barfbag

@ Hypervalent_Iodine,

We perceive hot temperatures above 45oC with thermo receptors as well, they are just different ones to those we use to detect cooler temperatures.

 

I think you are describing thermal nocireceptors, and I also think you are confusing the sensation of heat with the sensation of pain.

If your car seat is very hot when you sit in it that sensation is not pain. I think nocireceptors transfer signals of pain, and are not used as you describe.

NOTE: If you are NOT talking of nocireceptors I apologize and am curious what other nerves are at play here I am unaware of, but I think you must be because there is only the three involved in thermal detection.

The mild burning sensation you feel from hot sand or from your hot car seat is NOT pain. It is caused by heat exciting both the warm thermoreceptors and the cold thermorecptors at the same time.

I gave an example before that is apt.. Run barefoot in the snow for 10 minutes and then go inside a warm house. It will feel like your feet are on fire. Cold + Warmth (<45 degrees) = Burning sensation.

there are a number of thermo receptors that respond to different temperature ranges

 

(from post 4)

So how many are we talking about? I say three. Cold Thermoreceptor, Warm Thermoreceptor, and nocireceptors which are used in sensory overload to indicate pain ONLY.

What is your number?

Deja Vu,

This topic is open on multiple threads, but this one seems more popular.

attn moderators... please close alternate thread here...

http://www.scienceforums.net/topic/84359-is-it-possible-to-work-as-a-chem-eng-while-holding-chemistry-degree/?p=816262

My comment from there should be deleted when a mod closes it so I will copy paste into the more active thread.

Quoting me from other thread...

I see this is your first post so welcome, but I must say I am not quite sure what you are asking [Edit: Last Thread it was not as clear].

 

Chemical Engineers may be required in a variety of settings from simply an office to an ocean bound research vessel. Talk to associate students and discuss their long term goals maybe?

 

Soil Engineer, refinery, biological and bio-medical engineering, product design and development, and nano-processing, process engineering, consulting, plastics, paint, manufacturing, sugar refining, light metals, risk management are other possibilities.

 

I even saw one guy switch from Soil Engineering to become a Bylaw enforcement officer which is totally unrelated because he liked the Government position and the similar investigative techniques and travel made him a good candidate. Think he started around 90k/year salary

 

I was trying to be nice, but I do not want to teach.

You guys can pretend you are unable to understand this, but I think it's just argumentative.

Yeah. I should have said Hot (although I think it is obvious the intent) and not heat.

No. I am saying in no uncertain terms that your original statement is false,

 

Whew! Because from your post # 20 note, it looked like you had agreed with Inows faulty understanding of heat vs temperature.

If the FBI were criminal and murdering types that would kill with a drone then maybe they might try to pirate the software using bit torrents.

Please close this thread after you insult me again.

Isn't Spacial touch something lost during strokes? There is likely some research that helps stroke victims understand sensations.

@ Hypervalent_Iodine,

If you cannot understand the difference between warm and "Hot Heat" (term I used in post 18 adding Hot in front), then I understand your confusion, Let's say hot heat is roughly 45oC+.

My comment in post 13 was about a quote by Metacogitans who said,

feeling heat versus feeling something pushing up against you, for example), these have different nerves with dedicated roles

 

Hey Metacogitans.. You can't say feeling heat... (joking for a point, yes you can)

I think the dual nature of some nerves could aid someone designing a program attempting to learn (as in OP), but this thread does concern learning "spatially" the locations of feeling. I only mentioned it casually in a three sentence post (which is 100% correct). It has been others dragging this part out.

@ Inow,

The nerves detect heat because of a transfer of energy. I will say that. How is that not heat.

First, what you are trying to describe is the sensation of temperature, not heat. They are different. Heat is a transfer of energy wherein temperature is one type of measurement of it.

 

Where to even begin?

Before I link 20+ websites...

Are you saying (I want to be clear), "People cannot feel heat".

