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Star Cooler Than Venus Found
crossconnects writes to mention that Discovery is reporting that astronomers have found a nearby star with a mild surface temperature of 660 degrees fahrenheit. "The spectacularly unspectacular object is of special interest because it falls right smack in the middle of the final frontier that divides mega-planets from the puniest stars. Stars in that realm theoretically qualify as an entirely new stellar type -- what's called a Y class dwarf."
Venus never was that hip.
"I use a Mac because I'm just better than you are."
http://arxiv.org/abs/0802.4387
http://arxiv.org/pdf/0802.4387v2
Beware: In C++, your friends can see your privates!
Fascinating stuff indeed.
FTA: That means any water in there atmospheres will condense into droplets of water vapor
:)
Aside from the bad English, the quoted bit is actually the most interesting part of the article. Does that mean that a particularly low-temp one of this newly discovered kind of dwarf star could be a self-contained biosphere, with a source of heat in the center surrounded by a life-sustaining atmosphere with liquid water in it?
Dyson Sphere is to Ringworld as Cool Dwarf is to Smoke Ring!
Fun with Anagarams! LADS HOST, SHALT DOS. HAS DOLTS. AD SLOTHS, HATS SOLD. ASS HO, LTD.
... and I have a hard time believing there are many stars out there that are even "as cool" as Venus. Venus is so fucking awesome that it's just absurd for anybody to claim they've found a star cooler than her.
no.
Fahrenheit is much funner to say than Celsius, or *wretch* Centigrade.... those sound like crap.
J
Beer, now there's a temporary solution -- Homer Jay S.
No, not when audience is the American public.
We hope your rules and wisdom choke you / Now we are one in everlasting peace
What, they should have used Rankine?
...the future crusty old bastards are already drinking the Kool-Aid.
Even with an American audience at the temperatures discussed Fahrenheit has no real meaning.
The usefulness of Fahrenheit is how the range of 0 - 100 reflects weather temperatures people have experienced.
Temperatures beyond common experience are better expressed in Celsius.
D6 63 0D 70 89 81 BB 8E 7B 7C 5F 5D 54 EA AB 73
Even if it's the scientific American public?
Beware: In C++, your friends can see your privates!
lads shot, last shod, lost dash, halts sod
no big sig
Then we should use Degrees Delisle, which has the added bonus of going backwards. Body temperature is at 95 Delisle. The sun (ours, that is) is at negative several thousand degrees Delisle.
Kelvin is the best.
In a scientific article, I would expect stellar temperatures to be given in Kelvins.
In a popular article, Celsius or Fahrenheit (depending on country) are probably expected and more understandable to a general audience.
Ideally, any good article would give the measurement or estimate in the original units first (and with the original degree of precision), followed by a conversion if needed for the expected audience.
... venus added Uranus as a friend on its My Space profile.
The "temperature" of the Big Bang is the theoretical hottest you can ever get, since at that point all mass was in the form of energy, and therefore you had the maximum energy at the maximum density. Nothing can ever exceed that. Thus, if you knew what that was, you could assign it a fixed value as your upper end of the scale. The ideal would be to then have a set of functions (linear, logarithmic, whatever), where a given function was selected for a specific type of application, with the exception of some specific function chosen as the 'standard'.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
To some degree, you are correct; American scientists, the target audience of the original publication, would prefer the Kelvin unit, which was indeed used in the original publication. However, I don't think the Discovery channel's target audience is primarily scientists but rather the American public, which prefers Farenheit - hence the use of that unit on the Discovery channel's website (the location of TFA).
600 F has no meaning? The dial on my oven goes up to 600 degrees. It's also the temperature gasoline ignites at. We are hardly talking about astronomical temperatures beyond our comprehension.
We hope your rules and wisdom choke you / Now we are one in everlasting peace
Correction, gas ignites at 500, but my oven still goes up to 600.
We hope your rules and wisdom choke you / Now we are one in everlasting peace
I agree with that, best post in the silly temperature units argument, mod parent up ^^
Planck's temperature is theoretically the hottest anything can possibly be at - 1.41679 X 10^32 K. Beyond that, and the energy density will basically generate enough gravity that it collapses into a black hole. (We're talking "Big Bang" energy density here.)
Mater == energy, energy == matter, and enough of either in a small enough volume will collapse into a singularity.
So - if you want a possible temp scale, use 0K as starting point, Planck temperature at end, and add convenient subdivisions. But, remember, the resulting "degrees" will still be arbitrary.
Since the volume of space at t=0 was zero, but the energy content was not, the temperature at t=0 is infinite. That isn't useful for determining a scale. Alternatively, if the energy content was zero, then the temperature is lim(x->0) x/x, which is 0. If energy is zero but volume is nonzero, then temperature is 0/x (x>0), which is also 0. And if both volume and energy are nonzero, then you get a very large but finite amount, which is exceeded by classical black holes, where singularity has zero volume but nonzero energy content.
This is, of course, all assuming that neither volume nor energy can be (were not) negative, since if they are, you get all kinds of extra nastiness.
How do you define this numerical value ? How are you going to make such a scale any less arbitrary than Kelvin scale ?
I propose an alternative: since temperature is determined by the average kinetic energy of a particle, use that as a gauge: at the temperature of 1 base unit, the average kinetic energy per particle is 1 Joule.
Alternatively, use the blackbody radiation: the base unit corresponds to the temperature of a blackbody object who's peak of radiation has wavelength of 1 meter.
Forget magic. Any technology distinguishable from divine power is insufficiently advanced.
It also assumes it's useful to go back to a t=0, assuming one exists. Theoretical models can't usefully go back much further than the point immediately prior to the inflationary universe model kicking in. Since nothing before this point makes any difference to what happens after, we can use this point as the "Big Bang", which means we definitely have non-zero space.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
but the energy content was not, the temperature at t=0 is infinite.
:).
Okay, at time t= +e(psilon), wiseguy.
Of course, this quantity already goes by the name "Planck temperature", so we have a nice tidy number: 1.417 x10^32 Kelvin.
How are you going to make such a scale any less arbitrary than Kelvin scale
Well, any value on that scale gives a meaningful number in the sense that it expresses the portion of the maximum energy possible in this universe, with a well-behaved upper (100) and lower (0) bound.
Of course, on the down side, we'd have to use microyoctodegrees to measure temperatures in our everyday range of experience, with water freezing at 193myD and boiling at 263myD.
use the blackbody radiation: the base unit corresponds to the temperature of a blackbody object who's peak of radiation has wavelength of 1 meter.
Not a bad idea, but that just gives you the identity of Wein's law, or 2.898K. Not really all that bad as a base unit for scientific purposes, but it puts water in a range of 94.2 to 128.7... Still not all that great for expressing everyday temperatures.
The "right" unit of temperature measurement would be eV, or the Planck system of units. That's right: units of energy. It gives twice the average energy per degree of freedom of an object at said temperature. In this system, the Boltzmann constant would be equal to 1, as it should be and would have been had we known chemistry before coming up with the idea of "temperature".
Room temperature is about 1/40 eV on this scale, or 25.3 meV. Water boils at 32.2 meV and freezes at 23.5 meV. Absolute zero is, of course, 0 meV.
I say we use 0 for absolute 0 and 1 for the Planck temperature. Then the weather difference here in North Dakota, from one day to the next would be so small that it wouldn't seem daunting. I'd feel much better with a 1.2x10^32 temperature drop than a 50 degree drop.
Make that a 1.2x10^-32 temperature drop ;)