Zero is older than we thought it was

Carbon dating finds Bakhshali manuscript contains oldest recorded origins of the symbol 'zero'

The origin of the symbol zero has long been one of the world's greatest mathematical mysteries. Today, new carbon dating research commissioned by the University of Oxford's Bodleian Libraries into the ancient Indian Bakhshali manuscript, held at the Bodleian, has revealed it to be hundreds of years older than initially thought, making it the world’s oldest recorded origin of the zero symbol that we use today.

The surprising results of the first ever radiocarbon dating conducted on the Bakhshali manuscript, a seminal mathematical text which contains hundreds of zeroes, reveal that it dates from as early as the 3rd or 4th century - approximately five centuries older than scholars previously believed. This means that the manuscript in fact predates a 9th-century inscription of zero on the wall of a temple in Gwalior, Madhya Pradesh, which was previously considered to be the oldest recorded example of a zero used as a placeholder in India. The findings are highly significant for the study of the early history of mathematics.

The zero symbol that we use today evolved from a dot that was used in ancient India and can be seen throughout the Bakhshali manuscript. The dot was originally used as a 'placeholder', meaning it was used to indicate orders of magnitude in a number system – for example, denoting 10s, 100s and 1000s.

While the use of zero as a placeholder was seen in several different ancient cultures, such as among the ancient Mayans and Babylonians, the symbol in the Bakhshali manuscript is particularly significant for two reasons. Firstly, it is this dot that evolved to have a hollow centre and became the symbol that we use as zero today. Secondly, it was only in India that this zero developed into a number in its own right, hence creating the concept and the number zero that we understand today - this happened in 628 AD, just a few centuries after the Bakhshali manuscript was produced, when the Indian astronomer and mathematician Brahmagupta wrote a text called Brahmasphutasiddhanta, which is the first document to discuss zero as a number.

Although the Bakhshali manuscript is widely acknowledged as the oldest Indian mathematical text, the exact age of the manuscript has long been the subject of academic debate. The most authoritative academic study on the manuscript, conducted by Japanese scholar Dr Hayashi Takao, asserted that it probably dated from between the 8th and the 12th century, based on factors such as the style of writing and the literary and mathematical content. The new carbon dating reveals that the reason why it was previously so difficult for scholars to pinpoint the Bakhshali manuscript’s date is because the manuscript, which consists of 70 fragile leaves of birch bark, is in fact composed of material from at least three different periods.

The Bakhshali manuscript was found in 1881, buried in a field in a village called Bakhshali, near Peshawar, in what is now a region of Pakistan. It was found by a local farmer and was acquired by the Indologist AFR Hoernle, who presented it to the Bodleian Library in 1902, where it has been kept since.

Source - Bodleian Libraries, University of Oxford

Will Earth undergo 15 days of darkness in November 2017?

The days-of-darkness online hoax is back! Do these hoaxes ever die? No, Earth will not experience 15 days of darkness in November, 2017.

Did NASA announce it? No.

Will it happen? No.

YouTube videos are suggesting the event will be caused by “another astronomical event, between Venus and Jupiter.” Yes, Jupiter and Venus – the sky’s two brightest planets – are having a conjunction low in the east before dawn this month. It’ll be beautiful! It’s just so wrong to use this conjunction – which has happened countless times in Earth history, to the wonderment of all privileged to observe it – to perpetuate a hoax.

As for the idea that NASA has issued a “1,000-page document” on the event for the White House. Well. That’s just entirely fake.

Think about it. What would have to happen for Earth to experience 15 days of darkness? Our day-night cycle stems from Earth’s rotation on its axis around our local star, the sun. The sun shines on half of Earth for part of its 24-hour period; that’s daytime. Nighttime is simultaneously occurring on the opposite side of Earth.

For the whole Earth to undergo 15 days of darkness … what would have to happen? The sun would have to go out for 15 days? Or something would have to shroud the sun? Or pass between us and the sun?

All of those scenarios are unlikely to the point of ridiculousness, when you consider the vast size of our sun. That’s why zero days of all-Earth darkness have occurred in human history so far.

It’s never happened. It’s not going to happen.

This same hoax has been rearing its head every few years, since at least 2011, when the erstwhile Comet Elenin was supposed to pass between us and the sun and cause three days of darkness. In 2014, the number of supposed “dark days” increased to six.

In 2015, an article at Newswatch33 suggested NASA confirmation for 15 days of darkness between November 15 and November 29 of that year. The article said that – according to NASA – such an event hadn’t occurred in over 1 million years.

There were zero days of all-Earth darkness in November, 2015.

So. It didn’t go dark in 2011, 2014, or 2015, and it’s not going to go dark for 15 days in November this year.

It’s interesting that these “days of darkness” rumors all spring up around November and December, when the northern half of Earth is edging toward its winter solstice and shortest day of the year. Let’s face it, it’s darker out there now for us on this half of the globe. Just remember … it’s a natural kind of darkness, a resting kind of darkness.

