Category Science

Indian scientists discover ‘Saraswati’ – a supercluster of galaxies

The Saraswati supercluster of 43 galaxies is 4 billion light years away from Earth and roughly more than 10 billion years old. It spans 600 million light years and many contain the mass equivalent of over 20 million billion suns.

Superclusters are a chain of galaxies and galaxy clusters bound by gravity, often stretching to several hundred times the size of clusters of galaxies, consisting of tens of thousands of galaxies. The Milky Way, the galaxy we are in, is part of the Laniakea Supercluster.

The Shapley Concentration or the Sloan Great Wall superclusters are comparatively large, but the Saraswati supercluster is far more distant.

The supercluster was discovered by Shishir Sankhayan, of the Indian Institute of Science Education and Research (IISER), Pune, Pratik Dabhade, IUCAA research fellow, Joe Jacob of Newman College, Kerala, and Prakash Sarkar of the National Institute of Technology, Jamshedpur.

 

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Who is known for liquefaction of oxygen?

French chemist Antoine Lavoisier (1743-1794) is a celebrated scientist and nobleman who was central to the chemical revolution in the 18th Century. A meticulous experimenter who changed the way chemistry was done and perceived, he had a large influence on how both chemistry and biology developed. While it is impossible to cover everything that Lavoisier achieved in a short article, we will be looking at how one of his predictions came true nearly 100 years later.

A prophetic idea

Lavoisier had a prophetic idea that “[t]he air, or at least some of its constituents, would cease to remain an invisible gas and would turn into the liquid stage. A transformation of this kind would thus produce new liquids of which we as yet have no idea.” Given that until 1877, the dominant thought was that the permanent gases – oxygen, hydrogen, nitrogen and carbon monoxide – were not capable of existing in liquid form, such a statement was indeed beyond his time.

And yet, it did come true. For within days of each other, French physicist Louis Paul Cailletet and Swiss physicist Raoul Pictet arrived independently at methods for the liquefaction of oxygen in December 1877. A whole new field of research and science then opened up.

Born in 1832 into an industrial family, Cailletet was privileged to attend Lycee Henri IV in Paris, and the Ecole des Mines as an unregistered student. He returned to work on his father’s ironworks after his studies, and even though his exact nature of work remains unknown, it is evident that he applied the knowledge he had acquired while studying.

Observations in ironworks

Starting 1856, Cailletet published his studies based on observations in the ironworks and techniques to improve the quality of products. Most of these were presented by French chemist Henri Etienne Sainte-Claire Deville, a person with whom Cailletet shared a friendship that when beyond the typical Parisian scientific environment.

So when Deville became director of the chemistry laboratory at the Ecole Normale Superieure in 1868, it was no surprise that Cailletet also switched to a new series of experiments a year later – experiments that were no longer directly related to observations from ironworks. In 1869, Cailletet started experiments on high-pressure chemistry and most of his publications thereon dealt with compressibility of gases.

In 1877, Cailletet successfully attempted liquefaction of gases with an experimental arrangement based on a compression apparatus. Cailletet paced oxygen and carbon monoxide into his liquefaction apparatus on separate occasions, cooled and compressed them to a specific temperature and pressure and let the gases expand. He observed a thick mist at the end of the expansion and was able to identify that these were the condensed form of both gases.

 Deville is in the detail

Cailletet shot a letter to Deville on December 2, 1877, announcing the liquefaction of oxygen and carbon monoxide. Deville had the presence of mind to seal the letter in an envelope and deposit it with the Academie des Sciences. As a result, even when the Academie received a telegram from Pictet on December 22 stating that he had liquefied oxygen, there was no confusion over who got there first.

Pictet denied any priority claim and there was no dispute between the two parties. Pictet and Cailletet arrived at their results using different techniques and both of them were awarded the Davy Medal by the Royal Society of London in 1878.

