When a ball is thrown upward, its kinetic energy decreases & gravitational potential energy increases; the reverse is true on its way down (ignoring drag, mechanical energy is constant).

#thermodynamics #engineering #science #engineeringscience #physics #mechanicalengineering

Zoomposium with Prof. Dr. Arieh Ben-Naim: “Demystifying Entropy”

He believes that we need a new fundamental understanding of the phenomenon of entropy. Entropy, which originally stems from the second law of thermodynamics, has, in Arieh's view, been misused and incorrectly transferred as a concept to other areas of physics, biology, and everyday life.

More on this at:https://open.spotify.com/episode/6l0bnl0eU0CUqmAEo8DZf7?si=wJ2EEsQ6QK2HjZMTVGsJZw

or: https://philosophies.de/index.php/2024/02/22/entzauberung-der-entropie/

#Science #Philosophy #PhysicsAndItsLimits #ScienceAndPhilosophy #entropyzero2 #InformationTheory #SecondLawOfThermodynamics #LimitsOfPhysics #Entropy #SecondLaw #Irreversibility #StatisticalMechanics #Thermodynamics #ShannonInformation #Probability #Randomness #Time #ArrowOfTime #Metaphysics #LifeSystems #Evolution #Negentropy #AriehBenNaim #EntropyDemystified #PhysicsMyths

Only energy changes have physical meaning; absolute energies are reference state dependent. Don’t assume you know what these reference states are; always verify.

#thermodynamics #engineering #science #engineeringscience #physics #STEM #energy #mechanicalengineering

Basics of Numerical Weather Prediction (NWP):

1. THE HORIZONTAL MOMENTUM EQUATION:
\[
\frac{d\mathbf{V}}{dt} + f\hat{k} \times \mathbf{V} = -\nabla \phi + \frac{\sigma}{p_s} \frac{\partial \phi}{\partial \sigma} \nabla p_s + \mathbf{F}
\]

2. THE CONTINUITY EQUATION:
\[
\frac{\partial p_s}{\partial t} + \nabla \cdot (p_s \mathbf{V}) + \frac{\partial}{\partial \sigma}(p_s \dot{\sigma}) = 0
\]

3. THE THERMODYNAMIC ENERGY EQUATION:
\[
\frac{1}{R} \frac{d}{dt} \left[ \sigma \frac{\partial \phi}{\partial \sigma} \right] + \frac{RT}{C_p p} \left[ p_s \dot{\sigma} + \sigma\dot{p_s} \right] = -Q
\]

4. HYDROSTATIC EQUATION:
\[
\frac{\partial \phi}{\partial \sigma} = -\frac{RT_v}{\sigma}
\]

5. SURFACE PRESSURE TENDENCY EQUATION:
\[\displaystyle
\frac{\partial p_s}{\partial t} = -\int_{0}^{1} \nabla\cdot (p_s \mathbf{V}) \, d\sigma
\]

6. MOISTURE EQUATION:
\[\displaystyle
\frac{\partial}{\partial t} (p_s q) + \nabla\cdot (p_s q \mathbf{V}) + \frac{\partial}{\partial \sigma} (p_s q \dot{\sigma}) = p_s S
\]

The six primary unknowns are: \(\mathbf{V}\) (horizontal wind velocity), \(p_s\) (surface pressure), \(T\) (temperature), \(q\) (specific humidity or moisture), \(\phi\) (geopotential), and \(\dot{\sigma}\) (sigma velocity or vertical velocity in \(\sigma\)-coordinates).

#NWP #Weather #NumericalWeatherPrediction #Meteorology #Climate #ClimateScience #Earth #EarthScience #ClimateChange #ClimateSciences #Science #WeatherPrediction #Humidity #Moisture #Pressure #Velocity #SurfacePressure #HydrostaticEquation #WeatherPrediction #Ocean #Atmosphere #AOS #ClimateDynamics #WeatherDynamics #Geopotential #SigmaVelocity #VerticalVelocity #MoistureEquation #Thermodynamics #Dynamics #NavierStokes

Physics Expert (PhD)
Mercor

See the full job description on jobRxiv: https://jobrxiv.org/job/mercor-27779-physics-expert-phd/

#classicalmechanics #quantummechanics #statisticalphysics #thermodynamics #ScienceJobs #hiring #research
https://jobrxiv.org/job/mercor-27779-physics-expert-phd/?fsp_sid=1516

Heat transfer 🔥& work ⚙️are forms of energy 🔋; energy that is transferred into or out of a system. W (into the system) < 0 is a chosen sign convention. Be consistent w/ your sign conventions.

#thermodynamics #engineeringscience #engineering #physics #mechanicalengineering #thermosolutions