Recent comments in /f/askscience

silent_cat t1_j28didp wrote

Reply to comment by canadave_nyc in How fast does the Milky Way spin? How far does Earth move through space in a year? by Sabre-Tooth-Monkey

I think the bit you're missing is that when you move in a particular direction, light from that direction becomes slightly bluer and light behind you becomes slightly red.

If you assume the "expanding balloon" is expanding everywhere at the same rate, by looking at the colour of the expanding balloon you can determine a speed relative to you where the balloon will have the same colour everywhere.

Yes, it would have been more logical if we'd have been stationary relative to the global frame, but it turns out we're not. Science is more interesting when it gives you answers you don't expect.

(It could be that the "bubble" is not expanding at a uniform rate everywhere, but we (currently) have no way of distinguishing that. And it seems the weaker assumption that we're simply moving than some fancy new physics.)

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kittylikker_ t1_j28bsuz wrote

Reply to Do nails adapt over time to stress based on different ways of being trimmed? by pengl0ss

Hi! Certified nail tech here!

First off, please stop chewing your nails. Seriously, the amount of unsavoury sh!t you literally have under your nails would make you retch if you knew. Please stop putting that in your mouth.

Damage to the nail bed can absolutely affect the shape of the nail. Illness or traumatic events can affect the growth and structure of our nails (and hair!) as well. However, what you are describing sounds more like a potential fungal infection or a vitamin or mineral deficiency. You'll want to see a GP for a blood panel and potentially a scraping.

And stop eating your hands.

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cismo2010 t1_j28bgwe wrote

Reply to comment by team-tree-syndicate in How much does the liquid magma of the Earth affect it's surface temperature? by tripperfunster

Just to bei more specific, the radiation from the sun which get's blocked/deflected by earths magnetic field are charged particles (e.g. alpha/beta-radiation).

The radiation which "heats" earth ist gamma-radiation in form of photons. A good portion of those photons get reflected by clouds and ice (due to the reflectiveness of white surfaces), another part afterwards get's radiated as infrared-radiation. The Difference between the incoming and (reflected + radiated) photons are the energy earth get's from the sun.

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r2k-in-the-vortex t1_j2896qx wrote

Reply to How much does the liquid magma of the Earth affect it's surface temperature? by tripperfunster

Very little. It depends of course on local geology, but is generally well below 1W/m2 compared to sunlight being 1000W/m2

You can of course see the effect on poles, there is magma under Antarctica just the same, but it's still covered with couple km thick ice.

So in terms of temperature it makes no difference directly. But indirectly tectonic activity makes a very large difference. With a solid core we wouldn't have mountains left, it would have all eroded flat over billions of years. Without volcanic emissions we wouldn't have enough carbon for lush foliage, because it has a tendency to form sediments. Earth would be an iceball without enough CO2 to keep the heat in.

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Faelwolf t1_j2893k0 wrote

Reply to How old is the oldest bone that isn’t a fossil? Is there a limit for how long bones are preserved without becoming fossilised? by Worthyteach

Some Dinosaurs have been found partially unfossilized, one even in a fully non-fossilized state, with even the skin pigment preserved (mummification). It all depends on the circumstances surrounding it's burial over time. Of course, such finds are exceedingly rare.

You may find this of interest: https://en.wikipedia.org/wiki/List_of_dinosaur_specimens_with_preserved_soft_tissue

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