MIT Graduates Struggle to Light a Bulb with a Battery and Wire

The video: Scandalous!

I saw this video going around of engineering students at their graduation from MIT who were unable to power a light bulb using a battery and a single wire:

It is surprising that the engineers would have trouble rigging up the circuit. Let's take a look at the problem and see what this episode can teach us about effective learning.

 

The solution: Back to the basics of electricity

A conventional lightbulb has two terminals—one at the base and another at the threads of the bulb. If these two terminals are kept at differing voltages, current will flow across the bulb, causing the filament to glow.

The obvious way to close the circuit and light the bulb is to use two wires:

• connect a wire between one terminal of the battery and the rim of the light bulb
• and a second wire between the other terminal of the battery and the base of the bulb.

While the setup with one wire appears to be different, it is actually the same. We can see this by drawing a diagram.

 

Case 1: Closing the circuit with two wires

Consider the conventional circuit with two wires

Let’s ask ourselves a simple question: what is a wire? The answer is: a tool to connect two components of an electrical circuit. This is all the insight we need to close the circuit with one wire.  

Case 2: Closing the circuit with one wire

Looking at the battery and the light bulb, it's clear that we can touch one of the terminals of the battery directly to the threads of the bulb.

For instance, by touching the positive terminal of the battery to the thread of the bulb, we put the threads at the same potential as the positive terminal. If we now use the wire to connect the terminal at the base of the bulb to the negative terminal of the battery, the circuit will close, with a sustained voltage across the terminals of the bulb that's equal to the voltage of the battery—let there be light!

Thus, we can eliminate one of the wires without incident.

You may have noticed this isn't the only way to close the circuit. In fact, there are three other arrangements that will work. While the bulb requires a voltage across its terminals, it doesn't care about the polarity.

So, we could also do the following:

The simple lesson is: if there's a way to make two circuit components touch without using a wire, we don't need to.

 

A hazard of higher learning: Losing the basics

Those students probably all knew how lightbulbs, circuits, and batteries worked. However, they also probably spent the last several years of college in upper division classes that focused on abstraction and theory. When confronted with the basics, they no longer recognized where the lightbulb and the battery fit into their skill set and knowledge base. This is not a problem unique to MIT or elite academia. Losing track of the basics is an innate hazard of learning a lot very quickly.

Chief Happiness Officer Zorro consults with Pete.

 

Conclusion: Develop a firm understanding of simple cases

In any field that you find yourself in, you can protect yourself from a future light bulb + battery moment by laying your foundational knowledge in the firm understanding of simple cases. If you have a sound understanding of the fundamentals in your discipline, you will always be able to derive more sophisticated ideas from the basics. Conversely, it's extremely hard to rediscover the fundamentals from merely remembering the wealth of fancy results of your field of study. In other words, when you get lost… go back to the basics.

Want more like this? Check out the Physics of the Everyday course.

Note by Josh Silverman
4 years ago

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

• Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
• Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
• Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
• Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold
- bulleted- list
• bulleted
• list
1. numbered2. list
1. numbered
2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in $$ ... $$ or $ ... $ to ensure proper formatting.
2 \times 3 $2 \times 3$
2^{34} $2^{34}$
a_{i-1} $a_{i-1}$
\frac{2}{3} $\frac{2}{3}$
\sqrt{2} $\sqrt{2}$
\sum_{i=1}^3 $\sum_{i=1}^3$
\sin \theta $\sin \theta$
\boxed{123} $\boxed{123}$

Sort by:

Apparently, these Harvard grads haven't ever taken a flashlight apart. I mean, how many times have I had to take apart a flashlight because the battery wasn't making a good connection with the bottom of the bulb?

Then again, maybe they don't make flashlights like that any more. Maybe it's all done with Wi-Fi.

- 4 years ago

I didn't think of this. The flashlight definitely raises the stakes.

