Black box
A black box, in science and engineering, is a box whose inside working is not known.
It is a device, system or object with input and output. There is no knowledge of its internal workings.[1] The way it works is "opaque" (black). Almost anything might be referred to as a black box: a transistor, an algorithm, or the human brain.
Ashby expains that the term arose when a decision had to be made about opening an engineering box. The question was whether to return the box for repair, or just scrap it. Could this be decided without opening the box? There can be many reasons why a complex system cannot be repaired in the field, and even opening up some systems is a big deal. The question also comes up in surgery on brain damage patients. The more that can be discovered before operating, the better.[1]p86
The opposite of a black box is a system where the inner components or logic can be seen. It is sometimes known as a clear box, a glass box, or a white box.
Black Box Media
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Converting Blackbox3D-withGraphs.svg to /var/www/html/w/images/temp/transform_1d5346b2151d.png ... org.w3c.dom.DOMException: file:/var/www/html/w/images/temp/svg_839ef3c777809098580e4670/Blackbox3D-withGraphs.svg: The attribute "fill" represents an invalid CSS value ("context-stroke"). Original message: The "context-stroke" identifier is not a valid value for the "fill" property. at org.apache.batik.css.engine.CSSEngine.getCascadedStyleMap(CSSEngine.java:775) at org.apache.batik.css.engine.CSSEngine.getComputedStyle(CSSEngine.java:867) at org.apache.batik.bridge.CSSUtilities.getComputedStyle(CSSUtilities.java:81) at org.apache.batik.bridge.CSSUtilities.convertDisplay(CSSUtilities.java:563) at org.apache.batik.bridge.AbstractGraphicsNodeBridge.getDisplay(AbstractGraphicsNodeBridge.java:158) at org.apache.batik.bridge.GVTBuilder.build(GVTBuilder.java:134) at org.apache.batik.bridge.SVGMarkerElementBridge.createMarker(SVGMarkerElementBridge.java:83) at org.apache.batik.bridge.PaintServer.convertMarker(PaintServer.java:137) at org.apache.batik.bridge.PaintServer.convertMarkers(PaintServer.java:98) at org.apache.batik.bridge.SVGDecoratedShapeElementBridge.createMarkerPainter(SVGDecoratedShapeElementBridge.java:67) at org.apache.batik.bridge.SVGDecoratedShapeElementBridge.createShapePainter(SVGDecoratedShapeElementBridge.java:86) at org.apache.batik.bridge.SVGShapeElementBridge.buildGraphicsNode(SVGShapeElementBridge.java:91) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:224) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:219) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:219) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.build(GVTBuilder.java:82) at org.apache.batik.transcoder.SVGAbstractTranscoder.transcode(SVGAbstractTranscoder.java:210) at org.apache.batik.transcoder.image.ImageTranscoder.transcode(ImageTranscoder.java:92) at org.apache.batik.transcoder.XMLAbstractTranscoder.transcode(XMLAbstractTranscoder.java:142) at org.apache.batik.transcoder.SVGAbstractTranscoder.transcode(SVGAbstractTranscoder.java:158) at org.apache.batik.apps.rasterizer.SVGConverter.transcode(SVGConverter.java:1008) at org.apache.batik.apps.rasterizer.SVGConverter.execute(SVGConverter.java:719) at org.apache.batik.apps.rasterizer.Main.execute(Main.java:956) at org.apache.batik.apps.rasterizer.Main.main(Main.java:1009) ERROR: null Enclosed Exception: file:/var/www/html/w/images/temp/svg_839ef3c777809098580e4670/Blackbox3D-withGraphs.svg: The attribute "fill" represents an invalid CSS value ("context-stroke"). Original message: The "context-stroke" identifier is not a valid value for the "fill" property. org.w3c.dom.DOMException: file:/var/www/html/w/images/temp/svg_839ef3c777809098580e4670/Blackbox3D-withGraphs.svg: The attribute "stroke" represents an invalid CSS value ("context-stroke"). Original message: The "context-stroke" identifier is not a valid value for the "stroke" property. at org.apache.batik.css.engine.CSSEngine.getCascadedStyleMap(CSSEngine.java:775) at org.apache.batik.css.engine.CSSEngine.getComputedStyle(CSSEngine.java:867) at org.apache.batik.bridge.CSSUtilities.getComputedStyle(CSSUtilities.java:81) at org.apache.batik.bridge.CSSUtilities.convertDisplay(CSSUtilities.java:563) at