@

Hypervalent_Iodine,

Same question...

as iNow has noted you are not using standard definitions for what you are talking about.

 

Before I link 20+ websites...

Are you saying (I want to be clear), "People cannot feel heat".

@ Inow again,

If you take a metal ball and a plastic ball from your Freezer which one feels colder? The metal one would. This is NOT because there is a temperature difference. It is because the metal ball is more conductive and TRANSFER ENERGY ( HEAT IS A TRANSFER OF ENERGY) better than the plastic ball. THE SKIN CANNOT DETECT THE TEMPERATURE AT ALL , or else it would know both balls were the same temperature (Which it doesn't).

I am surprised by your first point because you said as much in your second point,

Second, it's not even temperature being perceived by the human body, but instead changes in temperature

 

When you say "Changes in temperature" do you mean a TRANSFER OF ENERGY?

Want a youtube video of little vibrating molecules, because I'm sure there are many?

Do you add to coals or is there any ignition device?

I would think most of your tar comes from starting and stopping where temperatures fall below 100C, but I'm also an Engineer and not a Chemist.

Any Chemists out there?

I just found this online.. I had not thought of wet pellets slowing down the burn...

Reply on the matter from Solid Energy, supplier of Natures Flame pellets;

"Tars are usually a sign of incomplete combustion due to lack of air/heat or wet biomass fuel. As long as the fuel is dry (and if they are pellets then they will be) then it will be the boiler settings. More air and heat will burn off the tars before they form on surfaces. Get you installer to adjust the boiler accordingly."

So we have started to slowly increase the fan settings of the boiler to have it burn more hot. Hopefully this will improve combustion and reduce the tar produced.

 

@ acme,

Yes. Just mentioning for whatever it was worth. Many others here link photos, but you are correct.

It still showed my point though so thanks pzkpfw.

@ Hypervalent_ Iodine,

which is that the combination of the two is what we use to detect heat, which is somehow different to warmth.

 

The difference between hot and warm is measured in temperatures.

It is a fallacy if you think Hot Heat ( I'm being made to describe the type of heat as it is obviously not perceivable enough in context) is only detected through the warm thermoreceptors and nocireceptors.

I have outlined an experiment where you could experience Heat with only exposing yourself to Warm and Cold. This is caused by a Paradoxical response to heat by the nervous system.

You are correct that a third pathway is turned on when this occurs.

 

I think that above a certain temperature, the receptors that detect cold have a burst of activity, but it is short lived and different to what you claimed

 

Okay. Are you saying the science center display should not activate Hot/Burning/pain receptors when your skin is only subjected to warmth and cold?

I thought it would be of interest to the OP, but this thread is "too much fun"

@ Inow and H_I,

Here's another fun fact: You're talking out of your ass and should probably just be ignored (unless, of course, we're correcting you so others genuinely interested in learning are not led astray).

 

Thanks Inow (was that supposed to be Iknow (curious)). I do not mind talking out of my ass when I am correct, but thanks for being so polite.

http://www.sciencemag.org/content/265/5169/252.abstract

The thermal grill illusion: unmasking the burn of cold pain

1. AD Craig,
2. MC Bushne
3. Division of Neurobiology, Barrow Neurological Institute, Phoenix, AZ 85013.

• Abstract

In Thunberg's thermal grill illusion, first demonstrated in 1896, a sensation of strong, often painful heat is elicited by touching interlaced warm and cool bars to the skin. Neurophysiological recordings from two classes of ascending spinothalamic tract neurons that are sensitive to innocuous or noxious cold showed differential responses to the grill. On the basis of these results, a simple model of central disinhibition, or unmasking, predicted a quantitative correspondence between grill-evoked pain and cold-evoked pain, which was verified psychophysically. This integration of pain and temperature can explain the thermal grill illusion and the burning sensation of cold pain and may also provide a basis for the cold-evoked, burning pain of the classic thalamic pain syndrome. [ color changed by me/bolded/underlined for emphasis of topic]

 

 

(maybe a nine year oldcan explain it better than me..)

