Could Goldberg jump too?

no. he was too fat to jump. too many particles

Hard to say for sure, but I would assume so. I imagine the brain can only handle so much jumping unless the rules are strictly followed, he probably broke a lot of the rules discovering them and doesn't jump anymore... unless he had a mentor too.

i guess. notice the fact that only people who could jump realized that he jumped and they barely changed them self. so i assume he could jump too.

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I'm very responsible, when ever something goes wrong they always say I'm responsible.

I believe he could jump also just because he was prevy to so much information and know how of jumping. You didnt hear normal people talking about jumping only people who could jump. And i dont think other jumpers knew that another jumper had jumped else the sister wouldnt have questioned him "You jumped without me didnt you?" If she had known he had jumped She would have said "Why did u just jump without me / Because you just jumped X has changed and so has Y." And because Goldberg knew of jumping if Sam came back and said "Damn because of this i changed that, Goldberg would immediately understand that he jumped because he knew of the capability of jumping.

I'm confused about this as well since Goldberg has no back story. He seems to know about time travel, but I am not sure it that is because he does it or he just smokes a lot of weed and other drugs.

i think he knew so much about time traveling only in theory... he was an professor, and is sure to assume that was an physics one.....

"It only ends once. Anything that happens before that is progress!"