In fact, for the Northern Hemisphere, the earliest sunsets of the year come in early December. After the solstice, for sure by early January, the longer days will be returning very noticeably as we move toward spring and rebirth.

That’s nature’s cycle, and we can depend on it!

Source - EarthSky.org

Warm air helped make 2017 ozone hole smallest since 1988

At its peak on Sept. 11, 2016, the ozone hole extended across an area nearly two and a half times the size of the continental United States. The purple and blue colors are areas with the least ozone.

Measurements from satellites this year showed the hole in Earth's ozone layer that forms over Antarctica each September was the smallest observed since 1988.

NOAA and NASA collaborate to monitor the growth and recovery of the ozone hole every year. According to NASA, the ozone hole reached its peak extent on Sept. 11, covering an area about five times the size of India - 7.6 million square miles in extent - and then declined through the remainder of September and into October. NOAA ground- and balloon-based measurements also showed the least amount of ozone depletion above the continent during the peak of the ozone depletion cycle since 1988.

The smaller ozone hole in 2017 was strongly influenced by an unstable and warmer Antarctic vortex - the stratospheric low pressure system that rotates clockwise in the atmosphere above Antarctica. This helped minimize polar stratospheric cloud formation in the lower stratosphere. The formation and persistence of these clouds are important first steps leading to the chlorine- and bromine-catalyzed reactions that destroy ozone. These Antarctic conditions resemble those found in the Arctic, where ozone depletion is much less severe.

In 2016, warmer stratospheric temperatures also constrained the growth of the ozone hole. Last year, the ozone hole reached a maximum 8.9 million square miles, 2 million square miles less than in 2015. The average area of these daily ozone hole maximums observed since 1991 has been roughly 10 million square miles.

Although warmer-than-average stratospheric weather conditions have reduced ozone depletion during the past two years, the current ozone hole area is still large because levels of ozone-depleting substances like chlorine and bromine remain high enough to produce significant ozone loss.

Scientists said the smaller ozone hole extent in 2016 and 2017 is due to natural variability and not a signal of rapid healing.

First detected in 1985, the Antarctic ozone hole forms during the Southern Hemisphere's late winter as the returning sun's rays catalyze reactions involving man-made, chemically active forms of chlorine and bromine. These reactions destroy ozone molecules.

Thirty years ago, the international community signed the Montreal Protocol on Substances that Deplete the Ozone Layer and began regulating ozone-depleting compounds. The ozone hole over Antarctica is expected to gradually become less severe as chlorofluorocarbons—chlorine-containing synthetic compounds once frequently used as refrigerants - continue to decline. Scientists expect the Antarctic ozone hole to recover back to 1980 levels around 2070.

Ozone is a molecule comprised of three oxygen atoms that occurs naturally in small amounts. In the stratosphere, roughly 7 to 25 miles above Earth's surface, the ozone layer acts like sunscreen, shielding the planet from potentially harmful ultraviolet radiation that can cause skin cancer and cataracts, suppress immune systems and also damage plants. Closer to the ground, ozone can also be created by photochemical reactions between the sun and pollution from vehicle emissions and other sources, forming harmful smog.

Ozone depletion occurs in cold temperatures, so the ozone hole reaches its annual maximum in September or October, at the end of winter in the Southern Hemisphere.

Although warmer-than-average stratospheric weather conditions have reduced ozone depletion during the past two years, the current ozone hole area is still large compared to the 1980s, when the depletion of the ozone layer above Antarctica was first detected. This is because levels of ozone-depleting substances like chlorine and bromine remain high enough to produce significant ozone loss.

NASA and NOAA monitor the ozone hole via three complementary instrumental methods. Satellites, like NASA's Aura satellite and NASA-NOAA Suomi National Polar-orbiting Partnership satellite measure ozone from space. The Aura satellite's Microwave Limb Sounder also measures certain chlorine-containing gases, providing estimates of total chlorine levels.

NOAA scientists monitor the thickness of the ozone layer and its vertical distribution above the South Pole station by regularly releasing weather balloons carrying ozone-measuring "sondes" up to 21 miles in altitude, and with a ground-based instrument called a Dobson spectrophotometer.

The Dobson spectrophotometer measures the total amount of ozone in a column extending from Earth's surface to the edge of space in Dobson Units, defined as the number of ozone molecules that would be required to create a layer of pure ozone 0.01 millimeters thick at a temperature of 32 degrees Fahrenheit at an atmospheric pressure equivalent to Earth's surface.

This year, the ozone concentration reached a minimum over the South Pole of 136 Dobson Units on September 25 — the highest minimum seen since 1988. During the 1960s, before the Antarctic ozone hole occurred, average ozone concentrations above the South Pole ranged from 250 to 350 Dobson units. Earth's ozone layeraverages 300 to 500 Dobson units, which is equivalent to about 3 millimeters, or about the same as two pennies stacked one on top of the other.