Fast and Furious

A bus driver was heading down a street in Colorado. He went right past a stop sign without stopping, turned left where there was a “no left turn” sign, and went the wrong way on a one-way street. Then he went on the left side of the road past a cop car. Yet, he didn’t break any traffic laws.

Why not?

The bus driver was not driving his bus, he was walking.

Moving to a New House

A man was moving to a new house. He rented a moving truck, put all his belongings in it, and drove to his new place. He entered the garage with the truck and took all his belongings out of the truck. When he tried to exit the garage with the truck, he couldn’t. Why?

The empty truck was just slightly taller than the garage door. When it was packed with items, the truck’s height got lower, so the man could enter the garage. Once the items were unpacked, the truck was once again taller than door, so it couldn’t get out.

Fascinating Dissection

First, print and cut the pieces below. Then, arrange them so that they form a triangle and then rearrange them so that they form a square.

The solution is shown below.

What is fascinating about these dissections is that one can transform into the other by keeping the pieces attached to each other in a chain and simply rotating them around the hinge points.

Einstein’s Puzzle

There are 5 houses and each of them has a different color. Their respective owners have different heritages, drink different types of beverages, smoke different brands of cigarettes, and look after different types of pets. It is known that:

  1. The Brit lives in the red house.
  2. The Swede keeps dogs as pets.
  3. The Dane drinks tea.
  4. Looking from in front, the green house is just to the left of the white house.
  5. The green house’s owner drinks coffee.
  6. The person who smokes Pall Malls raises birds.
  7. The owner of the yellow house smokes Dunhill.
  8. The man living in the center house drinks milk.
  9. The Norwegian lives in the leftmost house.
  10. The man who smokes Blends lives next to the one who keeps cats.
  11. The man who keeps a horse lives next to the man who smokes Dunhill.
  12. The owner who smokes Bluemasters also drinks beer.
  13. The German smokes Prince.
  14. The Norwegian lives next to the blue house.
  15. The man who smokes Blends has a neighbor who drinks water.

The question is, who owns the pet fish?

The German owns the pet fish.

Since the Norwegian lives in the leftmost house (9) and the house next to him is blue (14), the second house must be blue. Since the green house is on the left of the white house (4), the person living in the center house drinks milk (8), and the green house’s owner drinks coffee (5), the fourth house must be green and the fifth one must be white. Since the Brit lives in the red house (1) and the Norwegian lives in the leftmost house (9), the leftmost house must be yellow and the center house must be red. Therefore, the colors of the houses are: YELLOW, BLUE, RED, GREEN, WHITE.

Since the Norwegian from the yellow house smokes Dunhill (7), the man from the blue house must keep a horse (11). The person smoking Blends cannot be in the red house, because this would imply that the person in the green house keeps cats and the Swede keeps dogs in the white house (2, 10). However, in this case the Dane must be drinking tea in the blue house (3) and the person smoking Blends does not have a neighbor drinking water (5), which is a contradiction (15). Also, the person smoking Blends cannot be in the green house, because this would imply that the person in the white house drinks water (15), the Dane lives in the blue house (3), and the German and the Swede live in the last two houses. Since the German smokes Prince (13) and the Swede keeps dogs (2), there is nobody who could smoke Bluemaster and drink beer (12). The person smoking Blends cannot be in the white house either, because this would imply that the person in the green house drinks water (15), when in fact he drinks coffee (5).

Therefore, the person smoking Blends must be in the blue house, and then the German and the Swede must live in the last two houses (2, 13). Since the person who smokes Bluemasters drinks beer (12), this must be the Swede with his dogs in the white house (2). The only option for the person who smokes Pall Mall and raising birds (6) is the red house. Then the Norwegian must keep cats (10) and the German is left with the pet fish in the green house.

Seeing Theory

Seeing Theory is a beautifully designed website, which aims to educate people about probability theory via series of visual and interactive lessons. If anyone is struggling to grasp some of the basic concepts in this field of mathematics or is just getting into it, the website can be a very useful learning tool. Seeing Theory was designed by Daniel Kunin as an undergraduate project in Brown University and has won numerous awards. To visit the website, click the banner below.

Thief

A woman was standing in her hotel room, when somebody knocked on the door. When she opened the door, there was a man who said that he has mistaken his door, apologized, and continued down the corridor. When the woman closed the door, she called security to warn them about the thief. Why did she think the man was planning to rob her?

If the man really thought this was his room, he wouldn’t have knocked on the door.

Close the Loop

Alex and Bob are playing a game. They are taking turns drawing arrows over the segments of an infinite grid. Alex wins if he manages to create a closed loop, Bob wins if Alex does not win within the first 1000 moves. Who has a winning strategy if:

a) Alex starts first (easy)
b) Bob starts first (hard)

Remark: The loop can include arrows drawn both by Alex and Bob.

