The successful jump on Sunday by an Austrian stuntman from a balloon 39
kilometers above Earth was equivalent to the first successful climb of Mount
Everest, but it did not contribute to scientific knowledge, according to Hebrew
University astrophysicist Prof. Nir Shaviv.
“It was the highest-ever jump
from the stratosphere,” he told The Jerusalem Post on Monday, “but it has been
done before from about 30 kms. high,” he explained.
43-year-old Felix Baumgartner, landed in New Mexico by parachute and on his own
two feet at the end of the skydive, during which he broke the sound barrier by
reaching a speed of 1,342 kilometers per hour.
“It’s certainly possible
to fall at a speed faster than the sound barrier and survive if the jumper
doesn’t get dizzy, lose his orientation and is unable to open his parachute,”
said Shaviv, who admitted that he had not known about the achievement until his
13-year-old son told him about it.
“My wife has parachuted from a plane,
but I would not do it,” said the expert at HU’s Rakah Institute of Physics and
expert in astrophysics, space and cosmology who usually spends his time studying
the makeup of stars and black holes.
This is a height with particles
dense enough that the temperatures surrounding him would not burn him up as long
as he is in a protective suit, said Shaviv. “An ordinary plane could not reach
such heights, but a large balloon could. Nevertheless, if he were higher – at
about 100 kilometers from Earth – his speed while falling would have been so
fast that as a result of shock waves, the lower density of particles and the
temperature, he would have been consumed by fire.”
Space vehicles that
fall back to earth are protected from burning up by thick ceramic
Shaviv did not think astronauts would gain any knowledge from the
audacious stunt, as they do not abandon their spacecraft at such a height. “But
like the first conquest of Mount Everest – in stretching human boundaries and
following human curiosity – his courageous act has importance on its own,”
It took Baumgarten some 2.5 hours to reach the point where
he jumped from the small fiberglass and acrylic capsule that propelled him into
“As he rose, the temperature had to get colder, even to
-60 degrees celsius, until he reached 10 kms. to 15 kms.
away, but then
the ultraviolet light warmed him before he fell rapidly, and it was warm again.
His astronaut-like suit protected him,” suggested the HU scientist. “He broke
the sound barrier, but wouldn’t have heard anything inside anyway.
Theoretically, it he had gone higher, he would have needed a much larger
Dr. Noah Brosch of the astronomy and astrophysics department
and the Wise Observatory of Tel Aviv University speculated that “there might be
something to be learned about astronauts jumping off a space capsule in trouble,
but I do not know enough about this. The suit worked at mach one, but I am not
sure it would be effective at a higher speed.”