Archive for the Talks and Reviews Category

Fuzzy Cosmology at ITP2022

Posted in Biographical, Talks and Reviews, The Universe and Stuff with tags , , , on May 26, 2022 by telescoper

As I usually do when I give a talk (which hasn’t been for a while) I’ve uploaded the slides for the presentation I gave at the Irish Theoretical Physics meeting at DIAS this morning. The title of the talk was Fuzzy Cosmology and the abstract reads:

I discuss some applications of the Schrodinger-Poisson wave-mechanical approach to
cosmological structure formation. The most obvious use of this formalism is to “fuzzy” dark matter,
i.e. dark matter consisting of extremely light particles whose effective de Broglie wavelength is
sufficiently large to be astrophysically relevant, but it can be used to model more general scenarios
and has a number of advantages over standard methods based on Eulerian perturbation theory. I
illustrate the formalism with some calculations for cosmic voids and discuss its application to the
cosmological reconstruction problem(s).

I think it went reasonably well despite there being a hitch at the start because the touchpad on my laptop stopped working. Fortunately I was able to produce an emergency mouse. Anyway, here is a picture of me taken during the talk to prove I was there..

The Time of the Pandemic

Posted in Biographical, Books, Talks and Reviews, Covid-19, Science Politics, Talks and Reviews with tags , , , , on May 11, 2022 by telescoper

I’ve posted before about the way the Covid-19 pandemic has played havoc with my perception of the passage of time and today I’ve experienced another example because I was reminded that it was on this day (11th May) last year that I received my first shot of Covid-19 vaccine.

It’s very hard for me to accept that it was just one year ago that I was waiting in City West to get my injection as it seems in my memory further back than that in my memory. It’s not only how long ago things happened, but also even the sequence of events that has become muddled. I wonder how long it will take to restore any normal sense of these things?

Anyway, I’ve just updated the daily statistics on this blog and although case numbers remain relatively high they do seem to be falling steadily and things do seem to be under control in terms of hospital admissions and deaths. Only 254 people are in hospital with Covid-19 today and the trend is downward.

Maybe the time of the pandemic is drawing to a close?

Further evidence that things may be getting back to normal is that I’m giving the first in-person research talk I’ve done since before the pandemic started at the Irish Theoretical Physics Meeting (ITP22) at the end of this month in Dublin (at the Dublin Institute for Advanced Studies, to be precise). I’m looking forward to giving a talk in the same room as real people. I’m even top of the bill (though only thanks to alphabetical order):

I’ve only got a 30-minute slot so I hope my sense of the passage of time returns at least to the extent that I keep to schedule. My PhD student is travelling to Newcastle next week to give her first ever conference talk at the UK Cosmology Meeting. Hers is a 5-minute talk, which is quite a difficult thing to do well, but I have every confidence it will be excellent.

And talking of research, I see that tomorrow sees the public announcement of the results of the 2021 Research Excellence Framework. Universities have had their results since the start of the week but they are embargoed until tomorrow, no doubt to allow PR people to do their work. I’ll probably post a reaction tomorrow, but for now I’ll just send best wishes to colleagues in the UK – especially in Cardiff and Sussex – who are waiting anxiously hoping for a successful outcome and say that I’m very happy to be here in Ireland, out of the path of that particular bureaucratic juggernaut.

February Storms

Posted in Talks and Reviews, The Universe and Stuff with tags , on February 23, 2022 by telescoper

We’ve had three major storms over the past week (Dudley, Eunice and Franklin). Today I was reminded that precisely five years ago today I was trying to make it from Cardiff to Lincoln to give a lecture, so I thought I’d reblog the post I wrote at the time. It took me nearly all day and I was an hour late, but, you know, the show must go on and so it did.

There’s obviously a thing about February and storms!

In the Dark

What a day!

This morning I set out from Cardiff to travel here to Lincoln for mypublic lecture. I took the9.45 train via Birmingham which, after a change of trains in Nottingham, should have got me into Lincoln at 14.23, with plenty of time to have a look around and chat to people before the scheduled start of my talk at 18.00 hours.

That was the plan, but it omitted an important factor:Storm Doris.Fallen trees, broken down trains and general disorganisation meant that it took ninehours to get to Lincoln, even including getting a taxi from Nottingham because I missed my connection.

The strangest thing was that I never actually saw any particularly bad weather. In fact there was quite a lot of sunshine en route. All the chaos was caused elsewhere, apparently.

Anyway I finally turned up almost an hour late for my talk…

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The State of the Universe Video

Posted in Biographical, Talks and Reviews, The Universe and Stuff, YouTube on June 29, 2021 by telescoper

And now the moment you’ve all been waiting for. Here is a recording of the Invited Colloquium at the International School Daniel Chalonge – Hector de Vega I gave via Zoom on 23rd June 2021, introduced by Prof. Norma Sanchez.

In the talk I give a general review of the current state of cosmology, discussing the standard model of cosmology and some of the possible ways in which it might be revised or extended. It’s not a very technical talk but does assume some knowledge of cosmology. I hope a general audience will get something out of it.

I’m sorry if the recording is a bit choppy but that’s an occupational hazard with Zoom recordings and rather limited broadband!

This is an edited version of the session which in total lasted well over three hours including lengthy discussions and a trip down memory lane at the end. I cut out the introduction but kept a few of the questions and answers at the end, so it’s still rather long despite the rather brutal edits.

A video of the full event can be found here (1.6GB) and a PDF file of the slides can be found here. The slides are also available to be viewed here.

The State of the Universe Slides

Posted in Talks and Reviews, The Universe and Stuff on June 23, 2021 by telescoper

So I have given my talk on the State of the Universe. It’s a bit intimidating giving a talk with Nobel Laureates in the audience, but I think it went OK.

