasa's planning for). The Delta IV manages 700,000 lbs of thrust; the SLS will manage as much as ten times that, while being capable of lifting a payload of more than 130 tonnes to low-Earth orbit compared to the Delta IV's 26 tonnes.

The return to a capsule and rocket system instead of a reusable shuttle is for a good reason - we know it works in getting human crews to other worlds, and the modules can withstand much higher speeds on re-entry into the atmosphere when returning. And the similarities between Orion and the SLS to the Apollo spacecraft and its Saturn V lifter go beyond the practical, since this system is being designed to give Nasa the ability to take humans beyond mere low-Earth orbit and on to other worlds for years to come. An eventual mission to Mars in 2030 - landing a crew and then returning them, unlike some of the more outlandish colonisation schemes currently being hatched - will only happen if the other steps along the way go smoothly.

That means getting some humans safely into orbit and back again on a test flight sometime around 2021, and also achieving other goals throughout the course of the decade. That includes another Moon landing, a mission to intercept an asteroid as it passes Earth and study it, and even a mission to one of Mars' moons Phobos and Deimos. These missions will be taking place in conjunction with other unmanned ones, like the rover planned as the successor to Curiosity that will land on Mars in 2020 - it'll be able to test some of the technologies that, it's hoped, will ensure that astronauts who land there will be able to survive and return safely.

All of that is in the future, however, and thus contingent on the United States government still giving a damn about space exploration enough over the course of the next decade and a half. Space exploration is prestigious, but doing it with humans is extraordinarily expensive - and our ability to study the Solar System with robots has come on in leaps and bounds since Apollo. We no longer have to put humans inside spaceships because we can't make computers as smart as human brains, as small as human brains. Who knows if putting humans inside Orion will look a boondoggle or not to the scientists, or public, of 2030?

Ian Steadman is a staff science and technology writer at the New Statesman. He is on Twitter as @iansteadman.

Alan Schulz
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An Amazonian tribe is challenging scientific assumptions about our musical preferences

The Tsimane’ – a population of people in a rural village in Bolivia – are overturning scientists' understanding of why humans prefer consonant sounds over dissonant ones.

It was 29 May 1913. Hoards of Parisians packed out the newly-opened Théâtre des Champs-Élysées. Messrs Proust, Picasso and Debussy were in attendance. Billed for the evening was the premiere of Le Sacre du PrintempsThe Rite of Spring, a ballet and orchestral work debuted by Russian composer Igor Stravinsky.

The attention and conjecture focused on the theatre that day meant expectations were high. However, within moments of the piece beginning, all preconceived notions held by the audience were shattered, as what was unfolding in front of them was a musical tragedy unlike anything they had ever witnessed.

A bassoon hummed into the ether before ballet dancers stomped on stage; the music, unpredictable with its experimental edge, drove forth the onstage narrative of a young girl whose selection during a pagan ritual saw her sacrificially dance towards death. Stravinsky’s composition and the ensemble of the night caused the room to descend from laughter and disruption to chaos and uproar.

The employment of dissonance – sharp, unstable chords – largely contributed to the audience’s disturbed reaction. Dissonant chords create a tension, one which seeks to be resolved by transitioning to a consonant chord – for example an octave or perfect fifth. These musical intervals sound far calmer than the chords which riveted the audience of The Rite of Spring.

Dissonant and consonant intervals find themselves as binary opposites; the frequencies at which notes played together vibrate determine whether an interval is consonant or dissonant. Consonant intervals have simple mathematical relationships between them, but greater digression from that simplicity makes an interval increasingly dissonant.

It’s long been believed  both experimentally and anecdotally – that the preference among Westerners for consonant chords highlights a universal, perhaps biologically-rooted, leaning among all humans towards consonant sounds. If you were present at the introduction of Stravinsky’s The Rite of Spring on that night of furore in Paris, you’d find it hard to disagree.

There is, however, a growing movement against this consensus. Ethnomusicologists and composers alike argue that favouring consonance may just be a phenomenon that has evolved from Western musical culture. And following the visit of a group of researchers to a remote Amazonian society, these claims could well be grounded in scientific evidence.

