CDF Says No

Recall the excitement last week about the D0 result? I wrote a post called “An Exciting Asymmetry?”. Well, there’s a rule that says if you write a title as a yes/no question, the answer is often (usually?) “No”.

Sure enough. over at Resonances, Jester reports that the CDF experiment, also at the Tevatron, has looked for a confirmation of the CP violating result that D0 claimed to see, and did not find anything abnormal where it should have. Find further details (on the technical side for the experts) and links at that post, which, as is usual with material from that blog, is well-written and interesting.

This is one reason why we (the particle physics community) build multiple detector/experiments on the same accelerator machine, and this is a prime example […] Click to continue reading this post

An Exciting Asymmetry?

A big mystery in physics is why there is more matter than anti-matter. (Of course, which we call the matter and which we call the “anti-matter” is a… matter of convention. Take your pick.) It is hoped that there is some mechanism in the laws of physics (at a very basic level concerning particle interactions) that will become apparent that explains it. It’s also hoped that the mechanism itself might have some understandable origin too. The mechanism would operate in the first tiny fractions of a second of the universe’s life when the primordial soup of particles and antiparticles (created from, roughly speaking, the energy of the big bang) began to cool down as the universe expanded. Rather than them annihilating all back into energy again, the mechanism would create an imbalance between the two, giving rise to a matter-filled universe, from which we emerged. So what could be the mechanism, can we isolate it in our theories and in our experiments? Build a good model of it? Explain it?

This is all very first and foremost in people’s minds when there’s a new experiment switched on that is probing the unknown – the Large Hadron Collider. Well, actually, it has been recently announced that a suitable mechanism (or, more precisely, its […] Click to continue reading this post

Categorically Not! – Imagine

yossi_govrin_sculptureThe next in the Categorically Not! series the series of events is tomorrow, Sunday 18th April. It is, as usual, held at the Santa Monica Art Studios. It’s a series – started and run by science writer K. C. Cole – of fun and informative conversations deliberately ignoring the traditional boundaries between art, science, humanities, and other subjects. I strongly encourage you to come to them if you’re in the area. Here is the website that describes past ones, and upcoming ones. See also the links at the end of the post for some announcements and descriptions (and even video) of previous events. (At the right is an image of a beautiful sculpture by artist Yossi Govrin, who is on this week’s program.)

The theme this month is Imagine. Here’s the description from K. C. Cole: […] Click to continue reading this post

Ask a Nobel Laureate

mather_youtubeHere’s a fun thing to get involved with. You can ask John Mather (2006 Physics Nobel Prize) a question on YouTube! Go and submit yours!

What might you ask him? Something about physics, or something else? Religion, art, politics? His favourite colour? If you consider asking a question, and whether you go ahead and ask it or not, feel free to mention in the comments what you might ask.

This is how to proceed (from NASA education)*: […] Click to continue reading this post

More Book Fun!

bookfair_homeMark your calendar for Sunday! The West Hollywood Book Fair is on from 10 am to 6:00 pm that day, and there’s so much to see and do with readings, panels, discussions, authors, special celebrity guests, food, exhibitions, writing workshops, discount book offers, signings, swag (no doubt), and so forth. I’ve not been before, but as you know from reading here I’m a big fan of cities going gaga over books for a while, being a regular visitor to the LA Times Book Festival when it comes in the Spring. The calendar of events and much more about the event can be found at the website here.

Here’s another thing. Despite the fact there was no mention of a spankingly splendid […] Click to continue reading this post

Ten Things That Go Boom!

the_universeWell, ok… Boom is not quite accurate, but the idea is that there will be ten kinds of blasts/explosions/major_energetic_events discussed tonight on the History Channel’s The Universe:

The Universe is full of explosions that both create and destroy. The Chicxulub impact on the Yucatan peninsula, which may have wiped out the dinosaurs 65 million years ago, was two million times more powerful than the largest nuclear bomb ever detonated on Earth. But guess what? That’s only good enough for the very bottom of the Biggest Blasts top ten list. This episode works its way up through supernova explosions and gamma ray bursts all the way to the blast that started it all–the Big Bang.

Sounds good doesn’t it? There’s a lot of good people contributing again, so I know it’ll have some good material and explanations.

In addition, I’m reasonably confident I play a role in this one…This one was a blast (sorry) to film. You saw some posts earlier reporting on some of the filming. Assuming they used the material I did with them, you’ll get to see why I was at the […] Click to continue reading this post


Forgot to report on this email exchange from last semester:

From one of the staff in the physics office:

Subject: 499 Syllabus
Date: Thu, 09 Jul 2009 14:01:38 -0700
From: Beverly
To: Clifford V. Johnson

I was reading the syllabus you sent over for the 499 class. I am not sure if this is a type-o but in the Extra Books section it reads “/Black *_hoes_* and Time Warps: Einstein’s outrageous Legacy/” should it read
“/Black *_holes_* and Time Warps: Einstein’s outrageous Legacy/”.


