#!/usr/bin/env python3 """ Daily Curiosity #5 — Чому лід плаває у воді? Schematic: liquid water (densely packed molecules) vs ice (open hexagonal lattice with more empty space) → ice is ~9% less dense → floats. Below — a winter lake cross-section: ice on top, fish in liquid water below. """ import matplotlib.pyplot as plt from matplotlib.patches import FancyArrowPatch, Circle, FancyBboxPatch, Polygon import numpy as np # ---- Canvas ---- fig, ax = plt.subplots(figsize=(12, 7), dpi=160) ax.set_xlim(0, 12) ax.set_ylim(0, 7) ax.set_aspect('equal') ax.axis('off') # Cool, icy background bg = np.linspace(0, 1, 256).reshape(-1, 1) bg = np.repeat(bg, 256, axis=1) ax.imshow( bg, extent=(0, 12, 0, 7), cmap=plt.cm.colors.LinearSegmentedColormap.from_list( "icy_dark", ["#04111c", "#0a1d33", "#0f2a4a"] ), aspect='auto', zorder=0, ) # ---- Title and subtitle (Ukrainian) ---- ax.text( 6, 6.55, "Чому лід плаває у воді?", ha='center', va='center', fontsize=24, fontweight='bold', color='#eaf6ff', zorder=10, ) ax.text( 6, 6.05, "У льоді молекули шикуються в ажурні шестикутники — і займають більше місця, ніж у рідині", ha='center', va='center', fontsize=11.5, style='italic', color='#bcd9f5', zorder=10, ) # ---- Helper: draw a water molecule (one O + two H) ---- def draw_molecule(cx, cy, scale=0.18, angle=0.0, alpha=1.0, zorder=5): a = np.deg2rad(angle) # Oxygen O = Circle((cx, cy), scale, facecolor='#e84e4e', edgecolor='#7a1414', lw=0.8, alpha=alpha, zorder=zorder) ax.add_patch(O) # Two hydrogens at 104.5° h_off = scale * 1.55 h_ang = np.deg2rad(52.25) # half of 104.5 for sign in (-1, 1): hx = cx + h_off * np.cos(a + sign * h_ang) hy = cy + h_off * np.sin(a + sign * h_ang) # Bond ax.plot([cx, hx], [cy, hy], color='#cfe5ff', lw=0.9 * (1 + 0.4 * (zorder >= 6)), alpha=alpha * 0.85, zorder=zorder) # H atom H = Circle((hx, hy), scale * 0.55, facecolor='#cfe5ff', edgecolor='#5e7e9e', lw=0.6, alpha=alpha, zorder=zorder + 1) ax.add_patch(H) # ---- LEFT panel: liquid water (densely packed, irregular) ---- panel_left = FancyBboxPatch( (0.4, 2.6), 4.6, 2.85, boxstyle="round,pad=0.08,rounding_size=0.18", fc="#0d2138", ec="#9ec8f0", lw=1.2, zorder=2, ) ax.add_patch(panel_left) ax.text(2.7, 5.20, "рідка вода", ha='center', va='center', fontsize=13.5, fontweight='bold', color='#eaf6ff', zorder=11) ax.text(2.7, 4.92, "молекули рухаються близько одна до одної", ha='center', va='center', fontsize=9.5, style='italic', color='#bcd9f5', zorder=11) # Densely packed (jittered grid) molecules rng = np.random.default_rng(11) liquid_positions = [] for ix in range(7): for iy in range(4): x = 0.85 + ix * 0.62 + rng.uniform(-0.10, 0.10) y = 2.95 + iy * 0.45 + rng.uniform(-0.10, 0.10) if x < 4.85 and y < 4.65: liquid_positions.append((x, y, rng.uniform(-30, 210))) for (x, y, a) in liquid_positions: draw_molecule(x, y, scale=0.13, angle=a, zorder=6) # Density label ax.text(2.7, 2.78, "густина ≈ 1000 кг/м³", ha='center', va='center', fontsize=10, fontweight='bold', color='#9ec8f0', zorder=11) # ---- RIGHT panel: ice — open hexagonal lattice ---- panel_right = FancyBboxPatch( (7.0, 2.6), 4.6, 2.85, boxstyle="round,pad=0.08,rounding_size=0.18", fc="#0d2138", ec="#a9def0", lw=1.2, zorder=2, ) ax.add_patch(panel_right) ax.text(9.3, 5.20, "лід (твердий)", ha='center', va='center', fontsize=13.5, fontweight='bold', color='#eaf6ff', zorder=11) ax.text(9.3, 4.92, "шестикутна решітка — між молекулами більше «повітря»", ha='center', va='center', fontsize=9.5, style='italic', color='#a9def0', zorder=11) # Hex lattice positions (centers) inside right panel # We use a sparse hex grid so that "empty space" is visible hex_centers = [] hex_dx = 0.9 hex_dy = 0.78 for iy in range(3): y = 3.10 + iy * hex_dy x_off = 