Shadowing Practice: Philosophy of Science Lecture #2: Verificationism - Learn English Speaking with Video

בחר מצב תרגול

כל מצב פותח חדר תרגול במסך מלא.

516 משפטים

אם המשפטים קצרים או ארוכים מדי, לחץ על ערוך כדי להתאים אותם.

Thank you.

A lot of people have felt that the distinguishing thing about science

that makes it so special and cuts it off from other ways of examining the world is the method that science uses, some characteristic rigorous method

that ensures the accuracy of its conclusions better at least than do the methods in other areas of inquiry.

One very influential way of characterizing scientific method is in terms of its use of observation,

especially experimental test.

Now, while experiments are easier in some sciences than in others, nonetheless, the whole idea that theories should be testable,

that theories should be observable, that has been extraordinarily influential in the history of science.

Today, we're going to look at one popular and historically influential view about science's method called verificationism.

The man who invented the name positivism in the middle of the 19th century was August Comte.

It's spelled like August, except it's got an E on the end, just like the month.

And his interest was to banish metaphysics.

He thought that metaphysics had been the bane of all intellectual work that had gone before the 19th century,

and that the developments of science in the 17th century and in the 18th century, and then also through the first part of the 19th century,

had shown that the proper way to undertake an understanding of the world is science.

And I guess he meant by that something like rigor.

Now, he presumably had some sort of notion about what scientific method was since he meant to banish all other methods, calling them all metaphysical.

But in particular, he thought that all theological modes of reasoning ought to be kicked out.

These were misleading, led only to false conclusions, and hurt people.

So what he hoped for was a new dedication of society to science.

He believed on what we might now call sociological grounds that societies needed to have things like religions,

and so what he wanted to do was to replace all the organized and standard religions with the worship, if you like, of science.

Now that's sort of an interesting concept, I suppose.

He also felt that all areas of inquiry should be radically reformed to reflect this scientific bias,

or the scientific inclination, let's say.

He wouldn't have said bias, I think.

But that was his view, and positivism was widely regarded.

Just because science had been so successful, it was almost a cult among intellectuals for a while, the whole notion of positivism.

Again, meaning at that time, kicking out metaphysics, which was thought to be speculative and old.

As a matter of fact, you get analyses from people.

They talk about the religious mode of reasoning as being antiquated

and sort of located in tribes and maybe in the dim and dark history of Western civilization.

And then there's the metaphysical modes of reasoning.

which are sort of philosophical, they're kind of superior to theological modes of reasoning,

religious modes of reasoning, but the metaphysical modes of reasoning ought to be surpassed themselves by scientific modes of reasoning.

So the new future of society is going to be scientific, as far as Comte and his followers were concerned.

Now, his followers were not some small cult.

Does the name Ernst Mach ring a bell?

You nod yes.

Who is he?

He just rings a bell.

Does anybody know who Ernst Mach is?

He is a German scientist.

Does anyone know in what field?

Pardon?

Physics, generally.

Mechanics.

He wrote a book called Die Mechanique.

Why does the name Mach ring a bell?

I'm sure that a lot of you don't know anything about the history of science.

Mach 1, Mach 2, Mach 3.

That's the speed of sound.

Mach 1 is the speed of sound

and his name is now attached to the measure for the speed of sound in an airplane to travel twice

or three times, the speed of sound is said to travel at Mach 2 and Mach 3.

And that label owes its name to Ernst Mach.

He was a very influential German physicist, but he was a positivist.

He thought that metaphysics should be banned.

And what that meant to him, for example, in the 19th century, along with lots of other scientists who were right at the cutting edge of chemistry and physics,

and who are building what we now call the atomic theory of matter.

What that meant to them, to the positivists in that crowd, was that the atomic theory of matter should not be taken seriously as a characterization of reality.

What they said about it, Ernst Mock in particular and other positivists among the physicists, was these are all clever calculation devices, if you like.

These theories offer us a means.

We're going to return to this later when we talk about instrumentalism in science.

I just want to note this right here.

He said we should not take seriously the idea that there really are atoms out there that make up molecules.

These things are unobservable.

You can't see them.

Nonetheless, that doesn't mean we have to kick out the theory.

The theory is a nice device for organizing data, if you like.

It's a nice device for organizing data.

It's sort of like a filing system.

A theory allows us to assign certain variables to talk about, it's a language, it allows us to talk about phenomena in a certain way,

but we shouldn't get metaphysical about it.

We shouldn't think that just because the theory is useful in some way that there really are these things called atoms, I mean that would be ludicrous,

and so that's the kind of attitude

that i hope to characterize here is you know i want

you to understand is instead of 19th century positive hoping for not

and positive uh it's a sort of an unusual usage of the term

but what they meant by the reason they were talking about positivism is

because they were tired of what they took to be speculative

uh attempts to explain nature what they wanted was down to earth

verifiable that's the first time you've heard that word verifiable statements about the physical world.

And when you start talking about things that are not observable, then you're talking about things that are not verifiable.

You're starting to start getting spooky here, you're getting philosophical, metaphysical, and this is to be resistant.

In the middle of the 19th century, it still probably seems that they had only very recently managed to free,

to It will liberate science from the speculative character that it has had before the 17th century, say.

