## Earth Not Swallowed!

So, here we are. Still in existence. Hurrah!

The Large Hadron Collider (image right is courtesy of CERN) started a new phase of experimental work today, colliding particles at double the energy it was working at a few years back when the Higgs was discovered. By time I was making breakfast and checking email, their live blog, etc., this morning, it was clear that (contrary to fears expressed by some) the LHC had not created a black hole that swallowed the earth, nor had it created some sort of strange chunk of new vacuum that condensed that of the entire universe into a new phase. (Or if it did either of those things, the effects are hardly noticeable!!)

As I keep emphasising (actually I’ll be talking about this to a puppet character on a TV show tomorrow too – details later) the LHC (or any of the particle collision experiments we’ve ever done) is not doing anything that Nature does not do routinely right here at earth (and most times way more violently and […] Click to continue reading this post

## Has Hubble found the Culprit?

Recall that some years ago the Hubble telescope found a rude message in the sky:

It is said that many were offended by this sign. Some even thought it may have been left by their God as a sort of crude final message for those seeking meaning in the skies. Other, perhaps less imaginative people just figured it’s a random combination of shapes people are projecting onto.

Well, after much more searching through the sky for the perpetrator of the crime, it seems that the Hubble instrument may have caught a suspect on camera:

Of course, until the entity is brought in for questioning, it should be granted the presumption of innocence. (And even if it was its hand, it may have all been a big celestial misunderstanding…)

-cvj

P.S. The first NASA/ESA Hubble image is from a detail of gas clouds in the Carina nebula, and more can be found out about it here.

In the second NASA/ESA Hubble image the arcs of a circle that form the “head” shape are actually a gravitational lensing effect. 100 years ago this year Einstein published his General Relativity which shows, among other things, […] Click to continue reading this post

## Sometimes there is Smoke without Fire

…Or at least, not always the fire you’re looking for. So, as suspected for several months now, the signal seen by BICEP2 experiment and dubbed “a smoking gun” type of direct evidence for cosmic inflation (for which we have lots of strongly suggestive indirect evidence, by the way) is likely an artefact of the effects of galactic dust. I spoke about this in a post a while back, so I won’t repeat myself here. What everyone has been waiting for has been the results of a joint analysis between the BICEP2 people and the ESA’s Planck mission. The Planck satellite, you may recall from reading here or elsewhere, is also designed to carefully study the polarisation of the cosmic microwave background (the earliest light to shine in the universe), and so can (through thorough analysis of the effects of dust that it has measured independently) help rule in or out whether there is a signal. Planck studies essentially the whole sky, not just the patch that BICEP2 was carefully looking at, and one of […] Click to continue reading this post

## Interstellar Science at Screen Junkies!

As promised on Tuesday, below you will find my Screen Junkies interview where I chat with Hal Rudnick about some of the science in Interstellar. We covered a lot of topics and went into a lot of detail, but a lot of that is on the cutting room floor in order to make a svelte (but relatively generous) ten minute cut. I hope you enjoy it. (See my earlier thoughts on why I think scientists need […] Click to continue reading this post

## Interstellar Thoughts

After emerging from a spectacular 70mm viewing of Interstellar at the Arclight Dome last night, I was grinning from ear to ear, which is unusual these days after seeing a film in this subject area (science fiction, space travel, the future of humanity, etc). (And by science fiction here I mean proper science fiction, not space opera or space adventure. There’s a lot of that and some of it is fun and makes me grin too, like this Summer’s Guardians of the Galaxy. But that’s not at all the same sort of thing.)

I’m not going to go into any details, since I am very tired of the practice of talking about films to the extent that you say so much of what happens that it is impossible for someone to enjoy watching the film unfold in front of them without knowing what comes next, the way I like my films best. So I’m not going to ruin things for you.

Everybody keeps asking me “what did you think of the science?” since they know that there’s a lot of stuff in there that relates to my subject area and interests. Many seem to want me to pronounce on what’s “good” and whats “bad” about the science, as though I’ve (like many scientists in the public sphere seem to have done) elected myself some sort of guardian of scientific ideas. Let me say two things. The first is that this is a science fiction film, not a science documentary. I’m already hearing all sort of humourless declarations about this and that and the other being wrong and how shameful it is, as happened with Gravity last year. Done right, such discussions can be an opportunity to teach a bit about science ideas, but most often it just comes across as being a smartass, which is a bit tedious, and leads me to my second point.

