The practice of using stethoscopes started in a hospital in Paris, in the early 19th Century.

The Necker-Enfants Malades Hospital in Paris provided specialised medical care. Rene Laennec, one of the doctors there, was trained to use sound to diagnose diseases of the chest.

One day in 1816, a young woman who had a heart problem came to consult Dr. Laennec. Ordinarily, the physician would have put his ear to the woman's chest and listened to her heartbeats to detect if there was any aberration. But the woman who came to see Dr. Laennec was rather plump. Uncomfortable with the idea of putting his ear to her chest, the doctor's eyes fell on a newspaper lying there...and he got a brainwave!

He rolled the newspaper into a cylinder and applied one end of it to the region of the woman's heart and the other to his ear. And then his own heart thumped in joy and excitement! He could hear her heartbeats more clearly than if he had put his ear directly to her chest. It was a landmark moment in medical science.

Laennec fashioned a hollow, wooden cylinder and catalogued the various sounds he could hear through it when applied to a patient's chest, and what the sounds indicated about the health of the patient. He sent his findings to the Academy of Science, in Paris.

It was not long before his invention began to be used by physicians all over Europe.

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Food waste is a huge problem worldwide. In Japan alone, the edible food waste produced in 2019 amounts to 5.7 million tons. While their government aims to reduce that to around 2.7 million tons by 2030, there are others who are working on the same problem differently. Researchers from Tokyo University, for instance, have found a new method to create cement from food waste.

In addition to addressing the issue of food waste, the researchers also hope to reduce global warming in this way. Apart from the estimate that cement production accounts for 8% of the world's carbon dioxide emissions, there is also the fact that wasted food materials rotting in landfills emit methane. By using these materials to make cement, scientists hope to reduce global warming.

The researchers borrowed a heat pressing concept that they had employed to pulverise wood particles to make concrete. By using simple mixers and compressors that they could buy online, the researchers used a three-step process of drying. pulverising, and compressing to turn wood particles into concrete.

Heat pressing concept

Following this success, they decided to do the same to food waste. Months of failures followed as they tried to get the cement to bind by tuning the temperature and pressure. The researchers say that this was the toughest part of the process as different food stuff requires different temperatures and pressure levels.

The researchers were able to make cement using tea leaves, coffee grounds, Chinese cabbage, orange and onion peels, and even lunch-box leftovers. To make this cement waterproof and protect it from being eaten by rodents and other pests, the scientists suggest coatings of lacquer.

Cement that can be eaten!

Additionally, the researchers tweaked flavours with different spices to arrive at different colours, scents, and taste of the cement. Yes, you read that right. This material can even be eaten by breaking it into pieces and then boiling it.

The scientists hope that their material can be used to make edible makeshift housing materials for starters, as they are bound to be useful in times of disasters. If food cannot be delivered to evacuees, for instance, then they could maybe eat makeshift beds prepared from food cement. The food cement that they have created is reusable e and biodegradable.

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What is the furthest down humans have gone? What is the Kola superdeep Borehole? Read on to find the answers.

In Jules Verne's science fiction novel, Journey to the Centre of the Earth (1864), three men reach the centre of the Earth. Is this ever possible? Our planet is made up of three main layers- the crust, the mantle and the core. The continents and oceans are situated on the crust which is about 8 km thick under the oceans and between 35 and 40 km deep under the continents. Below the crust is the mantle which is about 2,900 km thick. Next comes the core. The outer core, about 2.250 km thick, is made up of melted iron and nickel, and contained within it, is a ball-shaped inner core believed to be made up of solid iron and nickel.

The centre of the innermost core is the centre of the Earth. So there are thousands of kilometres to descend to reach the centre of the Earth, and what is the furthest down we've gone? When the Russians and the Americans were engaged in a race to the moon several decades ago, they also embarked on a race to inner space to see how far down they could go. While the Americans did not make much headway in this race downwards (Project Mohole'), the Russians went at it, hammer and tongs, in the Kola Peninsula and dug a hole 12.262 km deep over a period of 24 years from 1965 to 1989. They wanted to go at least 15 km down,  but just could not. This is the closest we've been able to go to the centre of the Earth. The Kola Superdeep Borehole, as it is now called, attracts curious visitors from around the world.