And I think that a lot of them, when they started looking at theories like the atomic theory, which began to postulate these that you couldn't see,

you couldn't taste, you couldn't feel, it sure did look like that old metaphysical stuff coming back in.

It looked like impetus.

It looked like natural places, the kinds of things that I mentioned Aristotle used to talk about that really didn't look scientifically.

And so movement sprang up, the sort of vanity.

That was 19th century positive.

So positivism is to be equated with testability.

What different positivists said And testability was the criterion of, that's going to vary from theory to theory.

But what we're going to start off with is a hardcore version.

And we're then going to go to a foster core version, positive version.

Actually, we're going to, this is going to all be part of something called verification

100

because there's another branch of positive version that we'll talk about next time.

101

We'll talk about these today.

102

So, next time we'll talk about falsification.

103

It also expresses...

104

the importance of tests, but in a different sort of way.

105

Now, so positivism generally, all these theories we're going to discuss this time and next time,

106

is marked by its emphasis on tests, on observability, at least observability in principle,

107

and it's also positivism always emphasized the the deployment of tests in as experimental tests of theory

108

and try to talk about the logic of the relationship between theory and tests now

109

what goes what I'm calling the hardcore hardcore verification ism is associated with what with the verifiability criterion of meaning.

110

And the verifiability criterion of meaning says quite plainly and simply, if something, you choose what?

111

If proposition, sentence, theory, whatever, belief, if it's to have any meaning at all,

112

it must be verifiable, right?

113

Now, this is a very strong criterion.

114

That's why I call it hardcore core.

115

This is a criterion of meaningfulness.

116

In other words, what they're saying is anything that's not verifiable, and they've got metaphysics in the back of their mind, they've got any theory like the atomic theory that,

117

as far as you can tell, isn't verifiable.

118

Now, it's open to question whether it is or it isn't, but Mach didn't think it was.

119

It's certainly true.

120

They're talking about all religious theories that talk about gods that can't be seen, heard, felt, tasted, or whatever.

121

These are not just false.

122

I mean, they're not even good enough to be false or true.

123

They're meaningless.

124

I mean, if you say, are there gods or not, what the hardcore verificationist is going to say is that question isn't even good enough to be true or false.

125

I mean, I can't even tell you it's false.

126

It's just a meaningless question.

127

It's gibberish.

128

It's garbage.

129

It's not that you have to have verified it in fact.

130

There are things that are going on outside the solar system

131

or even on the dark side of the moon that you can make perfectly meaningful propositions about,

132

according to the hardcore verificationists.

133

You can make perfectly reasonable propositions about these things that are perfectly meaningful, provided that you have at least some idea of how one might verify it.

134

It doesn't even have to be technologically possible, but if you can say, well, all right, what I mean by saying

135

that there are things going on on the dark side of the moon is

136

that if someone were there or if some mechanism were there that could make suitable recordings, it would record suitable things.

137

You know, like it might take pictures, or it might make sounds, or it might record, if you're saying there's earthquakes on the dark side of the moon, even though there are no seismographs up there,

138

all you have to do is be able to specify what

139

sort of thing in principle would count as the kind of observation that would distinguish between the truth and falsity of that.

140

All you have to do is be able to say, well, if we did have a seismograph up there, then what my sentence comes down to is that it would be registering something other than the norm.

141

So all I mean is that you should, in order for the sentence to be meaningful, you should be able to specify what sort of thing would count as a verification of it,

142

and what you assert when you assert the thing is that you would observe x if you had the suitable equipment.

143

What this is just supposed to do is show that they're not being totally unreasonable when they try and banish metaphysics.

144

They just want to banish things that don't make any difference.

145

So that, for example, if I were to tell you that back there in that corner, everyone look, please, back there in that corner just below the clock is a six -foot -tall undetectable bunny.

146

And I say it's undetectable.

147

I mean it is absolutely undetectable.

148

There's no way at all to detect that.

149

There's no way to determine whether that's true or false.

150

There's no way to verify it.

151

Well, the positivist would say, well, it's all very nice.

152

but, you know, if it's in principle unverifiable, it's meaningless.

153

You've made no proposition whatsoever.

154

Now, if I said you can't see it, but indeed here are some tests you could perform.

155

I mean, you could put a carrot over here and it would be gone after 20 minutes.

156

Verification would say, ah, well, maybe that's not so meaningless after all.

157

At least you've offered us some potential observation that could be made that would tend to verify your assertion.

158

But now, if we've got two propositions, two different propositions that would equally well explain the missing carrot,

159

one of them, you know, the big six -foot -tall otherwise undetectable rabbit,

160

two, maybe there's somebody that likes carrots and they're sitting over there nibbling in the back of the room,

161

well, the positivist has some definite thoughts about which one we should prefer.

162

It's the one that requires less of an extension of our normal testing procedures and requires less imagination and speculation.

163

Gods, I think the hardcore verifications probably thought they'd banish most or all gods altogether by this criterion, but I suppose if there are some,

164

you know, some people would claim that, no, I mean, you know, God is not somebody who, or something that is undetectable.

165

I mean, you can see God's, you see evidence of God in all sorts of things.

166

The verificationist wouldn't say that that's meaningless, but would point out that there are other ways of explaining, you know, would say that there are other ways of explaining the same things

167

that God supposedly explains that do not require this extra hypothesis so that the hypotheses of physics,

168

for example, and the physics plus evolutionary biology say,

169

and the hypotheses of God are empirically equivalent if they explain the same data.

