Well, I’m off to get six hours of sleep before the big announcement tomorrow! The Event Horizon Telescope teams are talking about an announcement of “groundbreaking” results tomorrow at 13:00 CEST. Given that they set out to “image” the event horizon of a black hole, this suggests (suggests) that they … Click to continue reading this post

Black Holes and Time Travel in your Everyday Life

Oh, look what I found! It is my talk “Black Holes and Time Travel in your Everyday Life”, which I gave as the Klopsteg Award lecture at AAPT back in July. Someone put it on YouTube. I hope you enjoy it!

Two warnings: (1) Skip to about 6 minutes to start, to avoid all the embarrassing handshaking and awarding and stuff. (2) There’s a bit of early morning slowness + jet lag in my delivery here and there, so sorry about that. 🙂


Abstract: […] Click to continue reading this post

Science Friday Book Club Wrap!

Don’t forget, today live on Science Friday we (that’s SciFri presenter Ira Flatow, producer Christie Taylor, Astrophysicist Priyamvada Natarajan, and myself) will be talking about Hawking’s “A Brief History of Time” once more, and also discussing some of the physics discoveries that have happened since he wrote that book. We’ll be taking (I think) caller’s questions too! Also we’ve made recommendations for further reading to learn more about the topics discussed in Hawking’s book.

Join us!


(P.S. The picture above was one I took when we recorded for the launch of the book club, back in July. I used the studios at Aspen Public Radio.) 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:

Carina Hubble Image

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:
A smiling lens

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…)


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 toPlanck_view_of_BICEP2_field_node_full_image_2 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!

screen_junkies_interstellarAs 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

Screen Junkies Chat: Guardians of the Galaxy

Screen Shot 2014-09-11 at 3.13.03 PMYou 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

Dark Energy Discussion

dark_energy_discussionI 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

Collecting the Cosmos

i_2014_01_24_CollectCosmos_150x200Don’t forget that on the USC campus on Friday at 4:00pm, we’ll be kicking off the Collecting the Cosmos event! It will be in the Doheny library, and there’ll be a presentation and discussion first, and then a special opening reception for the exhibition. Be sure to get yourself on the waiting list since there’s some chance that you’ll get in even if you have not RSVPed yet. (The image is from the Visions and Voices event site, and includes parts of the artworks – by artists Victor Raphael and Clayton Spada – to be included in the exhibition, so come along and see.) The event description says, in part: […] Click to continue reading this post

Weinberg on Physics Now

I just spotted (a bit late) that Steven Weinberg (one of the giants of my field) has written a piece in the New York Review ofBooks entitled “Physics: What We Do and Don’t Know”. I recommend it. He talks about astronomy, cosmology, particle physics, and by casting his eye over the arc of their recent (intertwined) histories of ideas, experiments and discoveries, tries to put the Standard Models of particle physics and of cosmology into perspective.

The article is […] Click to continue reading this post

Known Unknowns Decreased a Bit

Well, the day is here. The Planck collaboration has announced a huge amount of results for the consumption of the scientific community and the media today. The Planck satellite looks with unprecedented precision at the very earliest radiation (“cosmic microwave background radiation”, CMB) from the universe when it was very young (a wee, cute 380,000 years old) and helps us deduce many things about what the universe was like then, and what it is like now. Here’s one of the representations of the universe using the new sky mapping Planck did (image courtesy ESA/Planck):

There’s a ton of data, and a raft of papers with analysis and conclusions. And there’s a very nice press release. I recommend looking at it. It is here, and the papers are here. The title of the press release is “Planck reveals an almost perfect Universe”, and some of the excitement is in the “almost” part. A number of anomalies that were hinted at by the previous explorer of the CMB, WMAP, seem to have been confirmed by Planck, and so there are some important things to be understood in order to figure out the origin of the anomalies (if they ultimately turn out to be real physics and not data artefacts). [Update: Andrew Jaffe has two nice posts I recommend. One on the science, and the other on the PR. Jester also has a nice post on the science from a particle physicist’s perspective.]

What is the title of my post referring to? Well, the refined measurements have allowed us to update some of the vital statistics of the universe. First, it is a bit older than previous measurements have indicated. The age is now measured as 13.82 billion years. (I’m already updating pages in the draft of my book…) Second, the proportion of ingredients […] Click to continue reading this post