How rapidly (or not) does a newborn star "ignite" once it reaches critical mass? Hours, days, years? | AskScience Blog

Pages

Tuesday, February 12, 2019

How rapidly (or not) does a newborn star "ignite" once it reaches critical mass? Hours, days, years?

How rapidly (or not) does a newborn star "ignite" once it reaches critical mass? Hours, days, years?


How rapidly (or not) does a newborn star "ignite" once it reaches critical mass? Hours, days, years?

Posted: 11 Feb 2019 06:17 PM PST

Are glaciers moving non-stop or is the movement staggered?

Posted: 12 Feb 2019 07:39 AM PST

Are they constantly on the move like a monolithic snail or do they move abruptly in response to their weight/environmental changes? Or neither, or both?

submitted by /u/Sun-lun
[link] [comments]

Is there anything analogous to relativistic velocity for angular velocity i.e. is there something as relativistic angular velocity?

Posted: 12 Feb 2019 04:45 AM PST

I have just learned about the Theory of Special Relativity and understood the constancy of speed of light and how that translates into the theory. I was wondering that if there was an upper limit like speed of light to the angular velocity of an object? I know that angular velocity and linear velocity are two different things but my question is that what would happen if the numerical value of angular velocity were to be equal to the speed of light maybe like 'c' rad/s(if possible at all). Is there a concept of relativity in case of rotating bodies or how is the theory of special relativity translated in rotational mechanics?

submitted by /u/ClarkDale123
[link] [comments]

Why do planets' rotational axes tilt?

Posted: 12 Feb 2019 08:01 AM PST

Why are planets not oriented perpendicular to the point they are orbiting around?

submitted by /u/rootstein
[link] [comments]

At present, what can quantum computers do that classical computers can't?

Posted: 11 Feb 2019 11:32 PM PST

This question was asked 9 months ago in https://www.reddit.com/r/askscience/comments/8c8es7/at_present_what_can_quantum_computers_do_that/

Have there been any new developments since then?

submitted by /u/LlewellynS96
[link] [comments]

Has the proportion of sedimentary and metamorphic rock increased as Earth has aged?

Posted: 12 Feb 2019 03:00 AM PST

Is the size of an anechoic chamber important? How tiny could you make it until it would stop working?

Posted: 12 Feb 2019 04:52 AM PST

I would like to build one myself, maybe even one with the size of a shipping box. would that still work?

submitted by /u/floriancarl
[link] [comments]

Was the 2014-2016 outbreak of Ebola the first Human Ebola case in the US?

Posted: 12 Feb 2019 08:03 AM PST

With Nat Geo's latest mini series their trailer is really contradictory to the actual book, the book was mainly about the reston mutation, while it did infect a few humans they didnt produce symptoms and if I remeber correctly they weren't infectious?

Where as the trailer portrays US citizens being infected with ebola as a few scenes shows US soldiers (side note it's supposed to be M88 pattern camp but it's a pretty terrible version of M88) carting some infected civilians...

submitted by /u/mcbride-bushman
[link] [comments]

What is a multi-chromosomal hub?

Posted: 12 Feb 2019 07:56 AM PST

Would it be possible to put a definitive end point on certain infinite numbers like pi if we used a mathematics system that wasn't base 10?

Posted: 11 Feb 2019 08:27 PM PST

When did life evolve sleep?

Posted: 11 Feb 2019 11:47 AM PST

As a secondary question, which modern animals don't sleep? Why?

submitted by /u/aquapearl736
[link] [comments]

On sky Rotation of the moon is linear?

Posted: 12 Feb 2019 05:58 AM PST

Due to the rotation of the earth the moon seems.to rotate on sky where say the 'right' limb comes up first from behind the horizon and then at moonset touches the ground first. Making it seem like it did a 180 Deg rotation.

I assume that the rate depends on the location on the earth but is it a linear one? Can we assume that if we know moonrise and moonset we can know the angle from the fraction of the path that it made?

E.g. https://www.zabkat.com/blog/bpic/moon2.jpg

submitted by /u/Synethos
[link] [comments]

what does silver nitrate do to open wounds? why is it used?

Posted: 11 Feb 2019 08:40 PM PST

i have an open wound that isnt healing from an operation and have revision surgery scheduled for next week. in the mean time, both my orthopedic surgeon abd my plastic surgeon have put silver nitrate on it to cauterize it. but is that all it does? why silver nitrate instead of electrical cauterization? why does it color your tissue such a gross grey color? my granulation tissue that the doc put the silver nitrate on today kinda sloughed off tonight when changing dressing. why does silver nitrate do that to tissue, and how can that be beneficial to wound healing?

submitted by /u/headyslabs
[link] [comments]

How does a baby/cells know to create a baby shape?

