It’s called a pilot chute. It’s a miniature parachute that is several feet in diameter and is attached to the peak of a parachute and whose function is to draw the parachute out of its pack and extend it in position for opening.
Saturday, 9 April 2016
ELI5: What is the purpose of the tiny parachute that is usually on top of the large parachute.
Monday, 4 April 2016
ELI5: The Panama Papers.
In business, you can avoid taxes by investing in something. If a company makes one million dollars, but spends 500,000 on investing in new technology for their product or something like that, they’re only taxed from the remaining 500,000 because that’s all of their “profit.” (I’m not a businessman so I’m not sure on the complete legality of all the kinds of spending but I think this is a basic summary). This is all normal and fine; all companies require investing in order to grow their company.
So a company in Panama basically made a business in creating fake businesses. Companies could “invest” million of dollars and then it wouldn’t be taxed, because according to legal documents it isn’t profit, it’s an “investment,” which is untaxable, and then they would get their money back from the fake business. So imagine if that $500,000 of investments from my above example was fake, and after awhile 90% of the money was given back to the business (I’m assuming the Panamian company took a cut of the money as payment). 2.6 TB of data in total, over 11 million documents and over 200,000 fake companies. According to the website that published the news of the leak, they were contacted by an anonymous source with encrypted files with the data sometime in 2015. Here’s am exerpt from the article:
Over a year ago, an anonymous source contacted the Süddeutsche Zeitung (SZ) and submitted encrypted internal documents from Mossack Fonseca, a Panamanian law firm that sells anonymous offshore companies around the world. These shell firms enable their owners to cover up their business dealings, no matter how shady.
Apparently there’s several trillion dollars of money that should’ve been taxed and wasnt. Not sure if that means trillions that should’ve been taxed off of, or trillions of dollars of straight tax money, but either way it’s a LOT.
Many political leaders (many seem to be in the Middle East), and celebrities are involved as well. To prevent any one person from being blamed for the leak, hundreds of news organizations are going to release further full details tonight (that’s what Ive heard, not sure how true it is) but the list apparently has thousands of people/companies on it. There’s 11 million documents though, and even though hundreds of journalists have been going through the data for months, there’s still information that has yet to come to light.
This goes much farther than tax evasion, and includes Syrian war crimes, human trafficking, and more. Here’s a video explaining it.
Saturday, 2 April 2016
ELI5: What is a 'Straw Man' argument?
It means that you’re not arguing against what your opponent actually said, but against an exaggeration or misrepresentation of his argument. You appear to be fighting your opponent, but are actually fighting a “straw man” that you built yourself. Taking the example from Wikipedia:
A: We should relax the laws on beer.
B: ‘No, any society with unrestricted access to intoxicants loses its work ethic and goes only for immediate gratification.
B appears to be arguing against A, but he’s actually arguing against the proposal that there should be no laws restricting access to beer. A never suggested that, he only suggested relaxing the laws.
Tuesday, 29 March 2016
ELI5: Why do flavors like garlic and onion stick around in the taste buds so much longer than others?
There is a compound in garlic called allyl methyl sulfide (AMS). It is a gas which gets absorbed into the blood when you are digesting the garlic (and onions and shallots). From the blood it is transferred to the lungs where it is then exhaled. A big part of flavor reception is through the nose so you get that lingering taste that way. Some of the AMS compound is also released through the skin.
ELI5:How come people can't be cryogenically frozen safely as the ice crystals destroy the cell membranes, but sex cells such as sperm are kept frozen for long periods of time yet remain functional?
I work in a lab where we freeze down cells all of the time. We freeze our cells in a medium that contains 5% DMSO, which among other things can be used as a cryoprotectant. However, DMSO is also toxic to cells at the concentrations necessary for cryoprotection. Consequently, when you freeze cells in DMSO, you add the DMSO medium at ice-cold temperatures and don’t allow the cells to warm up. When you later thaw the cells, you have to dilute out the DMSO as quickly as possible without causing osmotic shock, which can pop the cells. Such restrictions on freezing and thawing would basically be impossible to control at the level of a complete organism.
However, to contradict a lot of previous posts, individual cells can be recovered from freezing with high viability. When performed properly (and this varies quite a bit by cell type), you can expect >90% of cells to be alive following thaw.
The chemicals that allow cells to survive freezing are toxic to the body. Keeping the cells cold minimized the damage that this chemical does to the cells. With single cell solutions, adding the chemical at ice-cold temperatures and immediately diluting it out when you thaw the cells can keep 90% of the cells alive. There’s no way to do this with an intact body.
It’s also worth noting that this is probably not the only reason that this technique doesn’t scale to organisms.
Wednesday, 23 March 2016
ELI5: Does a sonic boom only occur at the moment you break the sound barrier or is it constant and if it is does it get louder the faster you go?
It is constant.
A sonic boom is a shock wave that travels outward from the plane. It follows the plane wherever it goes. When the plane flies by a person on the ground, the shock wave will hit that person (and be heard as a “boom”) shortly after. Since the boom moves at the speed of sound, and the plane is moving faster than that, a cone shape develops, with the plane at the point of the cone. Here’s an example image.
As for speed vs. loudness, it’s actually the opposite of what you’d expect. The faster the plane, the skinnier and pointier the cone. As a result, the energy of the shock wave gets spread out over a longer distance. Additionally, super-fast aircraft tend to fly at much higher altitudes, meaning the boom travels through a lot more air before it reaches the ground, dissipating it. So sonic booms actually get quieter the faster the plane flies.
Saturday, 19 March 2016
ELI5: Why is charcoal so effective in fire places/pits/barbeque stands if the most of the wood/fuel has been used up?
Wood burns in two stages: the hydrogen stage and the carbon stage. In the hydrogen stage, hydrocarbon molecules are broken and oxidise. In the carbon stage, the carbon oxidises.
The carbon stage burning is a hotter and cleaner chemical reaction than hydrogen stage burning.
Charcoal is made by burning wood in the hydrogen stage (hence removing the hydrocarbons) but not allowing the carbon stage (by limiting the amount of oxygen).
