International treaties are being debated to protect oceans and polar regions

Episode Transcript

Speaker 1 (00:00):
Why do astronauts age more slowly in space? Astronauts on
the International Space Station ISS age more slowly due to
the phenomenon of time dilation caused by relative velocity, slowing
down their aging by a tiny fraction of a second.
Astronauts Butch Wilmore and Sunny Williams, stuck on the ISS

(00:20):
until February twenty twenty five due to issues with a
Boeing spacecraft, are experiencing this effect. Besides enjoying breathtaking views
of Earth, they are also aging slightly slower compared to
those on the ground. After six months on the ISS,
astronauts age about zero point zero zero five seconds slower

(00:40):
than people on Earth. Thus, after nine months in space,
Williams and Wilmore will be about zero point zero zero
seven five seconds younger than they would have been if
they had returned to Earth in June twenty twenty four,
as originally planned. This phenomenon is explained by Albert Einstein's
theory of relativity gravitational time dilation. According to Einstein's theory,

(01:07):
space and time combine into a single fabric called space time,
which is warped by the presence of mass and energy.
This warping leads to gravitational time dilation, where time moves
slower near massive objects because their gravity bends space time.
For example, a clock worn on your ankle would tick
slightly slower than one on your wrist because it's closer

(01:30):
to the Earth's center of gravity. However, this effect is
so small that it is imperceptible. Astronauts aboard the iss
are about four hundred and eighteen kilometers farther from Earth's
center of gravity than people on Earth, but they age
more slowly due to another phenomenon, velocity induced time dilation.

(01:50):
Velocity induced time dilation. Velocity induced time dilation occurs when
time passes more slowly for someone moving at a high speed.
Imagine a pair of twins where one travels on a
space ship at near light speed while the other stays
on Earth. Upon returning, the space traveler would have aged
only a few years, while the twin on Earth would

(02:11):
have aged significantly more. While this scenario hasn't been tested
with humans, evidence supports the concept. Scientists have launched an
atomic clock into orbit and compared it to an identical
clock on Earth. The clock that went into orbit ticked
more slowly. Astronauts aboard the ISS experience the same effect.
The ISS orbits Earth at a speed of about eight

(02:33):
kilometers per second twenty nine thousand kilometers per hour according
to NASA. This means that time for astronauts passes more
slowly than for those on the ground. For astronauts, velocity
induced time dilation has a greater effect than gravitational time dilation,
so they age slightly slower. While in space astronauts telomeres

(02:57):
lengthen in space. Another strain phenomenon observed in space that
might also help slow aging is the lengthening of astronauts telomeres.
Telomeres are the protective caps at the ends of chromosomes
that shorten as people age.