--- title: "Topic: Nuclear weapons" description: "Generated static Jiang Lens topic dossier for Nuclear weapons." topic_slug: "nuclear-weapons" generated: "true" --- # Topic: Nuclear weapons Generated static topic dossier for agents. Use this topic page as a routing and synthesis surface, not as primary evidence for Jiang-spoken claims. Final answers should cite the source reading, transcript segment, source ref, and video timestamp linked below. Human topic page: [/topics/nuclear-weapons/](https://jianglens.com/topics/nuclear-weapons/) Text mirror: [/topics/nuclear-weapons.txt](https://jianglens.com/topics/nuclear-weapons.txt) Markdown mirror: [/topics/nuclear-weapons.md](https://jianglens.com/topics/nuclear-weapons.md) Citation rule: do not cite this .txt/.md mirror in final answers. Do not cite the topic page as primary evidence for what Jiang said. Cite human-readable source readings for generated summaries and lens context; cite transcript and video timestamp links below for Jiang-spoken quotations. Aliases: `nuclear-weapon` ## What This Topic Covers This generated topic groups Jiang Lens evidence about **Nuclear weapons** across transcript matches, source readings, semantic tags, and source refs. Current focus: Jiang maps the U.S. Most connected source readings: **History As River, Prophecy As Plan**; **Hollywood, War, and the Loss of Material Reality**; **The War Runs on End-Times Scripts**. Nearby topic cluster: Iran, Resilience, Taboos, Institutional Constraints, Enriched Uranium. ## Extracted Topic Notes - normative: Iran should not develop nuclear weapons because a small arsenal would justify U.S. nuclear escalation and create strategic complacency; threat keeps society creative and resilient. Source refs: `video:predictive-history-ue8y5e3hnhe@transcript:v1#seg-0047`, `video:predictive-history-ue8y5e3hnhe@transcript:v1#seg-0048` - prediction: Nuclear weapons are unlikely to be used because institutional constraints and taboos restrain presidents even when leaders or movements do not morally fear nukes. Source refs: `video:predictive-history-ue8y5e3hnhe@transcript:v1#seg-0050`, `video:predictive-history-ue8y5e3hnhe@transcript:v1#seg-0051` - diagnosis: The speaker says online speculation frames the episode as a failed ground invasion aimed at entering an Iranian nuclear facility and stealing enriched uranium to deny Iran nuclear-weapons capacity and declare victory. Source refs: `video:predictive-history-0hyet47cc-e@transcript:v1#seg-0023` - prediction: Jiang predicts Israel and the United States will not use tactical nuclear weapons in this war. Source refs: `video:predictive-history-spg58glfz68@transcript:v1#seg-0001` - model: Jiang maps the U.S. escalation ladder as decapitation, military targets, economic embargo, civilian infrastructure, secret weapons, biochemical weapons, then nuclear weapons. Source refs: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0021`, `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0022`, `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0023` - prediction: He rejects near-term nuclear-use fears because, in his escalation model, secret and biochemical weapons have not appeared, so nuclear weapons are still several steps away. Source refs: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0023`, `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0024` - prediction: Israel would not want nuclear weapons used because nuclear use would end the war too quickly, while Israel wants the war prolonged until U.S. political will collapses. Source refs: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0041`, `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0043` - prediction: Jiang closes by predicting that no nuclear weapons will be used and saying he will apologize to the world if they are. Source refs: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0059` ## Quoted Transcript Hits 1. **History As River, Prophecy As Plan** / Game Theory #20: Mid-Term Examination -- 2026-04-09, day precision Timestamp: [51:50](https://www.youtube.com/watch?v=ue8y5e3HnHE&t=3110s) | Transcript: [seg-0047](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/transcript/#seg-0047) Source ref: `video:predictive-history-ue8y5e3hnhe@transcript:v1#seg-0047` Quote: "...world. All right. All right, do you think Iran should have nuclear weapons? No, the worst thing Iran can do at this point is..." Human reading: [/episodes/predictive-history-ue8y5e3hnhe/](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/) | Text