(My personal favorites are Vsauce, Veritasium, SciShow, Crash Course & CPG Grey)
ASAPScience - Fun, short interesting facts/explanations https://www.youtube.com/channel/UCC552Sd-3nyi_tk2BudLUzA
BigThink - Predominant people talking about interesting issues in short segments https://www.youtube.com/channel/UCvQECJukTDE2i6aCoMnS-Vg
CPG Grey - an awesome professor talking about interesting facts https://www.youtube.com/channel/UC2C_jShtL725hvbm1arSV9w
Computerphile - short videos explaining concepts in CS https://www.youtube.com/channel/UC9-y-6csu5WGm29I7JiwpnA
Crash Course - beautifully designed courses for several subjects segmented into short videos. Highly recommended! https://www.youtube.com/channel/UCX6b17PVsYBQ0ip5gyeme-Q
Engineering explained - learn everything you wanted to know about car internals https://www.youtube.com/channel/UClqhvGmHcvWL9w3R48t9QXQ
IFLScience - short science news updates https://www.youtube.com/channel/UCvOTgnW7oj9ZWDd2y5TEApw
Minute Earth - beautifully animated short science fact videos https://www.youtube.com/channel/UCeiYXex_fwgYDonaTcSIk6w
Minute Physics - as above, but purely about physics https://www.youtube.com/channel/UCUHW94eEFW7hkUMVaZz4eDg
SciShow - this was one of the first short science video channels - awesome. https://www.youtube.com/channel/UCZYTClx2T1of7BRZ86-8fow
SciShow Space - as above, but about space https://www.youtube.com/channel/UCrMePiHCWG4Vwqv3t7W9EFg
SixtySymbols - short videos talking about interesting symbols https://www.youtube.com/channel/UCvBqzzvUBLCs8Y7Axb-jZew
SmarterEveryDay - awesome science explanation videos https://www.youtube.com/channel/UC6107grRI4m0o2-emgoDnAA
Veritasium - very high quality science explanation videos - awesome guy https://www.youtube.com/channel/UCHnyfMqiRRG1u-2MsSQLbXA
VSaurce - mindblowing videos, usually around 10m, taking you on a tour of interesting facts and ideas. Check out Vsauce2 & 3 too. https://www.youtube.com/channel/UC6nSFpj9HTCZ5t-N3Rm3-HA
(My personal favorites are Vsauce, Veritasium, SciShow, Crash Course & CPG Grey)
ASAPScience - Fun, short interesting facts/explanations https://www.youtube.com/channel/UCC552Sd-3nyi_tk2BudLUzA
BigThink - Predominant people talking about interesting issues in short segments https://www.youtube.com/channel/UCvQECJukTDE2i6aCoMnS-Vg
CPG Grey - an awesome professor talking about interesting facts https://www.youtube.com/channel/UC2C_jShtL725hvbm1arSV9w
Computerphile - short videos explaining concepts in CS https://www.youtube.com/channel/UC9-y-6csu5WGm29I7JiwpnA
Crash Course - beautifully designed courses for several subjects segmented into short videos. Highly recommended! https://www.youtube.com/channel/UCX6b17PVsYBQ0ip5gyeme-Q
Engineering explained - learn everything you wanted to know about car internals https://www.youtube.com/channel/UClqhvGmHcvWL9w3R48t9QXQ
IFLScience - short science news updates https://www.youtube.com/channel/UCvOTgnW7oj9ZWDd2y5TEApw
Minute Earth - beautifully animated short science fact videos https://www.youtube.com/channel/UCeiYXex_fwgYDonaTcSIk6w
Minute Physics - as above, but purely about physics https://www.youtube.com/channel/UCUHW94eEFW7hkUMVaZz4eDg
SciShow - this was one of the first short science video channels - awesome. https://www.youtube.com/channel/UCZYTClx2T1of7BRZ86-8fow
SciShow Space - as above, but about space https://www.youtube.com/channel/UCrMePiHCWG4Vwqv3t7W9EFg
SixtySymbols - short videos talking about interesting symbols https://www.youtube.com/channel/UCvBqzzvUBLCs8Y7Axb-jZew
SmarterEveryDay - awesome science explanation videos https://www.youtube.com/channel/UC6107grRI4m0o2-emgoDnAA
Veritasium - very high quality science explanation videos - awesome guy https://www.youtube.com/channel/UCHnyfMqiRRG1u-2MsSQLbXA
VSaurce - mindblowing videos, usually around 10m, taking you on a tour of interesting facts and ideas. Check out Vsauce2 & 3 too. https://www.youtube.com/channel/UC6nSFpj9HTCZ5t-N3Rm3-HA