org.apache.batik.bridge.AbstractGraphicsNodeBridge.getDisplay(AbstractGraphicsNodeBridge.java:158) at org.apache.batik.bridge.GVTBuilder.build(GVTBuilder.java:134) at org.apache.batik.bridge.SVGMarkerElementBridge.createMarker(SVGMarkerElementBridge.java:83) at org.apache.batik.bridge.PaintServer.convertMarker(PaintServer.java:137) at org.apache.batik.bridge.PaintServer.convertMarkers(PaintServer.java:98) at org.apache.batik.bridge.SVGDecoratedShapeElementBridge.createMarkerPainter(SVGDecoratedShapeElementBridge.java:67) at org.apache.batik.bridge.SVGDecoratedShapeElementBridge.createShapePainter(SVGDecoratedShapeElementBridge.java:86) at org.apache.batik.bridge.SVGShapeElementBridge.buildGraphicsNode(SVGShapeElementBridge.java:91) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:224) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:219) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:219) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.build(GVTBuilder.java:82) at org.apache.batik.transcoder.SVGAbstractTranscoder.transcode(SVGAbstractTranscoder.java:210) at org.apache.batik.transcoder.image.ImageTranscoder.transcode(ImageTranscoder.java:92) at org.apache.batik.transcoder.XMLAbstractTranscoder.transcode(XMLAbstractTranscoder.java:142) at org.apache.batik.transcoder.SVGAbstractTranscoder.transcode(SVGAbstractTranscoder.java:158) at org.apache.batik.apps.rasterizer.SVGConverter.transcode(SVGConverter.java:1008) at org.apache.batik.apps.rasterizer.SVGConverter.execute(SVGConverter.java:719) at org.apache.batik.apps.rasterizer.Main.execute(Main.java:956) at org.apache.batik.apps.rasterizer.Main.main(Main.java:1009) ERROR: null Enclosed Exception: file:/var/www/html/w/images/temp/svg_839ef3c777809098580e4670/Blackbox3D-withGraphs.svg: The attribute "stroke" represents an invalid CSS value ("context-stroke"). Original message: The "context-stroke" identifier is not a valid value for the "stroke" property. org.apache.batik.transcoder.TranscoderException: null Enclosed Exception: For input string: "auto-start-reverse" at org.apache.batik.transcoder.SVGAbstractTranscoder.transcode(SVGAbstractTranscoder.java:228) at org.apache.batik.transcoder.image.ImageTranscoder.transcode(ImageTranscoder.java:92) at org.apache.batik.transcoder.XMLAbstractTranscoder.transcode(XMLAbstractTranscoder.java:142) at org.apache.batik.transcoder.SVGAbstractTranscoder.transcode(SVGAbstractTranscoder.java:158) at org.apache.batik.apps.rasterizer.SVGConverter.transcode(SVGConverter.java:1008) at org.apache.batik.apps.rasterizer.SVGConverter.execute(SVGConverter.java:719) at org.apache.batik.apps.rasterizer.Main.execute(Main.java:956) at org.apache.batik.apps.rasterizer.Main.main(Main.java:1009) Caused by: org.apache.batik.bridge.BridgeException: For input string: "auto-start-reverse" at org.apache.batik.bridge.SVGMarkerElementBridge.createMarker(SVGMarkerElementBridge.java:134) at org.apache.batik.bridge.PaintServer.convertMarker(PaintServer.java:137) at org.apache.batik.bridge.PaintServer.convertMarkers(PaintServer.java:98) at org.apache.batik.bridge.SVGDecoratedShapeElementBridge.createMarkerPainter(SVGDecoratedShapeElementBridge.java:67) at org.apache.batik.bridge.SVGDecoratedShapeElementBridge.createShapePainter(SVGDecoratedShapeElementBridge.java:86) at org.apache.batik.bridge.SVGShapeElementBridge.buildGraphicsNode(SVGShapeElementBridge.java:91) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:224) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:219) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.buildGraphicsNode(GVTBuilder.java:219) at org.apache.batik.bridge.GVTBuilder.buildComposite(GVTBuilder.java:171) at org.apache.batik.bridge.GVTBuilder.build(GVTBuilder.java:82) at org.apache.batik.transcoder.SVGAbstractTranscoder.transcode(SVGAbstractTranscoder.java:210) ... 7 more ... error (SVGConverter.error.while.rasterizing.file)
A black box model can be used to describe the outputs of systems.
The open systems theory is the foundation of black box theory. Both have focus on input and output flows, representing exchanges with the surroundings.
The observed hydrograph is a graphic of the response of a watershed (a blackbox) with its runoff (red) to an input of rainfall (blue).
When the observer (an agent) can also do some stimulus (input), the relation with the black box is not only an observation, but an experiment.