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What happened when you browse the Net in incognito mode? Does it ensure anonymity?

You may have noticed a tab in Google Chrome and other browsers called private/incognito. Browsers usually store the web addresses or URLS of the sites you visit. That makes it easier for you to find them again later. In private (incognito) mode, your search history won't be stored on the device you are using.

Your browser also stores cookies. These small data files can not only automatically enter passwords, so you don't have to type them each time, they can also provide tracking information to advertising companies that want to figure out your browsing habits. If you have looked for the best sunglasses available in the market, for example, ads for sunglasses keep popping up on whatever website you are visiting! This is how the internet advertising industry creates detailed profiles of people's online activities over time.

Private or incognito browsing helps here, since it can temporarily disconnect someone's browsing from the technical means used to build up and maintain most of those profiles. Cookies won't provide advertisers with the detailed information they'd otherwise mine. Sometimes private browsing enables you to get around paywalls that block you from reading content on subscriber-only sites. However, going incognito won't make you anonymous or invisible online! Your internet service provider can track your web activities. The sites you visit will also know your location. And if you are logged in to your Google account when browsing, Google sees your search patterns, even in incognito mode.

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TikTok took the top spot for most downloaded app in the first three months of 2022, beating Instagram and Facebook. The short-form video sharing app TikTok was the most downloaded app worldwide in first three months of 2022, according to a report from Sensor Tower.

TikTok is one of the world’s fastest-growing social media platforms. Sensor Tower recently released its “Q1 2022: Store Intelligence Data Digest” report in which TikTok was the top app by worldwide downloads in Q1 2022. The app previously had surpassed 3.5 billion all-time downloads in the first quarter of 2021, becoming just the fifth app (and the only one not owned by Meta) to achieve this milestone.

Since the start of 2022, TikTok has been downloaded more than 175 million times. TikTok has surpassed 10 million downloads for the past nine quarters now, while YouTube has surpassed the same threshold for eight consecutive quarters. No app has had more downloads than TikTok since the beginning of 2018 when WhatsApp had 250 million worldwide downloads, per the report.

There’s a lot to be said about the success of TikTok and where it’s going. The social media app is mainly dominant for its relevant trends, unique algorithm and a diverse set of communities for every niche subject matter. Just recently, its updates include interactive add-ons for in-feed ads as well as a test on a private dislike button for comments. It also recently launched its own AR development platform, Effect House.

When examining the global downloads on iPhones and iPads, the order of the top five apps has remained unchanged over the past three quarters. TikTok exceeded 70 million App Store downloads for only the third time in Q1 2022, driven by 11% quarter-over-quarter growth in Asia. Despite being banned in India, which has one of the largest markets for app installs in the world, the app was ranked third place overall in Asia. It was No. 1 in the App Store, yet in seventh place for Google Play in Asia.

Looking at U.S. overall downloads, TikTok has been the top app each quarter since Q1 2021. The last app to beat TikTok was Zoom in Q4 2020. Also, since Q1 2021, TikTok and YouTube have been the top two apps on the U.S. App Store each quarter. TikTok was also the number one app on Google Play for the third quarter in a row, with installs up 19% year-over-year.

The same five apps have taken the top spots in Europe for each of the past four quarters. TikTok and WhatsApp were in the top two positions, while Instagram went down a ranking from last quarter to the number four spot. Even though WhatsApp has been the top App Store app in Europe for each of the past seven quarters, TikTok has also held on to the top spot on Google Play over the same period.

These estimates made by Sensor Tower include worldwide downloads for iPhone, iPad and Google Play for January 1 through March 31, 2022. This excludes preinstalled apps. The company only reports unique installs and Android estimates do not include third-party stores. The figures represent aggregate installs of all app versions.

Credit : Tech crunch \

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