Pictet proved to be an exception as a number of others jumped in and disputes ensued, Parallel priority claims were a constant theme between 1877 and 1908, during which time all the so-called permanent gases were liquefied. Cailletet’s liquefaction of oxygen had thus heralded cryogenics – a new field of research that concerned itself with the produced and behaviour of materials at very low temperatures.

 

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HOW IS SPORT AFFECTED BY THE WEATHER?

            Most outdoor sports events can be affected by adverse weather conditions in one way or another. “Rain stopped play” is a phrase familiar to followers of cricket in England, where the often unpredictable summer weather regularly interrupts a game. Tennis is similarly affected when heavy rain makes play impossible on open-air grass courts. Some sports can be played in almost all weathers (only severe snow and freezing temperatures will stop a soccer or rugby match), but the conditions can influence tactics and the outcome of the game.

            The effects of weather on sport are varied, with some events unable to take place while others are changed considerably. The performance of participants can be reduced or improved, and some sporting world records are invalid if set under certain weather conditions. While outdoor sports are most affected, those played indoors can still be impacted by adverse or advantageous weather conditions.

            Temperature has a significant impact on the performance of athletes. High temperature can cause various heat illnesses such as heat cramps and heat stroke, while very low temperatures may lead to hypothermia.

             Some major sporting events cannot be held when the temperature is too high. When AFC selected Qatar as the host of the 2011 AFC Asian Cup they opted to run the event in the January window rather than July or August because they considered it to be “too hot in the Gulf region”. However, the also set to be held in Qatar, is scheduled for the late fall and early winter.

            Some sports are cancelled because of precipitation. Some are deemed too dangerous to play when the ground is damp because of the danger of injury to a player through slipping.

            When the rain is excessive an event might be canceled because of a waterlogged pitch. Winter sports can sometimes be canceled due to the amount of snow on the ground, be it too little or too much.

            Wind can blow the equipment in a sporting event, changing the direction or travel of a ball. In golf the wind levels may influence the way a shot is taken.A headwind can slow runners, while they may gain wind assistance from a tailwind.Some sports rely on the presence of wind, especially surface water sports.

            Some sports cannot be played if there is insufficient visibility as it can make them dangerous or can be disadvantageous to a competitor. Cricket test matches often finish when the umpire decides that the light level is too low and the timing of this can sometimes be controversial. The difficulties of playing in bad light conditions is also disputed. Some events are called off when there is heavy fog.

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HOW DO FARMERS MAKE USE OF WEATHER FORECASTS?

            Farmers need to pay special attention to the weather in order to tend their crops or feed their animals. Knowledge of a severe frost or rain will influence the time that they sow seeds or harvest crops. Accurate weather forecasts also help farmers to decide when to treat crops with chemicals. For example, should it rain shortly after pesticides are applied, they will be washed away and have little effect — a waste of time and money for the farmer. Forecasts for farmers provide as much information as possible about the weather for the next week or so.

            Most people know that the weather has a significant impact on the agriculture industry. Indeed, crops need the basics of moisture, warmth, and sun to thrive. But what’s less obvious is how the details of weather information can drive a grower’s business decisions, helping them to plan efficiently, minimize costs and maximize yields—and profits—as a result.

             While farmers must make many day-to-day decisions related to weather conditions, there are four primary areas of farming that are fundamentally affected impacted by weather:

            Crop Growth/Irrigation: Crop growth, or crop yield, requires appropriate amounts of moisture, light, and temperature. Detailed and accurate historical, real-time and forecast weather information can help farmers better understand and track the growth status/stage to make informed decisions. Having access to this data can guide farmers in making significant and potentially costly decisions, such as whether, when and how much to irrigate.

            Fertilizer Timing and Delivery: One of the many decisions that farmers have to make is determining the proper time to apply fertilizer, as well as the application rate and fertilizer form to use. A misapplied application caused by weather can wipe away the entire field’s profits. Weather forecasts can be used to ensure that fertilizer is applied in the right conditions—when it’s dry enough so that it doesn’t wash away (which would create a waste of resources and money) but moist enough so that it gets worked into the soil.

