বিরল খনিজ উপাদান আসলে কী ?
পৃথিবীর বুকে এমন কিছু রাসায়নিক উপাদান রয়েছে যেগুলো কিছুটা দুষ্প্রাপ্য হলেও, আমাদের আধুনিক জীবনের জন্য এগুলো অপরিহার্য। মোবাইল ফোন, ল্যাপটপ, ইলেকট্রিক গাড়ি থেকে শুরু করে উইন্ডমিল, স্যাটেলাইট কিংবা মিসাইল ডিফেন্স সিস্টেম পর্যন্ত প্রায় সকল প্রযুক্তিপন্যেই এই উপাদানগুলোর ব্যবহার রয়েছে। এসব উপাদানকেই বলা হয় Rare Earth Elements বা বিরল খনিজ উপাদান। এগুলো টেকনোলজির হীরা হিসেবেও পরিচিত।
এই উপাদানগুলো পৃথিবীর ভূত্বকে এমনভাবে ছড়িয়ে রয়েছে যে, এগুলোকে সহজে আলাদা করা যায় না, সে জন্যই এগুলো ‘বিরল’ হিসেবে পরিচিত। শুধুমাত্র এইসব খনিজ পদার্থের জন্যই যুক্তরাষ্ট্র বানাম চীনের মধ্যকার বানিজ্য যুদ্ধ ভয়াবহ পর্যায়ে পৌছে গেছে।
Rare Earth Elements বা বিরল খনিজ উপাদানগুলো আসলে কী এবং এগুলো কতটা গুরুত্বপূর্ন, সে সম্পর্কে আলোচনা করা হবে কিকেনকিভাবে র এই পর্বে।

The Ocean Is Deeper Than You Think. We Need Better Maps.Why deep sea maps are SO BAD (and how to fix it)...
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Our maps of the ocean are surprisingly bad! On Google Maps it looks like we know so much… but we know less about the ocean floor than we do the surface of Mars. And that’s a big problem, because we are using the ocean all the time: We’re laying internet cables across it, we fight wars in it, we search it during a crisis - like the imploded OceanGate Titan submersible or the missing Malaysia Airlines Flight 370. 71% of the surface of the Earth is water! And yet we have a surprisingly limited view of what’s below it.

But that’s also understandable. Because cartographically speaking, water sucks. For Mars or Earth’s surface, we can take pictures. But light doesn’t get to the ocean floor, so we need other ways to see it. The good news is, we’re developing that tech right now, and an international group called Seabed 2030 is working to piece together a better map.

There is a terrifying, incredible, alien world on our own planet, and we’re FINALLY using technology to see it more clearly.

In this episode of Huge If True, I dive deep - with help from my friend and fellow video journalist ‪@johnnyharris‬
to show you how we’re mapping the ocean, the surprising things we’ve discovered in the depths, and why this new technology could be… huge if true :)

Chapters:
00:00 How bad are our ocean maps?
01:40 How deep is the ocean?
03:05 What is the deepest part of the ocean?
04:04 The craziest method to map the ocean
06:20 How does sonar work?
07:31 What did the first ocean maps look like?
09:30 How do we map the ocean now?
10:30 What is Seabed 2030?
11:40 How do we use underwater robots?
12:27 Concerns with mapping the deep ocean
13:11 Why deep ocean mapping is huge if true

In one of the driest places on Earth…
Fresh water is appearing — from thin air and sunlight.

In the Atacama Desert, Chilean scientists have created solar desalination domes that extract drinking water from the sea using only heat and condensation.

No filters.
No wires.
Just glass, saltwater, and sunlight.

Each dome pulls in ocean water, evaporates it using solar heat, then condenses clean water inside — like artificial rain.

They're off-grid, low-maintenance, and can produce thousands of liters per day.

In a world of water crises…
Chile just built a solution in glass.

Deep in the mountainous region of Gifu Prefecture, Japan has unveiled a stunning engineering achievement: a concrete bridge that repairs itself — no human workers needed. At first glance, it looks like any other bridge. But inside its foundation lies a living secret.

Scientists from the University of Tokyo embedded microscopic bacteria into the concrete mix. When cracks appear — even hairline fractures — moisture and oxygen activate these dormant microbes. The bacteria then produce limestone, sealing the cracks from the inside out. No machines. No manual patchwork. Just living concrete at work.

This breakthrough is more than impressive — it’s lifesaving. In Japan, where earthquakes frequently damage infrastructure, tiny cracks can lead to catastrophic failures over time. But now, this bridge senses damage and begins healing in real-time, sometimes within just 24 hours of a rupture.

Over a six-month test, engineers tracked dozens of fractures forming and then vanishing — sealed by biological action, not cement. The bacteria can stay dormant for up to 200 years, meaning the bridge could maintain itself longer than any human-built one in history.

Imagine cities where roads, tunnels, and skyscrapers quietly repair themselves every night — no closures, no traffic, no danger. This isn’t just futuristic thinking. It’s already real, and Japan is leading the way.