The slides are here:

I’ll add a link to the recording when I have it. Here is a link to the event. The video is very long because of a lengthy introduction and discussion at the end so if I get time I’ll put an edited version of just the talk on my Youtube channel.

In the meantime here’s a picture of me looking weird during the presentation:

The State of the Universe Talk – Reminder

Posted in Biographical, Books, Talks and Reviews, Sport, Talks and Reviews, The Universe and Stuff with tags on June 21, 2021 by telescoper

Just time for a quick reminder that I’m giving a talk on Wednesday (23rd June 2021). It’s at 4pm Paris Time which is 3pm Irish Time. See my original post here.

I had a sudden sense of dread that this Colloquium might clash with the Portugal-France game in the European Championship which takes place the same day but it turns out that won’t kick off until 9pm Paris Time which means that I should just about be finished before the football starts. I don’t think even I could overrun by 4 hours! Indeed I should finish before the earlier games that day, which kick off at 5pm Paris Time…

If you want to attend the Colloquium (via Zoom) you can register for it here.

The State of the Universe Talk

Posted in Biographical, Books, Talks and Reviews, Talks and Reviews, The Universe and Stuff on April 26, 2021 by telescoper

When I saw the calibre of the other speakers in the Chalonge – De Vega Series organized by Norma Sanchez- including a number of Nobel Laureates – it was with some trepidation that I accepted the invitation to give a Colloquium, but there we are. I’m on the list. If you want to attend the Colloquium (via Zoom) you can register for it here. This series was originally named after Daniel Chalonge but was renamed to honour Hector de Vega, who sadly passed away in 2015.

I used to get invited quite often to the famous Norma Sanchez Schools and Conferences in Paris and Sicily (both Erice and Palermo) but then, about a year ago. I was suddenly stopped receiving invitations. I gather that a number of other colleagues have also been abruptly “cancelled” over the years. Anyway it seems I’m back on the list, at least virtually, possibly owing to some form of administrative error.

I remember one year in Erice at the end of a talk I gave (in the OHP/Transparency era) Norma Sanchez, who was meant to be chairing the questions and discussion started writing on my transparencies, crossing out the word “theory” and replacing it with “model”. That event made quite an impression on the audience who thought it was hilarious and people who were there often remind me of it. Coincidentally, I thought of that event when I wrote Saturday’s post. Since the forthcoming colloquium is via Zoom I think I’ll be safe from any such intervention this time.

The Eddington Eclipse Expeditions and Astronomy Ireland

Posted in History, Talks and Reviews, The Universe and Stuff with tags , , , , , , on December 10, 2019 by telescoper

After a full shift during the day at Maynooth University, yesterday evening I made my way into Dublin to give a talk to a very large audience in the famous Schrödinger Lecture Theatre in Trinity College, Dublin, an event organized by Astronomy Ireland. I have given a number of talks on the topic of the 1919 Eclipse Expeditions during this centenary year, but I think this one had the biggest audience! We adjourned to a local pub for a drink afterwards before I dashed off to get the last train back to Maynooth.

Here are the slides I used during the talk:

This time there was an important addition to my usual talk, courtesy of Professor Peter Gallagher of DIAS. He brought along the actual 4″ object glass used in the expedition to Sobral (Brazil) in 1919. I have previously only shown a picture of it. The appearance of the actual lens drew a spontaneous round of applause from the audience, and I have to admit it was a remarkable feeling to hold a little piece of history in my hand!

Obviously I was careful not to drop this item. It is on permanent display in Dunsink Observatory, by the way, if you want to see it yourself. I hope it made its way back here safely!

After the talk was over I was chatting to a couple of members of the audience when Peter Gallagher took this nice picture actually through the lens:

Picture Credit: Peter Gallagher

I look rather old in this picture. Obviously a trick of the lens.

How Ireland Made Einstein Famous

Posted in History, Talks and Reviews, The Universe and Stuff with tags , on December 6, 2019 by telescoper

Before I depart for the weekend I thought I’d mention that I’m giving a talk on Monday evening (9th December) at 8pm in the Physics Building at Trinity College Dublin. The talk is followed by a reception in the Lombard Inn. Part of the advert is shown above but you can read more details at the Astronomy Ireland website.

If you’re around in Dublin on Monday then maybe I’ll see you there!

The Cosmic Web in Maynooth

Posted in Books, Talks and Reviews, Talks and Reviews, The Universe and Stuff with tags , , on November 5, 2019 by telescoper

Next week (10th to 17th November) in Ireland is Science Week and this will be celebrated by a number of events here in Maynooth, among which is a talk by yours truly on 15th November:

Here is a short description:

How can we map the distribution of galaxies over thousands of millions of light years? What does the Universe look like on these scales? How did get to look like that? And how do we know?This talk will explain how astronomers and cosmologists have come together over the past couple of decades to make huge surveys of the Universe, revealing the existence of a complex but beautiful `Cosmic Web’ with vast chains of galaxies strung out around immense dark voids. These observational breakthroughs have been mirrored by advances in theory and computer simulation that allow us to understand how this amazing structure was born 14 billion years ago in the Big Bang and has been growing and evolving ever since. Free and open to TY, 5th and 6th year students, this talk will be of particular interest in those interested astronomy, space, physics and the Universe itself!

It is on in the morning to make it possible for school students to attend and the talk is adapted to this audience, so it won’t be the same as the one I gave in Dublin last week. The timing seems to have worked because the lecture theatre has over 200 seats in it but is already almost full. There are still a few places available so if you’re in the area you can book here.