0 if iy % 2 == 0 else hex_dx / 2 for ix in range(5): x = 7.30 + ix * hex_dx + x_off if x < 11.40 and y < 4.75: hex_centers.append((x, y)) # Draw hex bonds (between nearest neighbors) for i, (x1, y1) in enumerate(hex_centers): for j, (x2, y2) in enumerate(hex_centers): if j <= i: continue d = np.hypot(x1 - x2, y1 - y2) if d < hex_dx * 1.05: # nearest neighbor ax.plot([x1, x2], [y1, y2], color='#7fc3e0', lw=1.3, alpha=0.6, zorder=4, linestyle='--') # Draw molecules at hex positions for (x, y) in hex_centers: draw_molecule(x, y, scale=0.13, angle=rng.uniform(-30, 210), zorder=6) # Density label ax.text(9.3, 2.78, "густина ≈ 917 кг/м³ (на ~9% менша)", ha='center', va='center', fontsize=10, fontweight='bold', color='#a9def0', zorder=11) # ---- Arrow between the two panels with caption ---- arr = FancyArrowPatch( (5.05, 3.95), (6.95, 3.95), arrowstyle='-|>', mutation_scale=22, color='#eaf6ff', lw=2.2, zorder=7, ) ax.add_patch(arr) ax.text(6.0, 4.30, "замерзає\n(0 °C)", ha='center', va='center', fontsize=10, fontweight='bold', color='#eaf6ff', zorder=11) ax.text(6.0, 3.55, "об'єм ↑\nгустина ↓", ha='center', va='center', fontsize=9.5, style='italic', color='#9ec8f0', zorder=11) # ---- BOTTOM section: lake cross-section ---- # Water body (deep blue) water_body = Polygon( [(0.5, 0.25), (11.5, 0.25), (11.5, 2.10), (0.5, 2.10)], facecolor='#0e3a64', edgecolor='#1a5a92', lw=1.0, zorder=2, ) ax.add_patch(water_body) # Ice layer on top (a sheet with a slightly jagged top) ice_top_y = 2.05 ice_pts = [(0.5, 1.65)] xs = np.linspace(0.5, 11.5, 60) for x in xs: bump = 0.08 * np.sin(x * 1.7) + 0.04 * np.sin(x * 4.3) ice_pts.append((x, ice_top_y + bump)) ice_pts.append((11.5, 1.65)) ice = Polygon(ice_pts, facecolor='#dff1ff', edgecolor='#9ec8f0', lw=1.0, zorder=3, alpha=0.92) ax.add_patch(ice) ax.text(6.0, 1.85, "лід (плаває зверху)", ha='center', va='center', fontsize=10.5, fontweight='bold', color='#1a3a5a', zorder=11) # Fish silhouettes below def draw_fish(cx, cy, size=0.22, color='#a9def0', flip=False): # Body — ellipse-ish polygon s = -1 if flip else 1 body = Polygon( [(cx - s * size * 1.3, cy), (cx - s * size * 0.5, cy + size * 0.5), (cx + s * size * 0.7, cy + size * 0.4), (cx + s * size * 1.0, cy), (cx + s * size * 0.7, cy - size * 0.4), (cx - s * size * 0.5, cy - size * 0.5)], closed=True, facecolor=color, edgecolor='#3a6a8a', lw=0.8, zorder=5, ) ax.add_patch(body) # Tail tail = Polygon( [(cx - s * size * 1.3, cy), (cx - s * size * 1.7, cy + size * 0.5), (cx - s * size * 1.7, cy - size * 0.5)], closed=True, facecolor=color, edgecolor='#3a6a8a', lw=0.8, zorder=5, ) ax.add_patch(tail) # Eye ax.plot([cx + s * size * 0.65], [cy + size * 0.12], 'o', color='#04111c', markersize=2.2, zorder=6) draw_fish(2.5, 1.10, size=0.20, color='#ffd86b', flip=False) draw_fish(5.7, 0.85, size=0.18, color='#a9def0', flip=True) draw_fish(8.6, 1.20, size=0.22, color='#ff9b6b', flip=False) draw_fish(10.2, 0.65, size=0.16, color='#cfe5ff', flip=True) # Liquid-water label ax.text(6.0, 0.45, "рідка вода (+4 °C на дні — найгустіша)", ha='center', va='center', fontsize=9.5, style='italic', color='#cfe5ff', zorder=11) # Subtle horizontal "thermocline" line near top of liquid water ax.plot([0.5, 11.5], [1.55, 1.55], color='#9ec8f0', lw=0.7, linestyle=':', alpha=0.6, zorder=4) # Bottom note about life on Earth ax.text(6.0, 0.05, "якби лід тонув — водойми промерзали б до дна, і риби, і життя зникли б", ha='center', va='center', fontsize=9.5, fontweight='bold', color='#ffd86b', zorder=11) plt.tight_layout() out = "/sessions/gifted-sharp-dijkstra/mnt/daily-curiosity/daily-curiosity-05.png" plt.savefig(out, dpi=160, facecolor='#04111c', bbox_inches='tight', pad_inches=0.15) print(f"Saved: {out}")