Readers ask about self-correcting quantum computers, oobleck’s experimental value

Experimenting with food

Mayonnaise’s texture is perfect for mimicking what a fuel capsule goes through when it’s blasted with lasers to ignite nuclear fusion, Emily Conover reported in “Mayonnaise may shed light on nuclear fusion experiments” (SN: 10/5/24, p. 5).

Reader Linda Ferrazzara wondered if mayo qualifies as a non-Newtonian fluid, one whose viscosity changes depending on the stress applied to it. If so, could researchers instead use oobleck — a non-Newtonian fluid made from cornstarch and water ­— as a stand-in for nuclear fuel capsules in experiments? Ferrazzara asked. Oobleck might be easier to keep consistent between experiments than mayo, which has different formulations depending on the brand.

Mayonnaise is a non-Newtonian fluid, says mechanical engineer Arindam Banerjee of Lehigh University in Bethlehem, Pa. But oobleck would not work for fusion experiments. The substance gets thicker, or more viscous, when hit by an outside force — a phenomenon called shear thickening. So it “would freeze up when we spin our experiment,” Banerjee says. Mayo is the opposite: It gets less viscous.

Repeatability is crucial to the team’s scientific process, so the materials used in each experiment need to be well-characterized and consistent, Banerjee says. “We have used Hellmann’s Real Mayonnaise for the last 12 years. We measure properties of each batch and have found them to be remarkably consistent. We do not make our own mayonnaise,” he says. “Prior to picking mayonnaise, we tried yogurt. But my students at that time were not able to replicate the yogurt consistency and thus the properties were different, leading to large variations in observed behavior.”

Move over, Simone Biles!

A globular springtail can backflip (shown below) at a rate of 368 spins per second, Jonathan Lambert reported in “How an arthropod does the world’s fastest backflip” (SN: 10/5/24, p. 4). X user @FluronaVirus wrote: “That’s incredible! The agility of globular springtails is truly remarkable. High-speed camera footage capturing their spin rate is a fascinating insight into their aerial abilities. Nature never ceases to amaze with its wonders.”

Machines make mistakes

A quantum computer improved its results by repeatedly correcting its mistakes midcalculation, Emily Conover reported in “A quantum computer fixes its errors” (SN: 10/5/24, p. 6).

X user @Lightning456243 asked how a quantum computer can identify its own errors.

“Quantum computers correct their own errors by inserting some redundancy in their data and periodically checking whether the information is still self-consistent,” Conover says.

Classical computers do this too by copying bits, which have a value of either 0 or 1. For instance, 1 can be copied three times to become 111. If one of those bits gets unintentionally flipped (say, 111 becomes 110), the mismatch between the three bits would indicate an error. By looking at which value is the majority, the computer can identify which bit needs fixing.

The complexities of quantum physics complicate this process, but quantum computers likewise encode information redundantly, Conover says. Rather than directly copying individual quantum bits, however, the computers spread the information between multiple quantum bits that are entangled, or linked (SN: 6/20/20, p. 18).