[Music]
welcome to rainy day story time with
minute physics today's book is how did
wales get so big by minute earth before
we begin i just want to say this is a
great book for both kids and adults it
is a collection of questions and answers
about our natural world it's a great
coffee table book or bedtime book that
you can just skim through and read one
little chapter or story or you can go
through the whole thing from cover to
cover if you'd like today we're going to
be reading from the first question of
the book where did earth's water come
from
unlike every other planet in our solar
system earth's surface is 70 liquid
water that's useful for sustaining life
but it's also weird because our planet
didn't start off with water the early
inner solar system was far too hot for
frozen water and any water vapor would
have been blasted away by the solar wind
so how did we end up with such splendid
oceans rivers ice caps and clouds like
the ones that are making the rain today
natural processes like burning and
breathing do create water through
chemical reactions but other natural
processes like photosynthesis use of
that water plus these amounts are so
tiny that we can be confident that
earth's water wasn't made here over the
eons
so water must have arrived here on
meteoroids comets or other objects that
originated far enough from the sun for
frozen water to survive
since comets are pretty much just dirty
ice balls they're a logical candidate
for the source of earth's water but
they're far richer in a special kind of
hydrogen called heavy hydrogen hydrogen
with a neutron as well as a proton in
its nucleus than earth water so comets
probably weren't the source
the more likely source is a kind of
stony meteorite known as a carbonaceous
chondrite
these meteoroids form far enough from
the sun that they can hold water and the
water they do have has similar levels of
heavy hydrogen as earth's water like the
water raining outside
so it seems as though the water that
turned our planet into a blue marble
came quite literally out of the blue
and if you want a copy of this book to
come into your hands out of the blue it
comes out on october 12th and is
available for pre-order now wherever
books are sold another thing about this
is that i was obviously involved in the
creation of this book and made lots of
the videos uh on which this book is
based and it's still a delight to have
these things actually in your hands i
think minute earth videos are maybe some
of the best videos to be converted into
a book because the illustrations that
the minute earth illustrators do are
just amazing and in particular in book
form where we actually kind of tone down
the narration and the text so to speak
and you just have more pictures it's
just great it's just really fun to flip
through even though i know all these
pictures and i know these these science
stories i am just super enjoying this
book so i highly highly recommend it
it's a great gift for anybody or just
for yourself to enjoy the world around
you
again
october 12th comes out
order it now wherever books are sold get
yourself
lots of copies
and thank you for joining us for story
time with minutephysics
and it has a glossary in the back for
those science words you might not be as
familiar with