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How Machilipatnam became site of a pioneering discovery in 19th century



How Machilipatnam became site of a pioneering discovery in 19th century

By Dr Biman Nath

Machilipatnam is one of the oldest port towns on the Andhra coast. Very few Indians would know that it was also the site of a landmark discovery 150 years ago that laid the foundation of a new branch in science – astrophysics.

It was in Machilipatnam that the world caught the first glimpse of light from a new material – helium. Though helium balloons may be commonplace today, helium was not known back then. The first sign that it existed came not from a chemistry laboratory but from looking at the Sun’s corona or outer layer during a total solar eclipse.

The total solar eclipse that occurred on August 18, 1868 caused much excitement among astronomers. It offered them a chance to look at the outer part of the sun. It made it possible for them to detect the presence of helium in the Sun. That is why the newly discovered element was named after the Greek word ‘helios’ for sun.

The eclipse was visible from the southern part of India for 6 minutes 47 seconds. During a total solar eclipse, the moon comes between the Earth and the Sun and blocks our view of the Sun (rather, the brightest part of the Sun). The most spectacular part of the event is the sighting of the corona which is otherwise not visible to us. The corona dazzles in the sky when the main disc is blocked.

Astronomers were hoping to study the corona during the 1868 solar eclipse. There were reasons to do so. We know that a prism ‘breaks down’ sun rays into different colours. If one looked closely, one would find numerous dark lines superposed on the background rainbow colours. It wasn’t clear where these dark lines came from. Darkness in a spectrum means a missing portion of light. Some light from the Sun was being robbed, and one didn’t know the culprit.

The path of totality of the eclipse cut across present-day Maharashtra and Andhra Pradesh. A team of astronomers from the Royal Astronomical Society set camps in Guntur under the leadership of Major James Francis Tennant. A French astronomer, Pierre Jules Janssen, too came to Guntur. He had designed a ‘spectroscope’ with which one could distinguish lines of adjacent colours in a spectrum. Then there was the Government Astronomer of Madras Observatory, Norman Robert Pogson, who had cobbled together a team of engineers from the Railways and the newly founded Telegraph Department for the expedition. He had camped in the nearby port town of Masulipatnam (present day Machilipatnam).

They were trying to validate a theory proposed in 1859 by German scientists – Gustav Kirchhoff and Robert Bunsen – that all materials radiate in characteristic colours when hot—like sodium burns with a yellow flame and copper with a bluish-green flame. When you look at the hot glowing gas through a prism you won’t see all the rainbow colours but a few discrete bright ‘lines’, shining at the characteristic colours of the material. Now let the gas cool and put it in the path of some background white light (which shines in all the colours). The cold gas would then absorb light of precisely those colours that it would have itself radiated when hot. And you would see dark lines in the spectrum of the background white source.

Handpainted spectrum (left) observed by Pogson (right), Photo credit : Indian Institute of Astrophysics Archives

Handpainted spectrum (left) observed by Pogson (right), Photo credit : Indian Institute of Astrophysics Archives

Kirchhoff-Bunsen’s theory implied that dark lines in the solar spectrum arose from cooler atoms in the solar atmosphere, which absorbed the white light coming from the core of the sun. It also meant that we could identify the material in the solar atmosphere, from the ‘colour’ of light it absorbed, because we could make the material hot in laboratory and check if it radiated in the same colour. In other words, having known that sodium radiates in yellow when hot, if one spots a dark line in the yellow part of the solar spectrum, one might guess that it was sodium atom at work.

It gave astronomers a handle to probe chemical and physical properties of the sun and other stars. Not satisfied with the studies of mere position and motion of stars, they became interested in the new field of spectroscopy. There was a promise of a whole new exciting field of science—that would be called ‘astrophysics’ one day. Who had ever thought that one could find out what was inside the Sun or the distant stars?

But it was still an unproven model. Luckily, like all good theories, it came with a testable prediction. The outer layer of the sun is relatively cooler than the core, but it is quite hot (now we know the temperature to be roughly 6000 Celsius). So if one could look at the outer layers through a prism—and only the outer layer—then one should be able to see it radiate and not just absorb. One should see bright lines in place of the dark lines, precisely in the same places (or colours) of the dark lines.

This was what the astronomers were hoping to confirm during the total solar eclipse on 18 August 1868. And they were handed with a bonanza. They indeed saw the dark lines ‘reverse’ to bright lines. Not only that, they also saw brand new bright line they could not identify with any existing terrestrial element.

August is not a particularly favourable month for viewing solar eclipses from India because of monsoons. The eclipse was supposed to begin slightly before 9am. Light clouds in the eastern sky made the astronomers wait with bated breath. Luckily the sky cleared, letting Janssen and Tennant witness the confirmation of Kirchhoff’s idea—the dark lines indeed turned bright. There was a bright yellow line that they thought was the signature of sodium. But Pogson in Masulipatnam had some doubts if it really coincided with the signature wavelength of sodium.

