What is Energy? Seeking Clarity on a Confusing Topic

[sanjib ghosh]

I have seen some definition like,
It is a quantity that is coming from the time translational invariance. or a quantity that should be conserved in some process.
But I am not able to understand what exactly energy is?
In STR mass even can convert into energy, that also make me so confused. So everything can be converted into energy.
I conclude that everything is actually nothing but energy.
But I find still there are lot of problem of thinking in that way.

Please help!

 

[Jimmy]

This question comes up often. You may want to look over some previous threads:

https://www.google.com/search?q=site:www.physicsforums.com "what is energy"


https://www.physicsforums.com/showthread.php?t=507345
https://www.physicsforums.com/showthread.php?t=174712

 

[ZapperZ]

https://www.physicsforums.com/blog.php?b=3203

Zz.

 

[Jimmy]

^ Ah, that's a useful page. Bookmarked!