Rex Brown @RocktRex

Quantum computing researcher, space 🚀 and AI 💻 enthusiast. Michigan aerospace 🛰️ Go Blue! Columbia physics, ex-CERN-LHC. Los Angeles, CA Joined January 2012

Tweets

2K
Followers

170
Following

269
Likes

4K

Rex Brown @RocktRex

4 hours ago

@NimaZeighami Makes me 1% less skeptical that they’re training on everything I would look at though

0 0 0 18 0

View Details

🫧 @sijuagain

2 days ago

Never stop being a good person, just change who receives your kindness.

159 9K 31K 535K 3K

View Details

Rex Brown @RocktRex

a day ago

@elonmusk If you are serious, and I think you are, you need to have a quantum computing development effort.

0 0 2 24 2

View Details

OpenRouter @OpenRouter

4 days ago

Introducing the Fusion API, the smartest compound model in the market. Fusion achieves Fable-level intelligence at half the price. How it works 👇

700 2K 15K 6.0M 13K

View Details

@itsmichaelluu $ARQQ is quantum-safe encryption, NOT quantum encryption. No direct connection to Starshield is documented either. $IONQ has no explicit ties to SpaceX either, so the connection is speculative at best.

2 0 3 2K 0

View Details

Anthropic @AnthropicAI

4 days ago

The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees. The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance. Access to all other Claude models is not affected. We apologize for this disruption to our customers. We believe this is a misunderstanding and are working to restore access as soon as possible. Read our full statement: anthropic.com/news/fable-myt…

13K 26K 88K 90.4M 24K

View Details

Rex Brown @RocktRex

7 days ago

Xhigh effort seems like a good choice, since it performs better than high for a modest cost delta. Max doesn’t seem worth it from the plot.

0 0 1 20 0

View Details

Rex Brown @RocktRex

7 days ago

Fable 5 in Claude Code can be used with your Claude Pro/Max/Team subscription through June 22nd. “/model claude-fable-5” to switch to it!

2 0 1 38 0

View Details

Rex Brown @RocktRex

7 days ago

It was evidently able to beat Pokémon FireRed in about 50 hours, and Anthropic shared the sped up video! anthropic.com/news/claude-fa…

0 0 0 10 0

View Details

Andrej Karpathy @karpathy

a week ago

This is a super exciting release - Claude Fable 5 is the same underlying model as Mythos but with added safeguards. The benchmarks are great and it's SOTA on everything by a margin but I'll add that *qualitatively* also, this is a major-version-bump-deserving step change forward (imo of the same order as Claude 4.5 was in November), peaking especially for long problem-solving sessions on very difficult problems. You can give it a lot more ambitious tasks than what you're used to, the model "gets it" and it will just go, and it's never felt this tempting to stop looking at the code at all (but don't do this in prod!). The model still has quirks that people will run into and the safeguards are configured to be a little too trigger happy for launch, which can hopefully be tuned over time. I feel a lot of things changing as working software increasingly comes out on a tap. The Jevon's paradox kicks in and I feel my own demand for software growing substantially. You can ask for anything - explainers, visualizers, dashboards, bespoke single-use apps (e.g. a full wandb that is hyper-specific just for your project), you can 10X your test suite, auto-optimize code, run giant research projects with custom HTML for the results, anything! "Free your mind" (Matrix ref). Really looking forward to all the things people build!

Claude @claudeai

a week ago

Fable 5 is state-of-the-art on nearly all tested benchmarks, with exceptional performance in software engineering, knowledge work, scientific research, and vision. The longer and more complex the task, the larger Fable 5’s lead over our other models.

513 2K 16K 5.5M 2K

1K 2K 25K 2.7M 6K

View Details

Claude @claudeai

a week ago

Introducing Claude Fable 5: a Mythos-class model that we’ve made safe for general use. Its capabilities exceed those of any model we’ve ever made generally available.

5K 15K 105K 56.1M 22K

View Details

AI Clubhouse @aiclubhouse_

a week ago

Do you have access to Fable 5 yet? Are you trying it out? Subscription plans have access until June 22, 2026 so get on it!

Claude @claudeai

a week ago

Introducing Claude Fable 5: a Mythos-class model that we’ve made safe for general use. Its capabilities exceed those of any model we’ve ever made generally available.

5K 15K 105K 56.1M 22K

1 1 3 387 0

View Details

Rex Brown @RocktRex

a week ago

@felixrieseberg AI should not be given responsibilities, especially at this stage. Too many people are already looking to sidestep responsibilities, and that’s the one thing we definitely need humans for, e.g. radiologists.

0 0 0 2K 0

View Details

Rex Brown @RocktRex

a week ago

Scientific method reminder that, “Results only matter if they can be reproduced”

0 0 0 10 0

View Details

Rex Brown @RocktRex

a week ago

Wondering what model you like to use for a main OpenClaw agent @davidguttman. Is high intelligence important when trying to configure (and fix) your setup, or do you find that something more modest is just as effective?

0 0 0 15 0

View Details

Rex Brown @RocktRex

2 weeks ago

No TSA precheck after 7:30pm at LaGuardia is a JOKE! @TSA what gives? Hopefully a temporary hiccup?

0 0 0 18 0

View Details

Rex Brown @RocktRex

2 weeks ago

@BradGalli Terrible angle to even try to make that call!

0 0 0 505 0

View Details

Samuel Hume @DrSamuelBHume

2 weeks ago

One of the most amazing things I’ve ever seen: a standing ovation for the full Daraxonrasib results I feel inspired and energised, to put it mildly — we have a targeted therapy for pancreatic cancer now, and nothing is undruggable anymore