In both cases, Bob wins. An easy strategy for part a) is the following:

Every time Alex draws an arrow, Bob draws an arrow in such a way that the two arrows form an L-shaped piece and either point towards or away from each other. Since every closed loop must contain a bottom left corner, Alex cannot win.

For part b), Bob should use a modification of his strategy in part a). First, he draws a horizontal arrow. Then, he splits the remaining edges into pairs, as shown in the image below. If Alex draws one arrow on the grid, then Bob draws its paired arrow, such that the two arrows point either towards or away from each other. The only places where a loop can have a bottom left corner are where Bob drew the first arrow or the grid points directly above it. However, if a loop has a bottom left corner there, then it is easy to see that it must have at least one more bottom left corner elsewhere, which is impossible. 

Physics Jokes

Who says science jokes are not funny? Below you can see some of the best Physics jokes we know, along with short explanations of the more obscure of them.

Do you know any funny Physics jokes yourself? Let us know in the comment section below.


“Where does bad light end up?”
“In prism.”

Explanation
A word-play with the word “prison”.


“Why does a burger have less energy than a steak?
Because it is in its ground state.”

Explanation
The ground state of a mechanical system has the least possible energy.


Einstein developed a theory about space. And it was about time too.

Explanation
The joke is a wordplay with the fact that Einstein developed a theory about space-time relativity.


“Theory is when you know everything, but nothing works. Practice is when everything works, but no one knows why. In our lab theory and practice are combined – nothing works and no one knows why.”


“What is a physicist’s favorite food?”
“Fission chips.”

Explanation
Fission chips” sounds like “fish’n’chips“. Fission is a radio-active process during which a nucleus splits into two or more nuclei.


Two theoretical physicists are lost at the top of a mountain. Theoretical physicist No 1 pulls out a map and peruses it for a while. Then he turns to theoretical physicist No 2 and says:
“Hey, I’ve figured it out. I know where we are.”
“Where are we then?”
“Do you see that mountain over there?”
“Yes.”
“Well… That’s where we are!”

Explanation
Theoretical physicists are regarded to be very detached from reality.


I have a new theory on inertia, but it doesn’t seem to be gaining momentum.

Explanation
Inertia and momentum are related to the motions of solid bodies.


“How did Einstein begin his stories?”
“Once upon a space-time…”

Explanation
The space-time is a mathematical model of the universe introduced by Albert Einstein.


Yesterday I was reading a book on anti-gravity. Couldn’t put it down.

Explanation
Anti-gravity is the concept of having a place or object which is free from the force of gravity.


A cop pulls Heisenberg and asks him:
“Do you know how fast you were driving?”
Heisenberg replies:
“No, but I know where I am.”

Explanation
Heisenberg’s uncertainty principle in quantum mechanics states that you can not know with certainty both the position and the momentum of a particle.


My friend Power has been very stressed all week. His boss keeps making him work over time.

Explanation
A word play with the formula:
POWER = WORK / TIME


One day, Einstein, Newton and Pascal met up and decided to play a game of hide and seek. Einstein volunteered to be “It”. As Einstein counted to 100, eyes closed, Pascal ran away and hid. Newton however stood right in front of Einstein and drew a 1 meter by 1 meter square around himself. When Einstein opened his eyes, he immediately saw Newton and said, “I found you Newton,” but Newton replied, “Nope, you found one Newton per square meter, that’s Pascal!”

Explanation
A word play with the formula:
1 PASCAL = 1 NEWTON / 1 SQUARE METER


A photon checks into a hotel. The bellhop asks, “Can I help you with your luggage?” The photon replies, “I don’t have any, I’m traveling light.”

Explanation
Photons are traveling light particles.


A student riding in a train looks up and sees Einstein sitting next to him. Excited he asks, “Excuse me, Professor, does Boston stop at this train?” 

Explanation
Physical observations depend on the point of view of the observer.


Why is electricity so dangerous? Because it doesn’t know how to conduct itself properly.

Explanation
Electricity is formed by conduction of electrons in a wire.


A male magnet says to a female magnet:
“From your backside, I thought you were repulsive. After seeing you from the front however, I find you rather attractive.”

Explanation
Depending on the way you connect magnets, they could either repulse or attract each other.


Schrodinger’s cat walks into a bar. And doesn’t.

Explanation
Schrodinger’s cat is a thought experiment related to the theory that a system can be in multiple states until interacts with the outside world. The classic setup is with a cat closed in a box with radioactive substance in it, which could potentially kill her. Before you open the box, the cat is supposedly both dead and alive.


The dean addresses the physics department:
“Why do I always have to give you so much money – for laboratories and expensive equipment and stuff? Why couldn’t you be like the mathematics department – all they need is money for pencils, paper, and waste-paper baskets. Or even better, like the philosophy department – all they need is pencils and paper.”

Explanation
Scientists like physicists and mathematicians consider philosophers to produce mostly useless results and materials.