Onderzoekers van Caltech onderzochten het en het antwoord is "Ja".Regelmatig post ik hier berichten over uitbarstingen van de zon en aurora borealis. We weten dat deze "prachtige lichtshows" ook zijn negatieve kanten heeft, zoals het effect op de dieren die navigeren op het aardmagnetisch veld en de impact op de radiogolven.
Wetenschappers van het Caltech instituut gingen op onderzoek of de mens hier nu ook gevoelig voor is en of ze er bewijzen voor konden vinden.
Hieronder is "de korte versie" te lezen. Wil je de gehele studie lezen kijk dan op:
Close your eyes and relax. Daydream about something pleasant. In this state your brain is filled with "alpha waves," a type of electrical brainwave associated with wakeful relaxation.
CAN HUMANS SENSE MAGNETIC STORMS?
Now try it during a geomagnetic storm. It may not be so easy. A new study just published in the journal eNeuro by researchers at Caltech offers convincing evidence that changes in Earth's magnetic field can suppress alpha waves in the human brain.
The human magnetoreception test chamber at Caltech.
Researchers have long known that living creatures can sense magnetic fields. For instance, honeybees, salmon, turtles, birds, whales, and bats use the geomagnetic field to help them navigate, and dogs can be trained to locate buried magnets.
"Many animals can do it, so why not us?" asks Connie Wang, Caltech graduate student and lead author of the eNeuro study.
To find out if humans can indeed sense magnetic fields, the researchers built an isolated radiofrequency-shielded chamber where participants sat in utter darkness for an hour. As magnetic fields shifted silently around the chamber, participants' brain waves were measured using electrodes positioned at 64 locations on their heads.
In some of the 34 participants, alpha brainwaves decreased in power by as much as 60 percent in response to the shifting fields. Additional runs of the experiment showed that the effect was reproducible.
Changes in alpha brainwave amplitude following rotations of an Earth-strength magnetic field. The darker the blue color, the more dramatic the drop.
Study co-authors Joseph Kirschvink and Shin Shimojo say this is the first concrete evidence of a new human sense: magnetoreception.
Remarkably, participants who experienced the changes reported no awareness of them. It appears to be a completely unconscious effect, never rising to the level of a conscious interruption. This led the researchers to suggest it may be vestigial, some remnant of an ancient ability to navigate using local magnetic cues.
"It is perhaps not surprising that we might retain at least some functioning neural components [of magnetoreception], especially given the nomadic hunter-gatherer lifestyle of our not-too-distant ancestors," says Kirschvink.
"As a next step, we ought to try bringing this into conscious awareness," adds Shimojo.
Does this mean people may be able to sense geomagnetic storms? It's unclear.
When solar storms hit Earth, they cause our planet's magnetic field to shake, moving back and forth. Compass needles at mid-latitudes can move by as much as 4 or 5 degrees (ref). The Caltech study did not look at changes of that size, however. Magnetic fields inside their test chamber shifted by +/- 90 degrees--much, much larger than a typical geomagnetic storm. As a result, we do not yet know if human magnetorecepton is sensitive enough to detect the relatively subtle changes associated with space weather.
Says Kirschvink, "the full extent of [human magnetoreception] remains to be discovered." Stay tuned.