Har Har Mahadev!!!
I will give this answer according to Shaiva Philosophy.
So basically the Supreme deities are Lord Sadāśiva and Ma Umā/Adi Shakti. Along with them Sri Lakshmi Narayan. So for the creation of the world, the Supreme deities mainly take three forms, i.e., Brahmā Vishnu Rudra and Sarasvati Lakshmi and Kāli.
So, Ma Kāli is form of Ma Adi Shakti, and she is considered as the Pūrna form. She is the supreme mother goddess herself in a different form.
Now what does she represent? She is the Mother of the Universe. She is the protector of her devotees from Evil. When we consider a little scientific view, then we can say she represents the Ultimate Cosmic Energy. That energy, which is the source of all the creation.
Nowadays, many people think that our scriptures are only symbolic and preach only the science behind it. The complete truth is not given. Yes, God is in the form of energy as well, No doubt about it. But restricting the Lord or the Mother Goddess to just one phenomenon in the Universe is total BOGUS. God is a Sat Chit Ananda Person who controls everything. The Supreme Parents do have a form, but it is not perceivable to our material eyes.
So yes, Ma Kāli represents some scientific phenomena, but she is not only that. We can learn both Para Vidya and Apara Vidya from her. If we take only some instances and try to get scientific theories, that is just a small portion called Apara Vidya. But if we completely surrender to her Lotus feet and gain complete knowledge from her about Bhakti, etc., that is Para Vidya.
जय माँ काली।
ॐ नमः शिवाय ॥