Staff - 4 years ago

Well you people should see India I guess then.Here from grade 8 onwards students know only 1 word...JEE.Just mug up huge books for 5 years just the sake of those 6 hours.By the time they reach IIT...they forget how to ride a bicycle.

- 2 years, 10 months ago

It is vital that there be practical/vocational training for students. I am from Afghanistan and most 5 year old kids there would be able to achieve this because they have played around with batteries and bulbs. I remember a Big Bang Theory episode where Howard was asked if he knew about internal combustion engines and he said something along the lines of "Yeah, I am an Engineer" but couldn't fix one. I would think practical portion of the field is just as important as the theory when teaching!

- 4 years ago

Ya I know at my school I learned that in 1st grade when I was 6

- 3 years, 1 month ago

Unbelievable. Really.

- 4 years ago

isn't that ur dog sir :)

- 3 years, 10 months ago

This is possible.

Staff - 3 years, 10 months ago

This is gold. Imagine being able to do pages and pages of physics problems and practice tests to end up not knowing how to light up a bulb🤣

- 5 months, 3 weeks ago

I know right. These people probably haven't touched physical objects other than books and pens in years lol

- 3 months, 3 weeks ago

I seriously wonder... how can engineers learn to build things without actually being able to build things? Wtf?

- 3 months, 3 weeks ago

I know, they must feel like they wasted their life after this. And to think that this can be done by 5th graders...Its embarassing...

- 3 months, 3 weeks ago

And to think that these are the people that are training to design the most complicated electrical systems in the world...

However, that being said, the hardest part is learning the mathematical aspect of the engineering. The practical aspect is much easier. But still; it's surprising that their conceptual understanding is so poor.

- 3 months, 3 weeks ago

Yes...See my new note on my profile, its about Murphy's Law @Krishna Karthik

- 3 months, 3 weeks ago

Murphy's Law? I remember that from Interstellar lol.

- 3 months, 3 weeks ago

LOL, ya it says that whatever can go wrong, will go wrong. I just tried to disprove it, but can't seem to be sure of it.

- 3 months, 3 weeks ago

It's just an adage. It isn't objective.

- 3 months, 3 weeks ago

Yes, but it is interesting nonetheless...

- 3 months, 3 weeks ago

Yeah; of course. Many people know about Murphy's law; it'll be interesting to disprove different cases of it.

- 3 months, 3 weeks ago

Yes. When something goes wrong, lots of people in my school used to be like, "Damn, Murphy's Law". The ones who knew about it anywway lol

- 3 months, 3 weeks ago

scary.

- 4 years ago

Engineering is about creating and most of the universities produce scientists and not engineers .Its an initiative u take upon yourself and do it

- 3 years, 7 months ago

You can see the guys spent time in vain at the university, since they can't do such an elementary task..... It directly shows the status of the university and students' interest....

- 9 months, 1 week ago

wtf it's spam https://writix.co.uk/buy-dissertation-help

- 8 months ago

Lol

- 3 months, 2 weeks ago

Yeah; the guy's clearly a bot: https://brilliant.org/profile/georgina-wyem6v/about/

- 3 months, 2 weeks ago

Are you talking about me ?

- 3 months, 2 weeks ago

No. I'm talking about "Georgina Begum"; see their profile: https://brilliant.org/profile/georgina-wyem6v/about/

You can clearly see that there are zero problems solved, and zero activity, except that comment below to promote writix. Well, the "guy above" wasn't a good choice of words. The comment got bumped down after I downvoted it.

- 3 months, 2 weeks ago

Wow. Interesting !!

- 3 years, 8 months ago

It's funny for some reason, but... I know perfectly well and I understand why it happens. The level of education is going down significantly right now. Lots of problems, though many of them are being solved. At least solvable with the help of the website https://writix.co.uk/buy-dissertation-help , which helps in writing materials on various topics.Used the website when I was in graduate school, when I could buy a dissertation. It was invaluable help then. And I'll say that it didn't affect my professional skills or my education.

- 9 months, 1 week ago