The second point is something I say a lot and needs to be said a lot more: Scientists don’t own science and its concepts and ideas. We should be careful […] Click to continue reading this post

## Interstellar Discoveries

I’m a fan of Chris Nolan’s work so I’ve been looking forward to Interstellar. I’ve also been fascinated by the McConaussance – the transformation of Matthew McConaughey into an actor of considerable stature in a series of excellent films (Mud, Dallas Buyers Club, etc…), so I’ve been doubly interested in seeing how he works in a film under Nolan’s direction. Same for the always amazing Casey Affleck. All quite exciting to see.

But then to my surprise it turns out there’s another reason to be interested. Kip Thorne. Some years ago, at a party when I last saw him, Kip told me that he had been working on some film or other with a major studio, but I did not know of the details. Then I ran into a mutual friend a couple of months ago who said something a long the lines of “Kip’s movie is coming out soon…”, and I learned that it was something to do with Interstellar! But I did not know any details.

Then I got sent* this Wired story, and then** this story, and I finally got around to looking. The Wired story has a lot of interesting detail, including a special film (that I ought to look at at) with interviews and behind the scenes material (the still to the right is a screen shot from it). The film will apparently feature a black hole and a wormhole in some way (I don’t want to know more – I like films to unfold in front of me in the theatre). Kip has been working with the visual effects people to get right exactly how such objects really look, an issue that has not really been fully addressed, it seems. He, like a number of us interested in science and film, is keen to help filmmakers really do a good job of representing some of these fascinating objects as accurately as possible. (Not, in my view, in order to stifle filmmakers’ imagination, as it so often seems when you hear scientists out there pontificating about what’s wrong in one film or another, but because the actual science is so very often far more interesting and full of delights and possibility than a visual effects kluge can be…) So apparently he wrote down […] Click to continue reading this post

## Dusting off Last Spring’s Excitement

There has been quite a bit of discussion of the realisation that the exciting announcement made by the BICEP2 experiment back in March (see my post here) was based on erroneous analysis. (In brief, various people began to realise that most, if not all, of what they observed could be explained in terms of something more mundane than quantum spacetime fluctuations in the ultra-early universe – the subtle effects of galactic dust. A recent announcement by another experiment, the Planck team, have quantified that a lot.)

While there has been a bit of press coverage of the more sober realisations (see a nice June post on NPR’s blog here), it is (as with previous such cases) nowhere near as high profile as the initial media blitz of March, for better or worse. I think that “worse” might be the case here, since it is important to communicate to the public (in a healthy way) that science is an ongoing process of discovery, verification, and checking and re-checking by various independent teams and individuals. It is a collective effort, with many voices and the decentralised ever-sceptical scientific process itself, however long it takes, ultimately building and broadening the knowledge base. This self-checking by the community, this reliance on independent confirmation of […] Click to continue reading this post

## Screen Junkies Chat: Guardians of the Galaxy

You may recall that back in June I had a chat with Hal Rudnick over at Screen Junkies about science and time travel in various movies (including the recent “X-Men: Days of Future Past”). It was a lot of fun, and people seemed to like it a lot. Well, some good news: On Tuesday we recorded (along with my Biophysicist colleague Moh El-Naggar) another chat for Screen Junkies, this time talking a bit about the fun movie “Guardians of the Galaxy”! Again, a lot of fun was had… I wish you could hear all of the science (and more) that we went into, but rest assured that they* did a great job of capturing some of it in this eight-minute episode. Have a look. (Embed below the more-click):
[…] Click to continue reading this post

## Perseids, Meet Supermoon!

So tonight (meaning the wee hours of Monday morning and the next few mornings, for optimum viewing – more civilised hours might work too, of course) the Perseid meteor shower will be on view! Have a look at this site (picked at random; there are many more) for more about how to view the meteors, in case you’re not sure. Well, here’s an interesting thing. The moon will be at its brightest as well, so that’ll mean that the viewing conditions for meteors will not be ideal, unfortunately. And it really will be extra bright (well, slightly, to be honest) because tonight’s full moon is during the moon’s closest approach to […] Click to continue reading this post

## Dark Energy Discussion

I was sent an interesting link a while ago* that I thought I would share with you. It is a really good discussion about Dark Energy – what do we think it is, why we think it exists, why some think it does not, and how to move forward with the discussion of what is, after all apparently *most* of our universe. It is a panel discussion that was hosted by the Institute for Arts and Ideas (which I *love* the idea of!). The discussion is described on the site as follows:

Dark energy is supposed to make up two-thirds of the universe. But troublingly CERN has yet to find any evidence. Have we got our story of the universe wrong – might dark energy be the aether of our time? Do we need a new account of the universe, or is it too soon for such radical solutions?

