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ZEUS – A new two-petawatt laser facility at the University of Michigan

(news.engin.umich.edu)
126 points voxadam | 4 comments | 21 May 25 15:17 UTC | HN request time: 0s | source
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baxtr ◴[21 May 25 18:03 UTC] No.44054307[source]▶
Instead of petawatts I’d love to hear what it can destroy.

I imagine a scale like:

1: Mosquito

…

10000: Planet (Death Star)

replies(1): >>44054678 #
vlmutolo ◴[21 May 25 18:37 UTC] No.44054678[source]▶
To kill a mosquito, you need "a few tens of millijoules, delivered within a few milliseconds" [0], so let's say 10W. To destroy the Earth (so that it turns into scattered dust and never reforms) you need about 10^32 J [1]; if we assume this is applied over maybe 100s, the laser would be 10^30W.

So the log10 scale goes from 1–30, where mosquitos die at 1 and the Earth dies at 30. The 2 PW in the article is about a 15.3. The Vulcan 20-20 project (set to complete in 2029) will register at about 20PW, or a 16.3 on the mosquito-Death Star scale [2].

So on a log scale, we're over halfway to building the Death Star.

[0]: https://spectrum.ieee.org/backyard-star-wars

[1]: https://www.scientificamerican.com/article/how-much-energy-w...

[2]: https://news.sky.com/story/worlds-most-powerful-laser-to-be-...

replies(7): >>44054836 #>>44055427 #>>44055458 #>>44055607 #>>44055831 #>>44056478 #>>44056479 #
1. beAbU ◴[21 May 25 21:29 UTC] No.44056479[source]▶
Every step is a doubling of the previous step, no?

So true "half way to a death star" is step 29/30?

replies(1): >>44056999 #
2. hnuser123456 ◴[21 May 25 22:41 UTC] No.44056999[source]▶
They used log10, so each step is 10x the previous, so in a linear sense, it would double when going from about 29.7 to 30. But it seems that humans tend to improve tech at exponential rates, where we are constantly making improvements here and there that keep stacking up, when it comes to things that are actually in a developmental stage anyways.

Say your "endstage" goal is GPU with 200 billion transistors. Using linear scale, the current biggest GPU is only halfway there, and it took all of human civilization to get this far, and it will take another civilization to get to 200b. In reality, we'll have that in a couple years with our current civilization.

replies(1): >>44057281 #
3. zahlman ◴[21 May 25 23:26 UTC] No.44057281[source]▶
>humans tend to improve tech at exponential rates

A hypothetical "death star" project like this would require improvements in energy generation/storage capacity/etc., which haven't improved in nearly the way transistor production has (and are also much more limited by physical realities, such as the specific heat, enthalpy of combustion etc. of materials).

replies(1): >>44057381 #
4. hnuser123456 ◴[21 May 25 23:41 UTC] No.44057381{3}[source]▶
Yes, extremely high sustained power lasers still have a hard time competing with hypersonic projectiles in energy delivered. The difference in being able to throw nuclei at the problem.