This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.
Skip to the content

Free weekly newswire

Sign up to receive all our latest news direct to your inbox.

Physics on film

100 Second Science Your scientific questions answered simply by specialists in less than 100 seconds.

Watch now

Bright Recruits

At all stages of your career – whether you're an undergraduate, graduate, researcher or industry professional – can help find the job for you.

Find your perfect job

Physics connect

Are you looking for a supplier? Physics Connect lists thousands of scientific companies, businesses, non-profit organizations, institutions and experts worldwide.

Start your search today

Tag archives: ultracold atoms

The landscapes of CERN, 20 years of BECs and the truth about toilet swirl


By Hamish Johnston

Everyone knows that water in a draining sink or toilet swirls in opposite directions on opposite sides of the equator…or does it? For the answer, watch the instructions in the above video and then go to “The truth about toilet swirl”.

Physicists at CERN are a lucky bunch. As well as having the world’s most energetic collider at their disposal, they are also surrounded by the natural beauty of the Alps and the Jura mountains. However, I’ve always felt that the CERN site itself and the flat farmland that overlays the Large Hadron Collider (LHC) are rather dull.


Posted in The Red Folder | Tagged , | 1 Comment | Permalink
View all posts by this author  | View this author's profile

Where is the coldest experiment on Earth?

Image of a refocused cloud of rubidium atoms

Chilly peak: a refocused cloud of rubidium atoms. (Courtesy: Tim Kovachy et al./Physical Review Letters)

By Hamish Johnston

California might be suffering a punishing drought, but a tiny corner of the Golden State is now the coldest place on Earth. This tiny super-cold patch was created at Stanford University by Mark Kasevich and colleagues, who have used “matter-wave lensing” to cool a cloud of about 100,000 rubidium atoms to less than 50 pK. That is just 50 × 10–12 degrees kelvin above absolute zero.

The temperature of a cloud of atoms is defined by the average velocity of the atoms as they drift about. Kasevich’s team used a series of lenses to reduce this average motion to less than 70 µm/s, which corresponds to 50 pK. This shatters the previous record of 1 nK for matter-wave lensing and represents “record-low kinetic temperatures” according to Physical Review Letters, where the research is described.


Posted in General | Tagged | 6 Comments | Permalink
View all posts by this author  | View this author's profile

Celebrating Louis Essen and the birth of atomic time

Peter Knight (left) and John Dudley unveiling the historical plaque

Peter Knight (left) and John Dudley unveiling the historic plaque.

By Hamish Johnston

On Friday I braved the torrential rains that have been soaking southern England to make the journey from Bristol to Teddington, which is the birthplace of the atomic clock. Situated in the leafy suburbs west of London on the swollen banks of the River Thames, Teddington is the home of the National Physical Laboratory (NPL), which is the UK’s standards and metrology lab.


Posted in General | Tagged , , | 1 Comment | Permalink
View all posts by this author  | View this author's profile