“A truly healthy immune system depends on a balanced healthy diet over time,” says registered dietitian Maxine Smith. “It’s like training for a battle and preparing your body ahead of time so it can through a good punch when attacked by viruses, bacteria and toxins. Other lifestyle practices such...

Perepelitsa and his colleagues are dubious that a massless photon could pack a powerful enough punch to melt part of a lead nucleus, which contains 82 protons and 126 neutrons. “It would be like throwing a needle into a bowling ball,” he says.

Instead, he thinks that just b...