The Panel
The BBC’s Sue Nelson asks Templeton Prize winning cosmologist George Ellis, Cambridge physicist David Tong and mathematician Peter Cameron to seek the invisible.

Ok, the “troublingly CERN has yet to find any evidence” part puzzles me a bit, since nobody’s really expecting CERN to find any evidence of it, in any large scale experiments that I’m aware of (please correct me if I am wrong)… Is the writer of the abstract confusing Dark Energy and Dark Matter? Even then I think it is an odd phrase to lead with, especially if you don’t mention the huge amount of evidence from astronomy in the same footing… but I imagine the abstract was maybe not written by a physicist?

Nevertheless, I strongly recommend it as a thought-provoking discussion, and you can find it embedded below. Do also check out their many other interesting […] Click to continue reading this post

## Longest Day

Longest day of the year? It sure felt like it. I spent about 6 hours of it standing high above the city in the sun talking about physics and astronomy to camera… Super tiring.

It is for a new show I’ll say more about later.

## A New Shower!

….Let’s hope it is not equipped with a low-flow shower head though. If you get a chance this evening, find a wide area of sky away from as many lights as you can (it does not have to be perfectly dark, but the darker the better). There is a new meteor shower, the Camelopardalids…. It is new because the comet debris responsible (we’re flying through debris left over from its tail) has not intersected with our orbit before, but things have been changing a bit (apparently due to Jupiter’s gravitational pull) and as a result we’ll go right through it for the first time (as far as records show). It is expected that there’s a good chance that it will be a high event shower, and it has also been said – I forgot where I read this – that the […] Click to continue reading this post

## When Stars Go Bang…

I learned* that over on the Huffington Post, Christian Ott (Caltech) wrote a piece describing research on modelling stellar explosions using supercomputers. When a star goes supernova, what exactly happens? Capturing the physics that goes on is a very difficult problem to do, and in the article he explains some of the difficulties, and some of the recent progress.

There’s a slide show showing some of the […] Click to continue reading this post

## News From the Front, XI: Holographic Heat Engines!

Yes, you heard me right. Holographic Heat Engines. I was thinking recently about black holes in universes with a cosmological constant and their thermodynamics. I had an idea, it led to another, then another, then some calculations, and then a couple of days of writing, calculating, and thinking… then a day to cool off and think about other things. Then I came back to it, decided it was still exciting as an idea and so tidied it all up as a paper, made some diagrams, tidied some more, and voila! A paper submitted to the arxiv.

I’m sort of pleased with all of it since it allowed me to combine a subject I think is really fun (although often so bleakly dull when presented at undergraduate level) – heat engines – with contemporary research ideas in quantum gravity and high energy physics. So I get to draw some of the cycles in the p-V plane (graph of pressure vs volume) representing the inner workings of engines of particular designs (just like you might have seen long ago in a physics class yourself) and compute their efficiency for doing mechanical work in exchange for some heat you supply. It is fundamental that you can’t do that with 100% efficiency otherwise you’d violate the second law of thermodynamics – that’s why all engines have to have some exhaust in the form of heat, giving an efficiency represented by a quantity $$\eta$$ that is less than one, where one is 100% efficient. The diagram on the left illustrates the key pieces all engines must have, no matter what working substance you’re using. The details of the design of the engine are what kind of cycle you taking it through and what the properties (“equation of state”) your working substance has. In the case of a car, for example, the working substance is cleverly mixed up with the source of heat – the air/gasoline mix forms a “working substance” that gets expanded and compressed in various ways (in the green bit of the diagram), but the fact that it also burns releasing heat means it is also the source of the heat that comes into the engine (the flow from the red bit) to be (in part) turned to work, and the remainder flowing out to the blue (exhaust). Very clever.

The cool thing here is that I’m using black holes as the working substance for […] Click to continue reading this post