this post was submitted on 16 May 2024
118 points (92.8% liked)

Technology

59534 readers
3168 users here now

This is a most excellent place for technology news and articles.


Our Rules


  1. Follow the lemmy.world rules.
  2. Only tech related content.
  3. Be excellent to each another!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, to ask if your bot can be added please contact us.
  9. Check for duplicates before posting, duplicates may be removed

Approved Bots


founded 1 year ago
MODERATORS
 

Experiments generate quantum entanglement over optical fibres across three real cities, marking progress towards networks that could have revolutionary applications.

you are viewing a single comment's thread
view the rest of the comments
[–] VindictiveJudge@lemmy.world 8 points 6 months ago (1 children)

Quantum entanglement communications also have fundamental problems that will likely render them effectively unusable. You need a key to decrypt anything you send, and the key has to travel no faster than c. It's impossible to tell the data from the noise without the key. Attempting to read the data or to change the data being sent also collapses the effect, which can only be fixed by bringing the two systems together. In short, you can only send a single packet of data and you can't use it without a key transmitted using traditional methods.

[–] Toes@ani.social 1 points 6 months ago (1 children)

Can that be scaled? c is still better than rotting cables.

[–] VindictiveJudge@lemmy.world 4 points 6 months ago (1 children)

The limit is c because you have to use cables, radio, or other traditional methods to send the key. The data in the entangled pair would also have to be set at the time the two devices are constructed, so that's not super useful. It might be useful for single use authentication, but that's about it.

Don't think of entanglement as being like one object in two spots. Think of it like identical twins. One twin getting a hair cut does nothing to the other twin's hair. Similarly, altering a property of one entangled particle does nothing to the other and actually means they are no longer entangled or identical.

[–] Toes@ani.social 2 points 6 months ago (1 children)

Oh that's really helpful thanks for the clarification

[–] VindictiveJudge@lemmy.world 2 points 6 months ago (1 children)

No problem. I was pretty disappointed when I learned all the sci-fi writers were getting it wrong. Though, to be fair, it really should be called something else.

[–] Toes@ani.social 3 points 6 months ago

Yeah that's exactly what I was comparing it too.