NOTE: She suggests an experiment where you cool your hands in the snow and then come inside and put your hands in lukewarm water or beside a low heat. Your hand will feel burning.

https://www.youtube.com/watch?v=s25o1ka1WeE

(or this 11 year old)

So you can learn this further by trying Thunberg's thermal grill illusion. Soooooo

All of this because I made a 3 sentence "Fun Fact" I thought the OP might appreciate.

Even though I can show this I am sure I will be found to be "wrong" somehow by you guys..

Does anybody ever admit being wrong around here ?

@ Inow again/still,

 

A thermoreceptor is a sensory receptor, or more accurately the receptive portion of a sensory neuron, that codes absolute and relative changes in temperature, primarily within the innocuous range.
<...>
In humans, temperature sensation enters the spinal cord along the axons of Lissauer's tract that synapse on second order neurons in grey matter of the dorsal horn, one or two vertebral levels up. The axons of these second order neurons then decussate, joining the spinothalamic tract as they ascend to neurons in the ventral posterolateral nucleus of the thalamus.
<...>
In mammals, temperature receptors innervate various tissues including the skin (as cutaneous receptors), cornea and urinary bladder. Neurons from the pre-optic and hypothalamic regions of the brain that respond to small changes in temperature have also been described, providing information on core temperature. The hypothalamus is involved in thermoregulation, the thermoreceptors allowing feed-forward responses to a predicted change in core body temperature in response to changing environmental conditions.

 

How does this relate in any way to what triggers the sensation of HOT heat? You claim I am talking out of my ass?

@ Hypervalent_Iodine,

barfbag, on 15 Jul 2014 - 8:00 PM, said:

Fun Fact: The body has no nerves designed to feel heat. The nerves can detect cold and they can detect warm, but not heat.

The heat sensation comes when something is so hot it can stimulate both the warm and cold receptors at the same time.

This seems fairly nonsensical. Would heat and warmth not be synonymous in this sense? Perhaps you could provide a better explanation and source for what you are taking about.

 

 

This is actually a Science Center center attraction. They have 2 coils close to each other that are in the shape of a hand. It looks like a stove burner but in the shape of a hand.

One element is cold to the touch, and the other element is merely warm (not hot).

If you place your hand upon this you will feel as if it is too hot to continue, and yet your hand is not exposed to excessive heat.

http://www.scholarpedia.org/article/Thermal_touch

The sensory system involved in perceiving the changes in skin temperature begins with two kinds of receptor found in the epidermal and dermal layers of the skin known as cold and warm thermoreceptors. These receptors respond similarly to radiant and conducted thermal energy and are involved in the perception of innocuous (harmless) temperatures.

 

mild cooling (25-31 °C) and warming (34-40 °C) of the skin can evoke sensations of burning and stinging as well as innocuous sensations of cold and warmth (Green, 2002)

 

 

I hope that satisfies. I am having a hard time using search terms like "hot and cold", and took an extra 20 minutes on this post because I was having search issues.

Here is a better "nonsensical" (your word) explanation/demonstration/experiment to try...

http://www.questacon.edu.au/outreach/travelling-exhibitions/perception-deception/exhibits/can-temperature-cause-surprising-sensations

@ pzkpfw,

Nice Cartoon. It shows my point quite well.

I am not trying to be rude (some don't know this), but if you right click on the image and "copy location" you can add the comic right into your post using image... (like so)

@ OP,

I cannot see much difference between points, 1,3,5,6,9... A reread and edit might have stopped you repeating the same content.

Let's pretend reincarnation is a possibility.

- Maybe god wants to experience everything from Margaritas to Jet Skiing, and we are all a part of god.

- Maybe your soul is not separate but simply a piece of god.then there could be 100 billion.

- There cannot be recognizable good without evil so Hitlers must be allowed to exist if an interesting world is to exist.

