Is matter that is absorbed by a black hole trapped forever? Can it ever escape or be recovered?

Is matter that is absorbed by a black hole trapped forever? Can it ever escape or be recovered?
Does one experience "lag time" when viewing a black hole?
Is it possible to calculate the speed of the engine components themselves ie pistons in kph/mph?
Why isn't there only iron? Why don't smaller atoms just fuse to "improve" their energetic states?
When a wheel or anything circular spins really fast, why does it sometimes look like its spinning backwards and then spin forwards again?
Why does rock salt help with thawing sidewalks, yet it's used in ice cream makers to make the ice cream even colder?
Could something as large as a planet, say Mars, spin quickly enough to simulate Earth's gravity?
[Particle/Quantum Physics] What is symmetry in quantum fields, and how and why is weak interaction tied to the Higgs field?
How did scientists come up with the mechanisms inside inkjet and laser printers?
What happens in our brain when making choices/react to something ?
Why does glass/crystal resonate or "ping" when struck while plastic does not?
How is my work radio/walkie talkie blockout a real radio's broadcast signal? (more explanation in comments)
Is there a link between an object's color and its thermal radiation?
Does chamomile actually have any medical properties or is it just a "trendy" thing to put in supplements?
So it seems that 5,500,000 years ago, the Mediterranean basin was invaded by the Atlantic; how would ocean life have expanded into and adapted to the previously-not-underwater environment?

Posted: 20 Dec 2015 09:30 AM PST

submitted by cantchangeits
[link] [25 comments]

Does one experience "lag time" when viewing a black hole?

Posted: 20 Dec 2015 07:22 AM PST

I just watched In a nutshell. I can't stop thinking about what two people would experience when A watches B enter a black hole - both with lights that flash every second.

For Example: When B draws near the black hole, as time slows and the light blink longer and slower, wouldn't the light emitted grow dimmer, longer lasting, and slower to occur to A? And wouldn't the lag time between where B is, and where A "see's B at" increase? (Like how the stars we see in the sky are long dead but the light remains?).

As A gets drops nearer the black hole wouldn't "everything" get brighter (more light photons getting to the eyes faster)? To the point they are blinded by light?

submitted by monoaudio35
[link] [4 comments]

Is it possible to calculate the speed of the engine components themselves ie pistons in kph/mph?

Posted: 20 Dec 2015 05:08 AM PST

It's just something that has fascinated me. Sure I know that at 5000rpm the crankshaft is spinning 5000 times per minute and the piston goes up and down for every rotation but what is the actual SPEED of the piston?

Say, my Harley which has a stroke of 101mm. What would the piston speed be at 5000rpm?

submitted by Paiste402
[link] [13 comments]

Why isn't there only iron? Why don't smaller atoms just fuse to "improve" their energetic states?

Posted: 20 Dec 2015 02:59 AM PST

I would expect smaller atoms to just fuse and release the energy that they lose in mass by fusing. I would also expect heavier nuclei to fuse if you supplied them with the necessary energy that they gain in mass by fusing. Why isn't this how it works?

submitted by TheVicarInATutu
[link] [5 comments]

When a wheel or anything circular spins really fast, why does it sometimes look like its spinning backwards and then spin forwards again?

Posted: 19 Dec 2015 06:27 AM PST

Video for reference https://m.facebook.com/story.php?story_fbid=834126196624211&id=250931438277026

edit: Thankyou Everyone for your responses, special shout out to /u/nik282000 for his link of a super helpful video with examples of what I'm trying to talk about https://www.youtube.com/watch?v=QYYK4tlCMlY

submitted by iZlatani
[link] [174 comments]

Why does rock salt help with thawing sidewalks, yet it's used in ice cream makers to make the ice cream even colder?

Posted: 19 Dec 2015 10:10 PM PST

This is something that has absolutely confused me since I was a fetus.

submitted by True_Roadie
[link] [12 comments]

Could something as large as a planet, say Mars, spin quickly enough to simulate Earth's gravity?

Posted: 20 Dec 2015 08:35 AM PST

If so, how quickly would Mars need to spin to match Earth's gravitational pull?

submitted by WolvWild
[link] [3 comments]

[Particle/Quantum Physics] What is symmetry in quantum fields, and how and why is weak interaction tied to the Higgs field?

