It is not letting me play and it is not letting me play and it is not letting me play and it is not letting me play and it is not letting me play and it is not letting me play and it is not letting me play

Minecraft Crash Report ----
// There are four lights!

Time: 7/2/15 5:45 PM
Description: Initializing game

java.lang.OutOfMemoryError: Java heap space
at bmi.a(SourceFile:230)
at bmh.b(SourceFile:130)
at bmh.a(SourceFile:77)
at bot.j(SourceFile:553)
at bot.a(SourceFile:139)
at bou.a(SourceFile:23)
at bnn.a(SourceFile:99)
at ave.am(SourceFile:448)
at ave.a(SourceFile:310)
at net.minecraft.client.main.Main.main(SourceFile:124)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at bmi.a(SourceFile:230)
at bmh.b(SourceFile:130)
at bmh.a(SourceFile:77)
at bot.j(SourceFile:553)
at bot.a(SourceFile:139)
at bou.a(SourceFile:23)
at bnn.a(SourceFile:99)
at ave.am(SourceFile:448)

– Initialization –
Details:
Stacktrace:
at ave.a(SourceFile:310)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.8.7
Operating System: Mac OS X (x86_64) version 10.10.2
CPU: 4x Intel(R) Core(TM) i5-4278U CPU @ 2.60GHz
Java Version: 1.6.0_65, Apple Inc.
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
Memory: 15754552 bytes (15 MB) / 1060372480 bytes (1011 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 5 total; -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.8.7
LWJGL: 2.9.2
OpenGL: Intel Iris OpenGL Engine GL version 2.1 INTEL-10.2.46, Intel Inc.
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because ARB_framebuffer_object is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: No
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: [SpaceCubeCraft-Pack-512x]
Current Language: English (US)
Profiler Position: N/A (disabled)