Led by Josh McDermott, an MIT researcher who studies how people hear, the group travelled to a village in the Amazon rainforest called Santa Maria. It’s populated by the Tsimane’ – a group of native Amazonians whose rural abode is inaccessible by road and foot, and can be reached only by canoe. There are no televisions in Santa Maria and its inhabitants have little access to radio, meaning exposure to Western cultural influences is minimal.

The researchers were curious to see how the Tsimane’ would respond to music, in order to determine whether they too had a preference for consonant sounds over dissonant ones. To everyone’s surprise, the Tsimane’ showed no preference for consonance; the two different sounds, to the Tsimane’ at least, were equally pleasant.

Detailing their research in a paper published by Nature, the group explains how the Tsimane’ people’s indifference to dissonance is a product of their distance from Western culture and music, removing any purported notion that humans are hard-wired to praise perfect fifths and fourths.

McDermott tells me that the Western preference for consonance may just be based on familiarity. “The music we hear typically has more consonant chords than dissonant chords, and we may like what we are most exposed to,” he says. “Another possibility is that we are conditioned by all the instances in which we hear consonant and dissonant chords when something good or bad is happening, for example in films and on TV. Music is so ubiquitous in modern entertainment that I think this could be a huge effect. But it could also be mere exposure.”

To fully gauge the Tsimane’ responses to the music, 64 participants, listening via headphones, were asked to rate the pleasantness of chords composed of synthetic tones, and chords composed of recorded notes sung by a vocalist. At a later date, another 50 took part in the experiment. They had their responses compared to Bolivian residents in a town called San Borja, the capital city La Paz, and residents in the United States – locations selected based on their varying exposures to Western music.

What made the Tsimane’ particularly interesting to McDermott and his group was the absence of harmony, polyphony and group performances in their music. It was something the researchers initially thought may prevent an aesthetic response from forming, but the worry was quickly diminished given the Tsimane’ participants’ measure of pleasantness on the four-point scale they were provided.

Unsurprisingly, the US residents showed a strong preference for consonance – an expected preference given the overrunning of Western music with consonant chords. Meanwhile, the San Borja and La Paz residents demonstrated inclinations towards consonant sounds similar to the US residents. The implication of these results – that consonance preferences are absent in cultures “sufficiently isolated” from Western music – are huge. We most probably aren’t as polarised by consonance and dissonance as we assume; cultural prevalence is far more likely to have shaped the consonant-dominant sounds of Western music.

McDermott raised the question about why Western music may feature certain intervals over others to begin with:

“One possibility is that biology and physics conspire to make conventionally consonant and dissonant chords easy to distinguish, and so that distinction becomes a natural one on which to set up an aesthetic contrast even if the preference is not obligatory. We have a little evidence for this in that the Tsimane' could discriminate harmonic from inharmonic frequencies, which we believe form the basis of the Western consonance/dissonance distinction, even though they did not prefer harmonic to inharmonic frequencies.”

There has been some criticism of this. Speaking to The Atlantic, Daniel Bowling from the University of Vienna said:

“The claim that the human perception of tonal beauty is free from biological constraint on the basis of a lack of full-blown Western consonance preferences in one Amazonian tribe is misleading.”

Though the results from the Amazonian tribe demonstrate a complete refutation of previous assumptions, people's musical preferences from other cultures and places will need to be analysed to cement the idea.

With research beginning to expand beyond WEIRD people – those from a Western, Educated, Industrialised, Rich and Democratic background – the tastes in music of people the world over may continue to surprise, just as the Tsimane’ did.

The Rite of Spring, which was met with ridiculing reviews has now been canonised and is considered to be one of the most important pieces of music of the twentieth century. A Tsimane’ crowd on that tender night a century ago in Paris may have responded with instant praise and elation. With further research, the imagined Bolivian adoration of a Russian composer’s piece in the French city of love may prove music to be the universal language after all.