Janssen (left) and James Francis Tennant (right) in later years. (Portrait by Biman Nath)

Janssen (left) and James Francis Tennant (right) in later years. (Portrait by Biman Nath)

Back in England, Norman Lockyer had a different idea. He did not want to chase eclipses around the world. He thought he could isolate the light of the outer layer of the Sun somehow by blocking out everything in the view of the telescope except a carefully positioned small slit. Lockyer confirmed Pogson’s doubt that the errant yellow line might not be due to sodium, and coined the name ‘helium’. Much later, in 1895, William Ramsay isolated an element from a radioactive material, which had the same spectral signature, and so could be identified as helium.

It is the only element that was discovered by astronomers and not by chemists. We now know that helium makes up a quarter of the universe. But it is a very light element—the second lightest element of all. Its lightness made it escape the gravity of the Earth since its formation and now all the helium that we can get from mines comes from the decay of radioactive material deep inside the Earth. Its absence from the Earth ensured that chemists won’t be able to find it here, but astronomers could. And that revolutionized astronomy. (India Science Wire)

The writer is a scientist at the Raman Research Institute, Bangalore.

Phones & gadgets

Apple launches iPhone 15 series, India price, features, availability  

The iPhone 15 series will be available in India from September 22 but iPhone lovers can also pre-order, starting from September 15 onwards.



Apple launched its most anticipated iPhone 15 series, including the iPhone 15, iPhone 15 Plus, iPhone 15 Pro and iPhone 15 Pro Max during the Wonderlust event globally on September 12 night.

The iPhone 15 series will be available in India from September 22 but iPhone lovers can also pre-order, starting from September 15 onwards.

People can buy a new iPhone 15 or upgrade it to the old one. There are five colours available for the people.  

According to reports, Apple has been manufacturing the iPhone 15 series in India and China. Apple has moved 7% of its iPhone production to India. Previously, India was not making the newest models. The Centre’s production-linked incentive (PLI) scheme for smartphones played a part in Apple moving its production to India.

The new iPhone 15 has been launched with the same starting price as its prototype, the iPhone 14. The 128GB variant is priced at Rs 79,900, while the 256GB variant costs Rs 89,900. For people who need more storage, the 512GB variant is available for Rs 1,09,900.

This latest iPhone series puffs a 6.1-inch display and comes in five different colours which are pink, yellow, green, blue, and black. While the design remains the same as the previous models, the iPhone 15 features a dynamic island notch instead of the usual notch, which was highly popular among the iPhone 14 Pro phones.

The camera part of the iPhone series has undergone significant upgrades, the new iPhone 15, with an enhanced 48-megapixel primary sensor replaces the 12-megapixel dual camera system which was available in the previous iPhone 14. This significant improvement promises better low-light photography and portrait shots.

The tech giant announced that the iPhone 15 has an all-day battery life, making it more convenient for users to go about their daily activities without worrying about their phone’s battery.

The iPhone 15 Pro models feature a lighter body and thinner bezels. The new AirPods Pro with USB-C charging case will support Lossless Audio with Apple Vision Pro.

Additionally, the iPhone 15 is powered by Apple’s A16 bionic processor, an upgrade from the A15 bionic chipset used in the previous iPhone 14 and iPhone 14 Plus models. The Pro models had the faster and better A16 chip, but now this feature is available in all iPhone 15 models.

The USB-C port on the standard iPhone 15 and iPhone 15 Plus remain limited to lightning speeds up to 480 Mbps. The iPhone 15 Pro and iPhone 15 Pro Max support USB 3 speeds up to 10 Gbps. People will need to buy a separate 1-meter Thunderbolt 4 Pro cable for Rs 5,724 or Rs 10,701 for the 1.8-meter cable to support faster speeds.

The dynamic island notch feature, which can adjust its size according to notifications, was widely discussed before the launch of the iPhone 15. This unique feature can now be available in all models of the phone.

Another important feature of the iPhone 15 is the shift to the USB Type C charging port. Apple has abandoned the lightning port in favour of the more commonly used USB Type C charging port. This means, there is no longer a need for a special iPhone charging cable to be carried around everywhere you go.

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OnePlus Onam Offers: Discounts, cashbacks, exchange offers, check details

ICICI customers can avail an extra Rs 500 discount through Net Banking on OnePlus 11 5G and OnePlus 11 5G Marble Odyssey purchases from OnePlus.in till August 31, 2023.



OnePlus Onam Offers: Discounts, cashbacks, exchange offers, check details

OnePlus, one of the leading global technology brands, has announced a captivating lineup of products to celebrate the festive spirit of Onam. According to reports, OnePlus 11 5G and OnePlus 11R 5G come with exclusive savings and exchange bonuses during this festive season.

OnePlus Ensemble Bundle: The technology brand has introduced a curated collection of OnePlus 11 5G, OnePlus Pad and Buds Pro 2. Following an instant discount of Rs 4000 through ICICI Bank and OneCard, prices began at Rs 1,07,997. Furthermore, customers of Axis Bank, Citi, HDFC Bank, ICICI Bank, SBI Cards, and OneCard can benefit from up to a 24-month No Cost EMI. 

