If you went back in time, what could you teach this civilization?

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*How much do you really know about our world?

Do you actually know enough detail to teach our ancestors to make concrete, steel, or a radio?  Sure you may know of germs, gunpowder, and electricity but when it comes down to it, how deep is that knowledge?

This site is dedicated to exploring these questions. You can start by taking the quiz.

Take the Quiz see how well you do at the details. 

It also tests you on using the technology of their time. Could you harness a horse? Operate a spinning wheel? Tan a hide? Try the quiz and see.

For our scenario, we are going to ignore the political, religious and language barriers you would face and focus on just the technical aspect. Let's face it, you would probably be burned at the stake as a witch and that makes for a short and uninteresting scenario.

Log in and share your knowledge! Help expand our knowledge of the underlying technology in our modern lives. If there is anything we have learned from the information age, it is that the power of internet is awesome.

The danger isn't over once you are rescued from the cold

In 1980, sixteen Danish fishermen were forced to jump into the North Sea after their fishing boat floundered. After about 1.5 hours in the water another boat approached and lowered a cargo net which they used to climb on board. They thanked their rescuers and they walked across the deck and went below to the galley where they were supposed to have hot drinks and warm up. Instead, all sixteen of them dropped dead.

Building a radio receiver - how the first receivers worked

The first receivers made use of something called a “coherer”. It’s really just a pile of metal filings that are loosely placed between two electrodes.

Creating electricity in the era of cavemen

Let's say you want to reinvent electricity.   The majority of the today’s electricity is generated by moving conductors through a magnetic field.  So you need a magnetic field, a conductor and motion.  A water wheel could provide motion, so then you just need the conductor (wire) and some magnets and you could generate electricity.   This sounds great on paper but in reality it glosses over an interesting Catch-22 in using permanent magnets to generate electricity.

Reinvent Pasteurization

Pasteurization is one of the more mild forms of thermal processing that kills pathogens in milk and increases its safety and shelf life.  Modern pasteurization uses high temperature and short time to kill pathogens in the milk. It kills off the most heat-sensitive pathogens while retaining the qualities of milk that consumers expect. This amounts to heating the milk to 161° F (72° C) for 15 seconds by running the milk through a tube of which the size and diameter takes the milk exactly 15 seconds to pass.


Reinvent radio - Build a radio transmitter

Before discussing radio waves and how to create them, I want to point out that if you understand the theory behind creating radio waves, you will understand how to create micro waves or X-rays. What are radio waves?

Let's say you've gone back in time - Fixed*

The academically anemic infographic under discussion. Click for a larger image.
Time travel infographic in question.

I've seen this infographic (at right) posted several times on the internet. My inner engineer couldn't help but to tinker with it and give it that little something extra[0].  I'll dial it up to '11' by making it useful without writing a dissertation on each subject. Here goes...


Build an evaporative refrigerator - no moving parts, no electricity

How to build a Zeer pot
Zeer Pot Construction

What is an evaporative refrigerator?

It is a device that uses the evaporation to cool a space that can be used to store food or water. An illustration of one version is shown at right.   This version was created by putting one earthenware pot inside another, filling the space between them with sand and then wetting the sand.  Food is stored in the inner pot which can be covered by a wet towel or a lid.  As the water evaporates from the sand, it cools the inner pot and its contents. The whole thing is easy to build and to operate and, best of all, it is inexpensive.  An added bonus is that the water used for cooling does not need to be potable. That sounds perfect for third world applications and it is most often in this context that the device is discussed. 


Busting myths about the Zeer pot

Zeer pot example - Image credit: Adam from ModernBushman.com
Zeer Pot

If you don't already know, a Zeer pot is a type of evaporative refrigerator.  It is a device that keeps being rediscovered even though various versions of the device have been used for thousands of years. I am going to call them evaporative refrigerators since they operate by evaporation and are used like a refrigerator.  Every new blog entry or YouTube video about them seems to spread misinformation and sometimes outrageous claims.  Let’s clear some things up.


Eating charcoal could save your life if you have ingested poison?

This is true but it should be clarified that the charcoal given in emergency medical treatment is “activated” charcoal and that it is only helpful against certain types of poisons.   A dramatic example of this is the tale of Professor Touery, who in 1831 in front of his colleagues at the French Academy of Medicine ingested 15 grams of the deadly poison strychnine (that is ten times the lethal dose). He lived to tell the tale because he mixed the strychnine with activated charcoal.



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