            Pest and Disease Control: Certain weather conditions encourage the development and growth of pests and diseases, which can destroy crops. Forecast guidance incorporated into pest and disease modeling can help determine whether—and when—it’s appropriate to apply pest or disease controls. Wind forecasts also play a role in this decision, as crop dusters, aircraft that spray fungicidal or insecticidal chemicals on plants from above, must be utilized when wind conditions are not apt to cause sprayed chemicals to miss their targets.

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WHY ARE WEATHER FORECASTS IMPORTANT FOR PEOPLE AT SEA?

            People who work at sea depend heavily on detailed, specialized weather forecasts because their lives can be at risk when stormy conditions bring high winds and steep seas. Fishermen may decide where to fish according to weather conditions, while sport sailors pay close attention to wind details to plan their racing tactics. All mariners listen to radio stations and coastguard broadcasts for advance warn-ings of weather conditions, which focus on the speed and direction of the wind, visibility and barometer readings.

            We receive weather information every day in a variety of ways – through television, radio, on our smartphones and through conversations around the water cooler. But how do you get weather forecasts on the high seas where WiFi is rarely an option? Across our oceans, NOAA’s Ocean Prediction Center (OPC) is delivering critical weather forecasts to keep you safe – at sea.

           Did you know 11 million Americans travel on cruise ships each year, and that our nation’s maritime shipping industry – the way we primarily receive goods from other countries – is a 1.5 trillion dollar economic activity annually for the U.S? This means accurate and reliable weather forecasts at sea are an incredibly important part of our nation’s economy.

            Every day, expert weather forecasters at OPC deliver more than 150 different products – like forecasting maps and guidance – for weather events across the Atlantic and Pacific Ocean basins, including the waters around Alaska. This forecast guidance makes its way into the hands of commercial shipping vessels allowing ship captains to dodge hurricanes, cruise ships to route around nor’easters and recreational boaters to return home safely.

            Hazards at sea can vary greatly and OPC forecasts for all of them. High winds, large waves, thunderstorms, sea ice, freezing spray, and volcanic ash all present significant safety issues to mariners traveling with precious cargo- the lives of their passengers and crew.

            Even with these challenges, OPC delivers life-saving forecasts around the clock each day, while also working hard to modernize the ways they provide forecasts to a geographically diverse community. And OPC has some great partners. OPC forecasters collaborate closely with the U.S. Coast Guard, the U.S. Navy and the international maritime community to continually advance services and ensure critical forecasts reach those who rely on them to make safety decisions at sea.

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DID THE GREAT FLOOD DESCRIBED IN THE OLD TESTAMENT ACTUALLY HAPPEN?

            Some experts believe that when glaciers melted 7000 years ago, this caused the Mediterranean to overflow into the Black Sea, then a small freshwater lake. This may form the basis of Middle Eastern tales, such as the one recorded in the Old Testament, of a hugely destructive flood.

           A flood of Biblical proportions just like in the story of Noah’s Ark may have actually happened, according to the oceanographer who found the Titanic.

            Acclaimed underwater archaeologist Robert Ballard claims his team of researchers have uncovered evidence that suggests The Great Flood described in the Bible was actually based on real events.

            Mr Ballard told how he investigated a controversial theory proposed by two scientists from Columbia University that there was a massive flood in the Black Sea region.

           In an interview with ABC News, he said around 12,000 years ago much of the world was covered in ice and the Black Sea had been a freshwater lake surrounded by farmland.

            But when the glaciers began to melt during a warming period in the cycle of the Earth’s temperature around 5600BC water rushed toward the world’s oceans, Mr Ballard said. This, he claimed, caused floods all around the world and water cascaded through Turkey’s Straits of Bosporus towards the Black Sea.

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