#worlds first

Top Image -The Redcliffe Shot Tower - Bristol

Lower Image - The 'NEW' Shot tower

The Redcliffe Shot Tower was a historic shot tower in the English city of Bristol. It was the progenitor of many similar towers built around the world. The tower stood at the corner of Redcliffe Hill and Redcliffe Parade, in the suburb of Redcliffe, between the years of 1782 and 1968 when it was demolished.

In 1775, William Watts, a plumber, started converting his house, near St Mary Redcliffe Church, into the world's first shot tower, in order to make lead shot by his innovative tower process. He did this by adding a tower atop his house, and by excavating a shaft into the soft sandstone below, achieving a total drop of around 90 feet (27 m). By 1782, the tower was complete and in production, and Watts was granted a patent on his process, which involved pouring molten lead through a perforated zinc pan into water below thus producing round shot pellets....

The lower image shows the "NEW" shot tower on Bristol's Cheese Lane. Its no longer in use for lead shot production, and is listed Grade II as "Sheldon Bush and Patent Shot Company Limited".

The "NEW" tower was designed as a replacement by E.N. Underwood and Partners, a firm of structural engineers, for the Sheldon Bush and Patent Shot Company Limited. It was constructed on a site already in use for other purposes by that company, and is some 500 yards (460 m) from the site of its predecessor. The structure is of reinforced concrete, with a twelve sided crucible room at the top, giving it an outline reminiscent of a cotton bud. It is the last such tower to be built, one of the few to be built in the 20th century, and one of only three to survive in England. It received the Civic Design Award from the Bristol Civic Society for the year it was completed in 1969.

DNA Replication Has Been Filmed For The First Time

Whoa.

“Here's proof of how far we've come in science - in a world-first, researchers have recorded up-close footage of a single DNA molecule replicating itself, and it's raising questions about how we assumed the process played out.The real-time footage has revealed that this fundamental part of life incorporates an unexpected amount of 'randomness', and it could force a major rethink into how genetic replication occurs without mutations.”

HOW IT WORKS:

“The DNA double helix consists of two intertwining strands of genetic material made up of four different bases - guanine, thymine, cytosine, and adenine (G, T, C and A).Replication occurs when an enzyme called helicase unwinds and unzips the double helix into two single strands.A second enzyme called primase attaches a 'primer' to each of these unravelled strands, and a third enzyme called DNA polymerase attaches at this primer, and adds additional bases to form a whole new double helix.”

WHY THIS IS WEIRD AND NOT WHAT WE EXPECTED:

“The fact that double helices are formed from two stands running in opposite directions means that one of these strands is known as the 'leading strand', which winds around first, and the other is the 'lagging strand', which follows the leader.The new genetic material that's attached to each one during the replication process is an exact match to what was on its original partner.So as the leading strand detaches, the enzymes add bases that are identical to those on the original lagging stand, and as the lagging strand detaches, we get material that's identical to the original leading strand. Scientists have long assumed that the DNA polymerases on the leading and lagging strands somehow coordinate with each other throughout the replication process, so that one does not get ahead of the other during the unraveling process and cause mutations. But this new footage reveals that there's no coordination at play here at all - somehow, each strand acts independently of the other, and still results in a perfect match each time.“

I risked my life