170

And what we should do is to prefer the more parsimonious one.

171

This is called Occam's razor.

172

We should prefer the one that requires us to postulate fewer unusual, or in this case, supernatural sorts of things.

173

Now, what it does banish is any divinity that is absolutely 100 % unverifiable, undetectable, unobservable.

174

And what the verificationist wanted to say is not just,

175

well, let's focus our attention here on a class of statements that are exceptionally interesting from the point of view of science,

176

namely the ones that are observable or have observable consequences is they wanted to say,

177

no proposition that is unverifiable is even meaningful.

178

That was a very bold, it was anti -metaphysics.

179

They want to say metaphysics is meaningless because unverifiable.

180

And in a way, they defined metaphysics as that which is unverifiable.

181

Remember what Mach says about atoms.

182

He says, look, I mean, well, it might be a useful device for some purposes, but we shouldn't take seriously the idea that these things exist. And B .F.

183

Skinner would say, this is quite apart from other things that Skinner might say, but he would say, there's nothing wrong with a mentalistic,

184

to say that I have a feeling or that I have a mind, if you're just kind of informally speaking.

185

He said, my mind tells me this, or I have a certain feeling.

186

That's a perfectly decent expression, according to Skitter.

187

But we don't have things called feelings that are somehow stored in there.

188

No, we feel.

189

It's an activity.

190

It's a process.

191

It's not a thing we have.

192

And we've got to be careful about the implications of these modes of speaking.

193

Well, this is precisely what the positives want to say.

194

These modes of speaking might be very, very useful for certain purposes.

195

But beware if you suddenly become committed to little things called atoms or electrons or quarks.

196

I mean, you can't see these things.

197

You can't even in principle see these things.

198

The argument about whether atoms even had structure is, you know, centuries old.

199

And the argument about whether electricity is to be understood as a particle -like

200

or wave -like phenomenon is still kind of weird to this day.

201

So whether these little things called particles, the electron is supposed to be the particle that bears the negative electric charge,

202

it's still kind of dubious how you're supposed to talk about those things.

203

There's a nice mathematical language, but what English words to use to describe these phenomena is not at all clear.

204

And what the positivists in any era would say is these mathematical languages do not abandon them.

205

But remember, they're just notation devices.

206

They're calculation devices.

207

They help us get from data to data.

208

We've got some input data.

209

We plug them into our equations.

210

And these equations allow us to make accurate predictions about what observables.

211

And that's all that counts is that we're able to make accurate predictions about what will happen in an experimental setting.

212

So you might want to say, we observe an electron.

213

It doesn't matter.

214

Forget about the electron.

215

The electron is just a convenient device to predict

216

that under certain circumstances we will hear a click on

217

that Geiger counter or that we will see a cloud trace in

218

that Wilson cloud chamber or that we will get a certain result on the oil drop experiment.

219

That's what's really going on here, according to the positivists.

220

Our theories are mere calculation devices.

221

We shouldn't take them seriously as talking about things in the external world.

222

And the criterion for meaningfulness is verifiability.

223

If a sentence or proposition, whether scientific or not, if it's not verifiable,

224

If there's no way that you can even say how we should go about demonstrating the proposition to be true, well then, it's not meaningful.

225

And I want to return to the remark made up there, and then we'll get into another brand of verificationism, the soft core, because it was the hardcore verificationists,

226

to their credit, that one day opened up their eyes and said, whoop.

227

They said, uh -oh.

228

And it involved the verificationist criterion of meaning itself.

229

The verifiability criterion of meaning says what?

230

It says a proposition is meaningful only if it is verifiable, otherwise meaningless.

231

Now, what kind of thing would it be to verify that?

232

I mean, how would you demonstrate it to be true?

233

It's not the sort of thing that you could demonstrate to be true.

234

It's sort of like a suggested norm.

235

It's saying, what it says tacitly is, we should no longer take seriously things.

236

It's a should statement, right?

237

It says we should steer clear of metaphysics.

238

We should not take seriously any metaphysical propositions.

239

We should only attend to verifiable propositions.

240

It's a norm.

241

It's not verifiable.

242

Well, if not verifiable, then what on the verifiability criterion of meaning?

243

Gibberish.

244

Meaningless gibberish.

245

So they said, whoop, and they fell back with a variety of different sorts of reactions.

246

Fell back to the soft core position, which involves not a verifiability criterion of meaning,

247

but instead the verifiability criterion of demarcation.

248

Those words we're going to have to talk about, and we will.

249

But first, one more question.

250

Yes?

251

What if you had a theory that was not verifiable at a present time?

252

If you mean is not verifiable because we lack the technology,

253

then that doesn't stand in the way of its being meaningful even on the hardcore theory, even on the verifiability criteria of meaning.

254

All that's required is that there be some way in principle, not in fact, that you could specify,

255

like, for example, having a seismograph on the dark side of the moon, something that you could explain what you meant,

256

what you would expect to find out if you performed the relevant tests.

257

Tell us what the relevant tests would be.

258

Like you could say, I think there's a giant zebra behind Pluto

259

that always stays back there and we can never see it.

260

That can be as meaningful as you please.

