# If we “turned universe upside-down” and changed all matter to anti-matter instantly

...what would be the immediate consequences?

Or putting it better, if (from big-bang or whathever), the universe were always made of what we call Anti-matter what would it be?

The scientists of this universe would call 'Matter' 'Anti-Matter'.

Will the universe looks like exactly the same? By "looks", I mean the laws of Physics, the constitution of the universe with its superclusters of galaxies containing clusters containing galaxies and so on...

• Antimatter behaves like matter travelling backward in time - can you please explain more specifically what do you mean by this? – tarit goswami Oct 9 '18 at 6:58