\d don't print all the tables

Hi community,
here's my shell:

postgres=# \d
Did not find any relations.
postgres=# create schema namespace_a;
CREATE SCHEMA
postgres=# create schema namespace_b;
CREATE SCHEMA
postgres=# create table simple (name varchar);
CREATE TABLE
postgres=# create table namespace_a.simple (name varchar);
CREATE TABLE
postgres=# create table namespace_b.simple (name varchar);
CREATE TABLE
postgres=# \d
         List of relations
 Schema |  Name  | Type  |  Owner   
--------+--------+-------+----------
 public | simple | table | postgres
(1 row)

postgres=#

I think it should print the table on namespace_a & namespace_b, not just public, it really confused me.
Can someone give me some advice?

Yours,
Wen Yi.