Insights Blog
-- Browse All Articles --
Physics Articles
Physics Tutorials
Physics Guides
Physics FAQ
Math Articles
Math Tutorials
Math Guides
Math FAQ
Education Articles
Education Guides
Bio/Chem Articles
Technology Guides
Computer Science Tutorials
Forums
Trending
Featured Threads
Log in
Register
What's new
Search
Search
Search titles only
By:
Latest activity
Register
Menu
Log in
Register
Navigation
More options
Contact us
Close Menu
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Forums
PeroK's latest activity
PeroK
reacted to
hjgfx697's post
in the thread
B
Are some objects in the night sky just older images of other objects?
with
Skeptical
.
It's a question I've pondered over for years and I've even asked a few people but I've never had a convincing answer. As per the...
Today, 12:12 PM
PeroK
reacted to
Chestermiller's post
in the thread
B
How does an object gain potential energy?
with
Like
.
The simplest way to interpret this is to say that the change in potential energy is minus the work done by gravity on the body...
Today, 9:41 AM
PeroK
reacted to
adjurovich's post
in the thread
B
How does an object gain potential energy?
with
Like
.
I’m thankful for your effort in this reply, but I don’t think this all answers my simple question. My question is rather technical, but...
Today, 9:41 AM
PeroK
reacted to
ohwilleke's post
in the thread
B
Will we ever communicate with extraterrestial life in a reasonable time frame?
with
Like
.
The argument that there are only four candidates in the solar system, a priori (we've probed enough to rule out advanced civilizations...
Today, 3:25 AM
PeroK
reacted to
DennisN's post
in the thread
B
Will we ever communicate with extraterrestial life in a reasonable time frame?
with
Like
.
Even though it's really painful (truly, :cry:) to write this I have to admit that I got fooled by Däniken too when I was young. We do...
Today, 3:23 AM
PeroK
replied to the thread
Bees and Trains: A distance problem
.
Time is of the essence!
Today, 2:23 AM
PeroK
reacted to
DaveC426913's post
in the thread
B
Does energy exist?
with
Like
.
If I pick up a bowling ball I imbue it with potential energy. If I let it go, that potential energy gets converted to kinetic energy and...
Yesterday, 12:18 PM
PeroK
reacted to
Vanadium 50's post
in the thread
B
Does energy exist?
with
Like
.
People are giving you a hard time because that is such an ill-defined and non-physical question. The fact that you are repeating rather...
Yesterday, 12:18 PM
PeroK
reacted to
Dale's post
in the thread
I
I want a good reference to a discussion of the meaning of "the speed of light is constant"
with
Like
.
The important thing about ##c## isn’t that it is constant. The important thing is that it is invariant.
Yesterday, 12:17 PM
PeroK
reacted to
Nugatory's post
in the thread
I
I want a good reference to a discussion of the meaning of "the speed of light is constant"
with
Like
.
Presuming that “g(t,t)” and “g(x,x)” represent ##g_{tt}## and ##g_{xx}##, components of the metric tensor written in some coordinate...
Yesterday, 12:17 PM
PeroK
replied to the thread
I
I want a good reference to a discussion of the meaning of "the speed of light is constant"
.
In GR, light moves on null worldlines, which means that the speed of light, as measured locally, is a universal invariant. Measured...
Yesterday, 9:27 AM
PeroK
reacted to
Lnewqban's post
in the thread
B
Does energy exist?
with
Like
.
Energy not only exists, it is very expensive! :oops: Many poor countries are supplying electrical energy to their populations only a...
Yesterday, 9:21 AM
PeroK
reacted to
Vanadium 50's post
in the thread
B
Does energy exist?
with
Haha
.
I don't know what the word "literally" means. I thought I did, but I have heard phrases like "I literally exploded" (did you now?) that...
Yesterday, 9:21 AM
PeroK
replied to the thread
B
Does energy exist?
.
Nothing in physics exists or everything in physics exists, depending on your definition of existence. In neither case does the theory...
Yesterday, 4:13 AM
PeroK
reacted to
PeterDonis's post
in the thread
B
Heisenberg's indeterminacy principle with non-point particles ?
with
Like
.
No, it's just describing what the basic math of QM does and does not tell us. Not "to interact", to be measured. "Measurement" is a...
Monday, 3:17 PM
Forums
Back
Top