How do you get Subspace Bubble in Minecraft?

Understand the trick: the Nether compresses distance 8:1, so 1 block traveled there equals 8 blocks in the Overworld.

What kind of advancement is Subspace Bubble?

Subspace Bubble is a Nether tab advancement in Java Edition, of challenge type, rewarding 100XP experience.

Subspace Bubble

Tab: NetherChallengeReward: 100XPDifficulty: Medium

Quick answer: Use the Nether to travel 7 km in the Overworld

Previous advancement: Nether

How to get Subspace Bubble

Understand the trick: the Nether compresses distance 8:1, so 1 block traveled there equals 8 blocks in the Overworld.
The advancement checks that your two Overworld portals are at least 7,000 blocks apart horizontally, which means 875 blocks in the Nether.
Enter your first portal, travel at least 875 blocks through the Nether (bring blocks, food and armor), and build a second portal there.
Step through. Landing at the far Overworld point completes the advancement and pays 100 XP.

Tips

Tunnel through netherrack at a safe height instead of crossing open lava lakes, and mark your route. If the exit portal links back to an old one, move it further: the check is pure horizontal distance between your two Overworld points.

More guides from this tab (Nether): Return to Sender Those Were the Days Hidden in the Depths A Terrible Fortress Who is Cutting Onions?Oh Shiny