Can I open Photos from my Mac without my external hard disk connected?

[iMore Question]

I store my pictures in an exeternal drive since the library is too big to have on my local HD and now my Photos library there as well.
I have uploaded all of my Photos library to iCloud now and would like to be able to open Photos on my Macbook even if I haven't my external hard disk attached. Since I have all of my pictures uploaded, why can't I have them on my macbook if I am connected to the internet.
Do I need to duplicate the library on my local hard drive and use it as a system Photos library to be able to do it?
Thanks
Thomas

 

[pkcable]

You should be able to open any picture that you have uploaded to the cloud, provided you have an internet connection. It may also be possible to directly view pictures on your external drive even with it disconnected, IF it has networking and IF its on the same network as you.