261

I mean, false in their view, but that's as meaningful as you please if what you mean is, well, if we had a spaceship and went around back there, there'd be this big, giant zebra.

262

I mean, if that's what you, that's fine.

263

That makes it meaningful.

264

The problem is when you say, I think there are some things that are just absolutely undetectable.

265

They'll say, well, think away, but what could you possibly be talking about?

266

What could you possibly mean?

267

in saying that there are things that couldn't possibly be detected by sight,

268

sound, any means, no machinery, no mechanism could possibly detect it?

269

What could you possibly mean?

270

I don't know how close this is or not.

271

Just in saying that, it struck me as bearing a resemblance to the following thesis, which I think is at least plausible.

272

And that's that there's nothing you could say that doesn't try to,

273

no description that you can offer that doesn't try to bring the thing described under known categories.

274

Like if I try to describe something that's strange or unusual, I will try and tell you what it's like.

275

And what I'm doing there is trying to show you what sort of thing to expect, even though I'm telling you it's strange and unusual, it's different.

276

It's kind of like this in that respect.

277

It's kind of like that in the other respect.

278

I think what the verificationists were grappling with was something like that idea, except they wanted to make it a little bit, they wanted to pin it down a little bit better than that.

279

So what they said was, you need to specify not just what kind of thing it is,

280

but to specify which steps you'd have to take in order to test what you just said.

281

That will establish what it means.

282

Now then, to perform the tests, we'll decide whether the sentence is true or false.

283

Like what the sentence, according to the verification, the hardcore ones, what the sentence about

284

that zebra floating out there in space means has something to do with what sorts of things would happen

285

if you were on a ship out there, an observing probe out there.

286

To specify which readings you'll get, what images you'll get, what pictures you'll get,

287

that exhausts the meaning of the sentence.

288

You will see something with stripes rather than something without stripes.

289

That's why we say it's a zebra.

290

That's what it means to say it's a zebra.

291

It will look sort of horse -like.

292

That's what it means to say.

293

That's another part of saying it's a zebra rather than a skunk.

294

And it will be very, very large, much larger than the normal horse.

295

That's what it means to say it's a giant, right?

296

Et cetera, et cetera.

297

And the way we flesh out, for the hardcore verificationist, the way we flesh out the meaning of any sentence at all, it doesn't have to be scientific,

298

is in terms of what would happen if we did that.

299

That's operationalizing it.

300

That shows you how you would perform, how you would investigate it, and what you would expect to get.

301

Now, let's get in a ship and go out there on the other side of Pluto and look, hot -nosed zebra.

302

Now, sentence turns out to be false, but it can't even be false or true until it is meaningful, unless it's meaningful.

303

Again, the simple question was, what about stuff we can't now verify, but we manage to verify it later?

304

No problem.

305

It's meaningful all the way through, as long as you could say what sort of things would have to be done to verify it, even though we can't.

306

An example, a case in point, and this is the sort of thing that the verificationists, whether hardcore or softcore, love of.

307

Albert Einstein proposed the general theory of relativity in 1916.

308

It's an extraordinarily abstract and difficult theory.

309

And it was proposed not in order to explain any known anomalies

310

or problems or any kinds of experiments that no one could explain.

311

That wasn't the problem at all.

312

The reason it was proposed is to offer a better organization or synthesis of physics.

313

I'll try and explain that a little later.

314

So right then in 1916, when it was proposed, there weren't any experiments that were especially well confirmed by that.

315

And Einstein and others who were sort of interested in theory had to try

316

and think of what kind of experiment could be performed that would verify the theory.

317

And it wasn't real easy to do.

318

Einstein himself thought up of at least one, and I don't know whether he thought up the other two, but for the longest time, right up into the 50s,

319

I think, there were only about three known ways to verify the theory.

320

And in 1916 in particular, the one way that seemed likely to be easiest to verify, it couldn't be done for practical reasons.

321

There was a war going on.

322

So it wasn't until 1919 that the observation was performed.

323

And when it was performed, it seemed to verify the general theory of relativity.

324

But in those intervening years, the theory wasn't meaningless, according to positivists.

325

It's just that Einstein had proposed how to test the theory, thereby establishing its meaningfulness.

326

He said, if you perform such and such an experiment, if my theory is right, you'll see this.

327

If my theory is wrong, you should see that.

328

And that's sufficient to establish its meaningfulness, even though the tests had not yet been performed.

329

But of course, we've got a problem.

330

Let us see what they did.

331

I've suggested that what they've done is to go from the hardcore verifiability or verificationism to soft -core verificationism.

332

And in this, they adopt, rather than a criterion of meaning, a criterion of demarcation.

333

Now, the whole idea of a criterion of demarcation was actually introduced, I mean, that expression, criterion of demarcation, was actually introduced later by Karl Popper,

334

who we're going to talk about next time.

335

But the general idea is this.

336

What we want to know is what's the difference between science and non -science?

337

What is the demarcation line?

338

What divides science from pseudoscience?

339

The way Popper explained it, or actually I should be careful here.

340

His student, Imre Lakatos, explained it this way.

341

He was telling this story about Popper.

342

Now I'm taking Lakatos to know what Popper went through.

343

But the idea was this.

344

Back in the teens, 1916, 17, 18, 19, 20, when Popper was going to school in Vienna,

345

Vienna was an extraordinarily booming place.