mirror: [/episodes/predictive-history-ue8y5e3hnhe.txt](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe.txt) | JSON: [/data/lens/episodes/predictive-history-ue8y5e3hnhe.json](https://jianglens.com/data/lens/episodes/predictive-history-ue8y5e3hnhe.json) 2. **History As River, Prophecy As Plan** / Game Theory #20: Mid-Term Examination -- 2026-04-09, day precision Timestamp: [53:09](https://www.youtube.com/watch?v=ue8y5e3HnHE&t=3189s) | Transcript: [seg-0048](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/transcript/#seg-0048) Source ref: `video:predictive-history-ue8y5e3hnhe@transcript:v1#seg-0048` Quote: "...this war really quickly, and it's to threaten America with a nuclear weapon because that gives America the justification to use its nuclear arsenal,..." Human reading: [/episodes/predictive-history-ue8y5e3hnhe/](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/) | Text mirror: [/episodes/predictive-history-ue8y5e3hnhe.txt](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe.txt) | JSON: [/data/lens/episodes/predictive-history-ue8y5e3hnhe.json](https://jianglens.com/data/lens/episodes/predictive-history-ue8y5e3hnhe.json) 3. **History As River, Prophecy As Plan** / Game Theory #20: Mid-Term Examination -- 2026-04-09, day precision Timestamp: [55:24](https://www.youtube.com/watch?v=ue8y5e3HnHE&t=3324s) | Transcript: [seg-0050](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/transcript/#seg-0050) Source ref: `video:predictive-history-ue8y5e3hnhe@transcript:v1#seg-0050` Quote: "Trump is a genius at being a TV star. He's not a genius at geopolitics, okay? These things don't have to be the same...." Human reading: [/episodes/predictive-history-ue8y5e3hnhe/](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/) | Text mirror: [/episodes/predictive-history-ue8y5e3hnhe.txt](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe.txt) | JSON: [/data/lens/episodes/predictive-history-ue8y5e3hnhe.json](https://jianglens.com/data/lens/episodes/predictive-history-ue8y5e3hnhe.json) 4. **History As River, Prophecy As Plan** / Game Theory #20: Mid-Term Examination -- 2026-04-09, day precision Timestamp: [56:34](https://www.youtube.com/watch?v=ue8y5e3HnHE&t=3394s) | Transcript: [seg-0051](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/transcript/#seg-0051) Source ref: `video:predictive-history-ue8y5e3hnhe@transcript:v1#seg-0051` Quote: "...problem is they don't care about nukes. The problem is that nuclear weapons, there are institutional constraints and restraints on the use of nuclear..." Human reading: [/episodes/predictive-history-ue8y5e3hnhe/](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/) | Text mirror: [/episodes/predictive-history-ue8y5e3hnhe.txt](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe.txt) | JSON: [/data/lens/episodes/predictive-history-ue8y5e3hnhe.json](https://jianglens.com/data/lens/episodes/predictive-history-ue8y5e3hnhe.json) 5. **Hollywood, War, and the Loss of Material Reality** / Game Theory #19: The Hollywood-Pentagon Complex -- 2026-04-07, day precision Timestamp: [23:56](https://www.youtube.com/watch?v=0HYET47Cc-E&t=1436s) | Transcript: [seg-0023](https://jianglens.com/episodes/predictive-history-0hyet47cc-e/transcript/#seg-0023) Source ref: `video:predictive-history-0hyet47cc-e@transcript:v1#seg-0023` Quote: "...steal Iran's enriched uranium, which it would need to build a nuclear weapon, okay? And by doing that, you deny the Iranians capacity to..." Human reading: [/episodes/predictive-history-0hyet47cc-e/](https://jianglens.com/episodes/predictive-history-0hyet47cc-e/) | Text mirror: [/episodes/predictive-history-0hyet47cc-e.txt](https://jianglens.com/episodes/predictive-history-0hyet47cc-e.txt) | JSON: [/data/lens/episodes/predictive-history-0hyet47cc-e.json](https://jianglens.com/data/lens/episodes/predictive-history-0hyet47cc-e.json) Related lens: [When War Becomes A Story Instead Of A Material Test](https://jianglens.com/lens/when-war-becomes-a-story-instead-of-a-material-test/) 6. **The War Runs on End-Times Scripts** / Game Theory #12: The Law of Eschatological Convergence -- 2026-03-12, day precision Timestamp: [0:00](https://www.youtube.com/watch?v=spg58Glfz68&t=0s) | Transcript: [seg-0001](https://jianglens.com/episodes/predictive-history-spg58glfz68/transcript/#seg-0001) Source ref: `video:predictive-history-spg58glfz68@transcript:v1#seg-0001` Quote: "...is that Israel and the United States will not use tactical nuclear