My sisters want to travel to a scientific conference while accompanied by our father and mother. I see it as seeking knowledge and a change of routine at the same time. What do you think? Is it halal or haram for us to go?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger. 

There is no harm in that your sisters travel whether to attend this conference or for recreation provided that no Sharia-violations are committed, such as not abiding by their proper hijab and prohibited mixing with men and the like. The prohibited mixing with men is that where there is no distinction between men and women as two separate groups.

The Kuwaiti Encyclopedia of Fiqh reads, “The Ruling on mixing between men and women differs according to whether it is in conformity with the rules of the Sharia or not. Thus, mixing is prohibited if it involves seclusion with a non-Mahram woman, looking at her with desire, that the woman is indecently dressed, flirtatious behavior, and bodies touching as in mixing in weddings, parties, and festivals...”

Allah knows best.