346

I mean, everything was going on there.

347

First of all, it just left the Austro -Hungarian Empire, which was just on the verge of collapse because of World War II,

348

but it had been collapsing for some time, probably for 15 years.

349

The war will be the end of it.

350

So in much the same way as the Soviet Empire is collapsing right now, at that particular time, the Austro -Hungarian Empire was collapsing.

351

Now, what's interesting is that as the Austro -Hungarian Empire collapsed, an empire

352

which had preached the evils of socialism for all of its

353

days since Karl Marx had written in the middle of the century,

354

the fact that the powers were collapsing meant that everyone felt free to move into this previously forbidden area.

355

Karl Marx's scientific socialism, his scientific approach to why it is that societies change.

356

They change because of the changing material conditions of production.

357

They change because, in the end, of economic forces that are out of the control of revolutionaries, out of the control of state leaders.

358

They just are facts that leaders and ideologues will just have to deal with.

359

I mean, Marx was extraordinarily impatient with ideology and revolutionaries who would try to inflict ideology on history.

360

History guides itself by facts.

361

And so this was scientific socialism, and this was just all the rage in Vienna.

362

At the same time, there was new architecture that was springing up in Vienna, new art forms, brand new sorts of music.

363

Freud, Sigmund Freud was in Vienna, and physics was in Vienna.

364

I mean, some of the great discoveries were going on in Berlin, but it was in Central Europe in Germany and in Austria,

365

where some of the great work was being done in physics in those years.

366

And Popper was being educated at that time.

367

And so Popper said to himself,

368

how is it that I am not as impressed with such supposedly scientific theories as Marx's or Freud's,

369

for that matter, as I am with Einstein's?

370

I mean, just to take an example, here are several, I mean, what Freud was doing, for example,

371

was offering what was billed at the time as the first scientific theory,

372

first scientific interpretation of human behavior, of human psychology.

373

And so all the intellectuals were flocking.

374

And again, there's this influence of positivism that says everything scientific is good.

375

And so what Popper says is, well, I do like science, but what is it that makes me suspicious about these things like Marxism and its claim to be scientific,

376

or Freudianism and its claim to be scientific?

377

And while at the same time I seem to find that I'm a believer in the scientific character anyway, of the general theory of relativity.

378

Even though it hasn't been tested yet, it's plainly a scientific theory.

379

And even though it may be wrong, it's clearly a scientific theory.

380

So he's not talking about what's right and what's wrong.

381

He even said, you know, he was kind of sympathetic to Marxism.

382

He was sympathetic to Freudianism.

383

But he did not think of them as scientific theories.

384

What's the difference?

385

How come Darwinian or Mendelian genetics and Darwinian evolutionary theory, how come they seemed scientific, he wanted to know.

386

But these other things don't.

387

What is the criterion I'm using?

388

There's some criterion I'm using to distinguish science from pseudoscience, to put it baldly.

389

Now, Popper's the one that, now that was when he was in school, and later in the 30s, he offered an alternative to the verifiability criterion of demarcation that we're going to discuss now.

390

But the verifiability criterion of demarcation goes like this.

391

It says, verifiability is not the necessary condition of meaningfulness.

392

Things can be meaningful even though they're not verifiable, like, for example, this sentence, that very sentence.

393

Things can be meaningful even though they're not verifiable.

394

However, in order to be scientific, ethic, a sentence must be verifiable.

395

Scientists, said the soft core verificationists,

396

scientists are concerned only with propositions,

397

sentences, beliefs, assertions that are in principle verifiable, etc., etc., etc. So it's a softening of the position.

398

It's no longer a criterion of meaningfulness, it's a criterion of demarcation.

399

And it's here that they would point to theories that are extraordinarily abstract,

400

like Einstein's, and explain what the difference is between Einstein's theory of general relativity,

401

for example, and some other theory like, well, any arbitrary philosophical theory, Plato's theory of forms, say,

402

which you may or may not know about, or Descartes' theory about mind and matter,

403

the bifurcation of the human being into a material and the mental realm.

404

The soft core verification has said the problem with those theories is not that they're meaningless, it's the fact that they're not verifiable,

405

there's nothing you could do to verify one of those theories, just shows that it's not scientific.

406

And so if you're, you know, if you want to do metaphysics, that's fine.

407

It wasn't for the hard core verification.

408

It's the soft core verification.

409

Well, you know, if you want to do metaphysics, that's okay.

410

It might even be useful, helpful, illuminating in some way, but it's not science.

411

If you want to get down to science, then that's when we should stick to these verifiable propositions.

412

Take, for example, Einstein's general theory of relativity.

413

Now, the point, the reason that Einstein was moved to seek

414

and to try to work out the general theory of relativity was because of a fact about the special theory of relativity.

415

It was incomplete.

416

I mean, he knew it was incomplete at the time.

417

What he was trying to do was to formulate the laws of physics.

418

This is what he was trying to do in the special theory of relativity so that they would remain the same.

419

He would get the same formulation of the laws of physics,

420

whether you were on an object that was stationary or whether it was in motion with respect to some arbitrary reference frame.

421

He'd wanted to sort of simplify the laws of physics

422

so they would come out the same from any so -called inertial frame of reference,

423

that is, frames of reference that were either at rest with respect to one another or in uniform motion,

424

uniformly motion with respect to one another.

