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Shades of pink: the Xamaleón ice cream in action. (Courtesy: IceXperience)
By Hamish Johnston
It has been a cracker of a summer here in south-west England, with lots of sunshine and temperatures in the mid-twenties just about every day. Not surprisingly, I have been eating my fair share of ice cream, but unlike this concoction whipped up by a physicist-turned-chef in Spain, the stuff you get in Bristol does not change colour when you lick it!
Created by Manuel Linares, owner of the IceXperience ice-cream parlour in Barcelona, the Xamaleón ice cream starts off as a sky-blue colour when scooped into a cone. Then it is given a spray of what Linares describes as a “love elixir”, which turns it dark pink after about 20 seconds. If you are brave enough to lick the ice cream, it will then transform through a number of shades of pink before melting. The story is reported in lots of different places and this article in the Daily Mail has the best pictures. If you are looking for more details about the science behind the colour changes, this article on Phys.org is your best bet.
Two physicists who deserve extra-large ice creams are Adeel Ajaib and Fariha Nasir – a couple who defended their PhD dissertations on two consecutive days in July. Both are at the University of Delaware and addition to unravelling the mysteries of particle physics, they have two very young children to look after.
“The last couple of months before our defence were totally disorganized in our house,” says Ajaib. “All we did was take care of the children and talk about physics. We had [whiteboards] that we were always writing on.” Nasir adds that “there wasn’t a lot of sleep”. “And I don’t think I sat down and ate a meal for three months,” she says.
The couple are originally from Pakistan and have no extended family nearby, making childcare arrangements tricky. Undaunted, the family is now moving to Pennsylvania, where both parents will pursue careers. You can read more about the couple in “Double Del doctors”.
One facility that could benefit from a pair of highly efficient physicists is the ITER fusion project that is currently under construction in France. This week Nature is running an interview with ITER’s director-general Osamu Motojima that is headlined “Five-year delay would spell end of ITER”.
ITER has been in the news for all the wrong reasons lately, with delays, possible funding cuts and political rows threatening the international project. Motojima has taken a lot of flak recently from critics of the project and in the interview the director-general gets his chance to hit back.
The ITER is just an experimental set up that is supposed to produce 10 times more energy from the fusion of deuterium and tritium for 1000sec than the input energy, but it will still be very far from the “triggering stage” allowing the system to operate by itself without any external input. Moreover, the laser-based NIF system in USA is suffering from a similar situation.
The simple fact is that this technology is getting far too complex to base a real world power station on.
It is full of exotic materials, weighs more than an aircraft carrier, and is so mind-bogglingly complicated that keeping one running for more than a few hours would be a triumph. Don’t get me wrong I am confident they will get the thing running, and solve the technical problems. It’s the economics that has me concerned.
We already have perfectly fine fusion reactor that comes up every morning. The economics of solar are struggling to compete with fossil hydrocarbons, ITER will not be able to compete against solar. But solar is fusion energy.
A power station needs to run for decades without interruption.
One cannot imagine simplifying this to the point where it compete with a hole in the ground with oil coming out of it.