READ THIS VERY CAREFULLY: The amniotic sac, commonly called the bag of waters, sometimes the membranes, is the sac in which the fetus develops in amniotes. It is a thin but tough transparent pair of membranes that hold a developing embryo (and later fetus) until shortly before birth.

...thin but tough transparent pair of membranes...

SPACE VACUUM AMNIOTIC FLUID IS WATER.

WHY IS FLUID OF SPACE/UNIVERSE TRANSPARENT?

So, why fluid is compressed in planet Earth spherically to be atmosphere amniotic sac?

OUR PLANET EARTH AND EVERYTHING WE KNOW IS:  INSIDE SKY/SPACE/UNIVERSE SPHERE.

WE HUMANS, DO NOT KNOW WHAT IS OUTSIDE THIS SKY/SPACE/UNIVERSE SPHERE.

WHAT IS WATER HOLE and AMNIOTIC FLUID

The Microwave Waves frequency has another interesting feature to recommend it as a place for interstellar communication: the “Water Hole.”

Some atoms and molecules in space emit radio waves at particular frequencies.

The hydrogen line, 21-centimeter line or H I line refers to the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms.

The "protected" band extends from 1400 MHz to 1427 MHz in order to allow observations of hydrogen gas moving at a range of velocities.

This electromagnetic radiation is at the precise frequency of 1420.405751786 MHz, which is equivalent to the vacuum wavelength of 21.10611405413 cm in free space.

This wavelength falls within the microwave radio region of the electromagnetic spectrum, and it is observed frequently in radio astronomy, since those radio waves can penetrate the large clouds of interstellar cosmic dust that are opaque to visible light.

The 21 cm spectral line appears within the radio spectrum (in the L band of the UHF band of the microwave window to be exact).

Electromagnetic energy in this range can easily pass through the Earth's atmosphere and be observed from the Earth with little interference.

Hydrogen one atom emit at 1420 MHz (a wavelength of 21 cm).

Oxygen one atom of oxygen (OH), emit at 4-four specific radio frequencies ranging from

1. 1612 MHz (a wavelenght 18.59 cm

2. unknown 16xx MHz (a wavelength of .... cm

3. unknown 16xx MHz (a wavelength of .... cm

4. to 1720 MHz (a wavelength of 17.42 cm).

So, there is few combination how to get liquid water from amniotic fluid from, space vacuum IF YOU KNOW HOW TO USE:

Dual Multi Receiving Frequency to COLLECT RAIN WATER FROM ATMOSPHERE or from AMNIOTIC FLUID FROM SPACE VACUUM.

Dual Multi Transmitting Frequency to PRODUCE RAIN WATER IN ATMOSPHERE or from AMNIOTIC FLUID FROM SPACE VACUUM.

THOSE IS KNOWLEDGE YOU MUST COMPREHEND AND UNDERSTAND AND HAVE, to comprehend what HAARP project is doing in Alaska and how they in narrow beam transmitting Dual Multi Transmitting Frequency to PRODUCE RAIN WATER IN ATMOSPHERE and make that water as RAIN COME TO SPECIFIC AREA ON THE SURFACE ON PLANET EARTH. HAARP - High Frequency Active Auroral Research Program.

Hydroxyl molecules, composed of one atom of hydrogen and one atom of oxygen (OH), emit at four specific radio frequencies ranging from 1612 MHz to 1720 MHz.

REMEMBER THIS
When a hydrogen atom combines with a hydroxyl molecule it forms a molecule of water, the most essential molecule for life as we know it.

Thus, the range of frequencies from 1420 to 1720 MHz is called the Water Hole.

It’s a band of radio frequencies sandwiched between emission from neutral hydrogen – 1,420 MHz (a wavelength of 21cm) – and emission from molecules of hydroxyl (1,666MHz, 18cm wavelength), which is composed of one atom of hydrogen, and one atom of oxygen.

Combine hydroxyl and neutral hydrogen, and you’ve got a water molecule, H20.

The 21cm line, the most famous in astronomy, is produced by a quantum peculiarity in the nature of the electrons within the hydrogen atom.

Particles have a property called spin, and every now and then the spin axes of the electron and the proton within a neutral hydrogen atom will switch from a parallel configuration to an anti-parallel one (to grasp what anti-parallel means, an analogy is to think of two bar magnets, lined up side by side, but with their north and south poles pointing in different directions to one another).

When the switch takes place – which for a single hydrogen atom is a very rare occurrence, but given all the countless neutral hydrogen atoms in the Galaxy the laws of probability suggest that it’s a surefire bet that there are plenty undergoing the switch at any one time – the electron moves to a lower energy state and a radio photon is emitted, with a frequency of 1,420MHz.