425

Not, in particular, the special theory of relativity did not formulate the laws of physics in such a way

426

so that they would come out the same on an object that was accelerating with respect to another frame of reference.

427

So that, for example, the laws of physics would have to be formulated differently on an object that was rotating another object, like the Earth around the Sun,

428

than it would from the point of view of the Sun.

429

Now, this was an embarrassment.

430

I mean, not an embarrassment, but this was an incompleteness in the special theory of relativity that needed correcting.

431

And so what Einstein spent time doing is trying to figure out just how to reformulate the laws of physics

432

so that they were completely general.

433

so that they would appear to be the same no matter whether you were on a, you know, just take an arbitrary frame of reference like the center of the sun,

434

they would be completely the same whether you were at the center of the sun, of course you'd be pretty warm there, or whether you were at rest with respect to the center of the sun,

435

or whether you were moving in uniform linear velocity with respect to the sun, or whether you were accelerating toward the sun, or accelerating the way from the sun, or orbiting the sun.

436

He wanted perfectly general laws of physics, laws of motion especially, that could be formulated so that they would come out the same for all those perspectives.

437

Now, that was his reason.

438

It was a systematic reason.

439

That was his main reason for trying to figure out the general theory of relativity.

440

Oh, I'm sorry.

441

Okay, so his reasons didn't have anything to do with trying to explain the perihelion of mercury,

442

nor were there any other phenomena that he was trying to accommodate in going from the special theory to the general theory.

443

Indeed, he was always mostly a systematic thinker and a generalist, very abstract.

444

Okay, so anyway, he formulates the theory.

445

It's all abstract work, all looks philosophical.

446

I mean, this is why it's a neat test case, because his reasons were abstract, didn't have anything to do with experiments or observables.

447

The theory that came out was extraordinarily abstract and looked really strange.

448

Really, really strange.

449

Let me give you an example of its strangeness.

450

In the normal course of things, we're taught Euclidean geometry.

451

And among the axioms of Euclidean geometry is this one.

452

Here is a, let's say the surface I'm drawing on is a Euclidean plane.

453

And the axiom goes like this.

454

If you've got a line in that plane and then there's a point off that line, but still on the plane,

455

then there is one and only one line that you can draw through that point parallel to that line in that plane.

456

Now, that's a lot of words, right?

457

It's a complex axiom to state, but if I stated it well enough, it should be obvious to you.

458

Does it seem obvious that, of course, that's true, that there's one and only one line parallel to that line through that point?

459

Not for Carl.

460

Well, okay.

461

But in any case, that is the fifth Euclidean axiom.

462

Now, it is so clumsy to say that for centuries, you know, because Euclid figured, Euclid was a student of Plato's, or I'm sorry, Aristotle was a student of Plato's and Euclid was a student of Aristotle.

463

So this is an old system, Euclidean geometry.

464

It's so clumsy that for centuries, people were trying to figure out whether they could possibly derive this one from the other four, which were much more simple.

465

And if they could just have a system of four axioms and not this clumsy one, that would be so nice.

466

Well, they never were able to do it, but part of that effort in the 19th century went this way.

467

A lot of people like a man named Riemann, a mathematician named, there's others.

468

Riemann is foremost among them.

469

Lobachevsky comes later.

470

He's another geometer.

471

But just to see if they could prove that this axiom,

472

this fifth one, was deducible from the others, they said, let's go in the back door.

473

Let's try an indirect proof.

474

Equals fifth.

475

Let's try an indirect proof.

476

Let's assume that it's wrong.

477

Let's pretend we can have, let's just say, we can't make sense of this, Let's say we can have two,

478

or three, or four, or even an infinite number of parallel lines through that point in that plane, to that line, et cetera.

479

Let's just assume the contrary.

480

Let's start out with two.

481

Now, we can't picture that, right?

482

That doesn't make any sense to picture, but let's just say it, and let's see if we can derive a contradiction with the other four.

483

Well, they worked, and they worked, and they worked, and not only did they not derive a contradiction, they proved that they couldn't derive a contradiction,

484

and instead, they they produced a perfectly consistent non -Euclidean geometry

485

that just had this new axiom placed in there instead of the old one.

486

And in addition, they then went on to try some other theories, and they got other non -Euclidean geometries.

487

Well, what general relativity theory says, now those were just sort of mathematicians' delights back then in the 19th century,

488

but what general relativity theory says is our universe is not Euclidean.

489

The physical theory that we believe now about the physical universe says it is not Euclidean.

490

But it's not any one of these others, either.

491

What it is is something that varies.

492

The very structure of geometry, the geometrical structure of space -time changes as you move from

493

place to place in the universe as a function of the concentrations of mass.

494

If you get real close to something with a lot of mass, like a star or a sun, the geometry of space changes.

495

The whole picture, the geometry of space changes, And it's very different there or near a black hole, which is even worse.

496

We haven't confirmed that definitely, but it certainly seems like a good theory and it works well with lots of other things.

497

Near a black hole, the geometry of space -time is even more perturbed, more disturbed.

498

And the differences between those places, which are near concentrations of mass, and places that are in relatively free space,

499

the differences in geometry are massive.

500

They're big, big differences.