Posted: 19 Dec 2015 04:39 PM PST

I am a high school student who is very interested in Quantum Mechanics and Particle physics and has taken the time to read (though not finished) many books on these topics (QED, A Brief History, and a few more) to further expand my knowledge along with research done on the internet through various means.

I am currently reading Sean Carroll's "The Particle at the End of the Universe", which talks about the in-depth search as CERN and the LHC for the Higgs Boson which occurred back in 2012.

In the second chapter the book mentions quantum fields (which I personally understand at the degree the book requires to convey most of the rest of the information). However, it then goes on to mention symmetries between these fields and how:

"The weak nuclear force, in particular, is based on a certain kind of symmetry. If that symmetry were unbroken, it would be impossible for elementary particles to have mass."

What is it about the Higgs field and especially its symmetry to other fields that, if not there, would prevent all particles from having mass? Would a non-symmetrical quantum field not allow the property of a particle that it's associated with to be a fundamental property of that particle? And what is the fundamental meaning of broken and unbroken symmetries?

submitted by EliteTazer
[link] [7 comments]

How did scientists come up with the mechanisms inside inkjet and laser printers?

Posted: 19 Dec 2015 10:37 PM PST

Specifically, what kind of calculations and testing did they have to go through to figure out how to make printers print out the right colors and brightness on every little dot/strip? I also want to know how the whole rest of it was figured out. So I'm not just looking for a how-to-make-a-printer but how the scientists actually figured out how to build the first one. Is there a good read somewhere on how they did it?

submitted by TwitchJonjonjonh
[link] [6 comments]

What happens in our brain when making choices/react to something ?

Posted: 20 Dec 2015 05:54 AM PST

Thanks.

submitted by BMG711
[link] [comment]

Why does glass/crystal resonate or "ping" when struck while plastic does not?

Posted: 19 Dec 2015 05:50 PM PST

I could only find one other question that was close to mine and that dealt with metallic crystalline structures. I understand that there is a difference in the makeup and structure between glass/crystal and plastic but the main question is why does glass/crystal resonate and plastic doesn't (assuming that both materials were the same size, thickness, and etc.).

If it's the material, why does glass/crystal, silicon and quartz, "ping" while plastic, organic polymers, doesn't.

If it's the structure, why does glass, amorphous solid, and crystal, crystal lattice, "ping" while plastic, crystalline/amorphous, doesn't.

If it's some other property, then feel free to explain why glass/crystal and plastic differ in their sounds after being hit.

The answer is due to the different Young's modulus of glass and plastic.

submitted by omnispark66
[link] [5 comments]

How is my work radio/walkie talkie blockout a real radio's broadcast signal? (more explanation in comments)

Posted: 20 Dec 2015 02:12 AM PST

So, at work we have to communicate with motorala "walkie talkies" that button to push and we broadcast on a specified level which is picked on the walkie talkie. I noticed the other day while working next to a traditional radio that when I pushed the walkie talkie button to talk to my coworkers that it completely blocked out the radio signal. I adjusted the radio frequency from about 100mhz to 88 mhz and the walkie talkie still blocked out the radio broadcast. Then I turned it to AM frequency and it still blocked out the signal completely. What is my work walkie talkie doing exactly to entirely block out a radio signal from working?

submitted by cephsdiablo
[link] [6 comments]

Is there a link between an object's color and its thermal radiation?

Posted: 19 Dec 2015 06:30 AM PST

If I put a copper coin on a table in front of me, I'll be seeing its yellow color. It's also emitting thermal radiation, but this is in a wavelength I can't see. Now if I heat it up until it starts glowing because of how hot it is and it turns red, what happened to its original yellow color?

submitted by NewStandards
[link] [10 comments]

Does chamomile actually have any medical properties or is it just a "trendy" thing to put in supplements?

Posted: 19 Dec 2015 02:18 AM PST

I have noticed that a lot of supplements at my store (relatively speaking) has chamomile in them. Does it have any actual medical use? I thought it was just one of those home remedies like hot milk.

submitted by TardyTardigrade
[link] [4 comments]

So it seems that 5,500,000 years ago, the Mediterranean basin was invaded by the Atlantic; how would ocean life have expanded into and adapted to the previously-not-underwater environment?

Posted: 18 Dec 2015 11:40 PM PST

submitted by d023n
[link] [2 comments]