Basically supporters of modern official science frequently raise this question only to make a point as if Philosophy actually cannot teach anything.
The answer is that Philosophy teaches us our right limits. We do not claim to have hard knowledge of things beyond of our limits. With philosophy we find the logical boundary of any assertion. We do not conclude out of proportion things like since we observe redshifts so whole Universe is expanding. There are logical barriers in the process of accepting that since galaxies are redshifted so Universe is expanding. Non Philosophical mind is almost free of these logical barriers and easily accepts this out of proportion claim. The two barriers that rightfully stop a philosopher are that observed redshift (cosmological redshift) is different from doppler’s effect and that mathematical possibility of expansion of ‘space’ does not mean an actual physical possibility of the same.
Philosophy thus keeps us in right limits. And Philosophy also liberates from artificial limits or boundaries that since we have not crossed a man-made criteria so we are not competent to get right knowledge of certain things. Our limit is not our official qualification. Our limit is our exposure to actual world and sources of information. To conclude the things, our minds need exposure to information and not any certificate issued by anyone.
Equipped with Philosophy, we know that anything mathematically possible does not imply that it is also physically possible. Neither mathematical things become physical for us like since gravity problems are solved through metric equations therefore gravity itself is metrical in nature or spacetime is a physical thing and there are physical ripples in this solid spacetime. Obviously, ripples were in anything actually physical and not pure mathematical or mathematical taken as physical.
Philosophy is straightening and strengthening of the process of thinking and concluding. Without right thinking process, Universe is expanding by way of expansion of space, spacetime is curved, there are ripples in spacetime, gravity is metrical in nature, first quantum moment of the creation of universe took place before our eyes and we know all the tiny details of that tiny moment and other like things.