My response: […] Click to continue reading this post

Wish the Observatory Good Luck!

60 inch at mount wilson The fires are racing up the sides of Mount Wilson as I write (19:38). They expect the burn to get to the top sometime in the next few hours, and yes, I imagine it’ll affect the Mount Wilson Observatory in some way.

[Update (20:59): You can get regular updates from the director at this page*. Seems that fire crews will remain on site for when/if the fires sweep through the grounds. ]

All of the working scientific equipment, including the solar telescopes and of course the historic telescopes (the 60 inch is pictured to the right) with which astounding discoveries were made about our universe (such as the fact that it is expanding, and the fact that the universe is vastly more than just our Milky Way Galaxy) are presumably in some danger, as well as support buildings of various kinds. I’ve no idea how much since I do not know what fire-proofing measures are in place up there, although I am sure there are several – such as keeping brush away from the buildings themselves. Here’s a camera up there on one of the solar telescopes where you can see regularly updated pictures that it snaps. I grabbed this one just now (click for larger view):


So keep your fingers crossed for luck for the instruments, and of course for all […] Click to continue reading this post

The Big Day!

Herschel & Planck Ariane 5 ECA V188 Launch CampaignTomorrow is the Big Day. For what? The launch of Planck and Herschel – Major new windows on our universe. Keep your fingers crossed for luck!

They’re on the launch pad right now. See here.

So, what are the missions and objectives of these fine spacecraft, I hear you ask.

Well, from the Planck site: […] Click to continue reading this post

Yesterday at JPL

jpl_open_house_2009_1I had a lot of fun at this year’s Jet Propulsion Laboratory (JPL) open house. I’m happy to report that there were, once again, lots of people wandering around looking at the displays and demonstrations, asking questions, hanging out, and so forth, and an impressive turnout of JPL staff answering questions and being very enthusiastic about the science (something which is easy to do because it’s such an excellent topic!). I’ve made a video for you that is coming up at the end of this post. (Click on stills for larger views.)

jpl_open_house_2009_5 jpl_open_house_2009_6

There was the usual huge emphasis on planetary exploration with rovers and robots and so forth – this seems to capture the imagination of everyone, so why not? – but I was more than a little surprised to find virtually no showing for the Planck mission. There was one poster somewhere, but no booth, no model, no description of the truly amazing science that it will do in unlocking more about the origins of the entire […] Click to continue reading this post

Tales From The Industry XXV – Parallel Universes

While most of the episodes of the History Channel’s The Universe series are firmly about scientific knowledge of the universe that has been tested and verified (from planetary science, to solar physics, to stellar evolution, and various topics in cosmology, and so forth), they also like to treat topics that have a higher component of more speculative material. This is of course fine, as long as it is made clear what is speculation, and what is established. Recall that I took part in a really fun episode called Cosmic Holes, which talked about white holes and wormholes -entirely speculative objects – right alongside the physics of black holes, objects that we know are physically realized in our universe. (See here, here, and here.) I think that Laura Verklan, the writer/director, did a really excellent job of separating out the speculative from the established. Similar things can be said for the episode Cosmic Apocalypse, done by writer/director Savas Georgalis (see here), which focused on scenarios about how the universe might end, given what we have already established about how it was in early times and how it is now.

I’m hoping that the upcoming (tonight!) episode entitled Parallel Universes will also be a nice and clear piece of work discussing the speculative ideas concerning the possibility of parallel universes – what the ideas are, why it is a fun idea, what it […] Click to continue reading this post


On campus yesterday, I ran into a colleague I had not seen in a long time. She was with her daughter. She introduced us, saying, among other things, that Professor Johnson is “Big in Cosmology”.

I’ll admit that I giggled like a naughty schoolgirl for a longish, unprofessorial moment. It was sort of hard to explain, and would have derailed the conversation, so I did not try. Why was I giggling? Well, it is just that the field of cosmology (which, for the record, […] Click to continue reading this post

GLAST, Fermi, and Early Results

Well, the new orbiting instrument, GLAST (Gamma-ray Large Area Space Telescope – launched June 11th this year) has passed all its tests with flying colours, apparently, and is working well. NASA has now renamed the craft the Fermi Gamma-ray Space Telescope, after Enrico Fermi. There’s a press release here.

The craft is a wonderful combination of the fields of particle physics, astrophysics and cosmology, and will teach us so much about the universe (such as the nature of dark matter), and so it is exciting to hear that it all on track.

Excitingly, they’ve also released images of the early results of the observations, and you can read more about them in the press release too. Here’s a sky map made from the observations.


This all-sky view from GLAST reveals bright emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes. Credit: NASA/DOE/International LAT Team.

Some words from the release: […] Click to continue reading this post