Reflection Relay

Reflection Relay

Description: A team of three students will work cooperatively to determine the path a light beam takes, as it reflects off a series of plane mirrors.


Event Supervisor: Ruth Cummins


 event supervisor info
 Download the current rules here.  
Small protractor template to print and cut out
Print your own LARGE FLOOR protractor
more event info be careful
  There may be a "Quick Start Kit"  available for this event. 
  See the Elementary Workshop List for this season
 Report problems at This email address is being protected from spambots. You need JavaScript enabled to view it.






elem faq button web

Can we draw lines on the paper in the 2D challenge?

The white piece of paper is for the students to do whatever they need to in order to complete the task.  They can write on it, tape things to it, whatever they think is necessary.

What is the diameter of the target in the 3D challenge (Part One)?

The red and green targets are approximately 11 inches in diameter and are made from construction paper.

Is the target always in the vertical plane (perpendicular to the floor)?

The target might be positioned anywhere in the room - on the wall, on the floor, on the ceiling - not necessarily perpendicular to the floor.

What is the height of the permanent mirror?

The permanent mirror will be fixed to the wall. It's height can ranng efrom 6 inches lower than the light source to 6 inches higher than the light source.

For the 3D challenge, during the 1 minute preparation time, will the light source be ON or it will be turned ON when the clock starts?

The team can use UP TO 1 minute to prepare with the room lights on, and the flashlight is off. 
That prep time is recorded and used as a tie breaker if necessary

The lights in the room are turned off, and we give the student's eyes time to adjust to the dark
The judge counts down 3-2-1 and the light source (flashlight) is turned on at the same time that the clock starts for competition.

Will part 1 and part 2 be in the same room?

No, they will do part one in one room – just the team and their judges (and any spectators from that school).  They will be in another room where a few teams will be working on Part 2.  Spectators will be allowed into the part 2 room also (as long as they can watch in silence).

Is there a suggested way for the students to hold the mirrors in the 3 D challenge (PART 1)?

Students need to experiment to see which way is the best way to hold the mirrors.  They need to think about how their feet should be positioned, how their hands are positioned, as well as how high they should hold the mirror.  Whichever way is the most comfortable and most stable will vary with each student.

Is there a suggested order for passing the light beam in the 3 D challenge (PART 1)?

There is no set order; however you may want to put your steadiest student holding the first mirror since he/she will have to hold the light steady for the longest amount of time.  

How big of a room should we practice in for the 3 D challenge (PART 1)?

You should practice in a room about the size of a normal classroom.  There should be plenty of furniture in the room.  The furniture serves as obstacles that the students will have to work around.  The room at the college will be a classroom with normal classroom furniture in it.  Students will not be able to move the furniture.

Can the students lean on the furniture in order to hold the mirror still in the 3 D challenge (PART 1)?

Yes, they can, however they should not practice this.  They won’t know what kind of furniture is in the room ahead of time.  Depending on furniture to hold them steady may not work if the furniture is different from what they are used to.

How will the Supervisor know when the team is done planning their strategy for the 3D challenge in the 3 D challenge (PART 1)?

You should have a team leader chosen before you get to the tournament. I will ask the team leader to tell me when they are ready.  Remember, the planning time is recorded and used as a tie breaker.

How high should the permanent mirror be placed in the 3 D challenge (PART 1)?

The permanent mirror can be up to 6 inches higher, or 6 inches lower than the light source.  The height of the light source may vary depending on the tables available in the room.  Students should practice with the light source at varying table heights.

How big is the Maglite flashlight used in the 3 D challenge (PART 1)?

It is approximately 12 inches long with a diameter of approximately 1.75 inches.


Where can we get a large floor protractor to practice the 3 D challenge (PART 1)?

You can download a file from the Reflection Relay page on the Science Olympiad website (Click here). 
Take it to any office supply store or Macomb Intermediate School District – teacher’s workroom to print it. 
You also can put a normal sized protractor under a document camera and project it onto a piece of roll paper. 
You’ll want it to be an 80 centimeter radius.  It is a good idea to laminate it so it will last. 

What equipment will the students be able to move in the 3 D challenge (PART 1)?

The only things they can move are the 3 mirrors (that are provided by the Supervisor).  They may not move the flashlight, protractor, permanent mirror, target or furniture in the room.

Is the permanent mirror always the 2nd mirror in the 3 D challenge (PART 1)?

No, the permanent mirror can come anywhere in the series of mirrors reflecting the light.  It will probably be the 2nd or 3rd mirror since it would be extremely difficult (or impossible) to make it the 1st or 4th mirror.

What is a good score in the 3 D challenge (PART 1)?

The most successful teams consistently get scores of 10 seconds or less for each of the 3D challenges.

If they accidentally break a mirror, can they get another one in the 3 D challenge (PART 1)?

Yes, I’ll have extra mirrors available.  (Don’t worry, I’ve removed the 7 years bad luck hex on all Reflection Relay mirrors)

Does it do the team any good to be done before the 5 minute work time is up for the 2D challenge (PART 2)?

In the 3D challenge preparation time is a tie breaker, however in the 2 D challenge there is no advantage to being done early.   

What happens if students bump the laser or target out of place for the 2D challenge (PART 2)?

We will work hard to make sure the laser, target, and any barriers are solidly attached to playing field.  However if they are bumped hard enough, they might be pushed out of place.  Neither the event supervisor nor the students will be able to touch these pieces of equipment to try to put them back in their original position.  At the end of the 5 minute work period, the laser will be turned on and the team’s score will be based on which mirrors and target areas the laser light reaches.   Students should practice extreme care not to move the laser, target, or barriers.

In regards to the "light source" should students practice with an LED or Incandescent light source.

As long as you can focus the light into a small bright beam, it doesn't matter.