Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Users Search
Help Dashboard Sign In Sign Up
Q&A Rigorous Science Meta
Q&A
Posts Tags Edits
Create Post

Post History

50%
+0 −0
Q&A What is the most economical barrier that can physically prevent any spaceships from trespassing into Earth?

In the 22nd century C.E. human already colonised the entire Solar system, and Earth becomes a dangerous place to live because of the spread of deadly synthetic virus that kills every animals and sc...

5 answers  ·  posted 8y ago by user6760‭  ·  last activity 8y ago by user6760‭

Question space planets technology space-constructs earth