Card 13

🔁 ⏰ 📖

If you travel back in time and give Shakespeare his own plays, who wrote them?

💭 How to Think About This

Imagine: You time travel to 1600, give young Shakespeare a book of "his" plays. He copies them and becomes famous. You got the book from the future where he's the author. But he only wrote them because you gave them to him! Where did the plays ORIGINALLY come from?

Who originally wrote Shakespeare's plays in this scenario?

You've identified the CAUSAL LOOP!

Future → Past → Future → Past...

There's no starting point - the information just exists!

The plays were NEVER originally created!

They just exist in the loop, passed endlessly.

But can information exist without being created?

Called "bootstrap" - like pulling yourself up by your own bootstraps!

Physically impossible.

The information "bootstraps" itself into existence!

Your answer reveals the paradox!

If nobody wrote them, they violate causation.

This suggests backward time travel may be impossible!

You've identified the Bootstrap Paradox perfectly!

The loop: The plays exist in the future → you take them to the past → Shakespeare copies them → they exist in the future. Circle with no beginning!

The problem: Information can't just appear from nowhere! Yet in this loop, the plays were NEVER originally created by anyone.

What this tells us: Backward time travel creates logical impossibilities. This is one reason physicists doubt it's possible - effects causing their own causes violates fundamental principles of causation!

You've recognized this scenario is IMPOSSIBLE!

It violates causation - effects can't cause themselves.

That's exactly the point of the paradox!

The scenario creates a loop: Future → Past → Future...

The plays exist without ever being created.

Information from nowhere!

This paradox suggests backward time travel is impossible!

Or: you can never actually change the past.

Or: changing past creates alternate timelines.

Paradoxes like this help us understand causation!

Effects need causes. Causes come before effects.

Violating this creates logical impossibilities!

You've grasped the Bootstrap Paradox - it IS impossible!

Why impossible: The scenario creates a causal loop where information exists without ever being created. Effects cause their own causes!

Solutions physicists propose:

1. Backward time travel is simply impossible

2. Self-consistency - you can't actually change the past

3. Many-worlds - changing past creates new timelines

Key insight: Paradoxes reveal fundamental rules of reality! Causation requires causes to precede effects. Violating this leads to logical impossibilities.

You say Shakespeare wrote them, but...

In this scenario, he only COPIED them from the book you gave him!

He never actually created them himself!

Where did YOU get the book?

From the future - where Shakespeare is the "author."

But he only "authored" by copying YOUR book!

Future → Past → Future → Past...

It's a loop with NO starting point!

The plays were NEVER originally written by anyone!

Your intuition says "someone must have written them"!

But the loop makes that impossible to identify.

This is why backward time travel creates paradoxes!

Your intuition is natural - but the loop breaks it!

Why Shakespeare didn't write them: In this scenario, he only COPIED the book you gave him. He never created anything original!

The loop: You got the book from a future where Shakespeare is credited → you give it to young Shakespeare → he copies it → becomes famous → the book you have exists. No one ever created the content!

The Bootstrap Paradox: Information exists without ever being created. This violates causation - and is why most physicists think backward time travel is impossible!

🤔 Which thinking lens(es) did you use?

Select all the lenses you used:

Learn more about the 7 Thinking Lenses →

👨‍👩‍👧 For Parents & Teachers

🌱 A Small Everyday Story

"What if I went back and gave myself the test answers?"
"Then you'd pass!"
"But where did the answers come from?"
"From... you? In the future?"
"But I only knew them because I gave them to myself..."
Time travel homework made everyone's head hurt.

See more guidance →

🧠 Thinking habits this builds:

Understanding causal chains
Recognizing circular reasoning
Appreciating the arrow of time
Questioning science fiction scenarios

🌿 Behaviors you may notice (and reinforce):

Tracing cause and effect carefully
Finding logical impossibilities
Understanding why time travel is problematic
Appreciating conservation laws

How to reinforce: "You discovered that information can't just appear from nowhere! The plays in this loop were never actually created by anyone. That's why backwards time travel creates impossible situations!"

🔄 When ideas are still forming:

Children might think the loop is fine because it's consistent. Help them see the "origin" problem.

Helpful response: "But who FIRST wrote the plays? Not Shakespeare - he copied them. Not you - you found them. They just... exist? That's the puzzle!"

🔬 If you want to go deeper:

What if objects, not just information, loop through time?
How does the Bootstrap Paradox differ from the Grandfather Paradox?
Could the universe be one big causal loop?

Key concepts (for adults): Causal loop, ontological paradox, entropy, thermodynamics, Novikov self-consistency principle.

If you travel back in time and give Shakespeare his own plays, who wrote them?

🔮 All Perspectives

🔁 "Nobody - It's a Loop"

🚫 "It's Impossible"

✍️ "Shakespeare Did"

🤔 Which thinking lens(es) did you use?