Readers discuss dark energy, Ötzi’s tattoos and sneaky plant invasions

Secrets and ways of space

New files hint that darkish energy’s density, ceaselessly thought to dwell constant, could vary over time, Emily Conover reported in “3-d plan hints at darkish energy’s secrets” (SN: 5/4/24 & 5/18/24, p. 6).

In the common describe of the cosmos, the amount of darkish energy is growing because the universe expands. Reader Place Granville wondered the place new darkish energy comes from.

Darkish energy’s offer is an everlasting thriller. Quantum fluctuations in empty space, one day of which particles pop into existence for extraordinarily transient moments, may very neatly be one clarification, Conover says. However these fluctuations yield even more questions. Some calculations predict that rather more darkish energy exists than researchers are staring at within the universe, by 120 orders of magnitude, Conover says. Scientists smooth don’t know note that discrepancy.

Essentially feel the misfortune

Tattooing experiments counsel that the tattoos of Ötzi the Iceman, who lived 5,200 years within the past, had been hand poked, no longer sliced, into his pores and skin, Bruce Bower reported in “How Ötzi the Iceman in actuality got his tattoos” (SN: 5/4/24 & 5/18/24, p. 4).

Reader Amy Perry wondered whether the tattooing course of was once painful for Ötzi and whether misfortune relief measures had been obtainable.

Tattoos in general also shall be painful. The misfortune a particular person experiences is reckoning on their misfortune tolerance, the instrument and methodology weak, and tattoo measurement and placement on the body, says archaeologist Aaron Deter-Wolf of the Tennessee Division of Archaeology in Nashville.

Scientists can’t know for certain the stage of misfortune Ötzi felt for the interval of the tattooing course of. However the somewhat small markings and his rugged daily life may mean that the tattoos did no longer goal him too mighty misfortune, Deter-Wolf speculates.

Whether or no longer Ötzi weak misfortune relief for the tattoos is unknown. His mummified body was once stumbled on with natural substances that own disinfecting and misfortune-relieving properties. Scientists explain that the Iceman could own weak these substances, which consist of lavatory mosses and a sort of fungus called birch polypore, to costume wounds for the interval of his final days. It’s inviting to disclose whether he utilized the substances to his tattoos, which had prolonged since healed, says Katharina Hersel, a spokesperson at South Tyrol Museum of Archaeology in Bolzano, Italy, the place Ötzi is saved.

Sleeper species

Some invasive vegetation lurk for hundreds of years in a new situation sooner than choking out native species there, Susan Milius reported in “Plant invasions can rob centuries” (SN: 5/4/24 & 5/18/24, p. 15).

Reader Christina Gullion asked if the lags are driven by genetic mutations that, over time, allow initially neatly-behaved invaders to thrive in a new atmosphere.

This is one potential clarification, says invasion ecologist Shaun Coutts of the University of Lincoln in England. Previous reviews own urged that adaptations may arise and unfold within an invasive inhabitants after it has arrived in its new dwelling, Coutts says.