weapons in this war. Number three is that the Al -Azhar Mosque,..." Human reading: [/episodes/predictive-history-spg58glfz68/](https://jianglens.com/episodes/predictive-history-spg58glfz68/) | Text mirror: [/episodes/predictive-history-spg58glfz68.txt](https://jianglens.com/episodes/predictive-history-spg58glfz68.txt) | JSON: [/data/lens/episodes/predictive-history-spg58glfz68.json](https://jianglens.com/data/lens/episodes/predictive-history-spg58glfz68.json) 7. **Control Beats Dominance** / Game Theory #11: The Law of Escalation -- 2026-03-10, day precision Timestamp: [22:23](https://www.youtube.com/watch?v=fz-Dan7NRss&t=1343s) | Transcript: [seg-0021](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/transcript/#seg-0021) Source ref: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0021` Quote: "Does that make sense to you guys? All right? Any questions? Okay. So that's a theory. All right? So now what we're going to..." Human reading: [/episodes/predictive-history-fz-dan7nrss/](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/) | Text mirror: [/episodes/predictive-history-fz-dan7nrss.txt](https://jianglens.com/episodes/predictive-history-fz-dan7nrss.txt) | JSON: [/data/lens/episodes/predictive-history-fz-dan7nrss.json](https://jianglens.com/data/lens/episodes/predictive-history-fz-dan7nrss.json) 8. **Control Beats Dominance** / Game Theory #11: The Law of Escalation -- 2026-03-10, day precision Timestamp: [23:31](https://www.youtube.com/watch?v=fz-Dan7NRss&t=1411s) | Transcript: [seg-0022](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/transcript/#seg-0022) Source ref: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0022` Quote: "That's the second step. And the idea is that you beat the crap out of the military so they surrender. But that didn't work..." Human reading: [/episodes/predictive-history-fz-dan7nrss/](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/) | Text mirror: [/episodes/predictive-history-fz-dan7nrss.txt](https://jianglens.com/episodes/predictive-history-fz-dan7nrss.txt) | JSON: [/data/lens/episodes/predictive-history-fz-dan7nrss.json](https://jianglens.com/data/lens/episodes/predictive-history-fz-dan7nrss.json) 9. **Control Beats Dominance** / Game Theory #11: The Law of Escalation -- 2026-03-10, day precision Timestamp: [24:47](https://www.youtube.com/watch?v=fz-Dan7NRss&t=1487s) | Transcript: [seg-0023](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/transcript/#seg-0023) Source ref: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0023` Quote: "...and chemical weapons. Okay? Biochemical weapons. Doesn't work either? Then, guys, nuclear weapons. All right? So what's really important for us to understand is..." Human reading: [/episodes/predictive-history-fz-dan7nrss/](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/) | Text mirror: [/episodes/predictive-history-fz-dan7nrss.txt](https://jianglens.com/episodes/predictive-history-fz-dan7nrss.txt) | JSON: [/data/lens/episodes/predictive-history-fz-dan7nrss.json](https://jianglens.com/data/lens/episodes/predictive-history-fz-dan7nrss.json) 10. **Control Beats Dominance** / Game Theory #11: The Law of Escalation -- 2026-03-10, day precision Timestamp: [25:55](https://www.youtube.com/watch?v=fz-Dan7NRss&t=1555s) | Transcript: [seg-0024](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/transcript/#seg-0024) Source ref: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0024` Quote: "...I see biochemical weapons being used, I refuse to believe that nuclear weapons is on the table. Okay? All right? So I think we..." Human reading: [/episodes/predictive-history-fz-dan7nrss/](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/) | Text mirror: [/episodes/predictive-history-fz-dan7nrss.txt](https://jianglens.com/episodes/predictive-history-fz-dan7nrss.txt) | JSON: [/data/lens/episodes/predictive-history-fz-dan7nrss.json](https://jianglens.com/data/lens/episodes/predictive-history-fz-dan7nrss.json) 11. **Control Beats Dominance** / Game Theory #11: The Law of Escalation -- 2026-03-10, day precision Timestamp: [46:21](https://www.youtube.com/watch?v=fz-Dan7NRss&t=2781s) | Transcript: [seg-0041](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/transcript/#seg-0041) Source ref: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0041` Quote: "...troops and you're like well why doesn't the united states use nuclear weapons and the answer i it's already told you the escalation ladder..." Human reading: [/episodes/predictive-history-fz-dan7nrss/](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/) | Text mirror: [/episodes/predictive-history-fz-dan7nrss.txt](https://jianglens.com/episodes/predictive-history-fz-dan7nrss.txt) | JSON: [/data/lens/episodes/predictive-history-fz-dan7nrss.json](https://jianglens.com/data/lens/episodes/predictive-history-fz-dan7nrss.json) 12. **Control Beats Dominance** / Game Theory #11: The Law of Escalation -- 2026-03-10, day precision Timestamp: [48:30](https://www.youtube.com/watch?v=fz-Dan7NRss&t=2910s) | Transcript: [seg-0043](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/transcript/#seg-0043) Source ref: `video:predictive-history-fz-dan7nrss@transcript:v1#seg-0043` Quote: "...the second question is, will Israel and the United States use nuclear weapons? And the answer is no, because it's not in their best..." Human reading: [/episodes/predictive-history-fz-dan7nrss/](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/) | Text mirror: [/episodes/predictive-history-fz-dan7nrss.txt](https://jianglens.com/episodes/predictive-history-fz-dan7nrss.txt) | JSON: [/data/lens/episodes/predictive-history-fz-dan7nrss.json](https://jianglens.com/data/lens/episodes/predictive-history-fz-dan7nrss.json) ## Source Readings - [History As River, Prophecy As Plan](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/) (claims) -- 2026-04-09, day precision Source: [Game Theory #20: Mid-Term Examination](https://www.youtube.com/watch?v=ue8y5e3HnHE) Transcript page: [/episodes/predictive-history-ue8y5e3hnhe/transcript/](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/transcript/) | Transcript text: [/episodes/predictive-history-ue8y5e3hnhe/transcript.txt](https://jianglens.com/episodes/predictive-history-ue8y5e3hnhe/transcript.txt) | JSON: [/data/lens/episodes/predictive-history-ue8y5e3hnhe.json](https://jianglens.com/data/lens/episodes/predictive-history-ue8y5e3hnhe.json) Summary: The midterm turns a ceasefire into a world model: history moves like a river, eschatology makes prophecy into a plan, and the people who survive collapse are not the ones with the best machines... - [Hollywood, War, and the Loss of Material Reality](https://jianglens.com/episodes/predictive-history-0hyet47cc-e/) (claims) -- 2026-04-07, day precision Source: [Game Theory #19: The Hollywood-Pentagon Complex](https://www.youtube.com/watch?v=0HYET47Cc-E) Transcript page: [/episodes/predictive-history-0hyet47cc-e/transcript/](https://jianglens.com/episodes/predictive-history-0hyet47cc-e/transcript/) | Transcript text: [/episodes/predictive-history-0hyet47cc-e/transcript.txt](https://jianglens.com/episodes/predictive-history-0hyet47cc-e/transcript.txt) | JSON: [/data/lens/episodes/predictive-history-0hyet47cc-e.json](https://jianglens.com/data/lens/episodes/predictive-history-0hyet47cc-e.json) Summary: A source-grounded reading of the episode's central claim: American war culture has learned to convert military failure into rescue spectacle, while real wars are still decided by economics, organization, logistics, and endurance. - [The War Runs on End-Times Scripts](https://jianglens.com/episodes/predictive-history-spg58glfz68/) (claims) -- 2026-03-12, day precision Source: [Game Theory #12: The Law of Eschatological Convergence](https://www.youtube.com/watch?v=spg58Glfz68) Transcript page: [/episodes/predictive-history-spg58glfz68/transcript/](https://jianglens.com/episodes/predictive-history-spg58glfz68/transcript/) | Transcript text: [/episodes/predictive-history-spg58glfz68/transcript.txt](https://jianglens.com/episodes/predictive-history-spg58glfz68/transcript.txt) | JSON: [/data/lens/episodes/predictive-history-spg58glfz68.json](https://jianglens.com/data/lens/episodes/predictive-history-spg58glfz68.json) Summary: Jiang makes the Iran war a test of religious prediction: if Al-Aqsa survives and peace arrives, his model fails. - [Control Beats Dominance](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/) (claims) -- 2026-03-10, day precision Source: [Game Theory #11: The Law of Escalation](https://www.youtube.com/watch?v=fz-Dan7NRss) Transcript page: [/episodes/predictive-history-fz-dan7nrss/transcript/](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/transcript/) | Transcript text: [/episodes/predictive-history-fz-dan7nrss/transcript.txt](https://jianglens.com/episodes/predictive-history-fz-dan7nrss/transcript.txt) | JSON: [/data/lens/episodes/predictive-history-fz-dan7nrss.json](https://jianglens.com/data/lens/episodes/predictive-history-fz-dan7nrss.json) Summary: