Knowledge Nexus

Top 5 Best-Selling Smartphones in the World: Based on Real Sales Numbers The smartphone industry is full of innovation and constant upgrades, but only a few models have truly made history by dominating global sales charts. In this post, we break down the top 5 best-selling smartphones of all time , based on real worldwide sales data. Let’s find out which models earned a spot in the smartphone hall of fame! 1st – iPhone 6 and iPhone 6 Plus Release Year: 2014 Estimated Sales: Around 220 million units The iPhone 6 series marked a turning point for Apple. It was the first iPhone to feature a larger screen (4.7” and 5.5”) , attracting many Android users who preferred big displays. Its sleek design, improved camera, and excellent performance helped make it Apple’s best-selling model ever. 2nd – iPhone 6s and iPhone 6s Plus Release Year: 2015 Estimated Sales: Around 174 million units Following the success of the iPhone 6, this model offered meaningful upgrades: ...

  Mouthwash vs Floss vs Waterpik vs Brushing vs Salt Water Rinse: Which Removes More Bacteria? Maintaining oral hygiene isn’t just about brushing your teeth anymore. 🦷 Many people ask, “Is mouthwash effective?” or “Should I use floss or a Waterpik?” Today, we’ll dive into a science-based comparison of five popular oral hygiene methods: 👉 Brushing, Salt Water Rinse, Mouthwash (like Listerine), Flossing, and Waterpik , focusing on bacterial removal rates (%) and real-world effectiveness. Let’s find out which method actually works best! 💡 🪥 Brushing Alone – The Basic but Not Enough Brushing is the foundation of oral hygiene, but it has its limits. Studies show brushing alone removes only 60–70% of oral bacteria . It’s less effective in cleaning tight spaces between teeth or along the gumline. ✅ Brushing is essential, but not sufficient on its own for full bacterial control. 🧴 Mouthwash (e.g., Listerine): Convenient but Temporary Mouthwash is popular be...

  Title: Do Teeth Shift After 1 Year Without a Retainer? Is Nighttime Removable Retainer Enough? 🦷 Why Retainers Are Essential After Braces Even after your teeth look straight, they’re not “locked” in place. Teeth naturally shift back if the supporting bone and ligaments haven't fully stabilized. That’s where retainers come in! ⏱ Is 1 Year of Wearing a Retainer Enough? No — wearing a retainer for only 1 year can cause relapse . Orthodontists typically recommend: Removable retainers : 1–2 years minimum Permanent retainers : Often lifelong It varies based on age, bone structure, and prior alignment 🌙 Is Wearing a Removable Retainer at Night Enough? Not always. Here's why: In the first 6 months , full-day wear is ideal Night-only wear can begin after stabilization But inconsistent use leads to teeth shifting 🔄 Fixed vs Removable Retainers Type Pros Cons Fixed Always active, no forgetfulness Requires careful cleaning Removable Easy to clean,...

  Title: Do You Really Need to Remove an Impacted Wisdom Tooth? Pain, Causes, and When to Extract 🤔 What is a Wisdom Tooth? Wisdom teeth, also known as third molars, typically appear between ages 17 and 25. However, in many cases, they do not erupt properly due to lack of space. This leads to impacted wisdom teeth , causing pain or complications. ⚠️ Why Do Impacted Wisdom Teeth Hurt? Pericoronitis (inflammation around a partially erupted tooth) Tooth Decay due to difficulty cleaning Pressure Pain from the tooth pushing nearby teeth Jaw Pain or Swelling from nerve involvement 🚨 When Should You Remove a Wisdom Tooth? You should consider removal if: Pain occurs repeatedly or intensifies Swelling or pus develops Nearby teeth are damaged or decayed CT scan shows nerve involvement You are preparing for braces or implants 🦷 An impacted tooth can cause long-term problems if left untreated. 🛑 When You Might Not Need Removal The tooth is ...

  How to Free Up KakaoTalk Storage in 2025 📱 Delete Group Chat History Easily KakaoTalk is Korea’s favorite messenger app — but it can eat up storage fast, especially with group chats (DanTalks) where media files accumulate daily. In this 2025 guide, learn how to check and delete chat history in KakaoTalk to free up space and speed up your device. 📊 Why Does KakaoTalk Take So Much Storage? Auto-saved images Shared videos & files Multiple group chats Duplicate content All this adds up quickly and can easily exceed 5–10 GB ! 📁 How to Check Storage Usage Open KakaoTalk Tap More (≡) → Settings Go to Chat → Storage Management You’ll see space used by photos, videos, and chat From here, you can delete content by type. 🗑️ Delete Group Chat History (Only) Don’t want to leave the group, but want to clear the clutter? Open the group chat Tap [≡] in the upper-right Tap “Chat Settings” → “Delete All Messages” The room remains, but all...

  🥇 Top 10 Best-Selling Korean Ramen (2025) Shin Ramyun (Nongshim) The world’s most iconic Korean ramen Spicy broth, chewy noodles Jin Ramen Spicy (Ottogi) Mildly spicy, budget-friendly A favorite among all ages Ansungtangmyun (Nongshim) Mellow and light broth Old-school Korean favorite Chapagetti (Nongshim) Black bean noodle classic Famous for “Chapaguri” in Parasite Buldak Bokkeummyun (Samyang) 🔥 Fire noodle challenge star Extremely spicy, addictively good Samyang Ramen Original Korea’s very first ramen Simple, savory, nostalgic Yukgaejang Cup Ramen Top-selling cup noodle Great for travel and convenience Teumsae Ramen Extra spicy & garlicky Cult favorite for spice lovers Neoguri (Nongshim) Thick udon-style noodles Seafood-flavored broth Jin Jjambbong (Ottogi) Deep, rich seafood & spice Tastes like real jjambbong! 🔍 Why Are These Ramen So Popular? Global ...

  🌌 How Was the Universe Born? Understanding the Origin of the Universe and What Came Before the Big Bang Have you ever stared at the night sky and wondered, “How did the universe begin?” It’s one of the oldest and most profound questions humanity has ever asked. Today, let’s explore the origin of the universe through the Big Bang theory —and go one step further to examine what may have existed before the Big Bang . Even if you’re new to cosmology, don’t worry—this guide is beginner-friendly and easy to follow. 🚀 🔭 What Is the Big Bang Theory? The Big Bang theory is the most widely accepted scientific explanation for how the universe began. 🧠 Key Concepts: Around 13.8 billion years ago , the universe started from a singularity —an infinitely dense point. In an instant, this singularity exploded and expanded , giving rise to time, space, energy, and matter . The universe has been expanding ever since , and still is today. 🧪 Scientific Evidence Supporting ...