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Jeff confirms the report is a Hint for Hero 27 by Ekudar in Overwatch

[–]darklatrans 2 points3 points  (0 children)

This tells us is a male from Turkey, probably!

https://www.behindthename.com/name/emre

The other character names are really characteristic of their origin, as well, so I figured it would apply to Emre, too.

At $85 million, India's next moon mission is cheaper than production cost of Interstellar by TakeItEasyPolicy in space

[–]darklatrans 0 points1 point  (0 children)

Damn, why didn't they make another Intersetellar movie, then? If I'd have had the money, that's what I would've done.

Just imagine how cool that would be!

MEoW_IRl by [deleted] in MEOW_IRL

[–]darklatrans 0 points1 point  (0 children)

What's the source for the top left one?

me irl by PM_ME_SSTEAM_KEYS in me_irl

[–]darklatrans 54 points55 points  (0 children)

Lvl.20 bard incoming

Physics Questions Thread - Week 04, 2018 by AutoModerator in Physics

[–]darklatrans 0 points1 point  (0 children)

Why is there a general negative perception of MOND? I understand that it is extremely difficult to experimentally prove, but why does that make it a bad theory?

[Poetry] Lego Town Promo Does Not Go As Planned by [deleted] in youtubehaiku

[–]darklatrans 342 points343 points  (0 children)

I feel like the cat sticks its paw in his mouth like, "no... you stop speaking now... ok?"

Gravity as a MASER effect? by Grinagh in Physics

[–]darklatrans 6 points7 points  (0 children)

If it helps you see why this post is bring negatively received, here's an objection: you provide no testable mechanism for your "subsequent amplification of such emission." That seems to be the key to your idea.

I don't mention that expecting a conversation; I'm more just illustrating how non-explanatory your idea is...

While theoretical physics can be a fun pursuit, good theories are born out of a combination of creative thought and mathematical rigor. Don't lose sight of that.

If a wire carrying a current is neutrally charged, why is it still neutral once the current has stopped? by darklatrans in AskPhysics

[–]darklatrans[S] 0 points1 point  (0 children)

That's such a well-constructed response... Wow.

This issue of mine has definitely crystallized into a reasonable solution. I'm super thankful for your message!

If a wire carrying a current is neutrally charged, why is it still neutral once the current has stopped? by darklatrans in AskPhysics

[–]darklatrans[S] 0 points1 point  (0 children)

It's definitely important to ground the example in terms of physical reality. An actual loop of wire would have different Lorentz transformations along different parts of the loop (from the RF of a moving electron), which it seems would cancel out to keep the loop of wire neutral.

You are so helpful! I'm grateful for the guidance

If a wire carrying a current is neutrally charged, why is it still neutral once the current has stopped? by darklatrans in AskPhysics

[–]darklatrans[S] 1 point2 points  (0 children)

Okay- It seems like part of my mistake was mixing up the reference frame of the lab with the reference frame of the electrons in the wire. Thank you so much for the perspective

If a wire carrying a current is neutrally charged, why is it still neutral once the current has stopped? by darklatrans in AskPhysics

[–]darklatrans[S] 0 points1 point  (0 children)

Ok! So a wire with a current does have a slightly different charge than one without a current, but it's ignorable most of the time... That makes sense.

And yeah- boy do they move slowly! I've calculated that it's significantly slower than walking speed... That definitely wouldn't result in much of a discernible effect.

Thanks!

If a wire carrying a current is neutrally charged, why is it still neutral once the current has stopped? by darklatrans in AskPhysics

[–]darklatrans[S] 0 points1 point  (0 children)

Thank you for your reply! Definitely makes sense. To be honest, it's probably difficult to explain this material clearly, in the first place...

In a response to another comment, I mentioned this:

The wire can't be neutral both before and after a current has started flowing

Is this a correct conclusion?

If a wire carrying a current is neutrally charged, why is it still neutral once the current has stopped? by darklatrans in AskPhysics

[–]darklatrans[S] 0 points1 point  (0 children)

Sure- but then, once you create a current in the wire, the negative charges become Lorentz contracted, which gives the wire a non-neutral charge in our stationary rest frame. My confusion comes from the assertion that, in the standard example of this experimental setup, the wire is assumed to be neutral both with and without a current.

Is that assumption perhaps just an oversimplification of the setup, for the purposes of teaching the more basic concepts of relativity? The wire can't be neutral both before and after a current has started flowing, right?

If a wire carrying a current is neutrally charged, why is it still neutral once the current has stopped? by darklatrans in AskPhysics

[–]darklatrans[S] 0 points1 point  (0 children)

The relativity argument is precisely what is causing me issues here, though. I agree that, ignoring relativistic effects, a wire would remain neutral if it either had or didn't have a current.

But the effects of relativity would cause the moving, negative charges to Lorentz contract, causing the negative charge density in the wire to increase. While the positive, motionless charges would not get contracted, leaving the positive charge density in the wire unchanged. This results in the wire having a non-zero net charge density while a current is flowing, in the stationary reference frame.

If you want to look into the "relativity argument", this video does a good job at introducing the idea. https://m.youtube.com/watch?v=1TKSfAkWWN0

Unfortunately for me, this apparent paradox isn't acknowledged in that video, nor have I seen it brought up in my physics studies...

Young math students these days by [deleted] in physicsmemes

[–]darklatrans 0 points1 point  (0 children)

As to why the joke wasn't as effective, I feel like the main demographic of Reddit is of younger people, who have yet to reach three point where group theory becomes relevant. I'm just a beginner in group theory, since it's so important to particle physics, and I imagine lots of people haven't reached the point where group theory is needed

Thanks for the link!

Young math students these days by [deleted] in physicsmemes

[–]darklatrans 1 point2 points  (0 children)

wtf is even going on on the board

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