- OP suggested we would be truly dead if we cannot recall our past lives, but that would be assuming time governed this imagined spirit world. What if time did not really exist? How do we know how long a lifetime is to these spirits (if true).

I don't know whether such things are possible, but the reasons you give in the OP do not seem like the best reasons to dump on the notion.

Why not try............

The first adverse argument usually presented is that the advocates of Reincarnation have not established the existence of a "soul" which may reincarnate; nor have they proven its nature, if it does exist.

I see this is your first post so welcome, but I must say I am not quite sure what you are asking.

Chemical Engineers may be required in a variety of settings from simply an office to an ocean bound research vessel. Talk to associate students and discuss their long term goals maybe?

Soil Engineer, refinery, biological and bio-medical engineering, product design and development, and nano-processing, process engineering, consulting, plastics, paint, manufacturing, sugar refining, light metals, risk management are other possibilities.

I even saw one guy switch from Soil Engineering to become a Bylaw enforcement officer which is totally unrelated because he liked the Government position and the similar investigative techniques and travel made him a good candidate.

feeling heat versus feeling something pushing up against you, for example), these have different nerves with dedicated roles

 

Fun Fact: The body has no nerves designed to feel heat. The nerves can detect cold and they can detect warm, but not heat.

The heat sensation comes when something is so hot it can stimulate both the warm and cold receptors at the same time.

(Note: I have had numerous comments about the use of the word heat here. I mean this to be roughly temperatures above 45 degrees, and shoulkd have said HOT not heat. I also think this is a fairly obvious assumption and it is ridiculous I need to clarify this.

@ Zurr,

 

What I want to ask first, is: is it necessary for our immune system to prepare a specific antibody for every kind of intruder? Are there general purpose antibodies that destroy a wide range of different disease vectors?

 

http://en.wikipedia.org/wiki/White_blood_cell

(Is this what you are wanting to see?)

Some of the higher end glues are two part that require you to activate it through mixing. This is not something typically found in a home though unless you have hobbies that include Fiberglass or some such.

@ Dekan,

Does the Earth really need anyone to "look out for it"? It's been doing its own thing, very successfully, for the last 4 billion years.

 

The Earth will be fine as you say, but can it sustain mankind without someone to "look out for it".

Nature has never been so connected with mankind before, and possibly keeping some species of animals around might play a role. I suppose we could ignore things like extinction, Ozone, GW, etc, but that will not help us much.

But I do agree. The Earth does not need any of us. Maybe in a few million years Humans can evolve again?

http://www.whyte.org/bears/mitigate.html

Attempts to reduce the negative effects of roads and railways on bears and other wildlife can be broadly grouped into two categories: structural mitigation and other types of mitigation. Examples of structural mitigation include the use of specially designed, strategically located crossing-structures intended to provide wildlife with access to habitats on either side of busy roadways, and road alignments that minimize destruction of quality habitat. Other types of mitigation that are not directly related to physical structures include managing human-use levels around important wildlife crossing areas, and educating people as to proper behaviour when viewing wildlife along roads or railways. Evaluating the efficacy of these measures, and identifying additional or improved approaches to mitigation is an important focus of current research in the Canadian Rockies.

 

is an example though of us "looking out".

Funny point Dekan, but I'm hoping the OP was speaking of "Life" on Earth.

@ Acme,

Seems to me that no matter what anyone says you will argue.

 

All I did was politely correct someone in post # 7, and I even said I made the same error (to be kind). If you wish to insult my intelligence, then why not do it in a thread where I am in the wrong.

Physics uses math, but is math Physics? is all science Physics? Is the study of Biology Physics (entirely, some of it is)? Etc.

I was being polite and they argue? I will stand up for my opinion, especially if it is factual as in this case. All science is not Physics. Is Evolution science? Is Evolution Physics? Is Archaeology Physics?

All science is not Physics despite what seems to be the consensus among you.

