ISF Talks – Island Universes

I’ve recently finished delivering two public lectures on Galaxies at this year’s Inverness Science Festival.

The theme of my talks was ‘Island Universes’, telling the tale of when and how we discovered our Milky Way isn’t the only galaxy, and how the teeming multitudes of spiral nebulae, hitherto believed to be collapsing dust clouds, were in fact individual galaxies.

The talk started with some observational astronomy, before discussing the great debate of 1920 between Harlow Shapley and Heber Curtis.  The main unresolved issue here was the distance to the spiral nebulae, particularly Andromeda, which was unknown.  This lead us into pulsating stars and the work of Henrietta Swan Leavitt, who systematically analysed and determined the period luminosity law for cepheid variable stars.

Finally we discussed Edwin Hubble and the ramifications of his observations on the red shift of distance galaxies, and how this has informed our current understanding of the history and future dynamics of the universe.

I’ll let some choice slides do the talking from here on.

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Our own galaxy ‘The Milky Way’ is big.  If you tried to travel from our position to the galactic nucleus at the speed of the Voyager spacecraft it would take you over 400 million years.

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A 1900s image of the Andromeda nebula.  Back then the consensus was these spirals were large collapsing dust clouds, a bit like the star forming Orion nebula.  The idea that they could be separate galaxies like our Milky Way seemed inconceivable, yet that’s where the evidence eventually lead in the 1920s.

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Determining the distance to spiral nebulae (as they were known pre 1900) required a new way of determining distance from so-called ‘standard candles’.  Leavitt’s law was invaluable when Hubble turned his attention to Andromeda in 1922.

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Hubble discovered the galaxies were all rushing away from us.  However this phenomena is actually a metric expansion of space itself, and therefore has no intrinsic centre.  Some of the most distant galaxies are receding away at faster than the speed of light – again due to the expansion of space itself, which has no speed limit imposed.

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There were lots of questions on M87, the giant elliptical galaxy whose black hole was recently imaged by the Event Horizon telescope.

Q&As are always lively after astronomy and space talks, and the younger audience members always surprise me with their amazing knowledge and frank curiosity.  Some choice sample from the two evenings below.  Answers on a postcard please .

1. Is the singularity at the end of a black hole the size of the Planck length?

2. If a giant hole suddenly appeared in the Earth how many Pluto’s could you fit inside it?

3. Do supermassive black holes continue to grow until they devour the host galaxy?

Star Stories – Glasgow Science Centre On Tour Special

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As part of the Star Stories programme up at Abriachan Forest we’ve invited the On Tour outreach team at Glasgow Science Centre to kickstart our daytime events on April 27th.

The GSC team will deliver indoor stargazing activities as well as meteorite handling, and comet and crater making. They’ll also be bringing a sample of their interactive science exhibits.

If you’d like to attend please book via the eventbrite link here and also look out for more astronomy events over the brighter months.  We have plans to purchase a Hydrogen alpha telescope in the next few weeks which will form the basis for some outdoor solar events.  Follow this blog or keep tabs on my facebook page for developments.

There’s still a few tickets left for the last dark sky observing session in March available here.

Upcoming Astronomy Outreach

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Here’s an updated list of events I’ll be hosting with Abriachan Forest, the Merkinch Nature Reserve in Inverness and others.  Tickets can be picked up via eventbrite (linked) or email contact.  Please follow the links below.

Saturday February 9th – Star Stories Aurora special with special guest Graham Bradshaw of Graham Bradshaw Photography.  Almost sold out, only a couple of adult and child tickets left.  Eventbrite link here.

Saturday 9th March – Star Stories Dark Sky Observing.  70% of tickets already allocated for this one.  Eventbrite link here.

Thursday February 28th – Stargazing and Guide to Deep Sky Observing at the Inverness Sea Cadet Hall and in partnership with the Merkinch Nature Reserve.  Event details here.

Thursday 28th March – The Life of Stars at the Inverness Sea Cadet Hall and in partnership with the Merkinch Nature Reserve.   Event details to be added.

I’ll also be involved in outreach at some festivals this year.  So far I can confirm my attendance at SCAPA Festival at Loch Fyne on the 3rd to 5th May  Details on the festival and booking info here.

 

Merkinch Astronomy Outreach – Beginners Guide to Observing

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Gazing Moonward from the grounds of the Sea Cadets Hall, Inverness

We had a very successful Merkinch astronomy evening last Thursday, the second I’ve hosted from our new base at the Sea Cadets Hall on Kessock Road.  All available tickets were allocated in advance and we had a healthy gathering of over 50 people in the end, along with some of the sea cadets.  Caroline had also secured a large consignment of 8×40 binoculars for this and future events, which we put to good use later in the evening.

I kicked proceedings off with a projector based talk on buying a first telescope, offering some recommendations for good beginner scopes that won’t break the bank.  Afterwards, we headed out into the carpark beside the hall for some projections of the Moon.  Despite high cirrus clouds the Moon was still very clear and we had workable views via video telescope, allowing us to discuss the infinitely enthralling topic of lunar geology.

A few stars popped out later on but not enough to warrant a walk over to the nature reserve – which was the original plan if skies were clearer.

The next event takes place on February 28th when I’ll discuss deep sky observing – including star clusters, nebulae, galaxies and supernova remnants – how to observe them and some of the incredible astrophysics behind them.  Links to this event here.

Winter Solstice Astronomy Outreach

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A captivating Clelland in full swing over the fire

Following the fantastic summer solstice  gathering last June we decided to add an astronomy themed winter solstice event to the Star Stories programme up at Abriachan.

Instead of stargazing the event was billed as a ‘Solstice and Moon night’, as I quickly realised the almost full Moon would be prominent in the sky and wash away significant views of the Milky Way and fainter galaxies and clusters.

As it was the evening was a fantastic success, with a bright mid winter Moon powering through some scattered light clouds and offering us lovely views of its surface via binoculars and video telescope.

 

 

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Before the Moon observing I presented a short indoor talk on the cultural and observational significance of the solstice, linking in various older mid winter traditions such as Saturnalia and Yuletide and outlining the folk connections with modern Christmas.

We also examined the importance of mid winter markers for the ancient settlers of high northern latitudes, where pitifully short days and long winters no doubt motivated a collective and religious celebration of the ‘turning point’ of the Sun’s midday altitude and its rising and setting points.  We followed this with a look at various solar aligned prehistoric monuments like Stonehenge and, much closer to home, the wonderful Clava Cairns which I visited recently with my family on Christmas Eve.

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Presenting my solstice talk before we stepped outside to observe the Moon

After the talk we moved outside to observe the Moon in binoculars and video telescope, with the aid of an outdoor projector and screen I had setup earlier.  The giant screen allowed everyone to see some of the striking features on the lunar surface up close and personal, like Tycho’s crater, the Apennine Mountains and various seas including the famous Sea of Tranquility where the first Apollo astronauts landed.

Meanwhile, Clelland took the second group into the forest for some dramatic campfire storytelling.  This evening he told a solstice inspired Celtic tale involving the mythological hero figure King Arthur, who some think may be connected with Welsh folk legend.  Participants also gathered up and tied together clumps of herbs to burn in the fire as they made new year wishes, another old winter tradition practiced in the Highlands and further afield.

 

 

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Feedback on this one has been great and we may well followup with a March Equinox event.  We’re also seeing many returning families and enthusiastic youngsters, which is fantastic.  Going forward Suzann and I will endeavour to capture some film interviews from some of the keenest young astronomers, recording their thoughts and feedback on their learning experience for future dissemination.

All pictures in this piece (aside from the Moon picture) are courtesy Abriachan Forest Trust.