OnePlus 11 5G: ICICI customers can avail an extra Rs 500 discount through Net Banking on OnePlus 11 5G and OnePlus 11 5G Marble Odyssey purchases from OnePlus.in till August 31, 2023. Meanwhile, OneCard users can also take an instant Rs 2000 bank discount on the same devices exclusively till August 31. Purchasers also have the opportunity to unlock an additional exchange bonus worth Rs 6000 and Rs 10000 on the OnePlus 11 5G and OnePlus 11 5G Marble Odyssey.

OnePlus Nord 3 and Nord CE 3: ICICI Bank Credit Card, Credit EMI and Debit Card EMI users can get an instant discount of Rs 1000 on purchase of the OnePlus Nord 3 5G. The offer is valid till August 31. Furthermore, OneCard credit card and EMI users can also enjoy an instant discount of Rs 1000 on the purchase of the OnePlus Nord 3 5G. 

Moreover, OnePlus Nord CE 3 5G purchase facilitates a Rs 1000 instant discount on Axis Bank and Citi Credit and Debit Cards through EMI transactions and all OneCard transactions. This particular offer will be valid from September 1, 2023. Reportedly, this offer also holds eligibility for No Cost EMI with Axis Bank, Citi, HDFC Bank, ICICI Bank, SBI cards and OneCard for six months.

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vivo v23: A comprehensive review of the latest smartphone



vivo v23

vivo V23 Overview

Looking for a new smartphone that blends design with performance and utility? Launched in January 2022, vivo V23 delivers a premium experience, both in terms of hardware and software, while keeping the cost in check. If you want a fast vivo 5G mobile with a professional-quality camera, vivo V23 can be a good choice.

vivo V23 Price and Specifications

The price for the base variant of vivo V23 (Sunshine Gold, 4GB RAM, 64GB storage) is Rs. 29,990 in the Indian market. 

1. Performance

vivo V23 has the efficient MediaTek Dimensity 920 chipset under the hood. Coupled with 8GB RAM, the processor allows you to breeze through heavy gaming sessions, HD streaming, and multitasking. Since the processor goes through a 6 nm fabrication process, it can deliver a benchmark performance without draining the battery too much. The handset runs on Funtouch OS (based on Android 12) that offers a seamless and intuitive performance. 

2. Design

vivo V23 weighs just 179g and is only 7.3mm thick, making it super easy to fit in your pocket. The mineral glass back gives the phone a classy, ergonomic feel, and the phone feels comfortable to operate even after long hours of usage. If you want to flaunt a unique-looking smartphone without paying too much, you should consider vivo V23.

3. Battery

A smartphone is only as good as its battery. vivo V23 seems to have taken this advice to heart – it packs a stunning 4,200 mAh battery that can last all day on a full charge. Additionally, the phone supports 44W quick charging that can charge the battery from 0 to 68% in only 30 minutes. If battery life is your main concern, vivo V23 can offer a promising solution. 

4. Connectivity

The vivo V23 supports the latest 5G and 4G bands along with Wi-Fi 5, ensuring blazing-fast internet speeds. You also get Bluetooth 5.2 and a USB Type-C port allowing easy and seamless data transfer between devices. For uninterrupted and accurate navigation, the phone includes GPS with A-GPS and GLONASS. You also get support for a dual nano SIM, so you can use two numbers in a single smartphone. 

5. Storage

vivo V23 packs 128GB of in-built storage, allowing you to store all your apps, multimedia, games, documents, etc. on the device. The storage capacity is sufficient even for heavy users who use their handsets as a portable hard drive. vivo V23 5G comes with the support for an OTG flash drive to store more if you run out of space. 

6. Camera

vivo V23 offers a triple rear camera with a 64MP primary sensor (f/1.89 aperture), an 8MP Ultra-Wide sensor (f/2.2 aperture), and a 2MP macro lens (f/2.2 aperture). The dual front camera setup comprises a 50MP primary camera (f/2.0 aperture) and an 8MP Ultra-Wide camera (f/2.28 aperture). You also get a dual LED flash (one at the front and one at the back) allowing you to capture unbelievable night shots with the utmost clarity.

7. Display

Passionate gamers and OTT binge-watchers can rejoice over vivo V23’s stunning display. The large 6.44-inch AMOLED screen with HDR 10+ supports life-like colours and brings all your favourite TV shows and movies to life. Impressively, a 91% screen-to-body ratio provides a bezel-free viewing experience. Thanks to its 90Hz refresh rate, the display is also awesome for HD gaming. 

With a premium design, amazing performance, and mesmerising display, vivo V23 is a value-for-money device and a mid-range smartphone marvel. If you want a premium handset experience without paying a premium price, you should definitely check out vivo V23 5G. The phone not only offers a smooth performance but also a long battery life on a single charge. So, what are you waiting for? Get your hands on this impressive device from Bajaj Mall online and walk away with the best deals and discounts in India.

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