Posted: 11 Feb 2019 04:11 PM PST

How does an animal "know" to form its shape while being created in the womb?

Why dont babys just come out as something different every time like a kinder surprise?

submitted by /u/Iinzers
[link] [comments]

Are black holes hot or cold?

Posted: 11 Feb 2019 08:11 PM PST

Alright so stars obviously burn pretty hot relative to humans, but a question thats been bothering me lately is when something collapses into the singularity of a black hole, is the black hole itself hot or cold if we can even tell. Thanks in advance :)

submitted by /u/drei-im-weggle
[link] [comments]

How do we define the nature of quantity"Q"that is to be always conserved in the conservation of energy?

Posted: 12 Feb 2019 03:28 AM PST

Noether's theorem to me explains how a certain defined quantity(Q) is conserved in time(due to the Time translation symmetry), and to be more specific, if we had a ball that is placed in a gravitational field suspended in a height, that ball has a potential energy (Q) that is conserved over time, and if certain translations where to occur, such as the ball falling... that quantity which is initially defined would always be the same regardless of that changes(the ball moving and changing it's height within that gravitational field).

It seems to me, that the initial quantity(Q) has to assumed first then Noether's theorem is applied, but what defines the quantity(Q) and how is it certain that it cannot be created nor destroyed, rather conserved?

For me, there is a gap of understand that is not clear.

submitted by /u/DeltaPhiOverDeltaT
[link] [comments]

How long does it take soap to “remove” bacteria?

Posted: 11 Feb 2019 12:12 PM PST

I've seen that the recommended amount of time for washing hands with soap is 20-30 seconds. I know that friction from rubbing is what allows the soap to remove the bacteria from your hands, but is the 20 second rule constant? Is that just to ensure you cover the full surface area of your hands?

If I get my wrist dirty, do I need to rub it with soap for 20 seconds? What about on other materials like ceramic or steel? Does the type of soap impact the amount of time you should spend creating friction (i.e dish soap vs hand soap)?

submitted by /u/QueenNibbler
[link] [comments]

How do doctors weigh a fetus in the womb?

Posted: 11 Feb 2019 08:15 PM PST

Seems like there's a lot of factors going on like the weight of the placenta and whatever else is going on. Do they somehow measure the dimensions and assume all babies have the same density?

submitted by /u/MySweetClayton
[link] [comments]

Why does heroin constrict one's pupils?

Posted: 11 Feb 2019 06:36 PM PST

Why do some people attract bug bites (mosquitos, black flies) a lot more than others?

Posted: 11 Feb 2019 09:48 AM PST

I've been an insect magnet all my life. I'll be walking in the woods, covered in DEET, with pale long clothes tightened at the ends alongside friends in shorts without repellent and I'll still end up being eaten to death while they get the occasional bite. What is there in my blood, or on my skin that attracts the mosquitos? Is there anything that can be done?

submitted by /u/Gaboury
[link] [comments]

Why is dimethylMercury highly toxic, while ethylMercury is safe?

Posted: 11 Feb 2019 08:53 AM PST

I recently saw a video by "Chubbyemu", in which he shows the symptoms of a scientist who comes into contact with dimethylMercury. How does this cause so much neurological damage, while ethylMercury is safe to use, such as in vaccines?

Edit: And what is the chemical reason for this? What makes dimethylMercury lipophilic, causing it to stay in fatty tissue for large amounts of time, while ethylMercury clears from the body much faster ?

submitted by /u/wangl3
[link] [comments]

Why is terminal dehydration known to cause mild euphoria?

Posted: 11 Feb 2019 08:18 PM PST

Dehydration has been known to cause a sense of "mild euphoria", provided no intravenous is used. - Wiki citation 7

Would also add the psychology flair if I could.

submitted by /u/Lone_Narrator
[link] [comments]

How do opticians know what prescription glasses to give babies/toddlers?

Posted: 11 Feb 2019 08:37 AM PST

It's not as though the baby can vocalize whether they can see better or worse in a test. Is there just a standard prescription for babies? How can you tell how bad their eyes are, or if it's near or far sighted?

submitted by /u/DoctrDonna
[link] [comments]

No comments:

Post a Comment