Tag: Boston

Study reveals why so many met a sticky end in Boston’s Great Molasses Flood

In 1919, a tank holding 2.3m gallons of molasses burst, causing tragedy. Scientists now understand why the syrup tsunami was so deadly

It may sound like the fantastical plot of a childrens story but Bostons Great Molasses Flood was one of the most destructive and sombre events in the citys history.

On 15 January 1919, a muffled roar heard by residents was the only indication that an industrial-sized tank of syrup had burst open, unleashing a tsunami of sugary liquid through the North End district near the citys docks.

As the 15-foot (5-metre) wave swept through at around 35mph (56km/h), buildings were wrecked, wagons toppled, 21 people were left dead and about 150 were injured.

Now scientists have revisited the incident, providing new insights into why the physical properties of molasses proved so deadly.

Presenting the findings last weekend at the American Association for the Advancement of Science annual meeting in Boston, they said a key factor was that the viscosity of molasses increases dramatically as it cools.

This meant that the roughly 2.3m US gallons of molasses (8.7m litres) became more difficult to escape from as the evening drew in.

Speaking at the conference, Nicole Sharp, an aerospace engineer and author of the blog Fuck Yeah Fluid Dynamics said: The sun started going down and the rescue workers were still struggling to get to people and rescue them. At the same time the molasses is getting harder and harder to move through, its getting harder and harder for people who are in the wreckage to keep their heads clear so they can keep breathing.

As the lake of syrup slowly dispersed, victims were left like gnats in amber, awaiting their cold, grisly death. One man, trapped in the rubble of a collapsed fire station, succumbed when he simply became too tired to sweep the molasses away from his face one last time.

Its horrible in that the more tired they get its getting colder and literally more difficult for them to move the molasses, said Sharp.

Leading up to the disaster, there had been a cold snap in Boston and temperatures were as low as -16C (3F). The steel tank in the harbour, which had been built half as thick as model specifications, had already been showing signs of strain.

Two days before the disaster the tank was about 70% full, when a fresh shipment of warm molasses arrived from the Caribbean and the tank was filled to the top.

One of the things people described would happen whenever they had a new molasses shipment was that the tank would rumble and groan, said Sharp. People described being unnerved by the noises the tank would make after it got filled.

Ominously, the tank had also been leaking, which the company responded to by painting the tank brown.

There were a lot of bad signs in this, said Sharp.

Sharp, and a team of scientists at Harvard University, performed experiments in a large refrigerator to model how corn syrup (standing in for molasses) behaves as temperature varies, confirming contemporary accounts of the disaster.

Historical estimates said that the initial wave would have moved at 56km/h [35mph], said Sharp. When we take models … and then we put in the parameters for molasses, we get numbers that are on a par with that. Horses werent able to run away from it. Horses and people and everything were all caught up in it.

The giant molasses wave follows the physical laws of a phenomenon known as a gravity current, in which a dense fluid expands mostly horizontally into a less dense fluid. Its what lava flows are, its what avalanches are, its that awful draught that comes underneath your door in the wintertime, said Sharp.

The team used a geophysical model, developed by Professor Herbert Huppert of the University of Cambridge, whose work focuses on gravity currents in processes such as lava flows and shifting Antarctic ice sheets.

The model suggests that the molasses incident would have followed three main stages.

The current first goes through a so-called slumping regime, said Huppert, outlining how the molasses would have lurched out of the tank in a giant looming mass.

Then theres a regime where inertia plays a major role, he said. In this stage, the volume of fluid released is the most important factor determining how rapidly the front of the wave sweeps forward.

Then the viscous regime generally follows, he concluded. This is what dictates how slowly the fluid spreads out and explains the grim consequences of the Boston disaster.

It made a difference in how difficult it would be to rescue people and how difficult it would be to survive until you were rescued, said Sharp.

Read more: https://www.theguardian.com/science/2017/feb/25/study-reveals-why-so-many-met-a-sticky-end-in-bostons-great-molasses-flood

Technorati Tags: , , , ,

Using Math During The Holidays

With the holidays coming upon us, and knowing that many people eat out during the holidays, I thought it would be nice to make a post which discusses how to use math and make the appropriate tip after eating or drinking. I found a nice article on this topic at articledashboard.com. Check it out!

How To Tip At US Restaurants And Bars

Tipping culture is rife in US restaurants, and it is an important custom for those working in the service industry. It’s become so ingrained that there are well-known consequences for skimping on gratuity. Failing to tip a bartender after each round of drinks, for example, well, it wouldn’t happen. After not tipping the first time, you’re not going to get another round. Here is a guide to tipping in restaurants and bars during your US travels.

If you get up and order your drinks at the bar the standard tip is one dollar per drink. For cocktails or specialty requests, such as a Boston sour with egg white, an extra buck is preferred for the time it takes to make these drinks. Custom dictates that after purchasing the drinks, you leave the tip on the bar. Don’t hand it directly to the bartender, especially if it is busy. They will see it and pick it up. If you see a few dollars on the bar, leave them. Those are tips from other customers. If you don’t have a lot of change on you, you can tip the bartender a larger sum after the first round which will cover the next few, just remember to return to the same one when ordering.

When settling a bar tab, you can calculate 20% of the total to determine the appropriate tip. Most won’t show the amount of drinks you’ve ordered, but the amount should come to about the same. If you want better service, tip more (a few dollars extra is all it takes). If you’ve bought drinks at restaurants with your meal that the waitperson has brought to you, the bartender will receive a percentage of the total tip that you leave with your bill. If there is a bouncer on the door of a club you regularly frequent, tip them a few bucks for future perks. They do remember.

At restaurants, 15 to 20% is the standard, left after the bill has been paid on the table. If paying by card, a tip can be added on the receipt. If you’re terrible at math, doubling the tax and rounding up is roughly correct. Tipping more is always encouraged, but tipping less is an insult. If you receive bad service, ask to speak with a manager rather than throwing a few coins down. In fact, no tip sends a stronger message than a measly dollar or two. For large parties, gratuity is usually included in the total. It will say so at the bottom of your bill.

Many tourists are against the tipping culture, but it’s important to follow customs in a host country. People in the service industry receive low wages, sometimes below minimum, so tips make up a large portion of their take home earnings. Minimum wage is also not a livable income in most areas, and workers in the industry are largely considered casual, meaning they are not provided with any benefits such as health insurance, sick pay, or even holiday leave. A few good tips can mean a doctor’s visit or a paid utility bill.

By: Anna Woodward

Fresno restaurants can satisfy the whole family. To help you choose the right one for a night out, visit: www.myyp.com

 Personally, I usually leave a 20% tip. And remember that the tip is calcualted before the tax is added in. To do that, just take the total and multuply it by 2 and drop the last digit! So a $25 meal would render a (25 x 2 = 50)  $5 tip.

Hope that helps!

Have yourself great holiday season!

 

Technorati Tags: , , , , , , , , , , , , , , , , ,