PeroK's latest activity
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PeroK replied to the thread Undergrad The quintessence as variable dark energy.It's not applicable, except on the largest scales. The fundamental assumption is uniform mass and radiation density. Moreover, the... -
I'm wondering how you would treat a modern day Ramanujan. Would you shout at them; "Go back to school, and learn PROPER maths!" ? Ok...
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One thought that occurs to me is that virtually all learning is self-learning. If you enroll in a course and listen to the lectures but...
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PeroK reacted to wrobel's post in the thread Undergrad Is calling fictitious forces "not real" just about terminology? with
Like.
I am sorry but I do not believe that a doctor can be confused by such a childish sophism -
PeroK reacted to robphy's post in the thread Undergrad Is calling fictitious forces "not real" just about terminology? with
Informative.
Possibly interesting: "Causal reasoning in understanding Newton’s third law" Cheng Chen, Lei Bao, Joseph C. Fritchman, and Hemin Ma... -
PeroK reacted to PeterDonis's post in the thread Undergrad The quintessence as variable dark energy with Like.
"Space" isn't an invariant. It varies in spacetime. Whether that means variation in "space" depends on your choice of coordinates...
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PeroK replied to the thread Impersonation News.A lot of videos on YouTube are fake now. I've seen videos of Barack Obama and Warren Buffet, where I've thought there must be something...
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PeroK reacted to Dale's post in the thread High School Why higher speeds need more power if the backward force is the same? with Like.
Yes, but sometimes there are shortcuts. In the case of running or walking up the stairs, neglecting the initial start and final stop...
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PeroK reacted to Hornbein's post in the thread High School Why higher speeds need more power if the backward force is the same? with
Skeptical.
Consider wall sits, something that serious skiers do. Lean against a wall as though sitting in a chair, held up only by friction... -
PeroK reacted to PeterDonis's post in the thread Graduate Couldn't the cosmological constant also have some sort of "dynamics"? with Like.
It's straightforward to write down the model; indeed doing that is an exercise in some advanced GR textbooks. The usual way is to use a...
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PeroK replied to the thread High School Why higher speeds need more power if the backward force is the same?.There is such a thing as hill racing, where athletes run up and down mountains. On the uphill, however, only the top athletes do more...
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PeroK reacted to Hornbein's post in the thread High School Why higher speeds need more power if the backward force is the same? with
Haha.
Actually running up stairs is easier. I learned it when I was a kid and have practiced it my whole life. It appears I am the only... -
PeroK reacted to Baluncore's post in the thread High School Why higher speeds need more power if the backward force is the same? with Like.
The rate of energy flow, that an engine can convert, is its power rating. Kinetic Energy; Ek= ½⋅m⋅v² Velocity; v = √ ( 2 ⋅ Ek / m ) As...