@ charony,

at that age she should not do any experiments that require protective gear.

 

Agreed. I had said...

If in the scenario she is using volatile chemicals or conducting some other dangerous experiments then I would retract my comment about good parenting.

What is the harm in allowing a 6 year old to play dress up in an early occupational "choice". Would you not buy your kid a fake Stethoscope if the showed interest in being a doctor, or an apron and toy hammer if the child was wanting to do construction.

 

I would discourage using them outside of these situations, especially if there is a chance that she may want to become a student in an actual lab at some point. If she is used to wear them for fun it may put her in the wrong mindset. [bold is mine for emphasis]

 

I have three children, and I see NO DANGER in having a 6 year old wear a kids lab coat. So what mindset are you trying to teach? Science is not fun? Where's the fun in that?

Just to clarify, dressing up for a Halloween shot, certainly, but dressing up on a more constant basis, potentially not such a good idea.

 

So where would that rank as child abuse on a scale of 1 to 10?

Dang! Let them be kids...

@ Strange,

But these are not "random" explorations. They are based on scientific hypotheses ("if there was water/life/atmosphere in the past then we would see x/y/z"); in other words, predictions of what would be found if the hyopthesis were true. Then instruments are built to test these predictions.

 

So you are proposing simply observing something is not scientific? That seems like a Unique view. Points for originality.

Science a word that derived from the word knowledge, and I believe observation alone has a place in it, but there might be various definitions. Find one that agrees with you, and I'll find one that agrees with me.

@ last two posts,

I had considered the notion Physics could be considered all science. The OP was discussing the world and not Math, Biology, Geology, Zoology, or whatever.

I suppose we could ignore them.

I don't see why people here are taking offense I pointed out a simple error (and it was). Physics does not encompass everything in science.

I suppose you could argue Chemistry is physics, and Biology is part Chemistry so it can be related.

I think there is more to the body than Chemistry though. Various organs and such require study.

Oh well. No matter what I say here I am expecting someone is "smarter", and will explain how everything in the Universe is Physics.

Is Math Science? Is Math Physics? I do not mind being enlightened.

@ ZVBXRPL

Motion is the result of energy transferring from one location to another and not as a result of matter transferring location

Motion is not matter moving through a medium with that medium being empty space

Motion is energy moving as a wave through a medium with that medium being the continuum of matter

 

Just ignore if this is off base, but in your construct does motion make matter. I read a Theory that sounded similar where the Author suggested a Spider Web could cut a diamond if it was moving fast enough, and the idea behind it is that we are in constant motion, and that motion creates matter.

It sounded similar enough I thought I'd refer you to it if it is what you are trying to say.

@ ajb,

I would say that physics is about

 

Eloquent answer, but you are answering the wrong question. The thread is about a Science definition, not just Physics.

I was confused at first because Physical is a part of the name and we all speed read somewhat..

@ Dirk,

My apologies. I had not seen your free offer.

Some publishers allow you to gift books without touching the price. I do not have time at the moment as I'm being dragged to some movie about Apes taking over the world, but I enjoy a good evolution thriller and I am an Engineer.

Normally science texts have limited appeal so prices are at least 100 times what you have now.

I found this paper,

@ OP,

What are the reasons that laws of nature doesn't change

 

They wouldn't be laws if they could be changed.

I am wondering if perhaps randomness does not work well in nature. Is there anything random in nature? This is more of a rephrasing of the question in the Opening post.

I cannot think of randomness in nature except maybe in behavioral studies.

80% of everything a person learns is before the age of 5. This includes social behaviors.

I started two of my three children in school when they were 3 months old, and they are both smart leaders among their peers. I recommend early education. Socialize your infants.

When my kids hit kindergarten and grade one they were like, "why are you crying, your mom will come back for you?" to all the terrified youngsters who have never left their mommas side.

Japan starts school at a younger age than most of us. I think school should start at birth.