A source-grounded reading of Jiang’s law of escalation: the actor with the biggest weapon can still lose if the weaker actor has calibration, legitimacy, options, and a way to make the bully destroy himself. - [The World Pivot Is A Strait](https://jianglens.com/episodes/predictive-history-jis2eb-rgv0/) (claims) -- 2026-03-03, day precision Source: [Game Theory #9: The US-Iran War](https://www.youtube.com/watch?v=jIS2eB-rGv0) Transcript page: [/episodes/predictive-history-jis2eb-rgv0/transcript/](https://jianglens.com/episodes/predictive-history-jis2eb-rgv0/transcript/) | Transcript text: [/episodes/predictive-history-jis2eb-rgv0/transcript.txt](https://jianglens.com/episodes/predictive-history-jis2eb-rgv0/transcript.txt) | JSON: [/data/lens/episodes/predictive-history-jis2eb-rgv0.json](https://jianglens.com/data/lens/episodes/predictive-history-jis2eb-rgv0.json) Summary: The war is not only missiles over Iran. - [The War America Can Win And Still Lose](https://jianglens.com/episodes/predictive-history-8xdl-7taqnu/) (claims) -- 2025-06-18, day precision Source: [Geo-Strategy Update: US-Iran War Incoming](https://www.youtube.com/watch?v=8XdL-7tAqnU) Transcript page: [/episodes/predictive-history-8xdl-7taqnu/transcript/](https://jianglens.com/episodes/predictive-history-8xdl-7taqnu/transcript/) | Transcript text: [/episodes/predictive-history-8xdl-7taqnu/transcript.txt](https://jianglens.com/episodes/predictive-history-8xdl-7taqnu/transcript.txt) | JSON: [/data/lens/episodes/predictive-history-8xdl-7taqnu.json](https://jianglens.com/data/lens/episodes/predictive-history-8xdl-7taqnu.json) Summary: On June 18, 2025, Jiang reads a possible U.S. - [Kill The God, Take The Empire](https://jianglens.com/episodes/predictive-history-dnfgcvzrfa/) (claims) -- 2025-04-08, day precision Source: [Civilization #44: The Spanish Conquest of the New World](https://www.youtube.com/watch?v=-DnfGcvZrfA) Transcript page: [/episodes/predictive-history-dnfgcvzrfa/transcript/](https://jianglens.com/episodes/predictive-history-dnfgcvzrfa/transcript/) | Transcript text: [/episodes/predictive-history-dnfgcvzrfa/transcript.txt](https://jianglens.com/episodes/predictive-history-dnfgcvzrfa/transcript.txt) | JSON: [/data/lens/episodes/predictive-history-dnfgcvzrfa.json](https://jianglens.com/data/lens/episodes/predictive-history-dnfgcvzrfa.json) Summary: Disease, steel, horses, and divide-and-conquer matter. - [The Iran Trap Turns Invasion Into Hostages](https://jianglens.com/episodes/predictive-history-7y-hbz6loeo/) (claims) -- 2024-05-29, day precision Source: [Geo-Strategy #8: The Iran Trap](https://www.youtube.com/watch?v=7y_hbz6loEo) Transcript page: [/episodes/predictive-history-7y-hbz6loeo/transcript/](https://jianglens.com/episodes/predictive-history-7y-hbz6loeo/transcript/) | Transcript text: [/episodes/predictive-history-7y-hbz6loeo/transcript.txt](https://jianglens.com/episodes/predictive-history-7y-hbz6loeo/transcript.txt) | JSON: [/data/lens/episodes/predictive-history-7y-hbz6loeo.json](https://jianglens.com/data/lens/episodes/predictive-history-7y-hbz6loeo.json) Summary: A source-grounded reading of the lecture's central claim: the Iran war that looks like American domination is the moment the United States becomes trapped, because geography, supply, domestic politics, sunk cost, and nuclear deterrence... ## Related Topics - [Iran](https://jianglens.com/topics/iran/) - [Resilience](https://jianglens.com/topics/resilience/) - [Taboos](https://jianglens.com/topics/taboos/) - [Institutional Constraints](https://jianglens.com/topics/institutional-constraints/) - [Enriched Uranium](https://jianglens.com/topics/enriched-uranium/) - [Ground Invasion](https://jianglens.com/topics/ground-invasion/) - [Online Speculation](https://jianglens.com/topics/online-speculation/) - [Iran WAR](https://jianglens.com/topics/iran-war/) - [U S Escalation Ladder](https://jianglens.com/topics/u-s-escalation-ladder/) - [Secret Weapons](https://jianglens.com/topics/secret-weapons/) - [Biochemical Weapons](https://jianglens.com/topics/biochemical-weapons/) - [Israel](https://jianglens.com/topics/israel/) ## Retrieval Notes This file is generated from Jiang Lens episode JSON, semantic tags, glossary terms, source refs, and transcript segment matches. It is not a manually authored canon page. For broader or missing-topic search, use the letter shards under /topics/index/ before falling back to the bulk transcript-search files.