Eksperyment (1) Przemiany fazowe H2O.
Diagram faz wody ilustruje ten efekt: zmniejszanie ciśnienia (przesuwanie się w dół osi Y) powoduje przejście wody ze stanu ciekłego w gazowy, a chłodzenie (przesuwanie się w lewo osi X) powoduje przejście wody ze stanu ciekłego w stały.
Jonny Kim @JonnyKimUSA 1:35 PM · Mar 28, 2025
T+417 (10.17.24): Experiment (1) H2O Phase Transitions
Place a bowl of water at room temperature under normal atmospheric pressure. Then, depressurize the chamber to a vacuum. You will observe the water beginning to boil slowly, then more violently, before eventually forming chunks of ice. Why does this happen?
Water exists in three phases: solid (ice), liquid (water), and gas (water vapor, sometimes called steam when above the boiling point). This experiment demonstrates the relationship between water's phase, pressure, and temperature.
At sea level, water boils at 100°C (212°F) under standard atmospheric pressure. If you travel to higher altitudes, where atmospheric pressure is lower, you may have noticed that water boils at a lower temperature. This occurs because a decrease in pressure lowers the boiling point, requiring less energy for water molecules to transition into the gas phase. While boiling is often associated with heat, it simply refers to the phase transition from liquid to gas, which depends on pressure as well as temperature.
In this experiment, as the chamber is depressurized to a vacuum, the pressure drops rapidly, lowering the boiling point of water to below room temperature. This causes the water to boil violently. As it evaporates, the process removes heat from the remaining liquid (a phenomenon known as evaporative cooling), causing the water’s temperature to drop quickly. This continues until the water cools below its freezing point, at which point it suddenly turns to ice.
A water phase diagram illustrates this effect: reducing pressure (moving down the Y-axis) transitions water from liquid to gas, while cooling (moving left on the X-axis) transitions it from liquid to solid.
https://x.com/JonnyKimUSA/status/1905599531724517663(2)
Eksperyment Galileusza
ze spadaniem obiektu wykonany przez astronautę w komorze próżniowej z użyciem kawałka mylaru i bloku teflonu.
Jonny Kim @JonnyKimUSA 3:01 PM · Mar 28, 2025
T+417 (10.17.24): Experiment (2) – Galileo's Fall Experiment
Until Galileo, a 16th-century astronomer, people believed that the speed at which an object fell depended on its mass—specifically, that heavier objects always fell faster than lighter ones. However, in the 1600s, Galileo proposed that if air resistance were negligible, objects of different masses would fall at the same rate.
In this experiment, I have two objects inside the depressed vacuum chamber: a piece of mylar (the stuff from helium balloons) and a Teflon block. Under normal atmospheric conditions, the Teflon block would fall faster than the mylar. However, in a vacuum, when both objects are dropped from the same height, they hit the ground simultaneously. Why?
This happens because, in normal atmospheric conditions, air molecules create resistance, and lighter objects like feathers experience more drag relative to their weight, slowing their fall. In a vacuum, with no air molecules to cause resistance, all objects accelerate equally due to gravity.
Astronaut David Scott demonstrated this principle during Apollo 15 when he dropped a hammer and a feather on the Moon, and both struck the lunar surface at the same time.
(3)
Załoga rozpoczęła serię przeglądów poprzedzających końcowy egzamin kwalifikacyjny, który odbywa się tuż przed kwarantanną i startem.
Załoganci skupiali się na pracy zespołowej w sytuacjach nietypowych, zarówno w rosyjskim segmencie ISS, jak i na pokładzie Sojuza.
Jonny Kim @JonnyKimUSA 11:47 AM · Mar 29, 2025
T+431 (10.31.24): After the launch of Don's Soyuz MS-26 crew, our backup crew (MS-27) became the prime crew. As members of the prime crew, we began a series of reviews leading up to a final qualification exam, which takes place just before quarantine and launch. Similar to how international astronauts receive integrated training when they travel to Houston, American astronauts also collaborate with international instructors on integrated training while overseas. During this trip, our Soyuz crew focused on teamwork in off-nominal situations, both in the Russian segment of the ISS and aboard the Soyuz. Photos courtesy of Roscosmos.
https://twitter.com/JonnyKimUSA/status/1905934751287877674
Wątek: JY'J' Kim - 05.02.1984 (Przeczytany 18308 razy)