501

Now, it's that fact that the general theory of relativity predicts that the geometry of space,

502

space -time actually, the geometry of space -time alters in the presence of massive objects.

503

That's the key to Einstein's bright idea about how to test his theory.

504

This is supposed to be a good illustration of the verifiability criterion demarcation.

505

This is supposed to show just the sort of thing that makes Einstein's speculative abstract endeavor a scientific one, as opposed to the equally abstract,

506

equally difficult intellectual endeavors conducted by the philosophers like Plato and the others.

507

Einstein's is different and scientific because verifiable, and it's this key fact about the geometry of space -time,

508

curiously enough, that turns out to be the key to figuring out how to perform a verification,

509

figure out what kinds of steps would be taken to show that his theory is true.

510

The verifiability criterion of demarcation offered by what I've called the soft core

511

verificationists seem to many to really capture the very special feature about science that made it so successful.

512

But as we'll see, even it came under rather or heavy fire, and this for logical reasons.

513

¶¶ Thank

514

you.

515

Thank you.

516

Thank you.

הורד אפליקציה

כל מה שאתה צריך כדי לדבר בשטף

הגיית AIציון לכל משפט

תרגול IPAשלוט בכל צליל

אוצר מיליםבנה את מאגר המילים שלך

משחק אוצר מיליםלמד תוך כדי משחק

סרוק QR

Download on theApp Store Get it onGoogle Play

אותו ערוץ

Philosophy of Science Lecture #1: Introduction

IELTS PrepTOEFL PrepCambridge Exam Prep

FOR YOU

המלץ על סרטון

654 משפטים

Stuart & Cliffe Knechtle | Do Agnostics Just Want To Have Control? | Give Me an Answer

Daily ConversationUniversity StudentsWorking Adults

332 משפטים

אוצר מילים והערות הגייה לשיעור הזה

שיעור הדיבור הזה ברמה C1 מבוסס על הסרטון “Philosophy of Science Lecture : Verificationism”. בסרטון הזה יש 516 משפטים ו-6737 מילים לתרגול Shadowing. הדיבור נמשך 45:57. הדובר שומר על קצב יציב של כ-147 מילים בדקה, קצב נוח לתרגול Shadowing. 83% מהמילים נמצאות בין 3,000 המילים הנפוצות ביותר באנגלית; כדאי ללמוד את השאר לפני שמתחילים.

אוצר מילים מרכזי בסרטון הזה

15 המילים המתקדמות ביותר בסרטון, עם ההגייה והמשמעות שלהן:

מילה	הגייה	משמעות
criterion שם עצם	/kɹaɪˈtɪɹ.i.ən/	קרִיטֶרִיוֹן
verify פועל	/ˈvɛɹɪfaɪ/	וידא
geometry שם עצם	/d͡ʒiˈɑ.mə.tɹi/	גֵּאוֹמֶטְרְיָה
verification שם עצם	/ˌvɛ.ɹə.fɪˈkeɪ.ʃən/	וידוא
axiom שם עצם	/ˈæk.si.əm/	אַקְסְיוֹמָה
atom שם עצם	/ˈætəm/	אָטוֹם
electron שם עצם	/ɪˈlɛk.tɹɑn/	אֶלֶקְטְרוֹן
atomic שם תואר	/əˈtɑː.mɪk/	אָטוֹמִי
contradiction שם עצם	/ˌkɑːntɹəˈdɪkʃən/	סתירה
gibberish שם עצם	/ˈd͡ʒɪ.bə.ɹɪʃ/	קַשְׁקֶשֶׁת f גִ׳יבְּרִישׁ
accelerate פועל	/ɪkˈsɛl.əˌɹeɪt/	האיץ
calculation שם עצם	/ˌkælkjuˈleɪʃn̩/	חִשׁוּב \ חישוב
arbitrary שם תואר	/ˈɑː.bɪ.tɹə.ɹi/	שרירותי, שרירותית
socialism שם עצם	/ˈsoʊʃəlɪzəm/	סוֹצְיָאלִיזְם
stripe שם עצם	/stɹaɪp/	פַּס

Phrasal verbs שתשמעו

מילה	הגייה	משמעות
figure out פועל		הֵבִין, מצא תשובה
come out פועל	/ˌkʌm ˈaʊt/	יָצָא
go out פועל		יָצָא

משפטים שכדאי לחזור עליהם

משפטים קצרים ושלמים מהסרטון שאפשר להשתמש בהם בשיחה יומיומית:

He wouldn't have said bias, I think.
We'll talk about these today.
That's why I call it hardcore core.
What could you possibly mean?
What is the criterion I'm using?

דקדוק בסרטון הזה

המבנים שהדובר משתמש בהם הכי הרבה, עם המילים המדויקות מהסרטון:

מבנה	בסרטון
משפטי תנאי (Conditional sentences) if + clause, will/would + verb — תנאי ותוצאה שלו	if my theory is right, you'll see
הווה מושלם (Present perfect) have/has + past participle — פעולה שקרתה בעבר ועדיין יש לה חשיבות או השפעה עכשיו	have felt · has been · you've heard
סביל (Passive voice) be + past participle — הדגש הוא על מה שקורה, לא על מי שעושה את הפעולה	be kicked · should be radically reformed · was widely regarded
משפטי זיקה (Relative clauses) who / which + clause — מידע נוסף על אדם או דבר	man who invented · metaphysics, which was · ones that are

הגייה ששווה לשים לב אליה

הדובר משתמש ב-125 קיצורים וצורות מקוצרות, כמו they're, can't, I'm. אמרו אותם בצורה הקצרה, כפי שאתם שומעים אותם.

