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Same for chickens the wattles signal Sexual Attraction & Mating (Tidbitting) Health, Vitality Indicator, Illness or Infertility,
Social Status and Pecking Order
👉 Hollow melanosomes evolved multiple times independently in birds.
🐦 Birds-of-paradise (Paradisaeidae)
e.g. Paradisaea raggiana
🐦 Some hummingbirds (Trochilidae)
e.g. Calypte anna
🐦 Sunbirds & related passerines (Nectariniidae)
e.g. Cinnyris jugularis
Textbook case of convergent evolution 🧬.
www.youtube.com/watch?v=q44z...
Elephants 🐘
Horses 🐴
Deer 🦌
Rabbits 🐰
Unlike human earlobes, a turkey’s earlobe:
Protects the ear opening (which is hidden under feathers)
May play a role in communication or signaling (color can change slightly)
Some researchers suggest earlobes may have been useful in:
Attractiveness cues (e.g., symmetry, health)
Adornment (like earrings), which plays a role in culture and identity
Evolutionary leftover
Earlobes are likely a vestigial trait, meaning they don’t serve a strong purpose today but came along as part of the overall ear structure during human evolution.
Social & sexual signaling
Sensation: They’re rich in nerve endings, making them sensitive to touch.
🧠 When to Use Each
✅ Choose Octave if:
You want free software
You’re learning linear algebra / numerics
Your tasks are basic to moderate
You don’t need specialized toolboxes
🚧 Limitations
LibreOffice Calc does NOT support:
Eigenvalues / eigenvectors
SVD or QR decomposition
For those, you’ll need tools like:
MATLAB
GNU Octave
Python with NumPy
🔍 4. Determinant
=MDETERM(A1:C3)
🔄 5. Matrix Inverse
=MINVERSE(A1:C3)
🧮 6. Solve a Linear System (Ax = b)
Suppose:
A is in A1:B2
b is in C1:C2
Then:
=MMULT(MINVERSE(A1:B2); C1:C2)
This gives solution vector x.
⚠️ Note: In Calc, semicolons (;) are often used instead of commas.
Steps:
Select the output range (correct size!)
Type the formula
Press Ctrl + Shift + Enter (for array formulas)
🔁 3. Transpose a Matrix
=TRANSPOSE(A1:C3)
Again:
Select output range first
Press Ctrl + Shift + Enter
You can do linear algebra in LibreOffice Calc (very similar to Excel), using built-in matrix functions.
🔢 1. Enter a Matrix
Just type values into cells.
Example (3×3 matrix in A1:C3):
1 2 3
4 5 6
7 8 9
✖️ 2. Matrix Multiplication
Use:
=MMULT(A1:B2; D1:E2)
Dat domrechts de eigen beloftes niet kan waarmaken, wanneer het eenmaal aan de macht is, leidt daarom niet automatisch tot electoraal verlies.
Steven Stillman, ‘A vicious circle?: Populists and their social-economic promises’, KEW (7 februari 2024).
De belangrijkste oorzaak van de woningnood is het wanbeleid van de afgelopen kabinetten, dat vooral bestaat uit decennialang bezuinigen op woningcorporaties. Met name de in 2013 Rutte II ingevoerde verhuurderheffing, een ⬆️belasting op de verhuur van sociale huurwoningen ...
Van Haga haalde met zijn partij BVNL geen zetel bij de verkiezingen van 2023 & begon daarna een ‘buitenparlementaire fractie’ in een kantoortje in Haarlem. Dat heeft verder geen vileine adjectieven nodig; vanuit dat hoofdkwartiertje zit hij nu vooral op sociale media:
www.youtube.com/@WybrenVanHa...
Quasiserieuze kanalen die tijdens corona groot werden, of een stuk opvallender aanwezig waren dan eerst. Zoals www.youtube.com/@blckbx
, www.youtube.com/@DeNieuweWer..., De Andere Krant en natuurlijk www.youtube.com/@OngehoordNe..., dat in 2021 een plekje in het publieke bestel wist te bemachtigen.
www.youtube.com/watch?v=sQkd...
www.youtube.com/watch?v=Bmd1...
Ze mogen grote goud voorraden hebben, kwaliteit verschepen ze niet. Stoffen uit 🇮🇳, maar kleding uit oost 💶/🇹🇷. Wapens uit de 💵 of 💶💷? In 4/5 jaar na de waterstof energietransitie 🌎🌍hebben we weer WW3? Volg Ray Dalio voor meer info.
www.youtube.com/watch?v=SoKr...
Some spiders, especially ambush predators like trapdoor spiders, have highly sensitive hairs and receptors that detect temperature differences and heat gradients—but this is more like "feeling" than "seeing." These abilities are usually mediated through mechanosensory and thermosensory hairs, not 👀.
The NKVD was renamed after Stalin's death (1954). Part of Khrushchev's efforts to distance himself from Stalin's policies & to reform the Soviet security agencies. The KGB, stood for Committee for State Security, reflecting the agency's new role as a more limited & accountable security organization
The brain filter has nothing to do with visual acquity in the birds of prey who lack UV Sensitivity.
🐾 Cats respond better to consistency and reward
They won’t obey out ∨ loyalty ∨ discipline (self-discipline) — but they’ll learn a operant conditioning if it’s:
Consistent (same word ∧ gesture each time)
Rewarded (treats, play, praise)
Taught during calm, short sessions
Under threat we evolve: 🐅🦁🐯🐆
🙀 2. But obedience depends on motivation
🐈aren’t pack animals like 🦮, so they don’t have the same instinct to follow a leader.
Their response depends on:
What’s in it for them (food, attention, curiosity)
Whether they feel safe ∧ calm
Their personality — some breeds are more responsive than others.
🐳Brain 🧠 Processing: Building a Sound Image
The whale's brain analyzes the echoes to determine:
Distance (based on the time delay)
Size, shape, and material of the object
Movement (direction & speed)
This allows whales to "see" their environment with sound — a huge advantage in deep or dark waters.
🌲 Raspaillebos (Vlaamse Ardennen)
Dit beukenbos, gelegen op de steile flanken van de Bosberg, is rijk aan flora en fauna. Het herbergt onder andere buizerds, sperwers, vossen 🦊 en zeldzame planten zoals wilde hyacinten en sleutelbloemen.