Pop Science

This week I acquired a copy of Steven Weinberg’s 1977 book The First Three Minutescourtesy of an emeritus colleague downsizing his library. It was the first detailed popularisation of the Big Bang and is a pop sci classic, written by one of the leading theoretical physicists of the modern era.  

An absolute classic, even if this copy has seen better days. 

An absolute classic, even if this copy has seen better days. 

As you can guess from the title, The First Three Minutes tells the story of the moments following the Big Bang. The early universe sets the stage for the development of the cosmos we see around us now, and the Cosmic Microwave Background is a key link between the distant past and the present day.  Discovered just a dozen years before the book appeared in 1977, the microwave background is a a time capsule buried moments after the Big Bang, and Weinberg explains how it reveals the nature of the infant universe 

And, as it happens, the latest addition to my library fell open to reveal these words:

Page 77

Page 77

This text is almost a time capsule on its own. In 1992 CoBE made headlines by providing a map of the microwave background sensitive enough to reveal minute variations in the temperature of different regions of the sky. In 2006, Mather shared the Nobel prize for his work on CoBE. Meanwhile, Rai Weiss moved on from CoBE to become a founder of LIGO which earned its own place in history by successfully detecting gravitational waves in 2015.

Bon voyage indeed. 

CODA: And it goes without staying that Weiss is an odds-on favourite to get the call from Stockholm a few weeks from now when this year’s prizes are announced.  

CODA 2: And indeed Weiss did win the 2017 prize, along with Barish and Thorne.  

IMAGE: The header image shows the temperature differences across the sky, as measured by the CoBE satellite. The temperature range corresponds to changes of a few parts in 100,000. 

Up, Up and Away…

Last night my twitter feed carried a string of “what’s that in the western sky” queries, including this picture from Rachael King @rachaelking70

Balloon in the Christchurch sky...

Balloon in the Christchurch sky…

There’s a clear disk showing in this snapshot, so we can immediately rule out “Venus”, a standard explanation for bright lights in the sky. (And, for good measure, Venus is currently only visible in the pre-dawn hours.)

“Weather balloon” is the next usual suspect for purported UFOs, and they are indeed far more common than flying objects with less terrestrial origins.

In this case, I knew that NASA was launching a high-altitude research balloon this week from Wanaka in the South Island, and a quick google revealed that they had succeeded after a string of aborted attempts. And this balloon is a monster, making it particularly easy to see. Meteorological balloons range in size from “large garbage bag” to “small house”, but this bad boy is closer to a flying football stadium – including the stands. 

Once we knew what it was, the next question on Twitter was “what is it doing?” The answer of course is “science“.

Balloon science is an often-neglected, older cousin of rocket science and NASA’s primary goal with this launch is to test a better balloon. Their aim is to produce balloons that can spend 100+ days aloft, providing experimental platforms on the edge of space that cost far less than an orbital mission (and with a decent shot at getting your payload back with a soft-landing rather than a fiery re-entry). 

This year’s mission carries a scientific payload since, if you are testing a giant balloon, why waste the chance to put it to work? Slung beneath the balloon is EUSO-SPB, the Extreme Universe Space Observatory on a Super Pressure Balloon, a project managed by the University of Chicago with Professor Angela Olinto as Principal Investigator.

The experiment is searching for the most powerful cosmic rays in the universe – charged particles that have been accelerated to within a hairsbreadth of the speed of light. To find them, the telescope looks down rather than up. These rare particles slam into the earth’s atmosphere, leaving glowing ultraviolet tracks in the air beneath the balloon which are caught and analysed by high speed cameras.

A more sophisticated version of the experiment will fly on the International Space Station. These exceptionally rare high-energy cosmic rays are catnip for astrophysicists – they are fascinating in their own right, and might well start their journeys towards us from the vicinity of the supermassive black holes at the centres of “active galaxies”, some of the most extreme objects in the universe. 

ANZAC poppy aboard balloon; Image: NASA

ANZAC poppy aboard balloon; Image: NASA

And because it launched on ANZAC Day the balloon carried a poppy aloft along with its scientific payload. So it turns out that as Christchurch residents watched an unexpected bright light rising in the western sky “at the going down of the sun“, they were also and unwittingly gazing at a small memorial for those who had fallen in the service of their country.

 CODA: Video of the launch (mis-captioned as a weather balloon!)

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