הצלילים של “th”: theological /θi.əˈlɑd͡ʒɪkl/, sympathetic /ˌsɪm.pəˈθɛt.ɪk/, hypothesis /haɪˈpɒθɪsɪs/, nonetheless /ˌnʌnðəˈlɛs/, mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/
הצלילים של “sh” ו-“zh”: proposition /ˌpɹɑpəˈzɪʃən/, demarcation /ˌdɛm.ɑːˈkeɪ.ʃən/, verification /ˌvɛ.ɹə.fɪˈkeɪ.ʃən/, banish /ˈbænɪʃ/, influential /ɪnflʊˈɛnʃəl/
מילים ארוכות — שימו לב להטעמה: criterion /kɹaɪˈtɪɹ.i.ən/, verifiable /vɛɹ.ɪˈfaɪ.ə.bəl/, relativity /ɹɛl.əˈtɪv.ɪ.ti/, proposition /ˌpɹɑpəˈzɪʃən/, metaphysics /mɛtəˈfɪzɪks/

צלילים שדוברי עברית מתקשים בהם:

/w/ — שפתיים מעוגלות, לא /v/: whoop /wuːp/, distinguish /dɪˈstɪŋ.ɡwɪʃ/, equation /ɪˈkweɪ.ʒən/, consequence /ˈkɑn.sɪ.kwəns/
/æ/ — פתוח יותר מה-“אֶ” העברית, לא כמו “a” ב-“cup”: axiom /ˈæk.si.əm/, banish /ˈbænɪʃ/, atom /ˈætəm/, calculation /ˌkælkjuˈleɪʃn̩/, seismograph /ˈsaɪz.mə.ɡɹæf/
/r/ — הלשון לא נוגעת בשום מקום, לא ה-“ר” הגרונית: criterion /kɹaɪˈtɪɹ.i.ən/, verifiable /vɛɹ.ɪˈfaɪ.ə.bəl/, relativity /ɹɛl.əˈtɪv.ɪ.ti/, proposition /ˌpɹɑpəˈzɪʃən/, hardcore /hɑː(ɹ)dˈkɔː(ɹ)/

איך לתרגל עם הסרטון הזה

הקשיבו לכל הסרטון פעם אחת בלי לדבר, ורשמו את המילים שאתם לא מכירים.
תרגלו Shadowing משפט אחר משפט במהירות רגילה, וחזרו על כל משפט עד שהקצב שלכם תואם את הדובר.
הקליטו את עצמכם והשוו למקור, תוך תשומת לב למילים כמו criterion, verify, geometry.

מהי טכניקת השאדואינג?

שאדואינג היא טכניקת למידת שפה מבוססת מדע שפותחה במקור להכשרת מתורגמנים מקצועיים ופופולרית על ידי הפוליגלוט ד"ר אלכסנדר ארגואלס. השיטה פשוטה אך עוצמתית: אתה מקשיב לאודיו באנגלית ילידית וחוזר עליו בקול רם מיד — כמו צל העוקב אחרי הדובר עם עיכוב של 1–2 שניות בלבד. בניגוד להאזנה פסיבית או תרגילי דקדוק, שאדואינג מכריח את המוח והשרירים בפה לעבד ולשחזר דפוסי דיבור אמיתיים בו זמנית. מחקרים מראים שזה משפר משמעותית את דיוק ההגייה, האינטונציה, הקצב, הדיבור המחובר, הבנת השמיעה ושטף הדיבור — מה שהופך אותו לאחת השיטות היעילות ביותר להכנה לIELTS Speaking ולתקשורת באנגלית בעולם האמיתי.

טכניקת Shadowing: קרא את המדריך המלא שלב אחר שלב →

Shadowing Practice: Philosophy of Science Lecture #2: Verificationism - Learn English Speaking with Video

בחר מצב תרגול

הורד אפליקציה

Philosophy of Science Lecture #1: Introduction

Stuart & Cliffe Knechtle | Do Agnostics Just Want To Have Control? | Give Me an Answer

Science Writing: Practice Makes It (Almost) Perfect

The Professor Who Taught People How To Think (1962)

What is History? E.H. Carr

Core Knowledge (Stanford Psych 60)

PHILOSOPHY - Plato

John Berger / Ways of Seeing , Episode 1 (1972)

What is Marxism? (And Why The Outrage is Wrong)

Has quantum mechanics proved that reality does not exist?

Research Source Mastery: How to Find & Verify Credible Data (2026)

The Seven Traditions: Mapping the Field of Communication Theory

The Jesus paradox | Yuval Noah Harari

אוצר מילים והערות הגייה לשיעור הזה

אוצר מילים מרכזי בסרטון הזה

Phrasal verbs שתשמעו

משפטים שכדאי לחזור עליהם

דקדוק בסרטון הזה

הגייה ששווה לשים לב אליה

איך לתרגל עם הסרטון הזה

מהי טכניקת השאדואינג?