The Fifth Conic Section - Straight Line

Alloys: Wood’s Metal

Also known as Lipowtiz’s alloy as well as the commercial names of Cerrobend, Bendalloy, Pewtalloy, and MCP 158 among others, Wood’s metal is a bismuth alloy consisting of 50% bismuth, 26.67% lead, 13.33% tin, and 10% cadmium by weight. Named for the man who invented it, a Barnabas Wood, Wood’s metal was discovered/created by him in 1860.

Wood’s metal is both a eutectic and a fusible alloy, with a low melting temperature of approximately 70 °C (158 °F). While none of its individual components have a melting temperature of less than 200 °C, a eutectic alloy can be considered as a pure (homogeneous) substance and always has a sharp melting point. If the elements in a eutectic compound or alloy are not as tightly bound as they would be in the pure elements, this leads to a lower melting point. (Eutectic substances can have higher melting points, if its components bind tightly to themselves.)

Useful as a low-temperature solder or casting metal, Wood’s metal is also used as valves in fire sprinkler systems. Thanks to its low melting temperature, Wood’s metal melts in the case of a fire and thanks to the bismuth it is made from, the alloy also shrinks when it melts (bismuth, like water ice, is one of the few substances to do so) which is the key to setting off the sprinkler system. Wood’s metal is also often used as a filler when bending thin walled metal tubes: the filler prevents the tube from collapsing, then can be easily removed by heating and melting the Wood’s metal. Other applications include treating antiques, as a heat transfer medium in hot baths, and in making custom shaped apertures and blocks for medical radiation treatment.

With the addition of both lead and cadmium, however, Wood’s metal is considered to be a toxic alloy. Contact with bare skin is thought to be harmful, especially once the alloy has melted, and vapors from cadmium containing alloys are also quite dangerous and can result in cadmium poisoning. A non-toxic alternative to Wood’s metal is Field’s metal, composed of bismuth, tin, and indium.

Sources: ( 1 - image 4 ) ( 2 - image 2 ) ( 3 ) ( 4 )

Image sources: ( 1 ) ( 3 )

What Are Earthquake Hazards?

Ground Shaking

The first main earthquake hazard is the effect of ground shaking. Buildings can be damaged by the shaking itself or by the ground beneath them settling to a different level than it was before the earthquake (subsidence).

Liquefaction

Buildings can even sink into the ground if soil liquefaction occurs. Liquefaction is the mixing of sand or soil and groundwater during the shaking of a moderate or strong earthquake. When the water and soil are mixed, the ground becomes very soft and acts similar to quicksand. If liquefaction occurs under a building, it may start to lean, tip over, or sink several feet. The ground firms up again after the earthquake has past and the water has settled back down to its usual place deeper in the ground. Liquefaction is a hazard in areas that have groundwater near the surface and sandy soil. 

Ground Displacement

The second main earthquake hazard is ground displacement along a fault. If a structure (a building, road, etc.) is built across a fault, the ground displacement during an earthquake could seriously damage or rip apart that structure. 

Flooding

The third main hazard is flooding. An earthquake can rupture (break) dams or levees along a river. The water from the river or the reservoir would then flood the area, damaging buildings and maybe sweeping away or drowning people. Tsunamis and seiches can also cause a great deal of damage. Atsunami is what most people call a tidal wave, but it has nothing to do with the tides on the ocean. It is a huge wave caused by an earthquake under the ocean. Tsunamis can be tens of feet high when they hit the shore and can do enormous damage to the coastline. Seiches are like small tsunamis. They occur on lakes that are shaken by the earthquake and are usually only a few feet high, but they can still flood or knock down houses, and tip over trees. 

Fire

The fourth main earthquake hazard is fire. These fires can be started by broken gas lines and power lines, or tipped over wood or coal stoves. They can be a serious problem, especially if the water lines that feed the fire hydrants are broken, too. For example, after the Great San Francisco Earthquake in 1906, the city burned for three days. Most of the city was destroyed and 250,000 people were left homeless. (Source)

Just imagine a world full of beautiful stained glass windows which also generate electricity…

[Oxford Photovoltaics]

Here’s every total solar eclipse happening in your lifetime. Is this year your best chance?

On Aug. 21, a total solar eclipse will be visible from the continental United States. It’ll be the first to traverse coast to coast in nearly a century. Learn more about past and future eclipses: See full graphic.

But that’s not all it can do. Microsoft and NASA teamed up to “bring” you, yes you, to Mars.

Follow @the-future-now

A sponge can’t soak up mercury. (Video) Facebook | Instagram | Scary Story Website

This is how scientists think birds see the Earth’s magnetic field.

See how the black patches align over certain areas? That dark patch at the base of their vision shows South, with the reverse indicating North. Researchers think this might be how birds like pigeons can use magnetic fields to navigate.

Here’s how it works: there’s a protein in their eyes called cryptochrome. When blue light hits it, it becomes active, and stays active for a little while. How long it stays active for, though, depends on the Earth’s magnetic field, and since cryptochrome is known to affect the sensitivity of the birds’ retinas to light, we think this is the effect it has on their vision.

We have this very same molecule in our eyes, but the molecule that lets it stay active for long enough to be affected by the magnetic field, superoxide, is toxic, so the antioxidants in our eyes lock it down too quickly.  Researchers think we’ve traded longevity for magnetovision.

Want to know more? We made a whole video answering the question, do blind birds can navigate!? Watch it here: https://youtu.be/7yBMUrlpe5s

There's an app for that

A “master list” of apps that are essential to student life.

Flashcards

Quizlet - Flashcard app that has pre downloaded flashcards and you can make your own flashcards. Available on multiple platforms

Duolingo - Language flashcard app

Flashcards+ - Another flashcard app

Math

Luna Calculator - calculator app ($2.99 on iOS)

Wolfram Alpha - online math solver

Symbollab - online math solver

Productivity & Planning

Forest - Grows a tree for every thirty minutes you are off your phone. If you touch your phone, the tree dies. ($0.99 on iOS)

FocusNow - Free version of Forest for iOS. Instead of trees, it grows fruits and vegetables. 

30/30 - Great time management app

Any.Do - Great app for creating to-do lists, organize tasks, syncs with other devices. You can also change the priorities on certain tasks. 

Studious - Great app on Android that reminds you when homework is due, when exams are and even silences your phone during class. 

StayFocused - A chrome extension that you can customize to limit the time on websites to stay productive

Self Control - Allows you to block your own access to distracting websites for a certain amount of time. Useful for people who get distracted on the computer (Also known as Cold Turkey for Windows).

My Study Life - Student planner app

myHomework Student Planner - another Student planner app

To-do List - extensive to do list, like an online bullet journal

Learning

Itunes U - For any apple device users, a app that gives you access to free educational courses 

TED - The whole catalog of TED talks at your fingertip. 

Wikipedia - Free encyclopedia that can be used for general references

Khan Academy - study videos (absolutely amazing app/website)

Music 

Coffitivity - coffee shop soundtrack

8tracks - great playlists, especially study playlists

Wake Up Calls

Alarmy - good alarm that will force you out of bed

Sleep Cycle - measures your sleep cycle

Math Alarm - alarm clock that forces you to do math to turn the alarm off, get’s your brain going 

Class Lectures and Note Taking

Dragon Dictation - takes notes for lectures (useful for classes where professors talk faster than you can type)

XMind - mind mapping tool

Notability - another app for recording lectures. ($2.99 on iOS)

These are just a few study apps that can be useful for studying. I will add more (or make a new list) later as I learn about them; feel free to message me to add some to this list. 

Vantablack absorbs 99% of light and is the darkest material ever made.